MANUAL OF DISSECTION 
AND 
PRACTICAL ANATOMY. 
FOUNDED ON 
GRAY AND GERRISH. 
BY 
WILLIAM T. ECKLEY, M.D., 
/// 7 7 
PROFESSOR OF ANATOMY IN THE MEDICAL AND DENTAL DEPARTMENTS OF THE UNIVERSITY OF ILLINOIS, 
THE CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY, THE CHICAGO CLINICAL SCHOOL 
AND WEST SIDE TRAINING SCHOOL FOR NURSES, 
AND 
CORINNE B. ECKLEY, 
DEMONSTRATOR OF ANATOMY IN THE MEDICAL AND DENTAL DEPARTMENTS OF THE UNIVERSITY OF 
ILLINOIS AND CHICAGO SCHOOL OF ANATOMY AND PHYSIOLOGY, AND MEMBER 
OF THE ASSOCIATION OF AMERICAN ANATOMISTS. 
ILLUSTRATED WITH 220 ENGRAVINGS, 116 OF WHICH ARE COLORED 
LEA BROTHERS & CO., 
PHILADELPHIA AND NEW YORK. Entered according to the Act of Congress, in the year 1902, by 
LEA BROTHERS & CO., 
In the Office of the Librarian of Congress. All rights reserved. 
DORNAN, PRINTER. TO 
ELMER F. CLAPP, M.D., 
FORMERLY PROFESSOR OF ANATOMY IN THE UNIVERSITY OF IOWA, 
IN RECOGNITION OF HIS SCHOLARLY ATTAINMENTS AND 
ABILITY AS A TEACHER OF HUMAN ANATOMY, 
THIS BOOK IS DEDICATED BY THE 
AUTHORS, 
HIS FORMER PUPILS. PREFACE. 
The present work has a twofold purpose, namely, to provide the student with 
a detailed guide for dissection, and to answer the requirements of the physician 
and surgeon wishing to review the anatomy of any region. The directions for 
dissecting and identifying the various structures of the human body have been 
given in full detail, with particular care as to sequence, so that each item of 
instruction should appear in its natural and most useful relationship. The 
general arrangement adopted is, first, to give the landmarks, then the integu- 
mentary incisions, and, finally, the description and relations of succeeding anatom- 
ical entities. Special effort has been devoted toward achieving precision in direc- 
tions for locating every structure-a matter of the utmost importance, particularly 
for the surgeon. 
Inasmuch as most students prefer Gray and Gerrish, this Dissector has been 
prepared for practical use with either. The publishers have placed at our disposal 
the incomparable series of illustrations found in these two standard works. The 
student can, therefore, enjoy the advantage of having in the dissecting-room a full 
and detailed guide for his work, presenting to his eye the same pictures with which 
he is familiar in his study and class-room. 
It scarcely needs to be said that no dissector can take the place of a standard 
descriptive anatomy. The arrangement of these two classes of books is opposite 
and correlative, the text-books following the systemic order, and the dissectors being 
necessarily regional. To increase the usefulness of the present volume it has been 
developed along this line to such an extent that it might with propriety be 
entitled a Regional Anatomy as well as a Dissector. It is hoped that the careful 
and complete treatment of the various areas will enable it to serve the needs of 
the surgeon and post-mortem pathologist. 
Much effort has been bestowed upon the tables, owing to the advantage this 
method offers for the presentation of anatomical knowledge systematically and 
clearly. 
Acknowledgments are due to the following anatomists : Dr. De Lee Shaw has 
tabulated with absolute fidelity to Gray and Gerrish the blood vascular system; 
Dr. C. M. Jackson prepared the articles on metamerism and conduction paths of 
the spinal cord and brain ; Dr. H. E. Santee read the proof on dissection of the 
nervous system ; Drs. Burkholder and Conboy read proof of the sections on the VI 
PREFACE. 
thorax and abdomen, and rendered valuable service in advising the judicious 
parenthetic use of the new nomenclature; Dr. P. Gad Kitterman tabulated the 
meningeal vessels, and cranial and spinal nerves; Dr. J. S. Brown assisted in read- 
ing the proof, and, moreover, made valuable suggestions regarding the legitimate 
scope of the book ; Dr. Mortimer Frank kindly furnished some of the illustra- 
tions. We are deeply indebted to Dr. Lewellys F. Barker for suggestions of a 
conservative nature looking to exactitude in dissecting-room study. 
Finally, acknowledgment is due to the works of Gray and Gerrish, on whose 
texts the present volume is founded, and from which most of the illustrations 
are drawn. 
Chicago, November, 1902. CONTENTS. 
CHAPTER I. 
The Face 17 
CHAPTER II. 
The Scalp, Meninges and Base of the Skull 51 
CHAPTER III. 
The Brain and the Spinal Cord 59 
CHAPTER IV. 
The Mouth 76 
CHAPTER V. 
The Eye 86 
CHAPTER VI. 
The Organs of Hearing 95 
CHAPTER VII. 
The Neck 106 
CHAPTER VIII. 
The Thoracic and Shoulder Regions 139 
CHAPTER IX. 
Cutaneous Veins and Nerves of Upper Extremity-Anterior Region of 
Forearm 150 
CHAPTER X. 
The Posterior Region of Arm and Forearm and Radial Region of Forearm 166 
CHAPTER XI. 
The Thoracic Walls 177 
CHAPTER XII. 
Thorax-Subdivisions and Contents 184 
CHAPTER XIII, 
The Abdominal Walls 200 
CHAPTER XIV. 
Identification of Abdominal Organs and Other Structures in Situ . . 209 
CHAPTER XV. 
The Peritoneum 216 VIII 
CONTENTS. 
CHAPTER XVI. 
The Abdominal and Pelvic Organs 220 
CHAPTER XVII. 
The Abdominal Vessels 238 
CHAPTER XVIII. 
The Pelvic Outlet 243 
CHAPTER XIX. 
Cutaneous Vessels and Nerves of the Lower Extremity .... 263 
CHAPTER XX. 
The Iliac Region 269 
CHAPTER XXI. 
The Anterior Femoral Region 285 
CHAPTER XXII. 
The Internal Femoral Region 293 
CHAPTER XXIII. 
The Gluteal Region 297 
CHAPTER XXIV. 
The Posterior Femoral Region 303 
CHAPTER XXV. 
The Anterior Tibiofibular Region 311 
CHAPTER XXVI. 
The Posterior Tibiofibular Region 316 
CHAPTER XXVII. 
The Fibular Region 324 
CHAPTER XXVIII. 
The Sole of the Foot 327 
CHAPTER XXIX. 
The Back 340 
CHAPTER XXX. 
The Sympathetic Nervous System 355 
CHAPTER XXXI. 
The Blood Vascular System 362 
(By De Lee Shaw, M.D.) 
CHAPTER XXXII. 
Sensory and Motor Conduction Paths between the Spinal Cord and the 
Cerebral Cortex 387 
(By C. M. Jackson, M.D.) A MANUAL OF DISSECTION 
CHAPTER I. 
THE FACE. 
Dissection and Identification. Fill the mouth with cotton and sew the lips together. 
Remove the integument as indicated in Fig. 1. Consult the illustrations and identify the 
structures found on the cadaver by comparison. Follow order given in text, viz. : mental, 
infra-orbital, pterygoid, supra-orbital structures, and parotid gland. After these have been 
studied then turn attention to the muscles, vessels, and nerves. 
Fig. 1. 
Dissection of the head, face, and neck. (Gray.) 
The Mental Nerve. The mental nerve is the cutaneous part of the inferior 
dental, a branch of the third division of the trifacial. The inferior dental, a 
sensory nerve, traverses the mandibular canal in the lower jaw, giving in its course 
branches to the teeth, called the dental ; to the gums, called the gingival. The 
cutaneous branches communicate with branches of the facial, a motor nerve. 
The Mental Artery is a branch of the inferior dental ; it emerges through the 
mental foramen. The inferior dental artery, a branch of the internal maxillary, 
in its course through the canal in the mandible, gives dental branches to the teeth, 
gingival to the gums. The mental artery, on emerging through the mental 
foramen, anastomoses with the inferior labial branch of the facial. 
The Infra-orbital Nerve emerges through the infra-orbital foramen with vessels of 
like name (foramen is under cover of the levator labii superioris muscle) and 
breaks up into a leash of branches. Communications between it and the facial 
form the infra-orbital plexus, which lies between the levator labii superioris and 
the levator anguli oris. The infra-orbital nerve is a continuation of the superior 
maxillary division of the fifth nerve. It traverses the sphenomaxillary fossa and 
infra-orbital canal, giving dental branches to the upper teeth ; gingival branches 18 
A MANUAL OF DISSECTION. 
to the gums ; infra-orbital branches to the skin of the nose, eyelid, and upper 
lip, and is accompanied by the artery and vein of same name. 
The Infra-orbital Artery emerges from the infra-orbital foramen, anastomoses 
with the facial, and is a branch of the internal maxillary, which in turn is a ter- 
minal of the external carotid artery. The artery traverses the infra-orbital canal 
in the floor of the orbit, giving dental branches to the teeth, gingival branches 
to the gums, cutaneous branches to the nose, eyelid, and upper lip. The veins 
accompany the artery, take the same name, traverse the same territory, convey 
the blood in an opposite direction, to the pterygoid plexus. 
Fig. 2. 
The nerves of the scalp, face, and side of the neck. (Gray.) 
The Pterygoid Plexus is formed by a confluence of veins from the deep parts of 
the face. It derives its name from its location on- the external pterygoid muscle. 
The veins returning the blood are the inferior dental, the infra-orbital, and 
certain muscular branches. These veins form a plexus between the external 
pterygoid and the temporal muscles, preparatory to uniting to form the internal 
maxillary vein. The veins forming the plexus correspond to the branches of the 
internal maxillary artery, while the internal maxillary vein corresponds to the 
internal maxillary artery itself. The internal maxillary joins the temporal vein 
in the parotid gland to form the external jugular. The veins of the pterygoid THE FACE. 
19 
plexus have no valves. They communicate in front with the facial vein by the 
deep facial ; at the base of the skull and with the cavernous sinus in the dura 
mater by the emissary veins. 
The Supra-orbital Nerve. The supra-orbital nerve is a branch of the ophthalmic 
division of the trifacial ; it passes through the supra-orbital foramen in the 
frontal bone, and supplies the skin of the eyelid and forehead with sensation ; it 
communicates with the facial nerve, and is accompanied by the vessels of like 
name. 
The Supra-orbital Artery is a branch of the ophthalmic ; it traverses the supra- 
orbital foramen, and anastomoses with the superficial temporal artery. 
Fig. 3. 
Internal maxillary artery. (Gerrish after Testut.) 
The Parotid is the largest salivary gland ; it weighs about one ounce, and is 
covered by a very dense fascia, which is continuous above with the temporal, in 
front with the masseteric, and below with the cervical fascia. 
Limitations. Superiorly, the zygomatic arch ; inferiorly, the mastomandib- 
ular line ; anteriorly, the mid-line of the masseter ; posteriorly, the ear and sterno- 
mastoid muscle ; internally, the styloid process. 
Surfaces. The anterior surface of the gland embraces the mandible ; the 
outer surface is lobulated and covered by the parotid fascia, superficial fascia, and 
the skin ; the inner surface embraces the styloid process of the temporal bone ; 
while the internal carotid artery and the internal jugular vein are in close relation 
with its deep surface. 20 
A MANUAL OF DISSECTION. 
Contents. 1. The facial nerve, whose temporofacial and cervicofacial divi- 
sions give off the pes anserinus. 2. The auriculotemporal nerve, a branch of 
the superior maxillary. 3. The external jugular vein, formed by a confluence 
of the posterior division of the temporomaxillary and posterior auricular veins. 
4. The external carotid artery, which breaks up into the temporal, internal maxil- 
lary, transverse facial, and posterior auricular arteries. 
The Blood-supply is derived from the external carotid, temporal, internal 
maxillary, posterior auricular, and transverse facial arteries. The veins which 
accompany the arteries from the parotid gland empty into the external jugular 
and take the name of the arteries. 
Nerve-supply. 1. Sympathetic, from the carotid plexus. 2. Motor, from 
the facial. 3. Sensory, from the great auricular and auriculotemporal. 4. Vaso- 
Fig.4. 
The salivary glands. The right half of the body of the mandible has been removed. GL. W., gland of Weber. 
GL. B., gland of Blandin. (Gerrish after Testut.) 
dilator, from the ninth nerve, via tympanic, small superficial petrosal, otic gang- 
lion, third division of fifth, and auriculotemporal. 
Stenson's Duct is the excretory conduit of the parotid gland. It lies in a 
line extending from the lower part of the lobule of the ear to the middle of the 
upper lip. It is about a quarter of an inch in diameter, and in its course 
crosses the masseter muscle, perforates the buccinator, and opens into the vesti- 
bule of the mouth opposite the second upper molar tooth. The duct is about 
one and one-half inches long, and the distal one-half inch lies between the 
mucous membrane and the buccinator muscle, the mucous membrane forming the 
valve. The duct may receive a tributary from the glandula socia parotidis-a 
small, detached portion of the parotid gland on the masseter muscle. The parotid 
gland is separated from the submaxillary by the stylomaxillary ligament. THE FACE. 
21 
THE MUSCLES OF FACIAL EXPRESSION. 
The Orbicularis Oris surrounds the mouth. It has two series of fibres : 1. An 
inner, which surrounds the mouth by continuity. 2. An outer, which decussates 
at the angles and intermingles with fibres of all muscles, above and below, that 
antagonize it. The continuous fibres constitute the labial, the decussating fibres 
Fig. 5. 
Superficial muscles of head and neck. (Gerrish after Testut.) 
the facial portion of the muscle. The labial fibres are pale, thin, and not attached 
to the bone. The decussating fibres are thinner, broader, attached to the alveolar 
processes, and have muscles inserted into them. The muscle is closely connected, 
both to the skin and to the mucous membrane. The labial glands and coronary 
vessels are between the mucous membrane and the muscle. Attachments, cartilage 22 
A MANUAL OF DISSECTION. 
of the nasal septum, incisive fossa of the maxilla, incisive fossa of the man- 
dible. 
The Zygomaticus Major. Origin: The malar bone. Insertion : The angle of 
mouth. The facial artery and vein are beneath, while Stenson's duct passes 
under this muscle. 
The Zygomaticus Minor. Origin: The malar bone. Insertion: The upper lip. 
It may be incorporated with the zygomaticus major, and it requires care to distin- 
guish the two muscles. 
The Levator Labii Superioris. Origin: The superior maxillary bone above the 
infra-orbital foramen. Insertion: The facial part of the orbicularis oris. Beneath 
the muscle is the infra-orbital plexus, formed by the fifth and seventh nerves, 
and also the anastomoses of the infra-orbital and facial arteries. Action, elevates 
and protrudes the lip. 
The Levator Anguli Oris. Origin: The canine fossa. Insertion: The facial 
part of the orbicularis oris. Between it and the preceding muscle is the infra- 
orbital plexus. 
The Levator Labii Superioris Alae que Nasi. Origin: The nasal process of the 
superior maxillary bone. Insertions: 1. The nasal cartilage of the ala of the 
nose. 2. Facial part of the orbicularis oris. 
The Levator Menti, or Levator Labii Inferioris. Origin : The incisive fossa. 
Insertion: The facial part of the orbicularis oris and skin of the chin. 
The Depressor Labii Inferioris. Origin: The oblique line of the mandible, below 
and internal to the mental foramen. Insertion: The facial part of the orbicularis 
oris. The muscle is quadrate, hence called quadratus menti. The outer and 
lower part of the muscle is covered by the depressor anguli oris. Action, draws 
the lip downward and outward. 
The Depressor Anguli Oris. Origin: The external oblique line below the cuspid, 
bicuspid, and first molar teeth. Insertion: The corner of the mouth. 
The Risorius. Origin: The masseter fascia. Insertion: The angle of the 
mouth. The muscle is horizontal, varies in size and shape, and draws the angle 
back. Morphologically, it is a divorced part of the platysma. 
The Platysma Myoides has (1) a facial part; (2) a cervical part. The facial 
part covers the facial vessels and supramandibular branch of the facial nerve. The 
muscle arises from the pectoral and deltoid fasciae, and is inserted into a part of 
the orbicularis oris. This muscle depresses the mandible. 
The Orbicularis Palpebrarum surrounds the base of the orbit and covers the eyelids. 
The interval between the lids is the palpebral fissure. The extremes of the fissure 
are the outer and inner canthi. The muscle consists of two parts : 1. An inner, 
that covers the lids, called the palpebral portion. The fibres of this are pale and 
thin, and not completely under control of the will. 2. An outer part, spread 
over the margins of the orbit. The fibres of this part are thicker, voluntary, 
and mingle with the occipitofrontalis, corrugator supercilii, levator labii supe- 
rioris alee que nasi, levator labii superioris, and zygomaticus minor. The muscle 
has the following attachments : 1. The nasal process of the maxillary bone. 2. 
The internal angular process of the frontal bone. 3. The lower margin of the 
orbit. 4. The tendo oculi. 
The Tendo Oculi. At the inner angle of the eye is a thin cord, one-sixth of an 
inch long. It arises from the nasal process of the superior maxilla, in front of 
the lacrymal groove. The tendon divides into two parts. One is inserted into 
the upper lid ; the other into the lower lid. A part of the tendon is attached to 
the lacrymal sac and margins of the lacrymal groove, in which the sac rests. 
The tendo oculi aids indirectly the flow of tears into the lacrymal sac. 
The Tensor Tarsi is a deep part of the orbicularis palpebrarum, specialized for 
drawing the eyelids and lacrymal canals into a position most favorable for receiv- 
ing the tears. The muscle arises from the crest of the lacrymal bone, passes 
across the lacrymal sac, and divides into two portions, which are inserted into 
the upper and lower tarsal cartilages. THE FACE. 
23 
The Corrugator Supercilii. Origin : The inner end of the superciliary ridge. 
Insertion: The under surface of orbicularis palpebrarum. This muscle produces 
vertical wrinkles of the forehead by drawing the eyebrows downward and inward. 
The Levator Palpebrae arises from the lesser wing of the sphenoid, above and 
in front of the optic foramen, and is inserted into the tarsal plate of the upper lid. 
The Pyramidalis Nasi arises from the occipitofrontalis, and is inserted, with 
the compressor nasi, into the fibrocartilage of the ala of the nose. It produces 
transverse wrinkles on the bridge of the nose by drawing the eyebrows down. 
The Occipitofrontalis consists of (1) an anterior belly, (2) an intermediary 
aponeurosis, (3) a posterior belly. The posterior belly arises from the outer 
two-thirds of the superior curved line of the occipital and mastoid process of the 
temporal bones. The frontal part is very thin. The internal fibres are continuous 
with the pyramidalis nasi ; the middle and outer fibres are blended with the corru- 
gator supercilii and orbicularis palpebrarum. The two bellies are united by an 
aponeurosis. The muscle raises the eyebrows. 
The Attrahens Aurem. Origin: The aponeurosis of the occipitofrontalis. In- 
sertion : The helix. The retrahens aurem arises from the mastoid and is inserted 
into the concha. The attollens aurem arises from the aponeurosis of the occipito- 
frontalis, and is inserted into the pinna. Tn man these muscles are rudimentary.1 
(See Chapter VII., External Ear.) 
The Compressor Naris arises from the canine fossa. It is inserted into the dorsum 
of the nose, joining here its fellow of the opposite side. The muscle is triangu- 
lar. Its origin is concealed by the levator labii superioris alee que nasi. 
The Compressor Narium Minor arises from the fibrocartilage of the nose, and is 
inserted into the skin of the end of the nose. 
The Dilator Naris Posterior arises from the margin of the nasal notch and sesa- 
moid cartilages, and is inserted into the skin near the margin of the nostril. 
The muscle is partly under cover of the levator labii superioris alae que nasi. 
The Dilator Naris Anterior is in front of the preceding muscle. It arises from the 
alar cartilage, and is inserted into the skin near the margin of the nose. 
The Depressor Alse Nasi arises from the incisive fossa, and is inserted into the 
septum and alar cartilage of the nose. 
The Buccinator arises from (1) the pterygomaxillary ligament; (2) the alveolar 
process of the upper jaw ; (3) the alveolar process of the lower jaw. Insertion : 
The orbicularis oris in this manner : The upper and lower fibres converge toward 
the angles of the mouth, where they decussate to become continuous with the 
fibres of the orbicularis oris. The highest and lowest fibres do not decussate. 
The buccinator and superior constrictor of the pharynx are united by the pterygo- 
maxillary ligament, and form a continuous muscular wall for the mouth and 
pharynx. The pterygomaxillary ligament may be readily felt in a patient. 
This is one of the structures so painfully put on the stretch in prolonged opera- 
tions on the mouth and teeth. This ligament extends from the hamular process 
to the posterior extremity of the mylohyoid ridge near the wisdom tooth. The 
principal use of the ligament, then, is to form a common attachment for the 
superior constrictor of the pharynx and buccinator. The buccinator muscle expels 
air and widens the mouth, but its principal use is to assist the tongue in keeping 
food between the molar teeth during mastication. (See Muscles of Mastication.) 
The Buccinator Fascia takes its name from the muscle which it invests and 
strengthens. This fascia adheres closely to the outer surface of the muscle, and 
must be removed to appreciate the direction of the muscular fibres. The fascia is 
thin in front and dense behind, where it is continuous with the aponeurosis of the 
pharynx ; it strengthens the junction between the mouth and pharynx, and for 
this reason it is called the buccopharyngeal fascia. Owing to the strength of this 
fascia, and to the great vitality of the buccinator and superior constrictor muscles 
of the pharynx, abscesses do not readily break into the mouth and pharynx. 
1 Also called attrahens, attollens, and retrahens auriculam. 24 
A MANUAL OF DISSECTION. 
Summary. The facial muscles are called muscles of expression. The three 
muscles about the ear are no longer muscles of expression in man, but they still 
retain this function in the horse and some other lower animals. The muscles 
about the inlet of the nose are all but obsolete in man, and should be studied on 
lower animals ; their names are perpetuated in human anatomy for comparative 
and morphological purposes only. The buccinator is intermediate between the 
muscles of expression and those of mastication. The platysma is given somewhat 
to expression, being, from an artistic stand-point, the chief agent in derision ; but 
the main function of this muscle is to depress the mandible. 
The Nerve-supply of the facial muscles may be summed up : The motor oculi 
supplies the levator palpebrte. The fifth and seventh nerves supply the bucci- 
nator. All the others are supplied by the facial nerve. The fifth nerve supplies 
the skin of the face with sensation. 
The involuntary muscular fibre of the eyelids and the muscle of Muller (a 
name given to some fibres crossing the sphenomaxillary fissure) are supplied by 
the sympathetic nerves, called white rami communicantes. These white rami 
originate in the motor roots of the thoracic spinal nerves, pass to corresponding 
vertebral ganglia of the gangliated cord, in which they ascend to the superior 
cervical ganglion, where they arborize about the cells, whose axons continue the 
journey upward with ascending branches of the superior cervical ganglion to the 
Gasserian ganglion. Here a second arborization occurs, whence axonic processes 
accompany the first division of the fifth nerve to the orbit. (See Gerrish.) 
Table of Muscles of Expression. 
Name. 
Origin. 
Insertion. 
Function. 
Orbicularis oris. 
Alveolus. 
Reciprocal. 
Closes lips. 
Levator labii superioris. 
Superior maxilla. 
Upper lip. 
Draws lip upward ; ex- 
presses sadness. 
Levator anguli oris. 
Canine fossa. 
Angle of lip. 
Elevates angle. 
Depressor labii inferioris. 
Oblique line. 
Lower lip. 
Depresses lip. 
Depressor anguli oris. 
Oblique line. 
Angle of lip. 
Depresses angle. 
Levator menti. 
Incisive fossa. 
Skin of chin. 
Protrudes lip. 
Zygomaticus major. 
Malar bone. 
Angle. 
Laughing. 
Zygomaticus minor. 
Malar bone, 
Upper lip. 
Sadness. 
Buccinator. 
Alveolus, pterygomaxil- 
lary ligament. 
Orbicularis oris. 
Assists tongue. 
Levator labii superioris 
ahe que nasi. 
Nasal process, superior 
maxillary. 
Lip and nose. 
Elevates lip and nose. 
Pyramidalis nasi. 
Occipitofrontalis. 
Nasal cartilage. 
Elevates ala. 
Dilator naris posterior. 
Nasal notch. 
Skin of nostril. 
Enlarges aperture. 
Dilator naris anterior. 
Ala of nose. 
Skin of ala. 
Enlarges aperture. 
Compressor naris. 
Superior maxillary. 
Nasal cartilage. 
Compresses alae. 
Compressor narium minor. 
Alar cartilage. 
Skin. 
Compresses alae. 
Depressor ake nasi. 
Incisive fossa. 
Septum. 
Depresses. 
Corrugator supercilii. 
Superciliary ridge. 
Orbicularis palpe- 
brarum. 
Frowning. 
Orbicularis palpebrarum. 
Superior maxilla and 
frontal. 
Surrounds orbit. 
Closes lids. 
Tensor tarsi. 
Lacrymal bone. 
Tarsal plate. 
Compresses lacrymal 
sac. 
Levator palpebrarum. 
Ala of sphenoid. 
Tarsal plate. 
Lifts upward lid. 
Attrahens aurem. 
Aponeurosis obcipito- 
frontalis. 
Helix. 
Forward. 
Retrahens aurem. 
Mastoid. 
Concha. 
Backward. 
Attollens aurem. 
Aponeurosis occipito- 
frontalis. 
Pinna. 
Upward. 
Platysma myoides. 
Deltoid and pectoral 
fascise. 
Lower lip. 
Melancholy. 
Risorius. 
Masseteric fascia. 
Corner of mouth. 
Laughing. 
FACIAL ARTERY AND VEIN. 
The Facial Artery has two stages : cervical and facial. The cervical stage 
extends from the external carotid artery, in the superior carotid triangle, to the 
anterior part of the masseter muscle, on the lower border and outer surface of THE FACE. 
25 
the mandible. This artery and the lingual may arise by a common trunk. In its 
course upward and forward the cervical part of the facial artery passes beneath 
the hypoglossal nerve, the posterior belly of the digastric, stylohyoid muscle, and 
submaxillary salivary gland. The vein passes superficial to the four preceding 
structures. 
Branches of Cervical Stage. (1) Ascending or inferior palatine ; (2) tonsillar ; 
(3) glandular ; (4) muscular ; (5) submental. The general course of the artery is 
from a point on the lower border of the mandible, in front of the masseter muscle, 
to the root of the nose. 
The facial stage of the artery rests on the mandible, buccinator, and levator 
anguli oris, and passes beneath the zygomatics, risorius, and levator labii superioris 
Fig. 6. 
The arteries of the face and scalp? (Gray.) 
muscles, and the supramandibular and buccal branches of the facial nerve. (See 
Shaw's Table, Chapter XXXI.) 
Branches of Facial Stage. (1) Masseteric; (2) buccal ; (3) inferior labial; 
(4) inferior coronary ; (5) superior coronary ; (6) lateralis nasi ; (7) angular. The 
masseteric branches pass to the masseter and anastomose with the transverse facial 
branch of the temporal and the masseteric branches of the internal maxillary 
artery. The buccal branches pass to the buccinator and anastomose with the 
internal maxillary, infra-orbital, and transverse facial arteries. The inferior 
labial passes beneath the depressor anguli oris and over the depressor labii infe- 
1 The muscular tissue of the lips must be supposed to have been cut away, in order to show the course of the 
coronary arteries. 26 
A MANUAL OF DISSECTION. 
rioris, supplying the skin and muscles. The inferior coronary passes beneath the 
depressor anguli oris to the angle of the mouth, thence between the mucous mem- 
brane and the orbicularis oris to the lower lip, and anastomoses with the fellow 
of the opposite side. The superior coronary passes beneath the zygomaticus major, 
between the mucous membrane and orbicularis oris of the upper lip, and anasto- 
moses with its fellow of the opposite side. The lateralis nasi is given off opposite 
Fig. 7. 
Superficial veins of the cranium and face, right lateral view. (Gerrish after Testut.) 
the wing of the nose and passes along the side of the nose to anastomose (a) with 
its fellow of the opposite side ; (6) with the nasal branches of the ophthalmic. 
The angular is the termination of the facial artery, and anastomoses at the inner 
canthus with the nasal branch of the ophthalmic artery. 
The Facial Vein has cervical and facial stages, and extends obliquely across the 
face from the inner angle of the orbit to a point on the lower border of the man- 
dible, in front of the masseter muscle. From this point the vein traverses the THE FACE. 
27 
digastric triangle and enters the internal jugular in the superior carotid triangle. 
In the cervical stage the facial vein passes superficially to : 1. The submaxillary 
gland. 2. The digastric muscle. 3. The stylohyoid. 4. The hypoglossal nerve. 
On the mandible the vein is posterior to the artery. In the facial part of the 
course the vein is superficial to : 1. The levator labii superioris. 2. The levator 
anguli oris. 3. The levator labii superioris ahe que nasi. It passes beneath 
the platysma and zygomatic muscles. Tributaries: The frontal, lateralis nasi, 
supra-orbital, transverse facial, superior and inferior coronary veins. Near the 
angle of the jaw the facial vein communicates with the external jugular. 
The superficial veins of the face and scalp communicate with the deep veins 
of the face in the region of the muscles of mastication and with the sinuses of the 
dura mater as follows : The angular communicates with the ophthalmic. The 
ophthalmic communicates with the cavernous sinus. The deep facial connects the 
facial vein and pterygoid plexus. The deep temporal connects the deep and super- 
ficial temporal veins. The vein of Vesalius connects the cavernous sinus and 
pterygoid plexus. The pterygoid plexus is between the temporal and external 
pterygoid muscles. It is formed by the confluence of veins from the region sup- 
plied by the internal maxillary artery. It communicates with the cavernous 
sinus in the dura mater through small veins, among which is the vein of Vesalius, 
as previously stated. 
FACIAL NERVE. 
Course in the Temporal Bone. The facial nerve enters the internal auditory 
meatus on the posterior surface of the petrosa with the auditory nerve and artery, 
and at the bottom of the meatus enters the facial canal-aquseductus Fallopii. In 
its course it passes (1) between the roof and inner wall of the tympanum above 
the fenestra ovalis ; (2) between the inner and posterior walls of the tympanum 
to the stylomastoid foramen. The geniculate ganglion is situated on the nerve, 
where the latter turns backward and outward to enter the tympanic part of its 
course'; it gives off the large superficial, small superficial, and external petrosal 
nerves. 
Fig. 8. 
The course and connections of the facial nerve in the temporal bone. (Gray.) 
Branches in the Facial Canal. 1. The great superficial petrosal, a branch of 
the geniculate ganglion, is joined by filaments from the carotid plexus, as it leaves 
the cranium, under the name of Vidian, through the foramen lacerum medium ; 
it passes along the Vidian canal and joins Meckel's ganglion in the sphenomaxil- 
lary fossa. 
2. The small superficial petrosal nerve, a branch of the geniculate ganglion, 
leaves the cranium through the canalis innominatus, between the foramen ovale 
and spinosum in the greater wing of the sphenoid bone, and joins the otic gang- 
lion. The nerve receives the tympanic branch of the glossopharyngeal (Jacob- 
son's nerve), which supplies the parotid gland, reaching the same through the 
otic ganglion, inferior maxillary division of the trigeminus, and the auriculo- 
temporal nerve. 
3. The external petrosal nerve joins the sympathetic plexus on the middle 
meningeal artery, near the foramen spinosum, and is distributed with this artery. 28 
A MANUAL OF DISSECTION. 
4. The tympanic • branch to the stapedius, the smallest muscle of the body, 
pierces the pyramid on the inner surface of the tympanum. 
5. The chorda tympani is a sensory nerve, and, while given in anatomies as a 
branch of the seventh nerve, is in reality functionally not so. It accompanies the 
seventh nerve in the same manner as the descendens hypoglossi-a deep cervical 
nerve-accompanies, in a part of its course, the hypoglossal nerve, and appears 
to be a branch thereof. 
The chorda tympani is an aberrant branch of the glossopharyngeal nerve. It 
originates, in the nucleus of the glossopharyngeal nerve, and, as the pars inter- 
media, passes with the seventh nerve in the facial canal to the iter chordae pos- 
terior, whence it traverses the middle ear and reaches the tongue through the 
lingual branch of the inferior maxillary division of the trifacial under the name 
of the chorda tympani. It supplies the submaxillary and sublingual glands, and 
confers the sense of taste on the anterior two-thirds of the tongue. (See Gerrish.) 
6. A branch is given off two lines above the stylomastoid foramen to the 
auricular branch of the vagus nerve. 
Branches at the Stylomastoid Foramen. 1. To the stylohyoid and posterior belly 
of the digastric (digastric branch). 2. To the attollens aurem, retrahens aurem, 
and posterior belly of the occipitofrontalis muscle (posterior auricular nerve). 
Branches on the Face and Neck. Subdivisions, two : cervicofacial (or lower) 
and temporofacial (or upper). 
The cervicofacial division is distributed, as its name implies, to the neck and 
lower parts of the face. Branches: Inframandibular, supramandibular, buccal. 
(a) The inframandibular branch skirts the angle of the mandible, is distributed 
to the platysma, and communicates with the superficial cervical nerve, a branch 
of the cervical plexus. 
(6) The supramandibular branch crosses the masseter muscle, lies on the body 
of the mandible, communicates with the mental branch of the mandibular nerve 
at the mental foramen, and supplies the inferior segment of the orbicularis oris 
and muscles inserted into the same. 
(c) The buccal branch crosses the masseter muscle below Stenson's duct, enters 
a quantity of fat in front of the masseter muscle, and supplies the buccinator 
muscle. This nerve communicates with the long buccal branch of the inferior 
maxillary division of the fifth nerve. The buccal branches from the fifth and 
seventh nerves unite to form a plexus, from which the buccinator muscle is sup- 
plied with motion, and the skin, glands, and mucous membrane of the cheek with 
sensation. 
The temporofacial or upper division of the facial nerve is larger than the 
cervicofacial. It crosses the neck of the mandible and external carotid artery. 
It receives communicating branches from the auriculotemporal, and divides into 
the temporal, malar, and infra-orbital branches. 
(a) The temporal branches cross the zygomatic and supply the anterior part of 
the occipitofrontalis, corrugator supercilii, tensor tarsi, and upper segment of the 
orbicularis palpebrarum. They communicate with the supra-orbital, temporal, 
lacrymal, and auriculotemporal nerves. 
(6) The malar branches cross the malar bone and supply the orbicularis palpe- 
brarum. They pass beneath the zygomatic muschs and communicate with the 
infra-orbital, lacrymal, and malar branches of the superior maxillary. 
(c) The infra-orbital branches cross the masseter, pass beneath, and supply the 
zygomatic muscles, and are distributed to the muscles of the nose, upper lip, and 
orbicularis palpebrarum. They communicate with the nasal and infratrochlear 
branches of the ophthalmic, the buccal branches of the facial, and the infra- 
orbital branches of the superior maxillary. THE FACE. 
29 
MUSCLES OF MASTICATION. 
Dissection and Identification. 
Temporal Fascia. Identify (1) by its origin from the temporal ridge, its insertion into the 
upper border of the zygomatic arch, and its location on the temporal muscle; (2) by the 
dense fibrous structure. Dissection : Cut at several attachments; remove and expose the sub- 
jacent temporal muscle. 
Temporal Muscle. Identify (1) by its origin from the temporal ridge and deep part of the 
temporal fascia; (2) by its insertion into the coronoid process. Dissection: Saw through the 
ends of the zygomatic arch and turn same down with the attached masseter muscle. 
Masseteric Fascia. Identify (1) by its location on the outer surface of the masseter 
muscle; (2) by its continuity with the parotid and temporal fasciae. 
Masseter Muscle. Identify (1) by its origin from the zygomatic arch and its insertion 
into the outer surface of the ramus ; (2) by its superficial relation to the pes anserinus. Dis- 
section: Turn down with the zygomatic arch previously sawn through and find its nerve pass- 
ing through the sigmoid notch. 
Fig. 9. 
The temporal muscle, the zygoma and masseter having been removed. (Gray.) 
External Pterygoid Muscle. Identify (1) by its origin from the greater wing of the 
sphenoid and pterygoid plate; (2) by its insertion into the condylar process and interarticular 
fibrocartilage. 
Internal Pterygoid Muscle. Identify (1) by its origin from the external pterygoid plate; 
(2) by its insertion into the inner surface of the ramus. Dissection : These muscles cannot 
be dissected until the mandible has been sawn through at the symphysis menti and the tongue 
split. Then work from the inner surface. 
Buccinator. Depress the jaw and put the muscle on the stretch; then identify by its loca- 
tion opposite the molar teeth and its attachment to the alveolar processes. 
The muscles of mastication derive their nerve-supply from the fifth ; their 
blood-supply from the internal maxillary artery. They are inserted into and 
move the mandible on the upper jaw for triturative purposes. The buccinator is 
also a muscle of facial expression, and is further innervated by the seventh nerve. 
Their collective use is the mastication of solid food ; hence the collective name, 
muscles of mastication. 
The Temporal Fascia. The temporal fascia covers the greater part of the tem- 
poral muscle. It arises from the temporal ridge. It is inserted into both the 
outer and inner borders of the superior part of the zygomatic arch, and is con- 
tinuous below with the masseteric fascia. It is in relation superficially with the 30 
A MANUAL OF DISSECTION. 
temporal vessels, the auriculotemporal nerve, and the temporal branches of the 
facial nerve. 
The Temporal Muscle. Origin: (1) The temporal ridge; (2) the temporal 
fascia ; (3) the greater part of the temporal fossa. Insertion: Coronoid process 
of the mandible. Action: To close and retract the jaw. Synergists: The masseter 
and internal pterygoid. Antagonists: Digastric, platysma, hyoid depressors, and 
gravity. Nerve-supply: The temporal branches of the inferior maxillary division 
of the trigeminus. Blood-supply: The muscular branches from the second stage 
of the internal maxillary artery. 
The Masseteric Fascia covers the masseter muscle. It is attached above to the 
zygomatic arch ; below to the posterior and inferior borders of the ramus. It is 
continuous above with the temporal, posteriorly with the parotid fascia, and is in 
relation superficially with the pes anserinus, part of the parotid salivary gland, 
and Stenson's duct. 
The Masseter Muscle. .Divisions: Superficial and deep layers. Origin: (1) The 
lower border of the malar bone and anterior two-thirds of the lower border of the 
Fig. 10. 
The pterygoid muscles, the zygomatic arch, and a portion of the ramus of the jaw having been removed. (Gray.) 
zygomatic arch ; (2) the inner surface of the zygomatic arch and the posterior 
third of the lower border of the zygomatic arch. Insertion: The onter surface 
of the ramus. Action: To close the mouth and draw the jaw forward. Syner- 
gists : Temporals and pterygoids. Antagonists: The same that antagonize the 
temporal muscle. Nerve-supply: The masseteric branch of the inferior maxillary 
division of the trigeminus. Its nerve passes through the sigmoid notch of the 
ramus with the masseteric vessels. Blood-supply : The muscular branches of the 
second stage of the internal maxillary artery. 
The External Pterygoid Muscle. Heads: (1) Upper; (2) lower. Origin of 
upper head: The greater wing of the sphenoid, internal to the pterygoid ridge, 
and external to the foramen ovale and foramen spinosum. Origin of lower head : 
The outer surface of the external pterygoid plate. Insertion of upper head: The 
interarticular fibrocartilage, the capsule of the joint, and neck of the condyle. 
Insertion of lower head: The neck of the condyle. Action: To draw the condyle 
and interarticular fibrocartilage forward and inward. Synergists: Superficial 
layer of masseter and internal pterygoid. Antagonists: The temporal and deep 
layers of the masseter. Nerve-supply: The pterygoid branch of the inferior THE FACE. 
31 
maxillary division of the trigeminus. Blood-supply: The second stage of the 
internal maxillary artery. 
The Internal Pterygoid Muscle. Origin : (1) The inner surface of the external 
pterygoid plate; (2) the tuberosity of the palate and adjacent part of the maxilla. 
Insertion: The internal surface of the ramus, as high as the mandibular foramen 
Fig. 11. 
7// 
Figs. 11 and 12 show attachments of the muscles of mastication to the mandible. (Mortimer Frank ) 
and mylohyoid groove. Action: To close the mouth and draw jaw forward and to 
the opposite side. Synergists : The temporal and masseter muscles. Antagonists : 
The digastric and platysma. Nerve-supply: The inferior maxillary division of 
the trigeminus. Blood-supply: The second stage of the internal maxillary artery. 32 
A MANUAL OF DISSECTION. 
The Buccinator arises from: (1) The pterygomaxillary ligament; (2) the alve- 
olar process of the tipper jaw ; (3) the alveolar process of the lower jaw. It is 
inserted into the orbicularis oris in this manner : The upper and lower fibres con- 
verge toward the angle of the mouth, where they decussate to become continuous 
with the fibres of the orbicularis oris. The highest and lowest fibres do not decus- 
sate. The buccinator and superior constrictor of the pharynx are united by the 
pterygomaxillary ligament forming a continuous muscular wall for the mouth 
and pharynx. The ligament extends from the hamular process to the posterior 
extremity of the mylohyoid ridge near the wisdom tooth. The principal use of 
the ligament, then, is to form a common attachment for the superior constrictors 
of the pharynx and buccinator. The buccinator muscle expels air from the mouth, 
widens the mouth, and assists the tongue in keeping the food between the molar 
teeth during mastication. Nerve-supply : The fifth and seventh cranial nerves. 
The Buccinator Fascia takes its name, according to a general rule, from the 
muscle which it invests and strengthens. This fascia adheres closely to the outer 
wall of the muscle, and must be removed to appreciate the direction of its fibres. 
It is thin in front and dense behind, where it is then continuous with the aponeu- 
rosis of the pharynx, and consequently strengthens the junctional area between 
the mouth and pharynx ; for this reason it is called the buccopharyngeal fascia. 
Owing to the strength of this fascia, and to the great vitality of the buccinator and 
superior constrictor muscles of the pharynx, abscesses do not readily break into 
the mouth and pharynx. 
Table of Muscles of Mastication. 
Name. Origin. 
Insertion. 
Action. Paralytic symptoms. 
Masseter. Malar process of 
superior max. ; 
anterior two- 
thirds lower bor- 
der zygomatic 
arch. 
Inner surface zygo- 
matic arch; post, 
one-third of 
lower border. 
Angle and lower 
one-half of outer 
surface of ramus. 
Outer surface of 
upper half of 
ramus and coro- 
noid process. 
To draw jaw for- Lessened ability to pro- 
ward and up- trude chin, 
ward. 
To draw jaw up Lessened ability to retract 
and back. and elevate jaw. 
Temporal. Temporal ridge 
and fossa. 
Coronoid process. 
Ant. half elevates Partial loss of power to 
the jaw ; post. elevate and retract jaw. 
half retracts and 
elevates jaw. 
External Ala of sphenoid, 
pterygoid. 
Interarticular car- 
tilage. 
To draw cartilage A peculiar creaking noise 
inward and for- produced by the con- 
ward onto the dyle riding over the 
eminentia articu- stationary fibrocartilage ; 
laris. noise both subjective and 
objective symptom. 
Outer surface of 
external ptery- 
goid plate. 
Neck of condyle. 
To draw jaw for- Inability to move jaw 
ward and in- toward the affected side ; 
ward. when chin is depressed 
deviation of jaw to 
paralyzed side (Gowers). 
Internal Inner surface of 
pterygoid. external ptery- 
goid plate; tuber- 
osities of palate 
and superior 
maxilla. 
Inner surface of 
lower half of 
ramus. 
To draw jaw for- Inability to draw closed 
ward, upward, jaw forward, 
and to the oppo- 
site side. 
Buccinator. Outer surfaces of 
both upper and 
lower alveolar 
processes; ptery- 
gomaxillary 
ligament. 
Orbicularis oris. 
To abduct corners Inability to widen the 
of mouth ; to . mouth ; pendulous 
force food into cheeks during mastica- 
vestibule. tion. THE FACE. 
33 
Summary of Nerve-supply. 
The buccinator receives a motor branch from the seventh and a sensory from 
the fifth nerve. The remaining muscles are innervated by the inferior maxillary 
division of the fifth nerve. 
Masseter. The nerve to the masseter passes outward above the external ptery- 
goid muscle with the masseteric vessels, through the sigmoid notch of the ramus, 
and enters the inner surface of the muscle. 
Temporal. There are interior and posterior deep temporal nerves, probably cor- 
responding to like physiological portions of the muscle which they supply. 1 hey 
pass over the upper border of the external pterygoid muscle, to the temporal muscle, 
and bone. 
External Pterygoid. The branch to this muscle is from the long buccal nerve. 
Fig. 13. 
Mandibular division of the trifacial nerve. (Gerrish after Testut.) 
Internal Pterygoid. The nerve to this muscle is distributed to the inner surface 
of the muscle. 
The Buccinator. The long buccal nerve passes between the upper and lower 
heads of the external pterygoid, with the buccal artery, and subsequently under 
cover of the temporal and masseter muscles to the buccinator muscle, and divides 
into the sensory branches for the skin and cheek. This muscle derives its motor 
branches from the seventh nerve. The muscles of mastication derive their blood- 
supply from the second or pterygoid stage of the internal maxillary artery. Col- 
lectively, branches of both the artery and nerves are called muscular ; individu- 
ally, each takes the name of the muscle it supplies. 34 
A MANUAL OF DISSECTION. 
TEMPOROMANDIBULAR ARTICULATION. 
Osteological Elements of the Temporomandibular Region. The tympanic plate 
is a thin lamina which forms the posterior part of the glenoid fossa and the 
anterior wall of the middle ear and external auditory meatus. It terminates 
externally in the auditory process, below in the vaginal process, above in the 
Glaserian fissure. 
The Eminentia Articularis is the broad, strong, anterior root of the zygomatic 
process of the temporal bone. It forms the anterior boundary of the glenoid fossa, 
and is covered with cartilage. The preglenoid tubercle, at the outer end of the 
anterior root, is for the attachment of a portion of the external lateral ligament. 
The Postglenoid Tubercle, or middle root of the zygoma, forms the posterior boun- 
dary of the articular part of the glenoid fossa, and separates the auditory process 
from the articular part of the glenoid fossa. 
The Glaserian or petrotympanic fissure is between the squamous and tympanic 
elements of the temporal bone. It separates the articular from the non-articular 
part of the glenoid cavity. It leads into the tympanum, lodges the processus 
gracilis of the malleus, and transmits the tympanic branch of the internal maxil- 
lary artery to the middle ear. 
The Canal of Huguier or iter chordae anterius is a subdivision of the Glaserian 
fissure. It transmits the chorda tympani nerve from the tympanum to the zygo- 
matic fossa, where, after communicating with the otic ganglion, it passes beneath 
the external pterygoid muscle to the outer side of the lingual nerve. 
The Glenoid Fossa is situated in a recess between the squamous and tympanic 
parts of the temporal bone. It is bounded anteriorly by the eminentia articularis, 
posteriorly by the tympanic plate. The anterior and posterior limiting structures 
of the glenoid fossa meet at the Glaserian fissure. The glenoid fossa consists of two 
parts : (1) One anterior to the Glaserian fissure, covered with cartilage and called 
the mandibular because it articulates with the condyle of the mandible ; (2) 
another, posterior to the Glaserian fissure, and occupied by a part of the parotid 
gland. The dome of the glenoid fossa is very thin and easily fractured. 
The Condylar Process of the mandible consists of (1) a condyle ; (2) a neck. 
The condyle articulates with the articular part of the glenoid cavity. Its convex 
surface is covered with cartilage. Its transverse axis is greater than its antero- 
posterior. Its articular surface is surrounded by the origin of the mandibular 
part of the capsular ligament. The neck is the constricted part of the process 
below the condyle. It is flattened in front and gives insertion to the external 
pterygoid muscle. 
The Styloid Process is, morphologically, not a part of the temporal bone. It 
was evolved from the dorsal extremity of the second visceral arch and became 
united to the inferior surface of the petrosa. It gives origin to three muscles and 
two ligaments, as follows : stylohyoid muscle, from the back and outer surface ; 
styloglossus muscle, front and lower part of the tip ; stylopharyngeus muscle, 
from internal part of the base ; stylomandibular ligament, from tip of the styloid ; 
stylohyoid ligament, from tip of styloid. 
The temporomandibular articulation is held in position or its range of move- 
ments limited by certain periosteal and fascial ligaments. One of these, the pos- 
terior, is always ruptured in dislocation of the jaw. 
LIGAMENTS OF LOWER JAW. 
The ligaments are the following : the capsular ligament; the anterior part of 
the capsule ; the posterior part of the capsule ; the internal lateral ligament ; the 
external lateral ligament; the sphenomandibular ligament ; the stylomandibular 
ligament; the interarticular fibrocartilage. THE FACE. 
35 
The Capsular Ligament is loose and flabby, and is attached externally to the 
articular surfaces, above and below. It is in relation internally with the circum- 
ference of the interarticular fibrocartilage, and lined by synovial membrane. 
The anterior, posterior, and lateral parts of the capsule are continuous in such a 
manner as to encapsulate the joint. (See Gray's Anatomy.) 
The External Lateral ligament is the strongest part of the capsule. It is attached 
to the outer surface of the zygoma and to the outer surface of the neck of the 
condylar process. The synovial membrane lines the compartments of the capsule. 
Fig. 14. 
Temporomandibular articulation in sagittal section. (Gerrish after Testut.) 
The upper is larger and looser than the lower. The nerve-supply of this articu- 
lation is derived from the masseteric and auriculotemporal branches of the inferior 
maxillary division of the trifacial nerve. The muscles of mastication move the 
temporomandibular articulation ; they are supplied by the trifacial nerve ; hence 
the nerve-supply of the temporomandibular joint is from the trifacial and in har- 
mony with a general law. The interarticular fibrocartilage divides the cavity of 
the temporomandibular articulation into an upper and a lower portion. It has an 
upper part accommodated to the surface, over which it glides-concavo-convex 
antero-posteriorly; a lower part, corresponding to the articular surface of the 
Fig. 15. 
Temporomandibular articulation, mesial view. (Gerrish after Testut.) 
condyle. The circumference of the cartilage, thicker than the central part, is 
attached to the inner surface of the delicate, loose, flabby, capsular ligament. A 
few fibres of the external pterygoid muscle are inserted into the anterior part of 
the cartilage, and by these the same is drawn forward onto the eminentia articu- 
laris when the mouth is opened. 
The Sphenomandibular (long internal lateral) ligament of the jaw extends from 
the spine of the sphenoid to the lingula of the mandible. Near the mandibular 
foramen this ligament is perforated by the mylohyoid nerve. Morphologically, 36 
A MANUAL OF DISSECTION. 
it is a degenerated part of the first visceral arch. Its inner surface is in relation 
with the internal pterygoid muscle ; outer, with the external pterygoid muscle, 
middle meningeal artery, mandibular nerve, and internal maxillary vessels. 
The Stylomandibular ligament is between the masseter and internal pterygoid 
muscles. It arises from the styloid process near the apex, and is inserted into 
the posterior border and angle of the mandible. It is of fascial derivation. 
Embryology. The temporal bone consists of three genetically distinct parts- 
petrous, tympanic, and squamous-which at birth are separate from one another. 
The Tympanic is the smallest of the three embryonal parts of the bone, and is 
wedged in between the petrous and squamous parts at the base of the skull in 
such a way as to form (1) the auditory process around the external auditory canal ; 
(2) the vaginal process and tympanic plate, which latter forms a partition between 
the middle ear and the glenoid fossa. Union between the tympanic and squamous 
parts of the bone occurs before birth. Union also occurs between the tympanic 
and petrous parts, except in the region of the dorsal end of the first visceral arch. 
Failure to unite here is known as the Glaserian or petrotympanic fissure, located 
between the articular and non-articular parts of the glenoid fossa. In near rela- 
tion with the three parts of the temporal bone in the embryo were developing, 
from an entirely different source, mandible, tympanum, Eustachian tube, bones 
of hearing, and styloid process. We must see now how these opposite factions 
became so firmly amalgamated as to make a comprehensive understanding of the 
adult temporal bone, in its relation to the organs of hearing and mastication, 
without embryological study an absolute impossibility. We refer io the adjacency 
of the dorsal extremity of the visceral arches and clefts to the genetic parts of 
the temporal bone. 
The first and second visceral arches and their intervening cleft evolved the bones 
of hearing, the middle ear, the Eustachian tube, the stylomandibular and spheno- 
mandibular ligaments, the styloid process, and jaw bones before the development of 
the cranium : the petrosa was subsequently built up completely around the middle- 
ear parts, and incompletely about the condyle of the mandible, hence the tympanum 
and glenoid cavity ; perfect union between the tympanic part and petrosa did not 
occur, hence the Glaserian fissure wedging in the processus gracilis of the malleus. 
Table showing the parts in the temporomandibular region, evolved from (1) 
temporal bone; (2) visceral arches. 
Temporal elements. Visceral arch structures. 
Auditory process. Condyle of mandible. 
Vaginal process. Styloid process. 
Tympanic plate. Stylomandibular ligament. 
Posterior glenoid tubercle. Sphenomandibular ligament. 
Anterior glenoid tubercle and eminentia articularis. Tympanic cavity. 
Glenoid fossa. Eustachian tube. 
Glaserian fissure and canal of Huguier. Ossicles of hearing. 
DEPRESSIONS AND CANALS. 
The locations of depressions and canals in the temporomandibular region, 
according to the lines of least resistance and junctional areas, are the following: 
1. The Glenoid Fossa is located between the tympanic and the squamous parts 
of the temporal bone. It lodges (a) condyle of the mandible ; (6) portion of the 
parotid gland. 
2. The Glaserian Fissure is located between the tympanic and petrous portions 
of the temporal bone. It represents the ununited region between these two parts. 
It has a subdivision, the canal of Huguier or iter chordae anterius, through which 
the chorda tympani passes from the middle ear to the zygomatic fossa. 
3. The Auricular Fissure is between the auricular process of the tympanic part 
and the mastoid process of the petrosa. The fissure transmits the auricular THE FACE. 
37 
branch of the vagus. This branch supplies the auricular process and communi- 
cates with the auriculotemporal branch of the trifacial nerve. 
4. The Tympanum or middle ear, like the facial canal, is in a junctional area, 
determined by ossification proceeding from the four ossific nuclei of the petrosa. 
It was evaginated from the inner part of the first visceral cleft and completely 
surrounded by the petrosa. 
5. The Facial Canal extends from the bottom of the internal auditory meatus 
to the stylomastoid foramen in the petrosa. It lodges the seventh nerve. . Its 
junctional area is determined by the ossification from the opisthotic, pterotic, 
pro-otic, and epiotic nuclei of the petrosa. 
DEPRESSOR AGENTS OF MANDIBLE. 
The depressors of the mandible are the following : 1. Gravity-that is, the 
weight of the jaw. 2. The platysma myoides muscle. 3. The digastric muscle. 
4. The mylohyoid muscle. 5. The geniohyoid muscle. These agents are antago- 
nized by the following muscles : 
(a) The anterior segment of the temporal muscle. (6) The masseter muscle, 
(c) The internal pterygoid muscle. 
Nerve-supply. The nerve-supply is in harmony with the general rule : nerves 
that supply the muscles moving a joint supply the joint moved by the muscles. 
The fifth nerve supplies the muscles of mastication ; it also supplies the temporo- 
mandibular articulation through (1) the articular branch of the auriculotemporal ; 
(2) the articular branches of the masseteric. 
Blood-supply. The blood-supply is from the ascending pharyngeal branch of 
the external carotid, middle meningeal, and temporal branches of the internal 
maxillary artery. 
Ligamentous Muscles. The ligamentous muscles of the temporomandibular 
articulation are the temporal, masseter, internal, and external pterygoids. Muscles 
that cross any joint are said to be ligamentous thereto; they are the elastic ligaments, 
in contradistinction to the periosteal ligaments. 
INTERNAL MAXILLARY ARTERY. 
The internal maxillary artery arises from the external carotid in the substance 
of the parotid gland, behind the neck of the jaw. It traverses the zygomatic 
fossa, passes between the upper and lower heads of the external pterygoid muscle, 
and gives off its terminal branches in the sphenomaxillary fossa. It has three 
portions: maxillary, pterygoid, and sphenomaxillary, and an accompanying 
internal maxillary vein. 
Branches of Internal Maxillary, Tabulated. 
Maxillary portion. Pterygoid portion. Sphenomaxillary portion. 
Deep auricular. Masseteric. Posterior dental (alveolar). 
Tympanic. Deep temporal. Infra-orbital. 
Middle meningeal. Pterygoid. The Vidian. 
Small meningeal. Buccal. The pterygopalatine. 
Inferior dental. The sphenopalatine (nasal). 
The ascending palatine. 
The descending palatine. 
The Maxillary Portion is between the neck of the jaw and the internal lateral 
ligament. From this are given off the following branches : (1) The deep auricu- 
lar, to the external auditory meatus and drum ; (2) the tympanic, which passes 
through the Glaserian fissure to the middle ear ; (3) the middle meningeal, given 
off between the neck of the jaw and the internal lateral ligament, passes between 
the two roots of the auriculotemporal nerve, through the foramen spinosum, into 38 
A MANUAL OF DISSECTION. 
the middle fossa of the skull, and is distributed to the dura mater ; (4) the small 
meningeal enters the skull through the foramen ovale and supplies the Gasserian 
ganglion and dura ; (5) the inferior dental accompanies the nerve of the same 
name, enters the mandibular canal, and is distributed to the teeth and gums of 
the mandible and to the skin of the chin. 
The Pterygoid Portion is between the external pterygoid muscle and the inser- 
tion of the temporal. Its branches are : (1) The masseteric, which supplies the 
masseter muscle and anastomoses with the facial and transverse facial branch of 
the temporal ; it gains the under surface of the muscle through the sigmoid notch, 
between the coronoid and condylar processes of the ramus, and is accompanied by 
the nerve and veins of like name ; (2) the deep temporal, anterior and posterior, 
attended by the nerves and veins of like name, and distributed to the deep sur- 
face of the temporal muscle ; (3) the pterygoid to the pterygoid muscles, attended 
by the nerves and veins of like name ; (4) the buccal, attended by the long buccal 
branch of the fifth nerve, to the buccinator muscle. 
Fig. 16. 
The internal maxillary artery and its branches. (Gray.) 
The Sphenomaxillary Portion is in the sphenomaxillary fossa. Branches: (1) The 
posterior dental, given off with the infra-orbital as the artery enters the spheno- 
maxillary fissure and gives branches to the molar and bicuspid teeth ; (a) gingival 
branches to the gums; (6) antral branches to the antrum of Highmore. (2) The 
infra-orbital arises with the inferior dental, passes along the infra-orbital canal, and 
appears on the face at the infra orbital foramen, between the levator labii superioris 
and levator anguli oris. Branches : (a) To the lacrymal gland ; (6) to the inferior 
rectus and inferior oblique muscles ; (c) to the mucous membrane of the antrum 
of Highmore ; (d) to the incisor and cuspid teeth ; (e) to the nose, lip, and eyelid. 
(3) The Vidian, small, passes through the Vidian canal at the junction of the 
lingula, pterygoid process, and greater wing of the sphenoid bone to the Eustachian 
tube, middle ear, and pharynx, and is attended by the Vidian nerve and veins. 
(4) The pterygopalatine passes through the canal of like name, with the pharyngeal 
branch of Meckel's ganglion, to the pharynx and Eustachian tube. (5) The 
sphenopalatine or nasal branch enters the nose through the foramen of like name, THE FACE. 
39 
in company with the sphenopalatine branches of Meckel's ganglion, and supplies 
the ethmoid cells and mucous membrane of the antrum of Highmore. (6) The 
ascending palatine passes through the posterior palatine canal, with the palatine 
nerves from Meckel's ganglion, thence along the roof of the mouth, to the anterior 
palatine canals, in which they inosculate on the septum with branches of the 
nasopalatine artery. (7) The descending palatine branches to the gums, glands, 
mucous membrane, and soft palate. 
The Internal Maxillary Vein accompanies and corresponds to the maxillary artery. 
Tributaries: Middle meningeal, deep temporal, pterygoid, masseteric, buccal, 
superior and inferior dental, palatine, and other veins. These tributary veins 
form a plexus corresponding to the pterygoid and sphenomaxillary portions of the 
internal maxillary artery-the pterygoid plexus. The internal maxillary vein 
passes behind the neck of the mandible and joins the temporal vein, forming the 
temporomaxillary. This divides into (1) a tributary of the facial vein ; (2) the 
external jugular, which receives the posterior auricular vein. 
THE TRIFACIAL NERVE ROOTS AND GANGLION. 
Roots. The trifacial has a motor and a sensory portion. The motor root arises 
from groups of cells in the floor of the fourth ventricle and in the aqueduct 
of Sylvius, and passes outward to supply the muscles of mastication. The fibres 
Fig. 17. 
Distribution of the second and third divisions of the fifth nerve and submaxillary ganglion. (Gray.) 
of the sensory portion arise in cells of the Gasserian ganglion, and, passing 
inward, end around the cells of the gelatinous substance and funiculi gracilis and 
cuneatus. 40 
A MANUAL OF DISSECTION. 
The larger or sensory root passes through the trigeminal notch near the apex 
of the petrosa and enters Meckel's space, where it spreads out, becomes plexiform, 
and enters the Gasserian ganglion. 
The smaller or motor root crosses beneath the Gasserian ganglion, and, joining 
the sensory portion of the third division, is distributed to the muscles of mastication. 
Gasserian Ganglion. The Gasserian ganglion gives origin to the sensory fibres. 
It lies in a depression on the anterior surface of the petrosa, near the apex of the 
bone in relation with the internal carotid artery and cavernous sinus. It is joined 
by sympathetic nerves from the carotid plexus, and gives branches to the dura. 
From the anterior convex border of the ganglion the ophthalmic, superior, and 
inferior maxillary divisions of the trifacial nerve arise. The first leaves the 
cranium through the sphenoidal fissure, the second through the foramen rotundum, 
the third through the foramen ovale. 
Ophthalmic Division of Trifacial. 
The ophthalmic division is sensory, and supplies the eyeball, ciliary muscle, 
iris, lacrymal gland, nasal and ocular mucous membrane, skin of eyebrow, fore- 
head and nose, and ciliary ganglion. Its branches are the lacrymal, frontal, and 
nasal. (See Fig. 18.) 
The Lacrymal Nerve passes through the outer angle of the sphenoidal fissure to 
the orbit. It reaches the lacrymal gland, having traversed the cavity of the 
orbit along the upper border of the external rectus muscle. Its branches are to 
the lacrymal gland, conjunctiva, skin of the upper lid, and communicating to the 
orbital branch of the superior maxillary nerve. 
The Frontal Nerve, the largest branch of the ophthalmic, enters the orbit through 
the sphenoidal fissure. It lies on the levator palpebrse, and, midway between 
the apex and base of the orbit, divides into supratrochlear and supra-orbital 
branches. The supratrochlear crosses the tendon of the superior oblique, passes 
over the inner angle of the orbital arch, and is distributed to the eyelid, con- 
junctiva, and forehead. Near the pulley of the superior oblique muscle it gives 
a branch to the infratrochlear branch of the nasal nerve. The supra-orbital branch 
leaves the orbit through the supra-orbital foramen, with an artery of like name, 
and supplies the skin of the forehead. 
The Nasal Nerve, on entering the orbit through the sphenoidal fissure, passes be- 
tween the two divisions of the third nerve, and also between the two heads of the 
external rectus muscle. It passes between the optic nerve and the superior 
rectus muscle to the anterior ethmoidal foramen, through which it passes into the 
cranial cavity, attended by the anterior ethmoidal vessels, and, running forward 
on the cribriform plate of the ethmoid, passes through a slit into the nasal fossa. 
It gives off the following branches : 
(a) Long ciliary nerves to the eyeball. 
(6) A septal branch to the mucous membrane of the septum. 
(c) An external branch to the outer wall of the nasal fossa. 
(d) A superficial branch to the lower part of the nose. 
(e) An infratrochlear branch to the conjunctiva, caruncle, inner canthus, lacry- 
mal sac, eyelids, and nose. 
The Ciliary Ganglion. 
The ciliary or lenticular ganglion is about the size of a pinhead ; it lies near 
the apex of the orbit, between the optic nerve and the external rectus muscle. 
Its roots are : 
(a) Motor, from the third nerve. 
(6) Sensory, from the nasal nerve. 
(c) Sympathetic, from the cavernous plexus. THE FACE. 
41 
The ciliary ganglion is a composite structure, and each branch of distribution 
has a definite physiological function. Its ciliary branches are called the short, in 
contradistinction to the long ciliary branches of the nasal nerve. 
Fig. 18. 
Oculomotor nerve and ciliary ganglion (C. 
J. G.). (Gekkish after Testut.) 
Function. The ciliary branches, derived from the nasal nerve element of the 
ganglion, confer trophicity and ordinary sensation on the eyeball. Branches of 
the ganglion derived from the third nerve element are motor to the ciliary muscle 
and sphincter of the iris. Branches of sympathetic derivation produce dilatation 
of the iris. (See Gerrish.) 
Superior Maxillary Division of Trifacial. 
The superior maxillary, a sensory nerve, begins in the Gasserian ganglion and 
ends on the face around the infra-orbital foramen. The nerve leaves the cranium 
through the foramen rotundum, in the greater wing of the sphenoid bone, and 
enters the upper part of zthe sphenomaxillary fossa. It then passes through the 
sphenomaxillary fissure (as infra-orbital nerve) in company with the vessels of like 
name, and enters the infra-orbital canal in the floor of the orbit. This nerve 
reaches the face through the infra-orbital foramen, and gives off the following 
branches : (a) A recurrent branch to the dura mater ; (6) two sphenopalatine 
branches to Meckel's ganglion ; (c) the orbital or temporomalar ; (d) the middle 
superior dental ; (e) the posterior dental ; (/) the anterior dental ; (^) the infra- 
orbital to the nose, lip, and eyelid ; (/i) a recurrent branch to the dura mater 
accompanying the middle meningeal artery. 
The Orbital or temporomalar branch enters the orbit through the sphenomaxillary 
fissure, and divides into the temporal and malar branches. It communicates with 
the lacrymal nerve and passes through a canal in the malar bone to the temporal 
region. The malar branch passes forward between the floor and outer wall of the 
orbit, and escapes on the face through a small foramen in the malar bone. 
The Posterior Dental Nerves, accompanied by vessels of like name, contribute 
branches to the mucous membrane of the cheek and gums, and enter the posterior 
dental canals in the zygomatic surface of the maxilla for the supply of the molar 
teeth and antrum of Highmore. 42 
A MANUAL OF DISSECTION. 
The Anterior Superior Dental nerves arise near the front of the infra-orbital canal, 
pass through the canals in the anterior wall of the antrum, and supply the nasal 
fossae, incisors, cuspid, and gums. 
The Middle Dental Nerves are given off in the infra-orbital canal. They pass 
through small canals in the outer wall of the antrum and supply the bicuspids. 
On emergence from the infra-orbital foramen the infra-orbital nerve breaks up 
Fig. 19. 
Dental branches of superior maxillary nerve and sphenopalatine ganglion. (Gerrish after Testut.) 
into eight or ten sensory branches, of which two-the inferior palpebral-supply 
the skin and conjunctiva of the lower lid ; two-the lateral nasal-supply the skin 
of the nose; the remaining branches-the superior labial-supply the skin and 
mucous membrane of the upper lip. These several branches communicate with 
the seventh nerve to form the infra-orbital plexus, a structure which lies between 
the levator labii superioris and levator anguli oris muscles. 
Meckel's Ganglion (Sphenopalatine). 
Meckel's ganglion is in the sphenomaxillary fossa, below the superior maxillary 
nerve, in a fatty mass surrounded by the terminal branches of the internal max- 
illary artery. 
Roots : (1) Sensory, from the superior maxillary divisions of the fifth nerve, 
through two sphenopalatine nerves; (2) motor, from the seventh nerve, through 
the great superficial petrosal ; (3) sympathetic, from the carotid plexus, through 
the great deep petrosal. The sympathetic and motor roots combine to form the 
Vidian nerve and pass through the Vidian canal. 
Branches. (1) The ascending, leave the sphenomaxillary fossa through the 
sphenomaxillary fissure to the periosteum of the orbit ; (2) the descending or 
palatine, leave the fossa at the apex, through the posterior palatine canal, and 
supply the gums, mucous membrane, glands of roof of mouth, and soft palate ; 
(3) the posterior : (n) the Vidian, formed by union of the great superficial petrosal 
(a branch of the facial) and the great deep petrosal (a branch of the carotid 
plexus), passes through the Vidian canal and forms the motor and sympathetic 
roots of Meckel's ganglion; (6) the pharyngeal, passes through the pterygopalatine 
canal and supplies the mucous membrane of the upper part of the pharynx ; (4) 
the internal: (a) the nasal, pass through the sphenopalatine foramen, in the inner 
wall of the sphenomaxillary fossa, and are distributed to the upper and back part THE FACE. 
43 
of the septum ; (6) the nasopalatine, enters the nasal fossa through the spheno- 
palatine foramen, passes along the groove on the vomer, thence through the 
foramina of Scarpa, where it communicates with the nerve of the opposite side to 
form a plexus, from which the mucous membrane of the anterior half of the hard 
palate is supplied. 
Inferior Maxillary Division of Trifacial. 
The inferior maxillary division arises from the Gasserian ganglion, leaves the 
cranium through the foramen ovale in the greater wing of the sphenoid, and 
enters the zygomatic fossa. It is composed of sensory and motor fibres. The 
motor root accompanies the sensory, and the two unite after they pass through 
the foramen ovale and form a mixed trunk, which divides into the anterior and 
posterior parts. 
Fig. 20. 
Mandibular division of trifacial nerve, seen from the middle line. The small figure is an enlarged view of the 
otic ganglion. (Gerbish after Testut.) 
The Branches from Mixed Trunk. (1) The sensory recurrent; (2) the motor, 
to the internal pterygoid. Branches of the anterior division: (1) The deep temporal ; 
(2) the masseteric ; (3) to the external pterygoid ; (4) the long buccal. Branches of 
posterior division: (1) The auriculotemporal; (2) the inferior dental; (3) the 
lingual or gustatory. 
The Branches of the Anterior Division, (a) The long buccal nerve, passes be- 
tween the upper and lower heads of the external pterygoid muscle ; then down- 
ward and forward, internal to the temporal and masseter muscles, to the outer 
surface of the temporal and buccinator muscles, where it forms the buccal plexus 
with the buccal branch of the facial nerve. From this plexus the buccinator 
muscle, skin, and mucous membrane of the cheek are supplied. 44 
A MANUAL OF DISSECTION. 
(6) The masseteric nerve passes through the sigmoid notch to the masseter 
muscle in company with the masseteric vessels. 
(c) The deep temporal nerves, two in number, pass above the external ptery- 
goid muscle, hugging the bone closely, and soon enter the temporal muscle as 
very small twigs. 
(d) The external pterygoid nerve arises with the long buccal, and supplies the 
external pterygoid muscle. 
Branches of the Posterior Division, (u) The auriculotemporal nerve, sensory, 
arises by two roots, between which passes the middle meningeal artery. The 
roots soon unite, and the nerve passes beneath the neck on the condyle, gains the 
space between, the ear and jaw, whence it passes through the parotid gland and 
lies beneath and accompanies the superficial temporal artery across the zygoma. 
Branches of auriculotemporal nerve: communicating, to the seventh nerve ; 
articular, to the temporomandibular joint; sensory, to the parotid gland ; auricu- 
lar, to the external auditory meatus and skin of the upper and anterior part of the 
pinna. (6) The inferior dental nerve passes beneath the external pterygoid 
muscle, across the internal lateral ligament of the jaw, and enters the mandibular 
canal with the inferior dental vessels. The inferior dental nerve gives dental 
branches to the teeth ; gingival branches to the gums ; mental branches to the 
skin of the chin ; muscular to the mylohyoid muscle and anterior belly of the 
digastric, (c) The lingual or gustatory, a sensory nerve, is joined on its outer side 
by the chorda tympani. Course: Under cover of the external pterygoid muscle; 
between the internal pterygoid and ramus, in front of the inferior dental nerve ; on 
the mylohyoid muscle, beneath the mucous membrane ; between the mylohyoid and 
hyoglossus muscles, below Wharton's duct ; it is connected to the submaxillary 
ganglion as it crosses the hyoglossus muscle. The nerve may be reached by cut- 
ting longitudinally through the mucous membrane opposite the second lower 
molar tooth. Branches: Sensory, to the anterior two-thirds of the tongue ; to 
the sublingual gland, secretomotor fibres from the chorda tympani ; to the mucous 
membrane ; communicating, to the hypoglossal nerve, submaxillary ganglion, and 
inferior dental nerve. . 
The chorda tympani is a branch of the seventh cranial nerve, passes through 
the tympanum, and leaves this cavity through the canal of Huguier, in the 
petrous portion of the temporal bone. It meets the lingual nerve near its origin, 
accompanies the same as far as the submaxillary gland, and gives branches to the 
tongue, submaxillary, and sublingual glands. 
The Submaxillary Ganglion. 
Location. The submaxillary ganglion is on the outer surface of the hyoglossus 
muscle, attached to the gustatory nerve, and about the size of a pinhead. 
Roots. (1) Sensory, from the gustatory ; (2) motor, from the chorda tympani ; 
(3) sympathetic, from the nervi molies, surrounding the facial artery. Distribu- 
tion: To the mucous membrane of the floor of the mouth and to the submaxillary 
gland. 
The Otic Ganglion. 
Location. The otic ganglion is on the inferior maxillary division of the fifth 
nerve. Its roots are : (1) Motor, from the inferior maxillary ; (2) sensory, from 
the auriculotemporal ; (3) sympathetic, from the plexus on the middle meningeal 
artery. Relations : (1) External, to the inferior maxillary nerve ; (2) internal, to 
the tensor palati ; (3) posterior, to the middle meningeal artery. Distribution: 
To the tensor palati, tensor tympani, and a communication to the tympanic branch 
of the ninth nerve. THE FACE. 
45 
NASAL FOSSAE AND ACCESSORY SINUSES. 
Dissection and Identification. 
Make median incision with sharp saw through the entire head, a little to one side of the 
mid-line, including the lower jaw. Usually this incision will expose the frontal, ethmoid, 
and sphenoidal sinuses sufficiently for study of these regions. Thoroughly cleanse the parts 
with warm water. (See Figs. 23, 24.) 
Nasal Fossse Identify (1) by the location vertically extending from the roof of the mouth to 
the base of the skull; (2) by the presence of the antrum and orbit externally; (3) by the anterior 
nasal openings (anterior nares) in front, and the posterior openings (posterior nares) discharg- 
ing into the pharynx behind. 
Turbinate Bones (superior, middle, inferior). Identify (1) by their location on the outer 
wall of the nose; (2) by their characteristic scroll shape. 
Meatuses (superior, middle, inferior). Identify (1) by the location of the superior meatus 
between the upper and middle turbinate bones; (2) of the middle meatus between the inferior 
and middle turbinate bones; (3) of the inferior meatus, between the floor of the mouth and 
the inferior turbinate bone. 
Posterior Narial Openings. Identify (1) by the location on each side of the posterior 
border of the nasal septum ; (2) by opening into the pharynx. 
Septum Nasi. Identify (1) by the location so as to divide the internal nose into a right 
and a left part; (2) by the composition of these parts (easily demonstrable when the mucous 
membrane is removed), the vertical plate of the ethmoid, triangular cartilages, and vomer; 
(3) by the location so as to form the inner wall of each nasal fossa. 
Nasal Duct and Valve of Hassner. Identify (1) by opening well forward into the inferior 
meatus, beneath the inferior turbinate bone; (2) by communication with the conjunctival sac 
through the lacrymal sac and canaliculi. An imperfect valve of mucous membrane guards 
the opening. 
Ostium Maxillaire. Identify (1) by the location in the middle meatus, beneath the middle 
turbinate bone; (2) by communication with the antrum of Highmore. 
Fig. 21. 
The bony sinuses of the head. (Geerish after Testut.) 
Infundibulum. Identify (1) by the termination in the middle meatus, well forward, beneath 
the middle turbinate bone; (2) by communication above with the frontal sinus and anterior 
ethmoidal cells. 
Frontal Sinuses. Identify (1) by the location in the frontal bone, corresponding to the 
superciliary ridges; (2) by the presence of an opening (infundibulum) leading into the middle 
meatus, on the outer wall of the nose; (3) by a delicate, loosely attached mucous membrane. 
Dissection: The incision commonly employed in the removal of the calvarium usually makes 
a good exposure from above. Access may also be gained by trephining through the super- 
ciliary ridge. In this latter method note the mucous membrane when the button is removed. 
If the sinus contains pus, examine other intramural sinuses for pus. 
Ethmoidal Cells. Identify (1) by their location in the lateral mass of the ethmoid bone; 
(2) by the communication in front with the frontal, behind with the sphenoid sinus ; (3) by 
the delicate mucous membrane; (4) by the spongy texture of the bone and cellular nature of 
the interior; (5) by their location between the os planum and ethmo-turbinals. Dissection: 46 
A MANUAL OF DISSECTION. 
Gain access through the very thin os planum of the ethmoid, behind the lacrymal bone, on 
the inner wall of the orbit. 
Sphenoidal Sinuses. Identify (1) by their location in the body of the sphenoid, beneath 
the sella turcica; (2) by their communication with the posterior ethmoid cells, and with these 
open into the superior meatus on the outer wall of the nose; (3) by the delicate mucous mem- 
brane lining the same. Dissection : Gain access through the floor of the sella turcica. 
Antrum of Highmore. Identify (1) by its location in the body of the superior maxillary 
bone; (2) by its communication with the middle meatus on the outer wall of the nose; (3) by 
subjacency to the floor of the orbit; (4) by the second bicuspid, first and second molars, 
whose roots occupy the floor of the antrum. (Note the delicate mucous membrane and its 
continuation into the nose through the opening-ostium maxillaire. Dissection; Sawaway 
one inch of the most prominent part of the cheek bone, the apex of the antrum. (See 
Fig. 21). 
Mastoid Cells. Identify (I) by their location in the mastoid process of the temporal bone; 
(2) by their delicate mucous membrane. The higher cells are strictly pneumatic, and contain 
no fat; the lower ones usually contain fatty connective tissue. Dissection: Saw away one inch 
of the mastoid and squamosa, as in Fig. 21. (Mastoid antrum-see tympanum.) 
NASAL FOSS^. 
The Nasal Fossae are limited above by the base of the skull, below by the hard 
palate. The former limiting wall separates the nose from the cranial cavity, the 
latter from the oral cavity. In the mid-line the two fossae are separated by the 
septum nasi. The nasal fossae are limited in front by the anterior, behind by 
the posterior nares ; the former open on the face, the latter into the pharynx. 
The Shape. The cribriform plate of the ethmoid bone, about one inch long, is 
the highest part of the nasal fossae, and from this the fossae slope laterally toward 
the teeth, forward toward the tip of the nose, and backward toward the pharynx. 
The Roof. The forward slope of the roof corresponds to the bridge of the nose, 
and is composed of the nasal bones and the nasal spine of the frontal bone. The 
horizontal part of the roof is formed by the cribriform plate of the ethmoid. 
The backward slope of the roof is formed by the body of the sphenoid, alae of 
vomer, and sphenoidal processes of the palate bone. The foramina in the cribri- 
form plate transmit the olfactory nerves. Posteriorly, the roof has an occasional 
opening for the sphenoidal sinus. 
The Floor of the nasal fossae is about one inch wide. It is somewhat canoe- 
shaped, ending in front in the anterior, and behind in the posterior nasal spine, to 
which latter the uvula is attached. The floor is formed by the palatine process 
of the superior maxillary bone, articulating with the horizontal process of the 
palate bone. On the floor, just behind the anterior nasal spine, are the openings 
of the anterior palatine canal, four compartments : (1) Two lateral, the foramina 
of Stenson, through which pass the posterior palatine arteries from the mouth to 
the nose ; (2) two median, the foramina of Scarpa, through which pass the naso- 
palatine nerves from the nose to the roof of the mouth. 
The Inner Wall is called the septum nasi, and is formed by the vomer, vertical 
plate of the ethmoid, triangular cartilage, crests of maxillae, palate, sphenoid, 
nasal bones, and nasal spine of frontal. The posterior border of the vomer is free, 
and separates the posterior nares. The anterior border articulates with the incisor 
crest of the superior maxilla ; the inferior, with the floor of the nasal fossae ; the 
superior, with the sphenoid, triangular cartilage, and vertical plate of the ethmoid. 
The Outer Wall is formed by the inner surface and nasal process of the superior 
maxillary, three turbinates, vertical part of the palate, pterygoid process of 
the sphenoid, and lacrymal bone. 
The Anterior Narial Openings are bounded by the nasal bones above, the maxil- 
lary bones below, and the nasal processes of the superior maxillary bones laterally. 
The Posterior Narial Openings are bounded above by the sphenoid, palate, and 
alae oF vomer ; below by the horizontal plate of the palate bone ; externally by 
the internal pterygoid plate ; internally by the vomer and posterior nasal spine. 
The posterior narial opening of each side is about one-half inch wide and one 
inch from above downward. THE FACE. 
47 
The Turbinate Bones are the superior, middle, and inferior, and are modified 
parts of the outer wall of the nasal fossae. The superior and middle are convoluted 
parts of the lateral mass of the ethmoid bone, hence called ethmo-turbinals ; the 
inferior turbinate is described as an independent bone, articulating with the max- 
illa, ethmoid, palate, and lacrymal ; still, morphologically, it is a dismembered 
part of the lateral mass of the ethmoid. 
Meatuses. There are three recesses or meatuses on the outer walls of the nasal 
fossae, superior, middle, and inferior. The superior meatus is between the 
superior and middle turbinate bones ; the middle meatus, between the middle and 
inferior turbinate bones ; the inferior meatus between the inferior turbinate bone 
and floor of the nasal fossae. 
Orifices of Meatuses. The superior meatus has (1) an orifice for the posterior 
ethmoidal cells, through which the sphenoidal sinus occasionally opens ; (2) the 
sphenopalatine foramen, covered by mucous membrane in the recent state, which 
transmits the nasopalatine nerve and vessels from the sphenomaxillary fossa to 
Fig. 22. 
External wall of right nasal fossa, parts of the turbinates having been cut away to show the orifices ot 
the sinuses which open into the meatuses. (Gekrish after Testut.) 
the nose. The middle meatus has (1) a curved groove, the sulcus semilunaris 
(continuous above with the infundibulum), into which the frontal sinus and an- 
terior ethmoidal cells open ; (2) an opening for the antrum of Highmore. The 
inferior meatus has an opening for the nasal duct in front, guarded by a circular 
fold of mucous membrane, called the valve of Hassner. 
The Mucous Membrane (called pituitary and Schneiderian) is thick over the lower 
turbinate bone and septum, thin in the meatuses and intramural sinuses, and inti- 
mately adherent to the periosteum and perichondrium. 
Communications. The nasal fossae communicate : (1) With the orbit, by the 
lacrymal groove ; (2) with the cranial cavity, by the nasal split and olfactory 
foramina ; (3) with the mouth, by the anterior palatine canal ; (4) with the spheno- 
maxillary fossa, by the sphenopalatine foramen ; (5) with the middle ear, mastoid 
antrum, and mastoid cells, through the Eustachian tube and pharynx ; (6) with 
the frontal, sphenoidal, maxillary sinuses, and ethmoid cells. 48 
A MANUAL OF DISSECTION. 
Areas. The nasal fossae are divided (1) into an upper or olfactory area ; (2) a 
lower or respiratory area. The former is supplied by the olfactory nerves and 
branches from the trigeminus, through the Vidian nerve and Meckel's ganglion. 
Nerve-supply of Nasal Fossae. The nasal nerve supplies : 1. The anterior half 
of the outer wall. 2. The anterior half of the septum. 3. The anterior half of 
Fig. 23. 
Nasal septum, showing olfactory nerves and nerves of common sensation. (Gerrish after Testut.) 
the roof. Meckel's ganglion supplies : 1. The posterior half of the outer wall. 
2. The posterior half of the septum. 3. The posterior half of the roof. The 
olfactory nerve supplies : 1. The upper third of the septum nasi. 2. The supe- 
rior turbinated bone. 3. The middle turbinated bone. The anterior dental 
supplies: 1. The inferior turbinated bone. 2. The inferior meatus. 
Fig. 21 
Outer wall of nose, showing olfactory nerves and nerves of common sensation. (Gerrish after Testut.) 
Nerve-supply of the Intramural Sinuses. The ethmoidal cells, by the orbital branch 
of Meckel's ganglion. The sphenoidal sinus, by the orbital branches of Meckel's 
ganglion ; the antrum of Highmore, by the posterior superior dental ; the mas- 
toid antrum, by the recurrent branch of the trifacial ; the mastoid cells, by the 
recurrent branch of the trifacial ; the frontal sinus, by the supratrochlear branch 
of the frontal nerve. THE FACE. 
49 
Vessels of the Intramural Sinuses and Nasal Fossae. The sphenopalatine artery 
supplies the vomer, the antrum of Highmore, the frontal sinus, the ethmoidal 
cells, the turbinated bones, and meatuses. 
The anterior and posterior ethmoidal arteries supply the septum, the roof and 
outer wall of the nose, the anterior and posterior ethmoidal cells. The descending 
palatine supplies the inferior meatus and the inferior turbinated bone. 
The Vidian and pterygopalatine supply the roof of the nose ; the stylomastoid, 
the mastoid cells ; the pterygopalatine, the ethmoidal cells. 
The source of the arteries to the preceding regions are the stylomastoid from 
the posterior articular, the ethmoidals from the ophthalmic, the remaining ones 
from the internal maxillary. 
INTRAMURAL OR ACCESSORY SINUSES. 
Intramural or accessory sinuses of respiration are in the bones of the head ; 
they contain air and are evolved by evagination from the nose, another and more 
highly specialized pneumatic cavity. They are absent in the very young, and 
attain full development and become pneumatically competent in early adolescence. 
Mucous Membrane. The mucous membrane of the intramural sinuses is weak, 
pale, thin, flabby, detachable, poorly nourished, and liable to infection, just the 
opposite of the predominating physical traits of the mucous membrane of the 
parent cavity, the nasal fossse. 
Frontal Sinuses. The frontal sinuses are between the outer and inner tables of 
the vertical portion of the frontal bone, corresponding to the location on the sur- 
face of the superciliary ridges, but are not governed in size by these. There may 
be a large bump in this locality, due to the heaping up of bone, and not neces- 
sarily to a large sinus. The frontal sinus may occupy the greater part of the ver- 
tical portion of the frontal bone ; on the other hand, it may be very small or 
entirely absent. Its absence is noted in some Indian hill tribes. Posteriorly, 
the sinus communicates with the anterior ethmoidal cells ; it opens into the middle 
meatus about on a level with the palpebral fissure. The frontal sinuses are lined 
by a delicate mucous membrane, are asymmetrical on the two sides, and separated 
from each other by an incomplete partition of bone. This sinus is formed by an 
evagination of the original nasal pit. The frontal sinuses obtain as imperfect 
cells before the tenth year, but are well developed by the twentieth. (See Gray.) 
Ethmoidal Cells. The ethmoidal cells occupy the lateral masses of the ethmoid 
bone, being limited externally by the os planum, and internally by the superior 
and middle turbinated bones. At the points where the frontal, lacrymal, sphe- 
noid, palate, and maxillary bones articulate with the ethmoid there are cells 
designated fronto-ethmoidal, lacrymo-ethmoidal, spheno-ethmoidal, palato-eth- 
moidal, and maxillo-ethmoidal. The ethmoidal cells are lined by delicate mucous 
membrane, and are divided into (1) anterior, which open into the frontal sinuses ; 
(2) posterior, which open into the sphenoidal sinuses. 
Sphenoidal Sinuses. The sphenoidal sinuses are in the body of the sphenoid 
bone. They are irregular in size, and separated from each other by an imperfect 
bony partition. They may extend into the basilar process of the occipital bone or 
even invade the pterygoid processes. They are lined by delicate mucous mem- 
brane, communicate with the posterior ethmoidal cells, and open into the superior 
meatus on the outer wall of the nasal fossae. 
Maxillary Sinus. The maxillary sinus or antrum of Highmore is the largest 
of the intramural sinuses. It is in the body of the upper jaw. Above it is the 
orbit, below it the mouth, internal to it the nasal fossa. Its capacity varies from 
three to eight drachms, and it is larger in the male than in the female. The 
antrum is formed by an evagination of the primitive nasal pit about the sixth 
month of foetal life, and is lined by a mucous membrane, continuous with that 
of the nose, through the nasal orifice or ostium maxillaire. As a rule the cavity 50 
A MANUAL OF DISSECTION. 
of the antrum is single ; still, it may be divided into pockets or recesses by im- 
perfect bony partitions. For purposes of systematic study the antrum should be 
considered as having the following parts : 
The Apex, which corresponds to the malar prominence. The antral cavity may 
even invade the substance of the malar bone. 
The Base is the part directed toward the nose, and is also called the internal or 
nasal surface. This surface is very thin, deficient behind, and presents one or 
more openings close up under the roof, by which the antrum communicates with 
the middle meatus of the nose. The inferior turbinated bone and the vertical 
portion of the palate bone close in the opening of the antrum. 
The Roof is formed by the orbital plate of the superior maxillary bone, and 
separates the antrum from the orbit. The roof of the antrum and floor of the 
orbit are the same, and contain the infra-orbital canal, in which are lodged the 
infra-orbital nerve and vessels. 
The Floor is formed by more or less of the alveolar process, and presents irregu- 
larities corresponding to the roots of the first and second molar and second bicus- 
pid teeth. It must be remembered, however, that, while the first and second 
molars are in the closest relation with the antrum, under some circumstances any 
of the sockets of the upper teeth may communicate with this cavity. 
The Anterior Wall is formed by the facial surface of the upper jawbone. It 
contains the anterior-superior dental canals, in which are lodged the vessels ami 
nerves for the supply of the incisor and cuspid teeth. 
The Posterior Wall is formed by the zygomatic surface of the jaw. This wall 
contains the posterior-superior dental canals, in which are located the vessels and 
nerves for the supply of the molar teeth. 
The walls of the antrum may be displaced by a large tumor in any direction 
(except in the line of the alveolar process and malar bone) on account of their frail 
structure. The antrum may be tapped (1) in the inner wall via the anterior 
nares ; (2) above the second bicuspid tooth ; (3) a molar tooth may be extracted ; 
still, this latter procedure is at variance with conservative dentistry. Large 
tumors of the antrum become painful on account of the pressure they exert on the 
nerves in the roof, anterior and posterior walls. Discharges from the frontal 
sinus may fill the antrum when, as occasionally happens, the opening for the 
antrum lies in the course of the infundibulum, in the hiatus semilunaris. 
The Mastoid Antrum is present at birth. It attains its largest size (about that 
of a pea) in the third or fourth year, becoming somewhat smaller in the adult. 
It lies behind and communicates with the tympanum. Its floor communicates 
with the mastoid cells. Its roof is continuous with the roof of the tympanum, 
and is called the tegmen antri. The outer wall is continuous with the squamosa, 
and is the place through which the operator reaches the antrum. CHAPTER II. 
THE SCALP, MENINGES AND BASE OF THE SKULL. 
THE SCALP. 
Definition. Soft structures covering the bones of the cranium. It may be 
moved both actively and passively on the living. 
Composition, (a) Very thick skin, covered with hair (except the forehead), and 
intimately attached to the subjacent superficial fascia; (b) superficial fascia, a very 
dense, fibro-fatty structure intimately attached to the skin and occipitofrontalis, 
and containing the vessels and nerves of the scalp; (c) occipitofrontalis (see 
muscles of expression); (d) vessels and nerves. The pericranium lies next to the 
bone, but does not form a part of the scalp. 
Fig. 25. 
Sensory areas of the head, showing the general distribution of the three divisions of the trifacial nerve. 
(Modified from Testut.) 
Nerves (sensory). (a) Supraorbital, passing onto the forehead through the 
supra-orbital foramen (with supra-orbital artery), a branch of the frontal division 
of the ophthalmic; (b) temporal branch of the temporomalar or orbital (from 
second division of the fifth nerve); (c) auriculotemporal; from the third division 
of the fifth nerve ; it pierces the temporal muscle and its aponeurosis one inch 
above the zygoma, and accompanies the temporal artery between the ear and the 
condyle of the jaw, giving off the anterior auricular, parotid, articular, temporal, 
and branches to the external auditory meatus; (cl) supratrochlear, from the frontal 
branch of the ophthalmic (internal to the supra-orbital); (e) auricularis magnus and 
occipitalis minor, from the cervical plexus; (f) great occipital, from the posterior 
division of the second cervical nerve; (g) auricular branch of the vagus to the 
posterior part of the meatus, back of the pinna and adjacent part of the scalp; 52 
A MANUAL OF DISSECTION. 
(A) posterior auricular of the facial (motor) to the posterior belly of the occipito- 
frontalis, retrahens aurem, and small muscles on the cranial surface of the pinna; (i) 
temporal branches of the facial (motor) to the frontal portion of the occipitofrontalis, 
orbicularis palpebrarum, corrugator supercilii, attollens, and attrahens aurem 
muscles (auriculam is also used for aurem). 
Arteries, (a) Frontal from the ophthalmic, leaves the orbit at its inner angle, 
anastomosing with the supra-orbital on the forehead ; (6) supra-orbital, a branch 
of the ophthalmic, leaves the orbit through the supra-orbital foramen (with the 
supra-orbital nerve) to the forehead; (c) temporal, anterior and posterior ter- 
minals of the external carotid, supplies the side of the scalp as far as the vertex; 
(d) posterior auricular, from the external carotid, distributed to the ear and the 
adjacent scalp; (e) occipital, from the external carotid, to the posterior part of the 
scalp. (See Chapter I. for illustrations of arteries and veins.) 
Technique of Removing the Brain. 
1. After the scalp has been dissected and the temporal muscle with its investing aponeu- 
rosis turned down over the zygomatic arch, saw through the calvaria, in a line extending from 
the glabella (the smooth place between the superciliary ridges) to the external occipital pro- 
tuberance. Care must be taken not to cut through the dura with the saw when the bony skull- 
cap is removed. Note adhesions of dura to same. 
2. Study (a) the attachment of the dura to the bone; (6) the meningeal arteries between 
the dura and bone (seen, however, on the outer surface of the dura); (c) an elevation (slight) 
in the mid-dural line, extending from before backward, and produced by clotted blood in the 
superior longitudinal sinus; (d) Pacchionian bodies near the sinus and their villi perforating 
the dura mater and producing depressions in the inner table of the skull; (e) frontal sinus 
between the two tables of the frontal bone, about one inch above the root of the nose. 
3. Cut through the entire length of the base of the superior longitudinal sinus in mid- 
line, remove the clotted blood; cleanse and study most of the veins opening into the sinus. 
This sinus is in the attached border of the falx cerebri. 
4. Cut through the dura, from before backward, one inch to the right and left of the pre- 
ceding incision ; at right angles to this latter (from a point midway between the anterior and 
posterior poles) cut to the region of the ear, turn the dural flaps back and expose the subdural 
space. Note (a) the shining appearance given to the surface of the brain by the arachnoid 
membrane; (6) sulci between the adjacent convolutions of the brain, and the vessels of the 
pia mater showing through the arachnoid; (<-) veins passing through the arachnoid, crossing 
the subdural space, and entering the superior longitudinal sinus, from behind forward, as a 
rule; (d) the falx cerebri, a process of the dura mater, in the great longitudinal fissure, 
between the hemispheres of the cerebrum ; (e) attachment of the front end of the falx cerebri 
to the crista galli. 
5. Cut the attachment of the falx cerebri to the crista galli; gently remove the falx from 
the great longitudinal fissure by backward traction, cutting the veins opening into the supe- 
rior and inferior longitudinal sinuses. Study (a) the great longitudinal fissure; (6) the upper 
surface of the corpus callosum, at the bottom of the fissure, seen by separating the hemi- 
spheres ; (c) the convolutions and sulci of the cerebrum. 
6. Gently retract the frontal lobe of the cerebrum, and study in succession (a) the olfactory 
bulb, with its twenty nerves (the latter passing through the cribriform plate of the ethmoid bone); 
(b) the optic nerve and the optic chiasm (the former entering the apex of the orbit through the. 
optic foramen); (c) the internal carotid artery to the outer side of the optic nerve (often called 
the ophthalmic by the inexperienced); {d) the pituitary body (in the pituitary fossa) con- 
nected to the tuber cinerium by a constriction-the infundibulum; (e) the motor oculi nerve ; 
(/) the tentorium cerebelli, attached to the superior border of the petrous part of the temporal 
bone. 
7. Cut the tentorium cerebelli along the upper border of the petrosa; make slight gentle back- 
ward traction on the brain-mass, and study (a) the patheticus (fourth nerve) in the free border 
of the tentorium ; (6) the trigeminus (fifth nerve) beneath the tentorium, enterihg the middle 
fossa through the trigeminal notch; (c) abducens (sixth nerve) seen perforating the dura on 
the dorsum sellee ; (d) the facial (seventh nerve), auditory (eighth nerve), and auditory artery 
are seen entering the internal auditory meatus on the posterior surface of the petrosa ; (e) the 
glossopharyngeal (ninth nerve), vagus (tenth nerve), spinal accessory (eleventh nerve), pass 
through the jugular foramen ; (/) the hypoglossal (twelfth nerve) pierces the dura as two 
small strands and emerges through the anterior condyloid foramen; (#) the foramen magnum 
transmits the spinal cord and its coverings, the vertebral arteries and the spinal portion of 
the eleventh nerve. 
8. Thrust a long, sharp scalpel as far as possible downward through the foramen magnum, 
and with side motion sever the cord and vertebral arteries. Now pass the middle finger 
through the foramen magnum and deliver the entire brain. THE SCALP, MENINGES AND BASE OF THE SKULL. 
53 
9. Locate the cranial nerves from the first to the twelfth, inclusive, by reference to Fig. 28 
and the subjoined table. Note the first, second, fifth, seventh, eighth, ninth, tenth, eleventh, 
and twelfth nerves passing through the dura and the bone in corresponding foramina. The 
third, fourth, sixth, and the three divisions of the fifth nerve pass through the dura and then 
run between the dura and the bone until the bony foramina are reached; in other words, 
these nerves do not leave the base of the skull through corresponding foramina in the dura 
and bone. (See primary and secondary foramina). 
10. Tear the dura from the anterior fossa and study (a) the Gasserian ganglion (on the 
sensory root of the fifth nerve) on the anterior surface of the petrosa near its apex ; (b) the 
great and small superficial petrosal nerve branches of the seventh on the anterior surface of 
the petrosa; (c) the first division of the fifth nerve (ophthalmic), dividing into three branches, 
which pass through the sphenoidal fissure into the orbit; (d) the second division of the fifth 
nerve (superior maxillary), passing through the foramen rotundum ; (e) the third division of 
the fifth nerve (inferior maxillary), passing through the foramen ovale. 
Cranial Nerve. 
By P. Gad Kitterman, M.D. 
Name. 
Superficial 
origins. 
Deep origin. 
Foramen of 
exit. 
Distribution. 
Function. 
1. 
Olfactory. 
Olfactory 
bulbs. 
Gyrus fornicatus, 
trigonum olfactorium, 
uncus hippocampi. 
Foramina in 
the cribriform 
plate of 
ethmoid. 
Upper one-third 
nasal mucous 
membrane. 
Special 
sense, 
smell. 
2. 
Optic. 
Optic chi- 
asma. 
External genicu- 
late, pulvinar of optic 
thalamus and ant. 
quadrigeminal 
body. 
Foramen 
opticum. 
Retina. 
Special 
sense, 
sight. 
3. 
Oculo- 
motor. 
Inner side 
crus cere- 
bri. 
Floor of aqueeduc- 
tus Sylvii. 
Sphenoidal 
fissure. 
To all the muscles- 
of the eyeball ex- 
cept external rec- 
tus and the supe • 
rior oblique. 
Motor. 
4. 
Troch- 
learis. 
Valve of 
Vieussens. 
Floor of aquseduc- 
tus Sylvii. 
Sphenoidal 
fissure. 
Superior oblique 
muscle. 
Motor. 
5. 
Trifacial. 
Middle of 
Motor root: floor 
1. Sphenoidal 
Sensory : to face, 
forepart of scalp, 
ear, eye, cheek, 
tongue, gum, and 
teeth. 
Motor : to muscles 
of mastication. 
Ordinary 
the lateral 
surface of 
the pons. 
of 4th vent, and 
beneath aquseduc- 
tus Sylvii. 
Sensory: cells in 
Gasserian gan- 
glion ; a sensory 
nucleus in 4th 
vent, and in nu- 
cleus of Rolando. 
fissure. 
2. Foramen 
rotundum. 
3. Foramen 
ovale. 
sensation 
Motor. 
6. 
Abducent. 
Groove be- 
tween pons 
and 
medulla. 
Floor of 4th ven- 
tricle. 
Sphenoidal 
fissure. 
External rectus 
and a few fibres to 
internal rectus of 
the opposite eye. 
Motor. 
7. 
Facial. 
Groove be- 
tween pons 
and 
medulla. 
Floor of 4th ven- 
tricle. 
Internal 
auditory 
meatus. 
Facial muscles, 
frontalis, platysma, 
stylohyoid, and 
posterior belly of 
digastric. 
Motor. 
8. 
Auditory. 
Groove be- 
tween pons 
and 
medulla. 
Chief nucleus in 
floor of 4th ven- 
tricle. Dieters' 
nucleus to inner 
side of restiform 
body. Accessory 
nucleus, postquad- 
rigeminal body and 
internal genicu- 
late by lateral 
commissure. 
Internal 
auditory 
meatus. 
Membranous laby- 
rinth. 
Special 
sense, 
hearing, 
equili- 
brium. 
9. 
Glosso- 
Groove be- 
Floor of the 4th 
Jugular 
Pharynx, post part 
of tongue, fauces ; 
soft palate and 
stylopharyngeus 
muscle. 
Ordinary 
pharyngeal. 
tween oli- 
vary and 
restiform 
bodies. 
ventricle. 
foramen. 
sense, 
special 
sense 
(taste), 
motor. 54 
A MANUAL OF DISSECTION. 
Name. 
Superficial 
origins. 
Deep origin. 
Foramen of 
exit. 
Distribution. 
Function. 
10. 
Pneumo- 
Groove be- 
Floor of the 4th 
Jugular 
Sensory to ear ; 
Ordinary 
gastric. 
tween oli- 
vary and 
restiform 
bodies. 
ventricle. 
foramen. 
motor and sensory 
to pharynx, 
trachea, larynx, 
lungs, heart, oeso- 
phagus, stomach, 
and liver. 
sense, 
motor. 
11. 
Spinal 
Groove be- 
Floor of 4th ven- 
Jugular 
Motor to trapezius 
Motor and 
accessory. 
tween oli- 
vary and 
restiform 
bodies and 
from cord. 
tricle and inter- 
mediary column of 
cells and spinal 
cord. 
foramen. 
and sternomastoid 
and accessory to 
pneumogastric. 
ordinary 
sense. 
12. 
Hypo- 
glossal. 
Between 
the pyra- 
midal and 
olivary 
bodies. 
Trigonum hypo- 
glossi in floor of 
4th ventricle. 
Anterior 
condyloid 
foramen. 
Intrinsic and ex- 
trinsic muscles of 
tongue and by a 
common branch 
(ansa hypoglossal 
loop) to depres- 
sors of hyoid. 
Motor. 
THE DURAL SINUSES. 
Definition. The dural sinuses are venous channels in the dura mater, which 
collect the blood from the brain and the orbit entire, and in some degree from the 
meninges. They are lined by endothelium, as are veins. The blood in the 
sinuses reaches the internal jugular veins. The sinuses communicate with the 
veins of the face, neck, and scalp, and are liable to infection in diseased conditions 
of these regions. 
Fig. -26. 
Names. Superior longitudinal sinus (one); inferior longitudinal sinus (one); 
straight sinus (one); lateral sinuses (two); occipital sinus (one); cavernous sinuses 
(two); superior petrosal sinuses (two); inferior petrosal sinuses (two); transverse 
sinus (one); circular sinus (one). 
The Superior Longitudinal Sinus is in the attached margin of the falx cerebri. 
It communicates in front, through a vein in the foramen caecum, with the lining 
mucous membrane of the nose, and ends in an enlargement, torcular Herophili, 
near the internal occipital protuberance. This sinus receives the superior cerebral 
veins, and communicates through the parietal foramen with the temporal veins of 
the scalp. In surgical operations involving the removal of the bone in the mid- 
line of the cranium, care must be taken not to injure this sinus. 
Vertical section of the skull, showing the sinuses of the dura mater. (Gray.) THE SCALP, MENINGES AND BASE OF THE SKULL. 
55 
The Inferior Longitudinal Sinus is in the free margin of the falx cerebri. It col- 
lects blood from the falx itself and from the mesial surface of the brain, and ends 
posteriorly in the straight sinus. 
The Straight Sinus is at the junction of the falx cerebri and tentorium cerebelli. 
It receives the vein of Galen and the inferior longitudinal sinus in front, and ends 
in the torcular behind. The lateral sinuses extend from the torcular to the com- 
mencement of the internal jugular vein. The distal curved part, in relation with 
the temporal bone, is called the sigmoid sinus. The greater part of the sinus is 
in the attached part of the tentorium cerebelli. The lateral sinus receives venous 
blood from the cerebellum, temporosphenoidal lobe, pons, medulla, diploe, and 
communicates through the mastoid emissary with the occipital vein. 
The Occipital Sinus is in the attached margin of the falx cerebelli, and extends 
from the foramen magnum to the torcular. Its tributaries are the inferior cere- 
bellar and spinal veins. > 
The Cavernous Sinuses are two in number. As they are similar, a description 
will be given in the singular. Although of limited extent, its relation to the 
orbit, base of the skull, and deep parts of the face, together with its important con- 
tents, makes its pathological importance great. The sinus extends in relation 
with the body of the sphenoid bone, from the sphenoidal fissure to the apex of 
the petrosa, where it ends in the superior and inferior petrosal sinuses. The two 
sinuses communicate on the superior surface of the body of the sphenoid, by two 
Fig. 27. 
Plan showing the relative position of the structures in the right cavernous sinus, viewed from behind. (Gray.) 
channels in the diaphragma sellse (one in front of and the other behind the pituitary 
body), forming the circular sinus. The tributaries of the cavernous sinus are the 
ophthalmic and the inferior cerebral veins. Its communications are with : 1. The 
pterygoid plexus, through the foramen of Vesalius. 2. The pterygoid plexus, 
through the ophthalmic vein. 3. The pterygoid plexus, through the foramen 
ovale. 4. The pharyngeal plexus, through the foramen lacerum medium. 5. The 
internal jugular vein, through the carotid canal. 
The cavernous sinus contains on its inner wall the sixth nerve and the cavernous 
stage of the internal carotid artery, with its plexus of sympathetic nerves; on 
its outer wall (from above down) the third and fourth nerves and the ophthalmic 
division of the trifacial nerve. 
Sympathetic Nerves on the Internal Carotid Artery. The ascending branch of 
the superior cervical ganglion accompanies the internal carotid artery through the 
carotid canal in the petrosa. Here it divides into two branches: one forms a 
plexus on the carotid artery in the carotid canal (called carotid plexus); the other 
forms a plexus on the same artery a little higher in the cavernous sinus (called 
cavernous plexus). 
The Carotid Plexus is situated on the internal carotid artery, in the carotid canal, 
in the petrous part of the temporal bone, receiving filaments from the tympanic 
branch of the glossopharyngeal nerve. The branches of this plexus are to (1) 
sixth nerve; (2) Gasserian ganglion; (3) tympanic plexus (small, deep petrosal 
nerve); (4) Vidian nerve (large, deep petrosal). 56 
A MANUAL OF DISSECTION. 
The Cavernous Plexus is situated on the internal carotid artery, in the cavernous 
sinus. Its branches are to the third nerve, fourth nerve, pituitary body, and 
ciliary ganglion. 
The Superior Petrosal Sinus occupies the superior border of the petrosa in the 
attached margin of the tentorium cerebelli. It extends from the cavernous to the 
lateral sinus. Its tributaries are from the middle ear, cerebellum, and temporo- 
sphenoidal lobe of the cerebrum. 
The Inferior Petrosal Sinus extends from the cavernous sinus along the posterior 
margin of the petrosa to the jugular foramen, where it becomes confluent with the 
lateral sinus to form the internal jugular vein. The two inferior petrosal sinuses 
communicate on the basilar process of the occipital bone, by the transverse sinus. 
Veins from the pons, medulla, internal ear, and cerebellum are tributary to the 
inferior petrosal sinuses. 
DURA MATER OF BRAIN. 
The dura mater is a dense inelastic membrane composed of two layers: (a) An 
outer endosteal, attached to the cranial bones; (6) an inner (covered by epithelial 
cells), which forms sheaths for the cranial nerves, a lining for the dural sinuses, 
and certain incomplete partitions called dural processes. The processes of the 
dura and their location are: (a) Falx cerebri, in the great longitudinal fissure, 
between the hemispheres; (6) falx cerebri, in the posterior notch of the cere- 
bellum; (c) tentorium cerebelli, in the great transverse fissure, between the 
occipital lobe of the cerebrum and the cerebellum; (d) diaphragma sellse, covering 
the pituitary body. 
The dura of the brain differs from that of the spinal cord in the possession of 
sinuses, processes, bony attachments, Pacchionian bodies, endothelial cells on the 
inner side only, and no space between it and the bony walls. The dura of the 
brain derives its nerves from the sympathetic, Gasserian ganglion, fourth, fifth, 
tenth, and twelfth cranial nerves; that of the cord from the spinal nerves, through 
sympathetic filaments. 
CLASSIFICATION OF MENINGEAL ARTERIES. 
The three fossae at the base of the skull form the basis of their classification, 
hence we speak of anterior, middle, and posterior meningeal arteries. There are 
numerous meningeal arteries, but each, with a single exception, is located in one of 
the three fossae, and falls into the category of anterior, middle, or posterior menin- 
geal. 
The Anterior Meningeal arteries supply the dura and bone in the anterior fossa. 
They are very small, and often stripped off with the dura unrecognized. 
The Middle Meningeal artery is a branch of the first stage of the internal maxil- 
lary. External to the cranium, it lies behind the internal pterygoid muscle. It 
passes between the two roots of the auriculotemporal nerve, enters the cranium 
through the foramen spinosum in the greater wing of .the sphenoid bone, and 
ramifies between the dura mater and the bone, both of which it supplies. 
The middle meningeal artery divides into anterior and posterior branches, which 
supply the greater part of the bones of the cranium and give off the following 
minor branches: (1) Small branches to the Gasserian ganglion; (2) a branch 
through the hiatus Fallopii to the seventh nerve and tympanum; (3) temporal 
branches, perforating the bone to the temporal fossa; (4) orbital branches, passing 
through the sphenoidal fissure to the orbit. 
The Posterior Meningeal arteries supply the dura and bone in the posterior fossa. 
They are intermediate in size between the anterior and middle. The small men- 
ingeal artery supplies the Gasserian ganglion and adjacent dura mater. THE SCALP, MENINGES AND BASE OF THE SKULL. 
57 
Table Showing Names, Source, and Position of Meningeal Arteries. 
Name. 
Source. Foramen. 
Fossa. 
Anterior meningeal . 
<< ii 
Cl u 
u u 
. . Anterior ethmoidal. Anterior ethmoidal. 
. Posterior " Posterior " 
. Ophthalmic. Internal artery. 
. . Internal carotid. 1 ' 
Anterior. 
Great meningeal 
Small " . 
Middle " . 
n n 
. Internal maxillary. Spinosum. 
. . " " Ovale. 
. . Ascending pharyngeal. Sphenotic. 
. . Internal carotid. Internal artery. 
Middle. 
Posterior meningeal . 
Il Cl 
Cl cc 
CC Cl 
I I Cl 
. . Occipital. Mastoid. 
" Jugular. 
. . Ascending pharyngeal. Anterior condylar. 
. . " " Magnum. 
. . Vertebral. 
Posterior. 
The ramus parietalis, a branch of the occipital artery, according to Cruveilhier, 
is occasionally found passing through the parietal foramen with the parietal emis- 
sary vein. 
ARACHNOID. 
The arachnoid membrane, the second meningeal covering, is a very delicate 
fibrous structure, covered on its outer surface by epithelial cells. It is in relation 
with the dura externally, and attached to the pia mater internally (by sub- 
arachnoid tissue), except at the base of the brain, where the anterior and posterior 
subarachnoid spaces (filled by subarachnoid fluid) intervene. 
The anterior space is between the temporal lobes, anterior to the pons; the 
posterior, between the medulla and cerebellum, communicates with the fourth 
ventricle through the foramina of Key, Retzius, and Majendie, located in the 
posterior choroid tela of the pia mater. 
PIA MATER. 
The pia mater, the innermost meningeal covering of the brain, is composed of 
arteries, veins, and connective tissue. Its outer surface is covered by epithelial 
cells, continuous with those of the subarachnoid tissue and spaces. 
The pia mater invests the surface of the brain, transmits bloodvessels into its 
interior, and forms sheaths for the cranial nerves. It forms (a) velum interposi- 
tum, located in the great transverse fissure, bet,ween the fornix and interbrain ; 
(6) a second process, covering the fourth ventricle (between the medulla and the 
cerebellum), is perforated by the foramina of Key, Retzius, and Majendie, by 
which the fluid in the ventricles of the brain communicates with that in the pos- 
terior subarachnoid space. Nerves: sympathetic, third, fifth, sixth, seventh, 
ninth, tenth, and eleventh cranial. (See circle of Willis for vessels.) 
FORAMINA AT THE BASE OF THE SKULL. 
The foramina at the base of the skull should be thoroughly studied on both dry 
and moist specimens. A student may become familiar with the base of a dry 
skull and be still at sea on a recent one, because the nerves do not always pass 
out through the dura and bone in corresponding openings. For example, the 
seventh and eighth nerves are readily recognized, entering the internal auditory 
meatus, having perforated the dura at a corresponding spot. Likewise there is a 
correspondence of the foramina in dura and bone, where the ninth, tenth, and 
eleventh nerves escape. On the other hand, the third, fourth, sixth, and the 58 
J MANUAL OF DISSECTION. 
three divisions of the trigeminus, after perforating the dura, pass long distances 
between this and the bone before they reach the bony foramina for final emergence. 
Primary Foramina at the base of the skull are those in which there is corre- 
spondence between the foramen in the dura and that in the bone. They are: 
(1) Optic; (2) trigeminal; (3) auditory; (4) jugular; (5) anterior condyloid; (6) 
petrosphenoidal; (7) foramen magnum. 
Secondary Foramina are those in which the cranial nerves perforate the dura, 
and, before passing through foramina in the bone, traverse a considerable dis- 
tance between the dura and bone. They are: (1) The sphenoidal fissure ; (2) 
foramen rotundum; (3) foramen ovale; (4) ethmoid canals; (5) infra-orbital 
canal ; (6) sphenopalatine foramen ; (7) sphenomalar foramen ; (8) malar canals ; 
(9) pterygopalatine foramen; (10) Vidian canal; (11) posterior palatine canal; 
^12) inferior dental canal ; (13) facial canal; (14) iter chordae posterius; (15) iter 
chordae anterius ; (16) sphenomaxillary fissure. 
Foramen csecum . . . Transmits an emissary vein to the nose. 
Nasal slit .... Transmits the nasal branch of ophthalmic nerve. 
Olfactory foramina . . Twenty in number, transmit the olfactory nerves. 
Optic foramina . . . Transmit the Optic nerves and the ophthalmic artery. 
Table of Cranial Foramina. 
Ant fossa. 
Sphenoidal fissure . . Transmits 3d, 4th, 6th, and 1st divisions of the 5th nerve, 
the ophthalmic vein and sympathetic nerve. 
Foramen rotundum . . Transmits the second division of the 5th nerve. 
Foramen ovale . . . Transmits the third division of the 5th nerve and the 
small meningeal artery. 
Foramen spinosum . . Transmits the great meningeal artery. 
Foramen sphenotic . . Transmits internal carotid artery and carotid petrosal 
for Vidian nerve. 
Hiatus Fallopii . . . Transmits petrosal branch of the Vidian nerve. 
Petrosal foramen . . . Transmits the smaller petrosal nerve. 
Carotid canal . . . Transmits internal carotid artery and its sympathetic 
nerves. 
Mid. fossa. 
Internal auditory meatus . Transmits 7th and 8th nerves and auditory artery. 
Jugular foramen . . . Transmits jugular vein, 9th, 10th, and 11th nerves. 
Anterior condyloid foramen Transmits the hypoglossal nerve. 
Foramen magnum . . Transmits (1) spinal cord and its meninges ; (2) the 
vertebral arteries and their sympathetic nerves ; 
(3) the spinal accessory nerve. 
Post, fossa. 
Constant Foramina transmits nerves ; conversely, the presence of a nerve assures 
the constancy of a foramen. All primary and secondary foramina are constant. 
Inconstant Foramina do not transmit nerves. They usually transmit veins which 
extend from the sinuses of the dura mater to the vessels in the soft parts, outside 
the bones of the cranium ; they are also called emissary foramina. CHAPTER III. 
THE BRAIN AND THE SPINAL CORD. 
DISSECTION AND IDENTIFICATION. 
1. Consult illustration of circle of Willis and superficial origins of the cranial nerves, then 
carefully read the text on these two. This identification will call for no cutting, except now 
and then the arachnoid or pia, to more fully expose the brain surface. 
2. To expose the fissure of Sylvius and branches of the middle cerebral artery given off on 
the island of Reil, cut through the arachnoid and pia mater and gently separate the frontal, 
temporal, and parietal lobes. 
3. After having identified the vessels and cranial nerves according to the text, remove the 
pia mater and arachnoid (in one mass) from the entire surface of the brain. Note that the 
vessels dip down into the fissure and sulci, and that the pia and arachnoid, except at the base 
of the brain, are intimately fused. 
4. The pia and arachnoid having been removed, as previously stated, study the lobes and 
fissures in the order of sequence of the text and illustrations. 
5. To study the interior, follow the illustrations, whose sequence and appearance will be a 
better guide than many pages of written directions. 
CIRCLE OF WILLIS. 
Arteries from Circle of Willis (anterior, middle, and posterior cerebrals) give off numerous 
branches, which supply, in the main, the hemispheres of the cerebrum, and constitute the 
cortical system. Branches from the circle supplying the ganglia and interbrain constitute the 
ganglionic system. 
Circle of Willis. Identify (1) by extent from the anterior part of the pons, one inch and 
a half forward, and one inch from side to side; (2) by formation from branches of the internal 
carotid and basilar arteries. 
Internal Carotid Artery. Identify (1) by location, lateral to optic chiasm ; (2) by anterior 
cerebral, middle cerebral, and posterior communicating branches. 
Anterior Cerebral Artery. Identify (1) by origin from the front of the internal carotid 
and its passage inward and forward into the great longitudinal fissure; (2) by climbing over the 
genu of the corpus callosum and the distribution to the mesial surface of the hemisphere as 
far backward as the parieto-occipital fissure; (3) by union with its fellow of the opposite side, 
through the very short anterior communicating artery; (4) by the antero-median ganglionic, 
inferior internal frontal, anterior internal frontal, middle internal frontal, and posterior internal 
frontal branches. 
Middle Cerebral. Identify (1) as the largest cerebral artery, and a branch of the internal 
carotid; (2) by its course outward along the fissure of Sylvius; (3) by dividing opposite the 
island of Reil into the antero-lateral ganglionic, inferior external frontal, ascending frontal, 
ascending parietal, and parieto-temporal branches. 
Posterior Cerebral Artery. Identify (1) by its origin from the basilar and its location in 
front of the third nerve ; (2) by a course outward across the crus cerebri to the under surface 
of the occipital lobe of the brain and the distribution to the temporal and occipital lobes; 
(3) by the postero-median ganglionic, posterior choroid, postero lateral ganglionic, anterior 
temporal, posterior temporal, and occipital branches. 
Anterior Communicating Artery. Identify (1) by location in front of the circle of Willis 
connecting the anterior cerebral arteries; (2) by its length, less than one-quarter inch. 
Posterior Communicating Artery. Identify (1) by the origin from the internal carotid and 
anastomosis with the posterior cerebral; (2) by forming the lateral boundary of the circle of 
Willis. 
The following arteries, given off from the circle of Willis or near thereto, are called ter- 
minal end arteries. They constitute the ganglionic system, and are arranged in six groups. 
The antero-median and postero-median groups are single and central; the others are bilateral. 
These vessels anastomose neither with the arteries of their own nor with those of the cortical 
system. 
Antero-median Group. Identify these small vessels (1) by the origin from the anterior 
cerebral and anterior communicating arteries ; (2) by piercing the lamina cinerea and anterior 
perforated lamina, and supplying the anterior wall of the third ventricle and bulb of the 
nucleus caudatus. 60 
A MANUAL OF DISSECTION. 
Postero-median Group. Identify (1) by the origin from the posterior cerebral and poste- 
rior communicating arteries ; (2) by the distribution to the interpeduncular space and crustae ; 
(3) by piercing the posterior perforated lamina, and the distribution to the third ventricle and 
the adjacent part of the optic thalamus. 
Antero-lateral Group. Identify (1) by the origin from the middle cerebral; (2) by passing 
through the anterior perforated lamina to the corpus striatum, optic thalamus, and the internal 
capsule. This group gives off the lenticulo-striate, called the artery of cerebral hemorrhage, 
on account of its frequent rupture. 
Postero-lateral Group. Identify (1) by the origin from the posterior cerebral after cross- 
ing the crus; (2) by the distribution to the corpora geniculata and quadrigemina and optic 
thalamus. 
Superior Cerebellar Artery. Identify (1) by the origin near the end of the basilar; (2) by 
the course parallel with the posterior cerebral, behind the third nerve, around the crus cerebri 
to the upper surface of the cerebellum; (3) by the distribution to the velum interpositum, 
pineal gland, valve of Vieussens, and the upper surface of the cerebellum. 
Anterior Inferior Cerebellar Artery. Identify (1) by the origin from the basilar; (2) by 
the course backward across the middle cerebellar crus and the distribution to the anterior 
border of the cerebellum. 
Posterior Inferior Cerebellar Artery. Identify (1) by the origin from the vertebral; (2) 
by the course around the upper part of the medulla, between the origins of the tenth and 
eleventh nerves, to the under surface of the cerebellum. 
Transverse Branches to Pons Varolii. Identify (1) by the origin from the basilar; (2) by 
the distribution to the pons and internal ear (cochlear and vestibular branches), which accom- 
pany the two divisions of the auditory nerve. 
Anterior Choroid Artery. Identify (1) by the origin from the internal carotid ; (2) by the 
course through the cortex to the descending horn of the lateral ventricle; (3) by the distri- 
bution to the choroid plexus, corpus fimbriatum, and hippocampus major. 
Postero-lateral Choroid Artery. Identify (1) by the origin from the posterior cerebral; 
(2) by the distribution to the choroid plexus and velum interpositum. 
Posterior-mesial Choroid Artery. Identify (1) by the origin from the posterior cerebral; 
(2) by the distribution to the choroid plexus of the third ventricle. 
Superior Cerebral Veins. Identify (1) by the location on the superior surface of the hemi- 
sphere ; (2) by receiving tributary, the median cerebral veins, and the opening from behind 
forward into the superior longitudinal sinus. 
Median Cerebral Veins. Identify (1) by the location on the median surface of the hemi- 
sphere; (2) by the opening into the superior cerebral veins and inferior longitudinal sinus. 
Inferior Cerebral Veins. Identify (1) by the location on the under surface of the hemi- 
sphere ; (2) by the following manner of reaching the sinuses: one large vein (middle cere- 
bral) from the under surface of the temporal lobe runs along the fissure of Sylvius and reaches 
the cavernous sinus; the great anastomotic vein of Trolard begins on the parietal lobe, passes 
along the fissure of Sylvius to the cavernous sinus; others open into the superior petrosal and 
lateral sinuses. 
Ventricular Veins (Veins of Galen). Identify (1) by the location between the layers of 
the velum interpositum; (2) by the emergence from the brain at the great transverse fissure, 
between the splenium of the corpus callosum and the tubercula quadrigemina; (3) by opening 
into the straight sinus; (4) by the following tributaries: basilar, choroid, and vein of the 
corpus striatum. 
Basilar Vein. Identify (1) by the origin at the anterior perforated space by union of the 
small anterior cerebral veins and the deep Sylvian vein, seen in the lower part of the Sylvian 
fissure; (2) by the course around the crus cerebri to the vein of Galen ; (3) by the receiving 
inferior striate, interpeduncular, ventricular, and uncinate veins. 
Cerebellar Veins. Identify (1) the superior, by the course across the superior vermiform 
process to the vein of Galen and the straight sinus; (2) the inferior, by the termination in 
the lateral, superior petrosal, and occipital sinuses. 
STRUCTURES ON THE BASE OF THE BRAIN. 
Longitudinal Fissure. Identify (1) by the location between the hemispheres, separating 
completely the occipital lobes, and, partially, the frontal lobes. Intermediately, it is filled by 
corpus callosum ; (2) by the presence of the anterior cerebral arteries, connected by the ante- 
rior communicating artery between the frontal lobes. 
Termination of the Corpus Callosum. Identify (1) by the location in the longitudinal 
fissure (seen by gently separating the frontal lobes); (2) by the connection to the tuber cine- 
reum through the lamina cinerea and to the hippocampal gyrus through the peduncles of the 
corpus callosum. 
Lamina Cinerea. Identify (1) by the location as gray matter extending from the corpus 
callosum to the tuber cinereum ; (2) by the continuity on each side with the gray matter of 
the anterior perforated space. To expose the lamina cinerea, gently draw the optic commis- 
sure back. THE BRAIN AND THE SPINAL CORD. 
61 
Peduncles of the Corpus Callosum. Identify (1) by the location as white bands, one on 
each side, extending from the under surface of the corpus callosum across the posterior margin 
of the anterior perforated space to the hippocampal gyrus; (2) by the continuity with the 
striae longitudinales, on either side of the raphe of the corpus callosum. 
Fig. 28. 
The arteries of the base of the brain. The right half of the cerebellum and pons have been removed.1 (Gray.) 
Anterior Perforated Space (posterior olfactory lobe). Identify (1) by the location at the 
beginning of the fissure of Sylvius, with numerous perforations for the ganglionic arteries; 
(2) by the boundaries : peduncle of the corpus callosum, optic tract, fissura prima, and fissure 
of Sylvius. This is the surface area of the lenticular and caudate nuclei and claustrum. 
1 It will be noticed that in the illustration the two anterior cerebral arteries have been drawn at a considerable 
distance from each other; this makes the anterior communicating artery appear very much longer than it really is. 62 
A MANUAL OF DISSECTION. 
Optic Commissure. Identify (1) by the location in the mid line, beneath the lamina 
cinerea, in front of the tuber cinereum; (2) by the junction of the optic tracts and the con- 
tinuation forward and outward, as the optic nerves. 
Tuber Cinereum. Identify (1) as the eminence of gray matter, situated between the optic 
tracts, limited in front by the optic commissure, behind by the corpora albicantia; (2) by the 
tubular neck of gray matter, the infundibulum, leading to the posterior lobe of the pituitary 
body. 
Pituitary Body (hypophysis cerebri). Identify (1) by the round form and the location in 
the sella turcica of the sphenoid bone; (2) by the connection with the floor of the third 
ventricle through the infundibulum; (3) by being held in the sella turcica by a process of 
the dura-diaphragma sellse. 
Corpora Albicantia. Identify (1) by the location in the interpeduncular space in front of 
the posterior perforated space; (2) by the small size (pea), round form, and white color. 
Posterior Perforated Space. Identify (1) by the location between the pons varolii and 
corpora albicantia ; (2) by transmitting numerous small, ganglionic arteries (postero-median) 
to the interior of the brain. 
Pons Varolii. Identify (1) by the location as a broad band of white fibres, extending from 
one hemisphere of the cerebellum to the other ; (2) by the location between the crura cerebri 
and medulla; (3) by the presence of the longitudinal groove (sulcus basilaris) for the basilar 
artery. 
Medulla Oblongata. Identify (1) by the location as a pyramidal body between the pons 
and the spinal cord; (2) by the anterior median fissure continuous with that of the spinal 
cord ; (3) by the origin of certain cranial nerves therefrom. 
Pyramids of the Medulla. Identify (1) by the location as two pyramidal bundles of white 
matter on either side of the anterior median fissure; (2) by the presence of the roots of the 
hypoglossal nerve, between the pyramid and the olivary body. The pyramids are repre- 
sented in the spinal cord by the direct and crossed tracts. 
Olivary Body. Identify by the location external to the pyramid, and separated therefrom 
by fibres of the hypoglossal nerve. Restiform body : Identify (1) by the location in the upper 
and posterior parts of the medulla; (2) by the presence, between this and the olivary body, of 
the band of fibres from the lateral tract, and the origins of the ninth, tenth, and eleventh nerves. 
Crusta Cerebri. Identify (1) by the location as two thick, cylindrical bundles of white 
matter emerging from the front of the pons Varolii; (2) by diverging and entering the cere- 
bral hemispheres; (3) by the presence of the longitudinal striae on the surface; (4) by the 
presence of the optic tract adhered to the surface. 
Optic Tracts. Identify (1) by the location on the crustae cerebri; (2) by the continuity with 
the optic commissure. 
Interpeduncular Space. Identify (1) by boundaries: In front, the optic commissure; 
behind, the pons Varolii; laterally, the crura cerebri and optic tract; (2) by contents: tuber 
cinereum, infundibulum, pituitary body, corpora albicantia, posterior perforated space. 
Fissure of Sylvius. Identify (1) by the location between the frontal and temporal lobes; 
(2) by the middle cerebral artery and the island of Reil continued therein. 
Middle Peduncles of the Cerebellum. Identify (1) as a broad band comprising most of 
the transverse fibres of the pons, entering the cerebellum at the anterior notch, between the 
margins of the great horizontal fissure. 
The Frontal and Temporal Lobes, separated by the fissure of Sylvius, need no further iden- 
tification here. The cerebellum cannot be mistaken. 
Olfactory Lobe. This is rudimentary in man, and consists of posterior and anterior olfactory 
lobules. Posterior olfactory lobule: Identify (1) by its synonym, the anterior perforated lamina; 
(2) by the foramina, transmitting the vessels to the interior of the brain ; (3) by the location 
and boundaries. (See " anterior perforated space.") Anterior olfactory lobule : Identify (1) 
by the olfactory bulb, olfactory tract, trigone, and olfactory area of Broca. 
Olfactory Bulb. Identify (1) as the anterior, expanded end of the olfactory tract; (2) by 
the location on the cribriform plate of the ethmoid ; (3) by the olfactory nerves, about twenty 
in number, received from the olfactory region of the nose, through the olfactory foramina. 
Olfactory Tract. Identify (1) as a white, triangular band in the olfactory sulcus, on the 
under surface of the frontal lobe ; (2) by the division into an outer and an inner root uniting 
the two ends of the limbic lobe. 
Outer Root of Olfactory Tract Identify by the course across the anterior perforated space 
to the gyrus hippocampi and the nucleus situated at the tip of the temporal lobe. Inner 
root of the olfactory tract: Identify (1) by the termination in Broca's area and gyrus forni- 
catus; (2) by the location between the trigone and the area of Broca. 
Trigonum Olfactorium. Identify (1) by the location between the diverging outer and inner 
roots of the olfactory tract; (2) by forming the base of the anterior olfactory lobule; (3) by 
the continuity with Broca's area; (4) by the boundaries: fissura prima, outer and inner roots 
of the olfactory tract. 
Fissura Prima Identify (1) by the location (horizontal part) between the anterior and 
posterior olfactory lobules ; (2) by the location (oblique part) between the area of Broca and 
the peduncle of the corpus callosum. 
Area of Broca. Identify (1) by the continuity with the trigonum olfactorium (inner root 
of the olfactory tract separating the two); (2) by the continuity with the gyrus fornicatus. THE BRAIN AND THE SPINAL CORD. 
63 
The Area of Smell is in the uncus hippocampi, which is reached by roots of the olfactory 
nerve in two ways: direct and indirect. The outer root, having crossed the anterior, perfor- 
ated space, ends directly in the nucleus amygdalae, and gyrus hippocampi. The inner root, 
having ended in Broca's area and the gyrus fornicatus, communicates with the uncus hippo- 
campi through two sets of long association fibres-cingulum and uncinate fasciculus. The 
uncinate fasciculus, crossing the bottom of the Sylvian fissure, connects the anterior end of 
the temporal lobe. The cingulum connects the anterior perforated lamina with the gyrus 
hippocampi. In its course it passes forward and upward, parallel with the rostrum, winds 
around the genu, runs immediately above the corpus callosum, passes to the anterior end of 
the hippocampus major, where it ends in association with the gray matter of the uncus. 
Optic Tracts. Identify (1) by the continuity with the optic commissure; (2) by the loca- 
tion on and attachment to the under surface of the crustse cerebri; (3) by the division (at 
the connection with the brain) into the external and internal bands. 
External Band of the Optic Tract. Identify (1) by the origin from the external genicu- 
late body, pulvinar of the optic thalamus, brachium of the anterior quadrigeminal body. 
Internal Band of the Optic Tract. Identify (1) by the course around the crusta and 
beneath the internal geniculate body ; (2) by the origin from the optic thalamus and the 
internal geniculate body. 
Motor Oculi (third cranial nerve). Identify (1) by the superficial origin from the inner 
surface of the crusta in front of the pons; (2) by investments from the arachnoid and pia 
mater; (3) by the course between the posterior cerebral and the superior cerebellar arteries ; 
(4) by piercing the dura in front of and external to the posterior clinoid process. 
Trochlear Nerve (fourth cranial). Identify (1) by the superficial origin from the base of 
the brain seen on the outer side of the crusta cerebri, in front of the pons Varolii, but origin- 
ating from the valve of Vieussens; (2) by piercing the dura in the free border of the tento- 
rium behind and external to the posterior clinoid process. 
Trifacial Nerve (fifth cranial). Identify (1) by the very large superficial origin from the 
side of the pons near the upper border ; (2) by the course beneath the tentorium cerebelli and 
through the trigeminal notch. 
Abducent Nerve (sixth cranial). Identify (1) by the superficial origin in the groove 
between the pyramid of the medulla and pons ; (2) by piercing the dura on the basilar surface 
of the sphenoid and passing through the notch below the posterior clinoid process of the 
sphenoid bone. 
Facial Nerve (seventh cranial). Identify (1) by the superficial origin from the upper end 
of the medulla in the groove between the olivary and restiform bodies ; (2) by the course for- 
ward and outward on the middle cerebellar peduncle with the eighth nerve to the internal 
auditory meatus; (3) by the presence of the auditory artery, accompanying the seventh and 
eighth nerves. 
Auditory Nerve (eighth cranial). Identify by the superficial origin in the groove between 
the pons and medulla, with the facial nerve in front and the restiform body behind. 
Glossopharyngeal Nerve (ninth cranial). Identify (1) by three or four filaments of origin 
from the upper part of the medulla, between the olivary and the restiform bodies; (2) by the 
outward course across the flocculus, and the emergence through the centre of the jugular 
foramen, external to and in front of the tenth and eleventh cranial nerves. 
Pneumogastric Nerve (vagus, parvagum-tenth cranial). Identify (1) by eight or ten fila- 
ments of the origin between the olivary and restiform bodies below the ninth nerve ; (2) by 
the emergence through the jugular foramen with the ninth and eleventh nerves and the 
internal jugular vein. 
Spinal Accessory Nerve (eleventh cranial). Identify (1) by two portions-spinal and 
bulbar; (2) by the superficial origin of the bulbar portion from the side of the medulla below 
the vagus ; (3) by the superficial origin of the spinal portion, by several filaments from the 
lateral tract of the cord, as low as the sixth cervical, and passage through the foramen 
magnum; (4) by emergence of both portions through the jugular foramen, with the jugular 
vein, ninth and tenth nerves. 
Hypoglossal Nerve (twelfth cranial). Identify (1) by the superficial origin between the 
pyramidal and olivary bodies, by several filaments; (2) by perforating the dura in two 
bundles and emerging through the anterior condyloid foramen. 
LOBES, CONVOLUTIONS, FISSURES, SULCI (OUTER SURFACE). 
Longitudinal Fissure. Identify (1) by the location between the cerebral hemispheres ; (2) 
by the presence of the falx cerebri; (3) by the corpus callosum forming the floor of the 
middle part. 
Sylvian Fissure. Identify (1) by the location on the base and side of the hemisphere, 
between the frontal and temporal lobes; (2) by the origin in the vallecula Sylvii (in which is 
situated the anterior perforated space), and the termination in the parietal lobe; (3) by the 
division into three limbs-anterior, vertical, and horizontal. 
Fissure of Rolando. Identify (1) by the location in the middle of the outer surface of the 
hemisphere; (2) by the downward and forward direction, dividing the hemisphere into about 
equal parts; (3) by the location between the frontal and parietal lobes. 64 
A MANUAL OF DISSECTION. 
Parieto-occipital Fissure. Identify (1) by the situation partly on the outer surface (external 
parieto-occipital fissure) and partly on the mesial surface of the hemisphere (internal parieto- 
occipital fissure). 
Calloso-marginal Fissure. Identify (1) by the location between the gyrus fornicatus and 
the marginal convolution; (2) by the posterior end, separating the paracentral lobule and the 
quadrate lobe, and terminating just behind the superior end of the Rolandic fissure. 
Great Transverse Fissure. Identify (1) by the location between the cerebrum and cere- 
bellum ; (2) by the presence of the tentorium in the posterior and velum interpositum in the 
anterior part; (3) by opening posteriorly between the splenium of the corpus callosum above 
and the corpora quadrigemina and pineal gland below ; (4) by the transmission of veins of Galen. 
Frontal Lobe. Identify (1) by the location at the anterior pole of the hemisphere in front 
of Rolando's fissure, external to the longitudinal fissure on the orbital plate of the frontal 
bone; (2) by its external, inferior, and mesial surfaces; (3) by its four sulci and eight convo- 
lutions. 
Fig. 29. 
Convolutions and sulci on the external surface of the cerebral hemisphere. (Gray.) 
Precentral Sulcus. Identify by the location, anterior to the ascending frontal convolution 
and parallel to the lower half of the fissure of Rolando. 
Superior Frontal Sulcus. Identify (1) by the location, running forward between the supe- 
rior and middle frontal convolutions; (2) by the origin in-the precentral sulcus. 
Inferior Frontal Sulcus. Identify (1) by the location, running forward between the middle 
and inferior frontal convolutions; (2) by the origin in the precentral sulcus. 
Superior Frontal Convolutions. Identify (1) by the location on the external surface of the 
frontal lobe, between the longitudinal fissure and the superior frontal sulcus ; (2) by forming 
the greater part of the marginal convolution on the inner surface of the hemisphere; (3) by 
the continuity with the internal orbital convolution on the inferior surface of the frontal lobe. 
Middle Frontal Convolution. Identify (1) by the location between the superior and infe- 
rior frontal sulci ; (2) by the continuation from the precentral sulcus to the orbital surface of 
the frontal lobe, where it forms the anterior frontal convolution. 
Inferior Frontal Convolution. Identify (1) by the location below the inferior frontal 
sulcus ; (2) by the continuation from the precentral sulcus to the under surface of the frontal 
lobe, where it forms the posterior orbital convolution. 
Parietal Lobe. Identify (1) by the location behind the fissure of Rolando and above the 
horizontal limb of the fissure of Sylvius; (2) by an intraparietal and a post-central sulcus ; 
(3) by the ascending, superior, and inferior parietal convolutions. THE BRAIN AND THE SPINAL CORD. 
65 
Intraparietal Sulcus Identify (1) by the origin midway between the lower end of the 
fissure of Rolando and the fissure of Sylvius; (2) by the course parallel with the fissure of 
Rolando as far as the superior parietal convolution, thence backward near the parieto-occipi- 
tal fissure, separating the superior and inferior parietal convolutions; (3) by the location 
posterior to the ascending parietal convolution. 
Postcentral Sulcus. Identify (1) by the location between the superior and ascending 
parietal convolutions; (2) as a very slight groove and a possible branch of the intraparietal 
sulcus. 
Ascending Parietal Convolution. Identify (1) by the location immediately behind the 
fissure of Rolando, in front of the intraparietal and postcentral sulci; (2) by the great longi- 
tudinal fissure above and the fissure of Sylvius below, where it becomes continuous with the 
ascending frontal convolution. 
Superior Parietal Convolution. Identify (1) by the postcentral sulcus in front, intra- 
parietal sulcus below, parieto-occipital fissure behind ; (2) by the continuity with the quadrate 
lobe on the inner surface of the hemisphere. 
Inferior Parietal Convolution. Identify (1) by the boundaries-the fissure of Sylvius 
below, the intraparietal sulcus above, the occipital lobe behind, and the ascending parietal 
convolution in front; (2) by dividing into the angular and supramarginal convolutions. 
The Internal Surface of the parietal lobe is continuous with the external. It is quite small, 
and is represented by a part of the paracentral convolution and quadrate lobe. The quadrate 
lobe is sometimes called precuneus, from its location in front of the cuneus. 
Occipital Lobe. Identify (1) by the location forming the posterior pole of the hemisphere; 
(2) by the location on the upper surface of the tentorium cerebelli; (3) by an external convex 
surface presenting two sulci and three convolutions; (4) by a mesial surface presenting a 
calcarine and a parieto-occipital fissure and a cuneate lobe. 
Occipital Convolutions. Identify the superior by the location above the superior sulcus 
and connected to the superior parietal convolution by the first annectant gyrus. Identify the 
middle by the location between the superior and middle sulci, connected to the angular con- 
volution by the second annectant gyrus and to the middle temporal by the third. Identify 
the inferior by the location below the middle occipital sulcus, connected to the inferior tem- 
poral convolution by the fourth annectant gyrus. 
Temporal Lobe. Identify (1) by the location posterior to the main branch below the hori- 
zontal limb of the fissure of Sylvius and in the middle fossa of the skull; (2) by the outer 
and inferior surfaces ; (3) by four sulci; (4) by five convolutions. 
First Temporal Sulcus (outer surface). Identify by the location between the first and 
second temporal convolutions, parallel with the horizontal limb of the fissure of Sylvius. 
Second. Temporal Sulcus (outer surface). Identify by the location between the second and 
third temporal convolutions. 
Third Temporal Sulcus (inferior surface). Identify by the location on the inferior surface, 
extending from near the occipital pole to near the anterior end of the temporal lobe. 
Superior Temporal Convolution (outer surface). Identify (1) by the location between the 
horizontal limb of the fissure of Sylvius and the superior temporal sulcus; (2) by the con- 
tinuity behind with the inferior parietal convolution. 
Middle Temporal Convolution (outer surface). Identify (1) by the location between the 
superior and middle temporal sulci; (2) by the continuity behind with the angular and middle 
occipital convolutions. 
Inferior Temporal Convolution (outer surface). Identify by the location between the 
middle and the third temporal sulci. 
Central Lobe (island of Reil). Identify (1) by the location in the Sylvian fissure, whose 
lips must be parted to expose the lobe; (2) by the opercula-orbital, frontal, fronto-parietal, 
temporal-convolutions which overlap the central lobe and form boundaries of the Sylvian 
fissure: (3) by the triangular form, with the apex directed toward the anterior perforated 
space ; (4) by being almost completely surrounded at the base by the limiting sulcus ; (5) by 
the composition of from four to eight convolutions-gyric operti; (6) by the presence of the 
middle cerebral artery, dividing into numerous terminals. 
MESIAL SURFACE OF THE HEMISPHERE. 
Gyrus Fornicatus. Identify (1) by the location on the mesial surface of the hemisphere, 
separated from the corpus callosum by the callosal fissure ; (2) by commencing below the 
rostrum of the corpus callosum and ending behind the splenium, where it is connected to the 
gyrus hippocampi by a narrow isthmus; (3) by forming part of the limbic lobe of Broca. 
Hippocampal Gyrus. Identify (1) by the location on the mesial surface, between the 
dentate and the collateral fissure; (2) by the continuity, behind and above, with the gyrus 
fornicatus (gyrus cinguli, callosal convolution), behind and below with the lingual convolu- 
tion. The uncus is formed by the anterior end of the hippocampal gyrus. 
Marginal Convolution. Identify (1) by the location on the mesial surface of the hemi- 
sphere-on the frontal lobe; (2) by commencing in front of the anterior perforated space and 
ending in the paracentral convolution ; (3) by the intervention of the calloso-marginal fissure 
between it and the gyrus fornicatus. 66 
A MANUAL OF DISSECTION. 
Paracentral Convolution. Identify (1) by the continuity with the marginal convolution ; 
(2) by the continuity with the upper ends of the ascending frontal and ascending parietal con- 
volutions about the upper end of the fissure of Rolando. 
Quadrate Lobe. Identify (1) by the location on the mesial surface of the hemisphere and 
continuous with the external surface of the parietal lobe ; (2) by the small size and quadrate 
form ; (3) by the intervention of the parieto-occipital fissure, between it and the cuneate lobe. 
Cuneate Lobe. Identify (1) by the location on the mesial surface of the hemisphere, and 
a part of the occipital lobe; (2) by the location between the parieto-occipital and the calca- 
rine fissures. 
Limbic Lobe of Broca. Identify (1) by the composition : gyrus fornicatus, hippocampal 
convolution, nerves of Lancisi, peduncles of the corpus callosum, fascia dentata, and one-half 
each of the septum lucidum and the body of the fornix. 
The Corpus Callosum shows on the mesial surface in sagittal section, but its identification 
is reserved until the interior of the brain is studied. 
Calloso-marginal Fissure. Identify (1) by the location between the marginal gyrus and 
the anterior and upper parts of the limbic lobe; (2) by following the course: (a) commences 
below the anterior end of the corpus callosum ; (6) runs parallel with the rostrum and in front 
of the genu of the corpus callosum ; (c) passes between the marginal convolution and the 
Fig. 30. 
Convolutions and sulci on the internal surface of cerebral hemispheres. (Gray.) 
gyrus fornicatus; (d) midway between the anterior and posterior poles ot the cerebrum, 
ascends, and reaches the upper margin of the hemisphere, posterior to the fissure of Rolando. 
Parieto-occipital Fissure (internal). Identify (1) by the location between the quadrate 
and cuneate lobes; (2)?^ the extent, in backward and upward direction, from beneath the 
splenium of the corpus callosum to the border of the mesial surface; (3) by the continuity 
with the external parieto-occipital fissure at the margin of the longitudinal fissure. 
Calcarine Fissure. Identify (1) by the location on the mesial surface of the hemisphere, 
between the occipital and temporal lobes; (2) by the termination a little below the level of 
the corpus callosum; (3) by the production of the hippocampus minor in the posterior horn 
of the lateral ventricle. 
Collateral Fissure. Identify (1) by the location on the tentorial surface below and external 
to the calcarine fissure ; (2) the middle part of the fissure corresponds to the eminentia col- 
lateralis in the descending horn of the lateral ventricle. 
Hippocampal Fissure (dentate). Identify (1) by the extent from the splenium of the 
corpus callosum, beneath the optic thalamus to near the end of the temporal lobe. This 
fissure is represented by the hippocampus major in the descending horn of the lateral ventricle. THE BRAIN AND THE SPINAL CORD. 
67 
UNDER SURFACE-TEMPORAL LOBE. 
Fourth Temporal Convolution (inferior surface). Identify by the location between the 
third temporal sulcus and the collateral fissure. 
Subcalcarine Convolution (lingulal lobe-inferior surface). Identify (1) by the location 
between the calcarine and collateral fissures; (2) by the continuity with the hippocampal con- 
volution in front. 
The Cortical Centres of smell, hearing, and taste are probably located in the temporal lobe. 
Collateral Fissure (inferior surface). Identify (1) by the location on the inferior surface 
below and external to the calcarine fissure; (2) by the course forward to near the tip of the 
temporal lobe. 
FRONTAL LOBE. 
Internal Orbital Convolution. Identify (1) by the location on under surface of the frontal 
lobe near the longitudinal fissure ; (2) by the continuity with superior frontal convolution of the 
external surface of the frontal lobe; (3) by the presence of the olfactory sulcus for the olfactory 
tract; (4) that portion of the convolution internal to the olfactory sulcus is the gyrus rectus. 
Fig. 31. 
Convolutions and sulci on the under surface ot the anterior lobe. (Gbay.) 
The Anterior and Posterior Orbital Convolutions are continuations, respectively, of the 
middle and inferior frontal convolutions on the external surface of the frontal lobe. 
Triradiate Sulcus (orbital). Identify (1) by the location near the centre of the inferior 
surface ; (2) by giving origin to the internal, anterior, and posterior orbital convolutions. 
The Inferior and Ascending Frontal and ascending parietal show in part on under surface ot 
frontal lobe. 
INTERIOR STRUCTURES OF THE BRAIN. 
Corpus Callosum. Identify (1) as a thick, white, flattened arch (of transversely directed 
nerve fibres), about four inches long, connecting the two hemispheres of the brain, and seen at 
the bottom of the middle part of the longitudinal fissure; (2) by the fibres passing into the 68 
A MANUAL OF DISSECTION. 
hemispheres, radiating in various directions and ending in the gray matter of the periphery; 
(3) by specialized anterior and posterior extremities-rostrum and splenium ; (4) composed of 
axons of cells in one hemisphere, which arborize about cells in the opposite hemisphere; (5) 
by forming the roof of the lateral ventricles. 
Rostrum. Identify (1) by the continuity with the corpus callosum turning sharply at the 
genu, passing backward to the base of the brain and becoming connected with the lamina 
cinerea; (2) by the peduncles of the corpus callosum, which, crossing the posterior part of the 
anterior perforated space, join the outer roots of the olfactory tracts in the hippocampal gyri. 
Splenium. Identify (1) by the location at the posterior end of the corpus callosum as a 
thick, rounded pad, continuous by the under surface with the fornix ; (2) by overlapping mesen- 
cephalon or mid-brain-crustee, substantia nigra, iter, tegmentum, corpora quadrigemina, and 
internal geniculate bodies. 
Nerves of Lancisi (striae longitudinales). Indentify (1) by the location on the upper sur- 
face of the corpus callosum, lateral to the raphe; (2) by continuity with the peduncles of the 
corpus callosum. 
Forceps Anterior (minor). Identify as the fibres of the corpus callosum curving forward 
into the frontal lobe and covering the anterior horn of the lateral ventricle. 
Forceps Posterior (major). Identify as fibres of the corpus callosum, passing from the 
splenium into the occipital lobe and lying in the roof of the posterior horn of the lateral 
ventricle. 
Tapetum. Identify as fibres of the corpus callosum (given off between the forceps minor 
and major), which extend into the temporal lobe and cover the body of the lateral ventricle. 
Fig. 32. 
Parts of the mesial and tentorial surfaces of the left hemisphere, showing callosum in the sagittal section with 
many of its relations, a.c., anterior commissure; alb., corpus albicans; chi., chiasma; hypoph., hypophysis; 
p., porta. (Gerrish modified from Testut.) 
Lateral Ventricles. Identify (1) by the location in the lower and inner parts of the cere- 
bral hemispheres, separated from each other by the septum lucidum and covered in by the 
corpus callosum; (2) by the central cavity and the anterior, middle, and posterior horns or 
cornua ; (3) by a lining ependyma covered by ciliated epithelium. 
Central Cavity of the Ventricle. Identify (1) by the location in the lower part of the 
parietal lobe; (2) by a roof formed by the tapetum of the corpus callosum; (3) by an inner 
wall formed by the septum lucidum connecting the corpus callosum with the fornix; (4) by a 
floor formed by the caudate nucleus, taenia semicircularis, optic thalamus, choroid plexus, one- 
half of the fornix and its posterior pillar ; (5) by an outer wall formed by the internal capsule. 
Anterior Cornu of the Lateral Ventricle. Identify (1) by the continuity with the central 
cavity, extending from the foramen of Monro into the frontal lobe, curving outward around 
the anterior end of the caudate nucleus; (2) by the boundaries-above, the corpus callosum ; 
below, the rostrum of the corpus callosum; internally, the anterior part of the septum 
lucidum; externally, the head of the caudate nucleus; the apex reaches the genu of the 
corpus callosum. 
Posterior Cornu of the Lateral Ventricle. Identify (1) by the location in the substance 
of the occipital lobe, extending backward, outward, and inward from the central cavity of the 
ventricle; (2) by the derivation of the roof from the fibres of the corpus callosum ; (3) by the 
presence of the hippocampus minor produced by the calcarine fissure. 'W' 
Descending Cornu of the Lateral Ventricle. Identify (1) by the location in the temporal 
lobe forming a curve around the back of the optic thalamus, backward, downward, forward, 
and inward to within one inch of the temporal lobe; (2) by the roof formed by the tapetum, THE BRAIN AND THE SPINAL CORD. 
69 
in which are located the tail of the nucleus caudatus and taenia semicircularis, ending in the 
amygdaloid nucleus; (3) by the floor presenting the hippocampus major (produced by the 
dentate or hippocampal fissure); the pes hippocampi; eminentia collateralis (produced by the 
middle part of the collateral fissure) ; the corpus fimbriatum, prolonged from the posterior 
pillar of the fornix and choroid plexus. 
Septum Lucidum. Identify (1) as a thin, double, semitransparent septum between the two 
lateral ventricles (forming their inner wall), attached above to the corpus callosum, below to 
the anterior part of the fornix and reflected part of the corpus callosum ; (3) by the presence 
of the fifth ventricle between its two laminae; (4) by the triangular form, its broad end being 
in front. 
Fornix. Identify (1) by the location on the floor of the lateral ventricle, continuous 
behind with the corpus callosum and separated in front by the septum lucidum; (2) by the 
two symmetrical halves ; (3) by the anterior pillars, body, and posterior pillars. 
Body of the Fornix. Identify (1) by the triangular form-narrow in front and broad 
behind; (2) by the upper surface on the septum lucidum and corpus callosum, undersur- 
face on the velum interpositum and optic thalami; (3) the outer edges free and connected with 
the choroid plexuses ; (4) by the continuity with the anterior and posterior pillars of the fornix. 
Fig. 33. 
Floor of the lateral ventricles. On the left side the vein of the corpus striatum is lifted up. The director is in 
the right porta. Dotted outlines indicate the position of the posterior cornua. (Gerrish after Testut.) 
Anterior Pillar of the Fornix. Identify as two white bands continuous with the body of 
the fornix in front, descending behind the anterior commissure into the lateral wall of the 
third ventricle to the base of the brain, and ending in the corpora albicantia (in the inter- 
peduncular space). 
Posterior Pillars of the Fornix. Identify (1) as the posterior continuations of the body 
of the fornix; (2) by the connection with the under surface of the corpus callosum ; (3) by 
winding divergently around the posterior end of the optic thalami, passing into the descend- 
ing horn of the lateral ventricle and lying along the concavity of the hippocampus major, 
some of its fibres extending into the uncus and corpus fimbriatum. 
Velum Interpositum. Identify (1) by the location in the lateral ventricle beneath the 
body of the fornix, forming part of the roof of the third ventricle; (2) by composition-a 
vascular membrane derived from the pia mater gaining the interior of the brain through the 
middle part of the transverse fissure; (3) by separating the fornix from roof epithelium of the 
third ventricle. 70 
A MANUAL OF DISSECTION. 
Choroid Plexus of the Body of the Ventricles. Identify (1) as the fringed, vascular 
border of the velum interpositum; (2) by the plexuses of the two sides communicating 
through the foramen of Monro. 
Choroid Plexus of the Descending Horn. Identify (1) by the continuity with the choroid 
plexus of the body of the ventricle; (2) like that of the body, it gains the interior of the 
brain through the transverse fissure, and is covered by epithelium. 
Ganglia of the Hemisphere (caudate nucleus, lenticular nucleus, claustrum, and amyg- 
dala). Identify as gray matter in the substance of the hemisphere somewhat divergently 
arranged, but uniting at a common surface area-the anterior perforated space previously 
identified. 
Caudate Nucleus (seen in the lateral ventricle). Identify (1) by the location in the lateral 
ventricle, anterior and external to the optic thalamus; (2) by the tail-like process, extending 
along the roof of the descending horn of the lateral ventricle, and ending in the amygdala at 
the front end of the temporal lobe; (3) by the separation (partial) from the lenticular nucleus 
by the internal capsule. 
Fig. 34. 
Horizontal section of the left hemisphere through the basal ganglia, viewed from above. 
C.N., caudate nucleus. (Geerish after Testut.) 
Lenticular Nucleus (seen in the horizontal section). Identify (1) by the lens-shape and 
the location to the outer side of the caudate nucleus; (2) by the contact with the internal 
and external capsules ; (3) by the continuity with the other basal ganglia at the common sur- 
face area--the anterior perforated space. 
Claustrum (seen in the horizontal section). Identify (1) by the location between the len- 
ticular nucleus and the island of Beil; (2) by the presence of the external capsule along its 
inner part; (3) by the continuity with the lenticular, caudate, and amygdalar nuclei at the 
common surface area-the anterior perforated space. 
Internal Capsule (seen in the horizontal section). Identify (1) by an anterior limb between 
the caudate and the lenticular nuclei; (2) by a genu connecting the two limbs and presenting 
at the tmnia semicircularis between the caudate nucleus and the optic thalamus; (3) by a 
posterior limb separating the optic thalamus from the lenticular nucleus ; (4) by the fibres 
from the following sources: crusta, tegmentum, caudate and lenticular nuclei, corpus callosum, 
and optic thalamus. 
External Capsule (seen in the horizontal section). Identify (1) by the location between 
the lenticular nucleus and claustrum; (2) by the continuity with the internal capsule below 
and behind the lenticular nucleus. THE BRAIN AND THE SPINAL CORD. 
71 
Tsenia Semicircularis. Identify (1) as a narrow, white band between the caudate nucleus 
and the optic thalamus; (2) by passing into the roof of the descending horn posteriorly and 
into the anterior pillar of the fornix and anterior commissure in front. 
Optic Thalamus. Identify (1) as two oblong masses on either side of the third ventricle 
behind and internal to the taenia semicircularis in the lateral ventricle; (2) by a narrow, ante- 
rior extremity forming the posterior boundary of the foramen of Monro; (3) by the pulvinar 
or posterior extremity ; (4) by a superior free surface, part of which is covered by ependyma ; 
another part located beneath the velum interpositum and wanting in the ependyma; (5) by 
the inferior surface resting on and continuous with the tegmentum ; (6) by the outer surface in 
contact with the posterior limb of the internal capsule; (7) by the internal surface forming 
the lateral wall of the third ventricle. 
Pineal Gland (conarium epiphysis cerebri). Identify (1) by the location between the ante- 
rior corpora quadrigemina resting on the posterior commissure; (2) by the location beneath 
the velum interpositum ; (3) by two peduncles extending to the anterior pillars of the fornix 
along the superior and mesial surfaces of the optic thalamus. 
Third Ventricle. Identify (1) by the location between the optic thalami; (2) by the roof- 
the velum interpositum and fornix; (3) by the floor-the tuber cinereum, infundibulum, 
pituitary body, corpora albicantia, posterior perforated space, and tegmenta of the crura 
cerebri; (4) by the lateral walls-the internal surfaces of the optic thalami; (5) by the 
Fig. 35. 
Median section through the third and fourth ventricles. Left half. M.C., middle commissure. 
(Gerrish after Testut.) 
anterior boundary-the anterior pillars of the fornix and lamina cinerea; (6) by the posterior 
boundary-pineal gland, posterior commissure, and iter a tertio ad quartum ventriculum; (7) 
by the foramen of Monro in front of the optic thalamus and behind the anterior pillars of the 
fornix, by which the third and lateral ventricles communicate; (8) by the aqueduct of Sylvius 
or iter a tertio ad quartum ventriculum, situated between the corpora quadrigemina and teg- 
mentum and leading from the posterior extremity of the third ventricle to the fourth ventricle ; 
(9) by the choroid plexus derived from the under surface of the velum interpositum. 
Anterior Commissure. Identify by the location as a bundle of white fibres in front of the 
anterior pillars of the fornix, connecting the two temporal lobes and containing fibres from 
the olfactory tract of the opposite side. Middle commissure: Identify by the location in the 
third ventricle, connecting its walls, and composed mostly of gray matter. Posterior commis- 
sure: Identify by the location ; it connects the optic thalami and lies just above the iter. 
Corpora Quadrigemina. Identify (1) as four rounded eminences, two in front and two 
behind (on either side), called nates and testes, respectively; (2) by the location on the teg- 
mentum, behind the third ventricle and posterior commissure, on the floor of the great trans- 
verse fissure, covered by the pia mater and in relation with the pineal body; (3) by the con- 
nection with the corpora geniculata through the brachia, as follows: anterior connects the 
nates with the external geniculate bodies ; the posterior brachia connect the testes with the 
internal geniculate bodies; (4) by the close relation to the superior cerebellar peduncles, 
which pass beneath them through the tegmenta to the optic thalami. A MANUAL OF DISSECTION. 
72 
Corpora Geniculata (external and internal). External geniculate body: Identify (1) by 
the location on the optic thalamus beneath the pulvinar; (2) by the continuity with the outer 
root of the optic tract; (3) by the connection with the anterior quadrigeminal body through 
the anterior brachium. It belongs to the optic thalamus. 
Internal Geniculate Body. Identify (1) by the location external to the corpora quad- 
rigemina ; (2) by the connection with the posterior quadrigeminal body through the posterior 
brachium; (3) by the continuity with the inner root of the optic tract. It belongs to the 
mid-brain. 
Aqueduct of Sylvius (iter a tertio ad quartum ventriculum). Identify (1) by the location 
between the tegmentum and the corpora quadrigemina, connecting the third and fourth ven- 
tricles; (2) as a very narrow canal, about one-half inch in length, through which a broom- 
straw may be passed. 
Trochlear Nerve. Identify (1) emerging from the upper end of the valve of Vieussens ; 
(2) by the course outward across the superior peduncle of the cerebellum and crus cerebri. 
Optic Tract consists of two bands or roots-external and internal. Identify the external 
root, the larger of the two, by the origin from the external geniculate body and pulvinar of 
the optic thalamus and its continuity with the anterior brachium. Identify the internal root 
by its course around the crusta and connection with the internal geniculate body and the 
posterior brachium. 
Superior Cerebellar Peduncle. Identify (1) by the extent, from hilum of corpus dentatum 
to a point beneath the corpora quadrigemina; (2) by its attachment to the valve of Vieussens. 
Valve of Vieussens (superior medullary velum). Identify (1) by the location stretching 
across from one superior peduncle to the other ; (2) by aiding the superior peduncle in form- 
ing the roof of the upper part of the fourth ventricle; (3) by its continuity with the white 
matter of the superior worm of the cerebellum below, and passing beneath the corpora quad- 
rigemina above. 
Middle Peduncle of the Cerebellum. Identify (1) by the large size, comprising most of 
the transverse fibres of the pons; (2) by the direct continuity with the superficial transverse 
fibres of the pons ; (3) by the location external to the superior peduncles. 
Inferior Peduncle. Identify (1) by connecting the cerebellum with the medulla (restiform 
bodies of the medulla oblongata) ; (2) by forming part of the lateral wall of the fourth ven- 
tricle and entering the cerebellum beneath the middle peduncle. 
THE CEREBELLUM. 
Dissection. Make incisions corresponding to the illustration in the text as nearly as possible. 
Study the marginal names of the parts in the illustrations and compare with the dissection. 
Identify (1) by the location in the posterior part of the cranium beneath the tentorium ; (2) by 
its two lateral hemispheres and a central part-the vermiform process; (3) by the three bands 
on each side connecting the cerebellum to the other parts of the encephalon (a superior 
peduncle connecting with the corpora quadrigemina; a. middle, connecting with the pons varolii; 
an inferior, connecting with the medulla); (4) by a flat upper surface marked by transverse 
fissures. 
Superior Surface of the Cerebellum. 
Name- 
Location. 
Importance. 
Superior vermis. 
Median portion between the hemi- 
spheres. 
Central and most prominent part of the 
superior vermis is called the mon- 
ticulus. Partially separated from 
the hemispheres by shallow grooves. 
Lingula. 
In front of the central lobe and 
connected by the same, partially 
or completely. 
Rests on and connected to the dorsal 
surface of the valve of Vieussens, 
the white matter of the two being 
continuous. It is represented in the 
hemisphere by the fraenulum. 
Lobulus centralis. 
Located in the anterior notch, 
overlapping the lingula. 
Extends laterally along the upper and 
anterior parts of the hemisphere, 
forming the ala lobuli centralis. 
Culmen monticuli. 
Forms bulk of the superior worm 
with the clivus. 
Overlaps the central lobe, and is sepa- 
rated from the clivus by the pre- 
clival fissure. Forms the most 
prominent part of the superior ver- 
mis, and is divided into lobules. It 
corresponds to the anterior crescentic 
lobe of the hemisphere. 
Clivus monticuli. 
Median area-a part of the supe- 
rior worm or vermis. 
Separated from the culmen by the 
preclival fissure and almost continu- 
ous behind with the folium cacu- 
minis, still separated therefrom by 
the postclival fissure. Represented 
in the hemisphere by the posterior 
crescentic lobe. THE BRAIN AND THE SPINAL CORD. 
73 
Name. 
Location. 
Importance. 
Folium cacuminis 
In the median area at the poste- 
rior part of the superior vermis. 
A short, narrow band concealed by 
the extremity of the vermis. Rep- 
resented in the hemisphere by the 
posterior superior lobe. 
Fraenulum. 
Upper surface of the cerebellar 
hemisphere. 
It lies on the superior peduncle of the 
cerebellum, continuous with the 
lingula of the superior vermis. 
Ala lobuli centralis. 
Upper surface of the cerebellar 
hemisphere. 
A prolongation of the lobulus cen- 
tralis of the central region. 
Anterior crescentic lobe. 
Upper surface of the cerebellar 
hemisphere. 
Continuous with the culmen monticuli 
of the superior vermis of the central 
region. 
Posterior crescentic lobe. 
Superior surface of the cerebellar 
hemisphere. 
Continuous with the clivus monticuli 
of the central region. 
Posterior superior lobe. 
Superior surface of the cerebellar 
hemisphere. 
Continuous with the folium cacuminis 
of the central region. 
Scheme Showing the Continuity of the Lobes of the Central and Lateral 
Regions of the Upper Surface of the Cerebellum, and the Location of the 
Fissures by which the Lobes are Delimited. Enumerated from Before 
Backward. 
Cerebellar Worm. Cerebellar Hemisphere. 
1. Lingula, continuous with ...... 1. Fraenulum. 
(Location of precentral fissure.) 
2. Lobulus centralis, continuous with . . . .2. Ala lobuli. 
(Location of postcentral fissure.) 
3. Culmen, continuous with ...... 3. Anterior crescentic lobe. 
(Location of preclival fissure.) 
4. Clivus, continuous with ...... 4. Posterior crescentic lobe. 
(Location of the great horizontal fissure.) 
Inferior Surface of the Cerebellum. 
Cerebellar Worm. Cerebellar Hemisphere. 
1. Nodule ......... Flocculus. 
(Location of the postnodular fissure.) 
2> Uvula ......... Amygdala. 
(Location of the prepyramidal fissure.) 
3. Pyramid ......... Biventral lobe. 
(Location of the postpyramidal fissure.) 
4. Tuber valvulae ........ Slender lobe, postgracile fissure, 
inferior semilunar lobe. 
THE MEDULLA OBLONGATA. 
Medulla Oblongata. Identify (1) by the location extending from the margin of the pons 
Varolii to the lower margin of the foramen magnum ; (2) by the location of the ventral surface 
on the basilar groove of the occipital bone, and the dorsal surface in the fossa between the 
cerebellar hemispheres; (3) by the continuity with the pons above and the cord below; 
(4) by the anterior and posterior median fissures continuous with similar fissures of the 
spinal cord; (5) by a ventrolateral groove in line with the anterior roots of the spinal 
nerves and a dorsolateral groove (continuous with the posterolateral fissure of the spinal 
cord), from which arise the seventh, eighth (mesial root), ninth, tenth, and eleventh cranial 
nerves. 
Ventral Surface. Identify by the presence of an eminence, the pyramid (on each side ot 
the anterior median fissure) represented in the cord by the direct and crossed pyramidal tracts. 
Lateral Surface. Identify (1) by the location between the ventrolateral and the dorso- 
lateral grooves; (2) by the olivary body, lateral tract, and external archiform fibres. 
Olivary Body. Identify (1) by the location in the lateral area of the medulla, just behind 
the pons; (2) by the elongated, oval shape, and situation external to the pyramid, separated 
therefrom by the emergence of the hypoglossal nerve; (3) by the separation externally from 
the restiform body by a band of fibres and a groove, from which latter arise the ninth, tenth, 
and eleventh cranial nerves. 
Dorsal Surface. Identify by the location between the dorsolateral grooves. 
Restiform Body. Identify (1) by the location between the lateral tracts in front and the 
funiculus cuneatus behind, from which eminences they are separated by grooves; (2) by form- 
ing the inferior peduncles of the cerebellum and the lower part of the lateral boundary of the 
fourth ventricle. 74 
A MANUAL OF DISSECTION. 
Posterior Surface. Identify (1) by forming part of the floor of the fourth ventricle, seen when 
the pia mater with the roof epithelium is removed; (2) by the triangular shape bounded by 
the restiform bodies, funiculi graciles and cuneati; (3) by a longitudinal furrow dividing the 
floor of the medulla into right and left lateral halves. 
Fourth Ventricle. Identify (1) by the location in front of the cerebellum and in the pons 
and medulla; (2) by its four angles-an upper, reaching the superior border of the pons at- 
the aqueduct of Sylvius; a lower, on a level with the lower part of the olivary body and con- 
tinuous with the central canal of the spinal cord; lateral angles, extending between the 
medulla and the cerebellum and forming a pointed lateral recess. 
Floor of the Fourth Ventricle. Identify (1) by the boundary of the anterior triangle-the 
superior peduncles of the cerebellum ; (2) by the boundary of the posterior triangle-the infe- 
rior cerebellar peduncles, funiculi graciles, and funiculi cuneati; (3) by the striae acusticae, 
which divide the floor into anterior and posterior triangles. 
SPINAL CORD. 
Dissection. Remove all soft structures ; cut through the laminae, removing these with the 
spinous processes, and study the structures according to the following steps. 
Spinal Veins. Identify by the location, formation, function, and arrangement in four sets, as 
follows: dorsi spinal, meningorachidian, venae basis vertebrarum, and medulli spinal veins. 
Dorsi Spinal Veins. Identify (1) by the location around the laminae, articular, transverse, 
and spinous processes of all the vertebrae; (2) by the tributaries from the muscles in the ver- 
tebral grooves and dorsal integument; (3) by communicating with the intraspinal veins pass- 
ing through the ligamenta subflava; (4) by terminating in the vertebral, intercostal, lumbar, 
and sacral veins. 
Fig. 36. 
Fig. 87. 
Veins of the spine, seen in a transverse horizontal section 
of a thoracic vertebra. (Gerrish after Testut.) 
Veins of the spine, seen in a sagittal section of two 
thoracic vertebrae. (Gerrish after Testut.) 
Meningorachidian Veins. Identify (1) by the location between the walls of the neural 
canal and the dura mater in a quantity of fat and connective tissue; (2) by receiving the 
venae basis vertebrarum; (3) by the termination in the vertebral, intercostal, lumbar, and 
sacral veins. 
Venae Basis Vertebrarum. Identify (1) by the emergence from the bodies of the vertebrae 
through the foramina on the posterior surfaces ; (2) by the termination in the meningo- 
rachidian veins. 
Medulli Spinal Veins. Identify (1) by the location as a minute venous plexus covering the 
entire surface of the cord between the pia mater and the arachnoid ; (2) by forming two or 
three small trunks near the base of the skull, communicating with the vertebral veins and 
terminating in the inferior cerebellar veins or inferior petrosal sinuses. 
Dura Mater. Identify (1) by the location in the spinal canal, extending from the foramen 
magnum to the third sacral vertebra, where it dwindles to a small fibrous cord, passes down, 
and is attached to the periosteum of the coccyx; (2) by the attachment to the margin of the 
foramen magnum and the bodies of the three upper cervical vertebrae and having no other 
bony attachments; (3) by containing the spinal cord, cauda equina, arachnoid, and pia mater; 
(4) by the brilliant inner serous surface in contact with the cerebro-spinal fluid ; (5) by the pro- 
longations on each side which transmit arteries and roots of the spinal nerves; (6) by the 
absence of sinuses, processes, Pacchionian bodies, and periosteal function. THE BRAIN AND THE SPINAL CORD. 
75 
Subdural Space. Identify (1) by the location between the dura and arachnoid, containing 
a small amount of cerebro-spinal fluid; (2) by the extreme narrowness, since the dura and 
arachnoid are in contact. 
Arachnoid. Identify (1) by the location in and correspondence in length to the dura, with 
whose inner surface it is in contact; (2) by the presence of two secreting, serous surfaces ; (3) 
by the tubular prolongations about the spinal nerves; (4) by the continuity with the cerebral 
arachnoid ; (5) by the attachment to the pia mater by the connective tissue ; (6) by the sub- 
arachnoid space situated between this and the pia mater. 
Subarachnoid Space. Identify (1) by the location between the arachnoid and pia mater ; 
(2) by the presence of the cerebro-spinal fluid and the cauda equina; (3) by communicating 
with the general ventricular cavity of the brain through foramina in the pia mater in the 
roof of the fourth ventricle; (4) by the continuity with the cerebral and subarachnoid space 
above. 
Pia Mater. Identify (1) by the location about and intimate adherence to the spinal cord ; 
(2) by forming a sheath for each filament of the spinal nerves and an investment for the 
spinal nerves themselves; (3) by sending a process into the 
anterior fissure'of the cord ; (4) by the contraction at the end of 
the cord to form the filum terminale; (5) by the formation of 
the linea splendens on the anterior surface. 
Filum Terminale. Identify by the continuation with the pia 
mater of the cord, extending down the centre of the cauda equina, 
perforating the arachnoid and dura at the level of the third lum- 
bar vertebra and fusing with the periosteum of the coccyx. 
Ligamentum Denticulatum. Identify (1) by the location on 
each side of the spinal cord, separating the anterior and poste- 
rior nerve roots; (2) by the possession of an inner border con- 
tinuous with the pia, and an outer composed of twenty-one 
tooth-like processes, which, pushing the arachnoid outward, are 
attached to the dura. The first attachment is between the ver- 
tebral artery and the hypoglossal nerve. The ligamentum dentic- 
ulatum and the filum terminale support the cord. 
Cauda Equina. Identify (1) by the location in the sheath of 
the arachnoid and dura; (2) by the composition (filum terminale 
and roots of the sacral and coccygeal nerves). 
Cervical Enlargement of the Cord. Identify (1) by the ex- 
tent from the medulla to the second dorsal vertebra; (2) by 
giving origin to the cervical nerves. 
Lumbar Enlargement of the Cord. Identify (1) by the loca- 
tion extending from the tenth to the twelfth thoracic vertebrae ; 
(2) by continuing, cone-like, into the filum terminale of the pia 
mater (conus terminalis.) 
Spinal Arteries. Identify (1) by the origin from the verte- 
bral, inferior thyroid, intercostal, lateral sacral, lumbar, and ilio- 
lumbar arteries. 
Anterior Spinal Artery. Identify (1) by the double origin 
from the vertebral on each side; (2) by union of its two roots 
to form a single artery at the level of the foramen magnum ; 
(3) by descending on the front of the spinal cord and uniting with the lateral branches from 
other sources. 
Median Spinal Artery. Identify (1) by the location in the pia mater along the anterior 
median fissure; (2) formed by the union of the anterior spinal with the lateral branches from 
the vertebral, inferior thyroid, intercostal, lumbar, iliolumbar, and lateral sacral arteries; (3) 
by the distribution to the spinal cord, pia mater, and cauda equina. 
Posterior Spinal Artery. Identify (1) by the origin from the vertebral on each side by the 
side of the medulla; (2) by the downward course behind the posterior roots of the spinal 
nerves; (3) by the frequent accessions from the lateral spinal arteries from the successive 
regions, entering the spinal canal through the intervertebral foramina. 
Posterior Roots. Identify (1) by the origin, by from six to eight fasciculi, from the 
posterolateral fissure of the cord arranged in a single linear series all down the spinal cord ; (2) 
by piercing the dura separately, developing the posterior root ganglion and uniting with the 
anterior root in the intervertebral foramen; (3) by the presence of the posterior spinal artery 
behind the posterior roots; (4) the posterior root is sensory. 
Anterior Roots. Identify (1) by the origin from the anterolateral columns of the cord, 
corresponding to the anterior horn of the gray matter; (2) by the composition of from four to 
eight filaments; (3) by union in the intervertebral foramen with the posterior root to form 
mixed nerve trunk; (4) the anterior or motor root is smaller than the posterior root in all 
except the first nerve. 
Ganglia. Identify (1) by the location on the posterior root (2) by the location as follows : 
the first and second cervical lie on the corresponding vertebrae; the sacral and coccygeal in 
the sacral canal; all the others in the intervertebral foramina. Ganglion of the first cervical 
nerve may be absent. 
Fig. 38. 
The spinal eord and its membranes 
(Gray.) CHAPTER IV 
THE MOUTH 
IDENTIFICATION. 
Lips (upper and lower). Identify (1) by location so as to form a complete boundary for 
the buccal orifice; (2) by a dry, red, sensitive mucous membrance (in the living) and a 
pronounced muco-cutaneous margin. 
Cheek. Identify (1) by its composition : all the soft structures, external to the angle of the 
mouth and anterior to the masseter muscle, corresponding to and forming the outer wall of 
the vestibule; (2) by the continuity with the lips anteriorly. 
Dental Arches. Identify (1) by their composition-teeth in the alveoli of the alveolar 
processes; (2) by their gum tissue covered by the mucous membrane and closely investing the 
teeth so as to form the gingival margin ; (3) by the vestibule external and the cavum oris 
internal to the dental arches. 
Fir. 39. 
The soft palate, mouth, and tonsillar regions. (Gerrish after Testut.) 
Hard Palate. Identify (1) as the roof of the mouth; (2) by the continuity with the alve- 
olar processes covered by the soft structures, continuous posteriorly with the soft palate. 
Isthmus of the Fauces. Identify as the space bounded by the arch of the soft palate 
and tongue, and leading from the mouth to the pharynx. 
Soft Palate. Identify (1) by its location between the mouth and pharynx, forming an 
incomplete partition between the two; (2) by its attachment to the posterior border of the 
hard palate, and composed of soft, freely-movable structures. 
Uvula. Identify (1) by its location as a small pyramidal, contractile, pendulous mass (apex 
down) in the mid-line of the soft palate; (2) by the marked tendency to chronic elongation; 
(3) by the marked shortening in the living when irritated. 
Anterior Pillar. Identify (1) by its location, extending from the base of the uvula, down- 
ward and forward to the side of the tongue; (2) by its coming into easy view when the 
tongue is drawn forward. THE MO UTH. 
77 
Posterior Pillar. Identify (1) by its location, extending from the base of the uvula down- 
ward, backward, and outward to the outer wall of the pharynx; (2) by its adjacency to the 
pharynx. 
Tonsillar Recess. Identify (1) as the triangular space between the pillars of the palate; 
(2) by its containing the tonsil and corresponding in location to the angle of the jaw. 
Tongue. Identify (1) by its location in the mouth and its attachment to the mandible, hyoid, 
hard palate, and styloid processes; (2) by the pointed, freely-movable apex; (3) by the ex- 
panded dorsum, with the oral and pharyngeal surfaces supporting the papillae; (4) by its 
reflection of the mucous membrane onto the pillars of the palate, tonsil, epiglottis, alveolar 
process of the mandible, and symphysis. 
Circumvallate Papillae (papillae maximae). Identify (1) by their location between the oral 
and pharyngeal surfaces of the tongue (eight to twelve in number); (2) by their arrangement 
in two rows like the letter V inverted ; (3) by the foramen caecum behind the apex of the V. 
Fungiform Papillae (papillae mediae). Identify (1) by their location principally at the tip 
and the sides of the tongue; (2) by their great number and deep red color. 
Filiform Papillae (papillae minimae). Identify (1) by their location on the anterior two-thirds 
of the tongue, arranged in lines corresponding with the rows of the circumvallate papillae ; 
(2) by their small size and conical shape. (Study with the glass.) 
Fig. 40. 
Under surface of tongue and the sublingual space, showing openings of salivary ducts. The lingual mucosa 
of the left side is partly removed, and shows the ranine artery, the lingual nerve, and the gland of Blandin. 
(Gerrish after Testut.) 
Fraenum Linguae. Identify by its location on the under surface of the tongue as a fold of 
the lingual mucous membrane extending in the mid-line from the tongue to the symphysis 
menti. 
Sublingual Elevation. Identify (1) by its location (one on either side) beneath the ante- 
rior part of the tongue, and corresponding to the sublingual salivary gland; (2) by the pres- 
ence of orifices and of small ducts of the gland. (Study with the glass.) 
Submaxillary Orifices (two in number). Identify (1) by their location near the fraenum, 
marked by the papillae; (2) by the exudation of saliva (in the living) following the application 
of gustatory stimulation to the tongue. 
Ranine Veins. Identify by their blue color, large size, and location on either side of the 
fraenum linguae on the under surface of the tongue. 
Plica Fimbriata. Identify (1) by its fimbriated margin (best seen in young people) just 
external to the ranine veins and about one-half inch external to the fraenum linguae; (2) by 
its derivation from the lingual mucous membrane. 
Lingual Nerve (gustatory). Identify by its location just external to the ranine artery 
(identify artery by pulsation), and it may be identified by pressure between the thumb and 
finger, as it is the sensory nerve of the anterior two-thirds of the tongue. 78 
A MANUAL OF DISSECTION. 
DISSECTION. 
Coronary Arteries. Turn the lower lip down and cut through the mucous membrane as 
far as the angle of the mouth. This incision will expose the inferior coronary artery. Turn 
the upper lip upward and incise similarly its mucous membrane to expose the superior 
coronary artery. The coronary arteries are branches of the facial, given off near the angle of 
the mouth. 
The Lips. Cut through the entire thickness of each lip with scissors one-half inch to the 
outer side of the median line. Study (a) the fraenum of each lip (a fold of the mucous mem- 
brane in the mid-line connecting the lip and gum); (5) the orbicularis oris fibres; (c) the 
cut ends of the coronary vessels; (d) the median tubercle of the upper lip. 
The Cheeks. Cut with scissors through the cheek from the angle of the mouth to the 
masseter muscle and study («) the orifice of Stenson's duct (opposite the second molar), 
guarded by a fold of mucous membrane; (b) the fibres of the buccinator muscle; (c) the 
cushion of fat called the sucking cushion. 
Vessels of Tongue. Pass a thread through the tip of the tongue so as to hold and move 
the same. Cut through the mucous membrane (Fig. 40) and expose the ranine vessels (imme- 
diately beneath the mucous membrane) and the lingual nerve. At the root of the tongue 
these vessels are between the hyoglossus and geniohyoglossus muscles. 
Sublingual Gland. Remove the mucous membrane covering the sublingual elevation and 
expose the sublingual salivary gland. This lies on the mylohyoid muscle. 
Soft Palate. Saw through the lower jaw between the central incisor teeth. With a sharp 
scalpel cut through all the soft structures, including tongue, from the hyoid bone to the epi- 
glottis (seen now behind the base of the tongue). Draw the parts of the several structures 
aside so as to gain space, and the soft palate may be dissected fairly well. 
The Uvula. Grasp with the long dressing forceps near the tip and draw the same forward; 
incise the mucous membrane and study its muscle, the azygos uvulae. (Fig. 39.) 
The Tonsil and Tonsillar Recess. Make traction on the tongue and bring into view the 
tonsil between the pillars (Fig. 39), corresponding deeply in location to the angle of the jaw. 
Study (a) the openings on the inner surface; (6) the continuity of the mucous membrane of 
the tonsil with the pillars. 
Palatoglossus Muscle. Put the tongue on the stretch, incise the mucous membrane from 
the base of the uvula to the side of the tongue along the anterior pillar of the palate, and 
expose the palatoglossus muscle. 
Palatopharyngeal Muscle. Incise the mucous membrane along the posterior pillar of 
the palate and expose the palatopharyngeus muscle. 
Lingual Nerve and Mylohyoid Muscle. Draw the halves of the tongue toward the mid- 
line and cut through the mucous membrane in the bottom of the groove between the molar 
teeth and the tongue, when will be exposed the lingual nerve lying on the mylohyoid muscle. 
Find the lingual nerve communicating with the hypoglossal on the geniohyoglossus muscle. 
Hypoglossal Nerve. Draw the tongue well to the median line and cut through the mucous 
membrane along the gutter lateral to the tongue, and find this nerve, the mylohyoid and 
geniohyoglossus muscles. Further back it lies to the outer side of the hyoglossus muscle with 
the lingual vein. 
Geniohyoid Muscle. Examine the cut surface of the tongue (in mid-line) and find the 
cellular space between this and the geniohyoglossus muscles. The geniohyoid passes from 
the mandible to the body of the hyoid bone. 
Geniohyoglossus Muscle. This muscle extends from the mandible to the hyoid bone and 
tongue. It is above the geniohyoid. Between its outer surface and the hyoglossus muscle are 
the lingual vessels (known as ranine vessels, in front of the hyoglossus muscle). 
Stylohyoid Muscle. Remove the mucous membrane of the posterior lateral part of the 
tongue and find the muscle inserted into the side and under part of the tongue. 
Glossopharyngeal Nerve. Find beneath the styloglossus muscle. The tongue must be 
drawn well out and to the opposite side to make the proper exposure. 
THE CAVUM ORIS. 
Location. The mouth or cavum oris is the space, limited roughly, above by 
the superior maxillary bone, below by the mandible, laterally by the cheeks, pos- 
teriorly by the pendulous soft palate and isthmus of the fauces, in front by the 
buccal orifice and lips. 
Communications. The mouth communicates directly with the pharynx through 
the isthmus of the fauces, with the external world through the buccal orifice, 
with the nose through the anterior palatine canal, with the sphenomaxillary fossa 
through the posterior palatine canal. It communicates indirectly with the nose THE MO UTH. 
79 
through the posterior nares; with the frontal sinuses through the infundibulum; 
with the antrum of Highmore through the ostium maxillaire; with the sphenoidal 
sinus and ethmoidal cells through an unnamed opening ; with the tympanum 
through the Eustachian tube, with the larynx through the chink of the glottis, 
with the oesophagus through the pharynx. 
Contents. The mouth contains the teeth, in their alveoli ; the termini of the 
ducts of Stenson, Wharton, and Ravini; the buccal, labial, and palatine mucous 
glands ; the tongue, endowed with motor, sensory, sympathetic, and special sense 
taste nerves. The mouth is an organ of prehension, mastication, taste, respiration, 
speech, and pantomime. 
The Lips. The lips vary in thickness in different races and in different people 
of the same race. The upper lip has a median tubercle (especially prominent in 
young children), a remnant of the distal part of the embryonal nasofrontal process. 
The lips are composed of skin, orbicularis oris, connective tissue, coronary arteries, 
veins, lymphatics, mental and infra-orbital nerves, and mucous membrane. The 
fraenum labii superioris and inferioris are two pronounced folds of mucous mem- 
brane connecting the gums and lip in the mid-line. On examining a patient's 
mouth care should be exercised on the part of the operator not to exert undue 
traction on the fraenum, and thereby produce unnecessary pain. 
The Mucous Membrane of the lips (in the living) is dry, red, and sensitive. The 
lips are in a sense prehensile organs, hence they are provided with nerve endings 
resembling touch corpuscles. Racemose labial glands occupy the connective 
tissue lamina beneath the mucous membrane. The junction of the mucous 
membrane and skin is called the muco-cutaneous margin. The lips, by virtue of 
their rich blood-supply and nerve-supply, undergo rapid repair after surgical 
operations. The labial mucous membrane is reflected onto the gums. 
THE CHEEK. 
Shape. The cheek is quadrilateral, bounded below by the inferior border of 
the lower jaw, above by the lower margin of the orbit, behind by the ramus of 
the mandible, in front by the side of the nose and geniolabial sulcus. (See Ger- 
rish.) 
Composition. 1. Integument, similar to and continuous with that of the lips, 
and in the male is covered with hair. 2. Areolar tissue, containing the long buccal 
nerve and vessels, molar glands, and sucking cushion of fat, which latter gives 
rotundity to the cheek. In nursing children this pad of fat is encapsulated, 
resembling very much in shape and appearance the yolk of an egg. 3. The 
buccinator and masseteric fascia? covering their respective muscles. 4. The 
buccinator and masseter muscles. The masseter muscle is crossed by Stenson's 
duct; the buccinator is pierced by the same. The mucous membrane is continuous 
with the labial mucous membrane, and contains the openings of the buccal and 
molar iuucous glands and Stenson's duct. 
THE SOFT PALATE. 
Location. The soft palate is easily seen by firmly depressing the tongue. At 
times other than deglutition it forms an imperfect partition between the oral 
cavity and pharynx, and its movements should be, as far as possible, studied on 
the living. 
Attachments. The soft palate is attached (1) to the posterior border of the hard 
palate (2) to the side of the tongue through the palatoglossus muscle ; (3) to the 
lateral wall of the pharynx and thyroid cartilage through the palatopharyngeus 
muscle. The free border of the soft palate has a wide range of motion forward, 
backward, and upward. 80 
A MANUAL OF DISSECTION. 
Composition. 1. The velum, uvula, and mucous membrane. 2. The anterior 
pillar and palatoglossus muscle. 3. The posterior pillar and palatopharyngeus 
muscle. 4. The tonsillar recess and tonsil. 5. Nerves from the pharyngeal 
plexus and otic ganglion. 6. The palatine arteries and veins. 
The Uvula is a small, pendulous process, composed of muscle aud mucous mem- 
brane, situated in the median line of the velum palati. Its great tendency to move 
depends on its richness of muscular fibre, by which it is influenced. The uvula 
has one intrinsic muscle, azygos uvulae, taking origin in the posterior nasal spine. 
The extrinsic muscles are the tensor and levator palati, palatoglossus, and palato- 
pharyngeus. 
Fig. 41. 
Muscles of the soft palate, viewed from behind. The dorsal wall of the pharynx has been laid open, 
(Gerkish after Testut.) 
Pillars of Palate. Near the base of the uvula the soft palate splits iuto the 
anterior and posterior pillars, leaving a triangular region (tonsillar recess) be- 
tween them. 
The Anterior Pillar passes downward, forward, and outward to the side of the 
tongue, and consists of (1) a fold of mucous membrane ; (2) the hidden palato- 
glossus muscle beneath the mucous membrane. Action, to lift the tongue, depress 
the velum, and narrow the isthmus. 
The Posterior Pillar of the palate passes downward, backward, and outward to 
the lateral wall of the pharynx and thyroid cartilage. It consists of (1) a fold 
of mucous membrane ; (2) a hidden palatopharyngeus muscle beneath the mucous THE MO UTH. 
81 
membrane. Action, to pull down the velum, lift the tongue and larynx, and 
shut off the mouth from the pharynx by narrowing the isthmus. 
The Levator Palati, as its name implies, lifts the palate. Its origin is from the 
petrosa, in front of the carotid canal. It is inserted into the base of the uvula 
with its fellow of the opposite side. 
The Tensor Palati tightens the velum by lateral traction, just as the lips may 
be rendered tense by lateral traction at the corners of the mouth. The muscle 
arises from (1) the root of the internal pterygoid plate ; (2) the spine of the sphe- 
noid ; (3) the cartilaginous end of the Eustachian tube. Its tendon turns inward 
at a right angle around the hamular process, and is inserted into the soft palate 
and palate bone. 
The Isthmus of the Fauces is bounded by the anterior pillars of the palate, the 
uvula, and dorsum of the tongue. It is the aperture by which the mouth and 
pharynx communicate. The isthmus may become obliterated by its own boundary 
structures-that is, relations of the surrounding parts are so changed during the act 
of swallowing that for the moment a perfect partition exists between the mouth and 
pharynx. The digastric and stylohyoid muscles, aided by the palatopharyngeus, 
elevate the tongue ; the levator and tensor palati muscles render the velum tense ; 
the palatoglossus and palatopharyngeus draw the velum downward and inward 
in close apposition with the tongue. 
The Tonsils are in the tonsillar recess, between the pillars of the palate. They 
are evolved from the lateral wall of the pharynx, between the second and third 
visceral arches. In the adult the tonsils resemble glands of intestine, and belong 
physiologically to the lymphatic system. The location of the tonsil corresponds 
to the angle of the jaw. Its dimensions are one-half inch wide, one-half inch 
thick, and one inch in length. The tonsils have recesses fed by numerous follicles. 
The openings are on the inner surface of the tonsil, and through these the mucous 
membrane extends into and lines the follicles. The outer surface of the tonsil is 
in relation with the superior constrictor of the pharynx ; the latter intervenes 
between the tonsil and the ascending pharyngeal artery. The internal carotid 
artery is about one inch behind and external to the tonsil. Nerve-supply: (a) 
The glossopharyngeal; (6) Meckel's ganglion. Arteries: Dorsalis linguae, ascend- 
ing pharyngeal, internal carotid, ascending palatine, and descending palatine. 
THE TONGUE. 
Definition. The tongue is an organ of taste, speech, touch, deglutition, prehen- 
sion, and mastication. It is composed of muscles and mucous membrane, and 
has an abundant supply of vessels and nerves. 
The base of the tongue is attached to the hyoid bone and mandible ; the sides 
to the hard palate and styloid process. The dorsum has an oral and a pharyngeal 
surface. The oral surface is anterior to the circumvallate papillae, and bears the 
lingual taste-organs ; the pharyngeal surface is posterior to these, and rich in 
mucous glands and lymphoid tissue. The tongue was evolved from (1) the tuber- 
culum impar, from the middle of the anterior wall of the pharynx below the first 
visceral arch ; (2) the ventral extremities of the second and third visceral arches. 
The line of union is at the thyroglossal duct, and the foramen caecum on the back 
of the tongue is its vestige. 
The Mucous Membrane is reflected from the tongue, (1) laterally and anteriorly, 
onto the gums ; (2) anteriorly, beneath the tip, onto the symphysis menti, to form 
the fraenum linguae ; (3) onto the palatoglossus muscle, to form the anterior pillar 
of the palate ; (4) onto the superior surface of the epiglottis, to form the glosso- 
epiglottidean folds-central and lateral. 
The peculiarities of the lingual mucous membrane are : 1. Immovable, on the 
base and upper surface of the tongue. 2. Absence of the mucous glands. 3. 
Presence of papillae and lymph foilices. (See Gray's Anatomy.) 82 
A MANUAL OF DISSECTION. 
Muscles of the Tongue. The muscles of the tongue, both intrinsic and extrin- 
sic, are supplied by the hypoglossal or twelfth cranial nerve. The intrinsic 
muscles collectively form the musculus lingualis, and have origin and insertion in 
Fig. 42. 
the tongue-niass proper. The extrinsic muscles have origin outside the muscle- 
mass proper of the tongue, and insertion in the musculus lingualis. The specific 
origin and insertion of each group is given in the table of the muscles (page 84). 
Arteries and veins of the tongue, viewed from the right side. (Gerrish after Testut.) THE MO UTH. 
83 
Intrinsic Muscles. 1. The superior lingualis produces shortening and longi- 
tudinal grooving of the dorsum. 2. The inferior lingualis shortens the tongue 
and rounds up its dorsum. 3. The transverse lingualis diminishes the width and 
increases the length. 4. The vertical lingualis broadens and flattens the organ. 
Extrinsic Muscles. 1. The styloglossus lifts the base and retracts. 2. The 
hyoglossus retracts and depresses. 3. The geniohyoglossus has three actions : 
(a) The back fibres protrude the tongue ; (6) the front fibres retract the tip ; (c) 
the median fibres produce a dorsal gutter. 4. The chondroglossus retracts and 
depresses the tongue. 
Fig. 44. 
Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves. 
(Gerrish after Testut.) 
Nerves. 1. From the gustatory of the trifacial, to the anterior two-thirds. 
2. From the glossopharyngeal (taste) to the posterior one-third. 3. From the 
hypoglossal, to the intrinsic and extrinsic muscles. 4. From the superior laryn- 
geal, to the base of the tongue. 5. From the chorda tympani, to the anterior two- 
thirds (tasle). 6. From the superior cervical ganglion-vasodilators. 84 
A MANUAL OF DISSECTION. 
Artery. The tongue has a rich blood-supply through the lingual artery, a 
branch of the external carotid; the facial and ascending pharyngeal, from the 
external carotid. 
THE PHARYNX. 
Location. The pharynx is limited above by the base of the skull, below by the 
beginning of the oesophagus opposite the cricoid. It is situated behind the nose 
(nasopharynx), behind the mouth (oropharynx), and behind the larynx (laryngo- 
pharynx). 
Openings. 1. The Eustachian tube. 2. The posterior nares. 3. The isthmus 
of fauces. 4. The oesophagus. 5. The larynx. 
PHARYNGEAL PLEXUS. 
Location. The pharyngeal plexus is on the posterior and lateral aspect of the 
pharynx, on the outer surface of the middle constrictor. (Fig. 44.) 
Formation. 1. The internal branch of the spinal accessory nerve. 2. The 
pharyngeal branch of the glossopharyngeal. 3. The pharyngeal branch of the 
pneumogastric. 4. The pharyngeal branch of the superior laryngeal. 5. The 
pharyngeal branch of the superior cervical ganglion. 
Distribution. To the levator palati, palatoglossus, palatopharyngeus, superior, 
middle, and inferior constrictors of the pharynx. 
Table Giving Origin, Insertion, Action, and Nerve-supply of the Muscles of 
the Tongue, Palate, and Pharynx. 
Name. 
Origin. 
Insertion. 
Action. Nerve-supply. 
Palatopharyngeus. 
By two heads near 
median line of soft 
palate. 
Into upper and pos- 
terior borders of the 
thyroid cartilage. 
Constricts the Pharyngeal 
fauces, elevates plexus, 
the larynx and 
tongue, closing 
off the naso- 
pharynx. 
Palatoglossus. 
Near median line of Into the side and base Constricts the Pharyngeal 
soft palate and from of the tongue. fauces, elevates plexus, 
its fellow of the the tongue, and 
opposite side. pulls down the 
velum. 
Levator palati. 
Inferior surface of 
petrous portion of 
temporal bone and 
of the cartilage of 
Eustachian tube. 
Into the median line 
with its fellow of 
the opposite side. 
Elevates the soft Pharyngeal 
palate. plexus 
through the 
eleventh. 
Tensor palati. 
a. Scaphoid fossa of 
pterygoid plate. 
b. Spine of the sphe- 
noid. 
c. Eustachian tube. 
Into the median line 
of soft palate con- 
tinuous with its 
fellow of the oppo- 
site side and under 
surface of the pal- 
ate bone. 
Tightening of soft From the otic 
palate and open- ganglion on 
ing of Eustachian the mandibu- 
tube during deg- lar division 
lutition. of the tri- 
facial. 
Azygos uvulae. 
Posterior nasal spine. 
Into uvula. 
Shortens the uvula. Pharyngeal 
plexus. 
Hyoglossus. 
From great horn and 
body of the hyoid 
bone. 
Into side and dorsum 
of tongue between 
styloglossus and 
superior lingualis. 
Depression and Hypoglossal, 
retraction of the 
tongue. 
Genioglossus. 
Upper genial tubercle. 
Into the hyoid bone 
and median line of 
tongue and just ex- 
ternal to it from 
base to apex. 
Its anterior fibres Hypoglossal, 
retract the lip ; 
its posterior fibres 
protrude the 
tongue. 
Styloglossus. 
Styloid process of 
temporal bone and 
stylomandibular 
ligament. 
Into side and under 
part of the tongue 
from base to apex. 
To draw the Hypoglossal, 
tongue backward 
and to lift the 
base and sides. THE MO UTH. 
85 
Name. 
Origin. 
Insertion. 
Action. 
Nerve-supply. 
Chondroglossus. 
Lesser horn and 
body of hyoid. 
Into dorsum of 
tongue. 
Retracts and de- 
presses the 
tongue. 
Hypoglossal. 
Superior lingualis. 
From upper and 
posterior part of 
tongue and hyoid 
bone. 
Into submucous 
tissue of upper sur- 
face of tongue 
throughout its en- 
tire length. 
Shortens the 
tongue. 
Hypoglossal. 
Inferior " 
From external and 
posterior part of 
tongue. 
Under the edge of 
the tongue through- 
out its entire length. 
Shortens the 
tongue. 
Hypoglossal. 
Transverse " 
From medium sep- 
tum. 
Into dorsum and 
margin of tongue. 
Narrows and 
lengthens the 
tongue. 
Hypoglossal. 
Vertical " 
Under surface of 
tongue. 
Upper surface of 
tongue. 
Flattens and 
broadens the 
tongue. 
Hypoglossal. 
Sty loph ary n geus. 
Styloid process of 
temporal bone. 
Upper and posterior 
border of the thy- 
roid cartilage. 
Elevates pharynx 
and larynx. 
Glosso- 
pharyngeal. 
Constrictor 
Internal pterygoid 
Into mid-line of 
Narrows upper 
Pharyngeal 
superior. 
plate; side of 
tongue, mylo- 
hyoid ridges, and 
pterygomaxillary 
ligament. 
pharynx. 
half of pharynx. 
plexus. 
Constrictor medius. Greater- horn of 
hyoid and stylo- 
hyoid ligament. 
Into mid-line 
throughout entire 
length of pharynx. 
Narrows the 
pharynx antero- 
posteriorly. 
Pharyngeal 
plexus. 
Constrictor- 
Coracoid and thyroid 
Into mid-line of 
Compresses the 
Pharyngeal 
inferior. 
cartilage. 
pharynx. 
pharynx and lifts 
it upward and 
backward. 
plexus and 
inferior 
laryngeal. 
Fig. 45. 
Muscles of the pharynx. External view. (Gbay.) CHAPTER V. 
THE EYE. 
IDENTIFICATION OF STRUCTURES IN SITU BY INSPECTION OF 
THE EYE ON THE LIVING. 
Supercilia. Identify (1) by the location above the circumference of the base of the orbit 
and arched shape; (2) by the numerous, short, thick, oblique hairs. Composition: thick 
skin connected with orbicularis palpebrarum, corrugator supercilii, and occipitofrontalis 
muscles. 
Palpebrse (lids). Identify (1) by the location in front of the eyeball, which they protect; 
(2) by the attachment of the eyelashes to their free edges; (3) by their mobility and the 
presence of an elliptical space between the occlusal margins. 
Fissura Palpebrarum. Identify (1) by the location between the free margins of the lids; 
(2) by the extent from the inner to the outer canthus palpebrarum. 
Canthi. Identify the canthi (inner and outer canthus) (1) by the location at the angles of 
junction of the upper and lower lids ; (2) by the location at the extremities of the palpe- 
bral fissure. The inner canthus contains the lacus lacrymalis, caruncula lacrymalis, papilla 
lacrymalis, and puncta lacrymalia. 
Lacus Lacrymalis. Identify (1) as a triangular space separating the lids at the inner 
canthus; (2) by the prominent lacrymal caruncle in its centre. 
Papilla Lacrymalis. Identify (1) as two small elevations on the margins of the lids at 
the commencement of the lacus lacrymalis; (2) by the presence of a small opening in the 
apex of each papilla. 
Puncta Lacrymales. Identify (1) by the location at the apices of the lacrymal papillae; 
(2) by the adjacency of the caruncula lacrymalis. 
Cilia. Identify (1) as thick, short, curved hairs at the margins of the lids; (2) by the 
arrangement of the hairs in two or three rows; (3) by the upward curve of the superior and 
the downward curve of the inferior cilia. 
Glandulse Molli. These modified sweat glands are identified (1) by the location near the 
free margin of the lids; (2) by the arrangement in several rows. 
Conjunctiva. Identify (1) by the location on the inner surfaces of the lids and its reflec- 
tion onto the sclerotica and cornea; (2) as a very transparent mucous membrane through 
which may be seen the bead-like rows of the Meibomian follicles, corresponding in length (the 
rows) to the width of the tarsal plates. 
Palpebral Folds. Identify (1) by the location above and below the fornix; (2) as the con- 
junctiva reflected from the lids to the eyeball. Folds are called the superior and inferior 
palpebral. The point of reflection of the conjunctiva from the lid to the eyeball is the fornix 
conjunctivae. 
Plica Semilunaris. Identify (1) by the location at the inner angle of the eye; (2) 
as a half-moon-shaped fold of mucous membrane; (3) by the adjacency of the lacrymal 
caruncle. This and the lacrymal caruncle represent the nictitating membrane of the lower 
animals. 
Caruncula Lacrymalis. Identify (1) by the location at the inner canthus in the lacus 
lacrymalis; (2) by the adjacency of the plica semilunaris; (3) by the presence of a few 
attached slender hairs. The caruncle is composed of skin, contains sweat glands, sebaceous 
glands, and is the source of a whitish secretion. 
Meibomian Glands. Identify (1) by the location on the inner surface of the eyelids 
beneath the palpebral conjunctiva in the grooves of the tarsal plates; (2) by the appearance 
of strings of small beads; (3) by the minute openings of these glands on the free margins of 
the lids. 
Conjunctival Sac. This is the space limited by the cornea, sclerotica, fornix and conjunc- 
tiva of the upper and lower lids. The palpebral fissure leads into the sac. When the eye- 
lids are closed the conjunctival sac is a potential cavity. Tears traverse the sac, moistening, 
purifying, and keeping the cornea free from foreign bodies. Tears originate in the lacrymal 
gland, pass through the openings in the conjunctiva of the upper lid near the outer canthus, 
and leave the conjunctival sac through two puncta lacrymalia in the lacrymal papillae, 
situated at the beginning of the lacus lacrymalis at the inner canthus. 
Cornea. Identify (1) by the location so as to form the anterior sixth of the eyeball; (2) 
by the circular shape, transparency, and continuity with the sclerotic coat at the corneal 
margin. THE EYE. 
87 
Sclerotica. Identify (1) by the location about the cornea and white color; (2) by the 
extreme density, hardness, and unyielding character; (3) by the insertion of the recti and 
obliqui muscles; (4) by the investment of the anterior part by the conjunctiva, and the poste- 
rior part by the capsule of Tenon ; (5) by the continuity with the cornea in front. 
Anterior Ciliary Arteries. Identify (1) by the location beneath the conjunctiva of the 
sclerotic coat; (2) by the sudden disappearance near the margin of the cornea, where they 
pierce the sclerotic coat and end in the circulus major of the iris. They are derived from 
the muscular branches of the ophthalmic. In iritis the vascular zone around the cornea is 
due to inflammation of the anterior ciliary arteries. 
Iris. Identify (1) as the colored membrane of the eye (gray, brown, black, blue); (2) by the 
location in the anterior chamber in the aqueous humor behind the cornea; (3) by the presence 
a little to the nasal side of the centre of the pupil, limited on all sides by the pupillary margin 
of the iris. 
Fig. 46. 
The lacrymal apparatus of the right eye. (Gerrish after Testut.) 
LACRYMAL APPARATUS. 
Dissection of the Lacrymal Sac and Canaliculi. (1) Locate the punctum lacrymale on 
the summit of the papilla at the outer end of the lacus lacrymalis on the margin of the lid ; 
(2) enter the lacrymal sac through the superior canaliculus with Bowman's grooved lacrymal 
catheter in upward, inward, and downward directions in succession ; (3) move the catheter in 
various directions to demonstrate the strength, elasticity, and limited distensibility of the sac. 
(Pass catheter into the sac through the inferior canal downward and inward); (4) cut down 
on the director with delicate scissors and expose the interior of the canals and sac; (5) make 
a vertical incision three quarters of an inch long and lay open the nasal duct. 
The Lacrymal Gland (Fig. 46) is an oval, compound, racemose structure, 
lodged in a depression beneath the external angular process of the frontal bone. 
It rests on the globe of the eye, conjunctiva, superior and external recti muscles, 
and is in contact with the orbital periosteum externally. It opens by six or seven 
ducts on the upper and outer half of the palpebral conjunctiva into the conjunctival 
sac. 
The Canaliculi are two canals commencing at the puncta lacrymalia, the supe- 
rior passing upward and inward to the lacrymal sac, the inferior passing down- 
ward, inward, and upward. 
The Lacrymal Sac is a dilatation of the upper part of the nasal duct, lodged 
in the groove formed by the lacrymal bone and nasal process of the superior 
maxillary; its walls are of fibrous tissue covered in by the tensor tarsi muscle and 
an expansion from the tendo-oculi attached to the lacrymal bone. 
The Nasal Duct is a membranous canal, three-fourths of an inch long, extending 
from the end of the lacrymal sac through a bony nasal canal to the inferior 
meatus. Its direction is downward, backward, and outward, its lumen being 
narrowest about the mid-point. The valve of Hasner is an imperfect fold of 
mucous membrane guarding the opening of the duct into the inferior meatus of 
the nose. 88 
A MANUAL OF DISSECTION. 
THE EYELIDS. 
Dissection of the Eyelids. Pass two stitches through the palpebral border of each lid, 
one-quarter of an inch apart near the mid-line, an assistant making traction on the threads; 
cut through the lids vertically and secure the same by the four threads, so as to make full 
exposure of the conjunctival sac. Study carefully their composition. 
Composition of eyelids seen in the transverse section from without in : integu- 
ment, loose areolar tissue, orbicularis palpebrarum, tarsal plates, tarsal ligaments, 
involuntary muscular fibre of Miiller, Meibomian sebaceous glands, conjunctiva, 
palpebral arteries from the facial and ophthalmic, nerves from the third, seventh, 
fifth, and sympathetic. 
The Tarsal Plates, one in each lid, consist of dense connective tissue. The upper 
is semilunar, the lower elliptical in form. They are attached to the margin of 
the orbit by fibrous membranes, the tarsal ligaments. The outer angle of 
each tarsal plate is attached by the external tarsal ligament to the malar bone. 
The inner angles of the tarsal plates are attached to the nasal process of the supe- 
rior maxillary bone by the tendo-oculi-the internal tarsal ligament-formed by 
fusion of the superior and inferior palpebral ligaments. Into the anterior surface 
of the superior plate is inserted the levator palpebrae muscle, in which are some 
smooth muscular fibres-the superior palpebral muscle of Miiller. The inferior 
palpebral muscle of Miiller is in the lower tarsal plate. Muller's muscles are 
supplied by sympathetic nerves on which depend the involuntary action of the 
eyelids. (See nerve-supply of the muscles of expression, p. 24.) 
MUSCLES OF THE EYE. 
Dissection. Recti and oblique-tendons of insertion. Be guided by the illustration in the 
book as to the general insertion of the recti and oblique tendons. The recti tendons are in- 
serted into the sclerotic coat of the eye, three or four lines external to the margin of the 
cornea. Each muscle perforates the capsule of Tenon, and its tendon receives a tubular 
sheath therefrom. Locate the insertion of the tendon as above indicated, and pinch up and 
Fig. 47. 
Muscles of the right orbit. (Gray.) 
cut the conjunctiva over the insertion. Now pinch up and cut the tubular sheath of the 
tendon derived from Tenon's capsule, when the white sclerotic coat and the insertion of the 
muscle will appear. Elevate the tendon on a blunt hook. Study carefully the insertion of 
the muscles in the subjoined table, and note the extent of the tubular sheath derived from the 
capsule of Tenon. THE EYE. 
89 
Function and 
Name. 
Origin. 
Insertion. 
nene-supply. 
Levator 
Under surface of the 
Aponeurotic into the upper margin 
Elevates the lid and an- 
palpebne 
lesser wing of the 
of the superior tarsal plate ; skin 
tagonizes the orbicu- 
superioris. 
sphenoid above and 
in front of the optic 
foramen. 
of lid ; conjunctiva. 
laris palpebrarum. 
Supplied by the third 
nerve. 
Superior 
Upper margin of the 
Sclerotica, by tendinous expansion, 
Elevates, adducts, and 
rectus. 
optic foramen ; 
fibrous sheath of the 
optic nerve. 
three or four lines from the sclero- 
corneal junction. Tendon covered 
by tubular process of Tenon's 
capsule. 
rotates the cornea in- 
ward. Supplied by the 
third nerve. 
Inferior 
Ligament of Zinn with 
Sclerotica, three or four lines from 
Adducts the cornea. Sup- 
rectus. 
the internal rectus. 
the sclerocorneal junction. Has 
sheath from Tenon's capsule. 
plied by the third 
nerve. 
External 
(1) Outer margin of 
Sclerotica, three or four lines from 
Turns the cornea down- 
rectus. 
the optic foramen ; 
(2) ligament of Zinn 
and lower margin of 
the sphenoidal fis- 
sure. 
the corneal margin. 
ward. Supplied by the 
sixth nerve. 
Internal 
Ligament of Zinn by 
Sclerotica, three or four lines from 
Turns the cornea inward. 
rectus. 
common tendon with 
the inferior rectus. 
the corneal margin. 
Supplied by the third 
nerve. 
Inferior 
Depression near the 
Outer part of the sclerotica, between 
Rotates the cornea out- 
oblique. 
anterior margin of 
the maxillary bone, 
external to the 
lacrymal groove 
the superior and external recti, 
behind the tendon of the superior 
oblique. 
ward on the antero- 
posterior axis. Sup- 
plied by the third 
nerve. 
Superior 
One line above the 
Passing around the trochlea beneath 
Abducts and rotates the 
oblique. 
inner margin of the 
optic foramen. 
the internal angular process of the 
frontal bone, the tendon passes 
backward, outward, and down- 
ward beneath the superior rectus, 
and is inserted into the sclerotica 
behind the equator and between 
the superior and external recti 
muscles. Sheath derived from 
Tenon's capsule reaches the floor 
of the orbit. 
cornea inward on the 
antero-posterior axis. 
Supplied by the fourth 
nerve. 
Muller's 
superior 
palpebral. 
Aponeurotic insertion 
of the levator pal- 
pebral. 
Upper lid fibres. 
Involuntary action of the 
upper lid. Supplied 
by the sympathetic 
nerve. 
Muller's 
inferior 
palpebral. 
Inferior tarsal cartilage 
plate. 
Lower lid fibres. 
Involuntary action of the 
lower lid. Supplied by 
the sympathetic nerve. 
Muscles of the Eyeball, Tabulated. 
INTRA-ORBITAL STRUCTURES. 
Dissection. Remove the orbital plate as far back as the optic foramen. To do this saw 
through the internal and external angular processes of the frontal bone and give the interven- 
ing bony arch a gentle tap, when it will fracture transversely. Remove the remaining bone 
so as to expose the orbital contents and the sphenoidal fissure. (Fig. 48.) The orbital peri- 
osteum is now exposed. Study step by step the directions for identifying the structures. 
(For a short, systematic description of the muscles, branches of the ophthalmic artery, and 
orbital cranial nerves, see respective tables. For contents of the cavernous sinus, see dural 
sinuses, p. 55. For sphenoidal fissure and its contents, see osteology of the orbit.) 
Periosteum of the Orbit. Identify (1) by the location in the orbit and the attachment to 
the orbital walls ; (2) by the continuity with the dura through the sphenoidal fissure. 
Orbital Fascia. Identify (1) as a thin transparent layer of connective tissue immediately 
beneath the periosteum; (2) by forming a loose, delicate sheath for the lacrymal gland and 
muscles; (3) by the formation of the capsule of Tenon. Elevate the orbital fascia and incise 
the same from the base to the apex of the orbit. Turn the fascia aside. 
Frontal Nerve. Identify (1) by the location immediately beneath the orbital fascia (with 
the supra-orbital artery) on the levator palpebrse muscle in the mid-line; (2) by the division 
midway in the orbit, into the supratrochlear and supra-orbital branches; (3) by the derivation 
from the ophthalmic division of the trifacial nerve in the cavernous sinus. 
Supratrochlear Nerve. Identify (1) by derivation from the frontal nerve ; (2) by the 
oblique course inward above the trochlea of the superior oblique muscle to the inner angle of 
the orbit; (3) by the communicating branch to the infratrochlear branch of the nasal nerve. 90 
A MANUAL OF DISSECTION. 
Supra-orbital Nerve. Identify (1) by the derivation from the frontal nerve; (2) by the 
location on the levator palpebrte and the emergence from the orbit onto the face through the 
supra-orbital notch. 
Supra-orbital Artery. Identify (1) by the derivation from the ophthalmic; (2) by the loca- 
tion on the levator palpebne with the supra-orbital branch of the frontal nerve; (3) by the 
emergence through the supra-orbital foramen. 
Frontal Artery. Identify (1) by the location on the inner wall of the orbit with the supra- 
trochlear nerve; (2) by the derivation from the ophthalmic artery; (3) by the emergence 
from the orbit at the inner angle and anastomosis with the supra-orbital artery. 
Levator Palpebrse. Identify (1) by the location beneath the frontal nerve and supra-orbital 
artery ; (2) by the insertion into the tarsal plate of the upper eyelid ; (3) by the location on 
the superior rectus muscle. Cut this muscle in the middle and expose the superior rectus 
beneath. 
Superior Rectus. Identify (1) by the location in the upper part of the orbit beneath the 
levator palpebrae; (2) by the insertion into the upper part of the sclerotic coat. 
External Rectus. Identify (1) by the location on the outer side of the orbit with the 
lacrymal nerve and artery ; (2) by the insertion into the outer side of the sclerotic coat of the 
eyeball; (3) by the distribution of the sixth nerve to its ocular or inner surface. 
Lacrymal Nerve. Identify (1) by the location on the upper border of the external rectus 
muscle, with the lacrymal artery; (2) by the derivation from the ophthalmic division of the 
trifacial nerve; (3) by the passage through the lacrymal gland with the lacrymal artery. 
Fig. 48. 
Ophthalmic division of the trifacial nerve. (Gerrish after Testut.) 
Lacrymal Artery. Identify (1) by the location along the upper edge of the external rectus 
muscle with the lacrymal nerve; (2) by the derivation from the ophthalmic ; (3) by the dis- 
tribution to the lacrymal gland and conjunctiva. 
Sixth Cranial Nerve. Identify (1) by the distribution to the ocular surface of the external 
rectus muscle; (2) by entering the orbit between the two heads of the external rectus muscle 
through the sphenoidal fissure. 
Inferior Oblique. Identify (1) by the origin from the orbital plate of the superior maxilla 
on the outer side of the lacrymal groove; (2) by the course outward and backward between 
the orbit and inferior rectus, then between the globe and the external rectus; (3) by the inser- 
tion into the outer and back part of the sclerotic coat. Gain this muscle from in front for 
dissection. 
Superior Oblique Muscle. Identify (1) by the location on the inner and upper sides of the 
orbit with the fourth nerve; (2) by the passage through the pulley of cartilage attached 
to the trochlear fossa in the frontal bone; (3) by the insertion into the outer part of the 
sclerotic coat (near the insertion of the inferior oblique), having passed beneath the superior 
rectus muscle. • 
Fourth Cranial Nerve. Identify the patheticus (1) by the location on the inner side of the 
orbit and the distribution to the superior oblique muscle; (2) by the passage through the 
sphenoidal fissure above the other nerves. (Fig. 49.) THE EYE. 
91 
Internal Rectus. Identify (1) by the location on the inner side of the orbit; (2) by the 
insertion into the inner side of the sclerotic coat; (3) by the origin from the ligament of Zinn 
with the inferior rectus. 
Fig. 49. 
Nerves of the orbit and ophthalmic ganglion. Side view. (Gray.) 
Fig. 50. 
The ophthalmic artery and its branches, the roof of the orbit having been removed. (Gray.) 
Inferior Rectus. Identify (1) by the location in the inferior part of the orbit; (2) by the 
origin with the internal rectus from the ligament of Zinn ; (3) by the insertion into the sclerotic 
coat on the inferior part of the globe. 
Third Cranial Nerve. Identify the motor oculi (1) by the large size, firm texture, and 
rounded form; (2) by the distribution to all the orbital muscles, except the superior oblique 
and the external rectus. 92 
A MANUAL OF DISSECTION. 
Nasal Nerve. Identify (1) by the derivation from the ophthalmic; (2) by the course 
through the sphenoidal fissure between the superior and inferior divisions of the third nerve; 
(3) by the course above the optic nerve, beneath the superior rectus and levator palpebrae; 
(4) by the emergence from the orbit between the internal rectus and the superior oblique, 
through the anterior ethmoidal foramen into the cranium; (5) by the passage from the 
cranium to the nose through the nasal slit. 
Optic Nerve. Identify (1) by the large size and the central location in the orbit; (2) by the 
passage through the optic foramen with the ophthalmic artery; (3) by the fact of being the 
largest structure piercing the posterior part of the eyeball. 
Ciliary Ganglion. Identify (1) by the location in the orbit between the optic nerve and the 
external rectus muscle; (2) by its pinhead size ; (3) by the source of the roots-motor-from 
the branch of the third nerve to the inferior rectus muscle; sensory, from the nasal nerve; 
sympathetic, from the cavernous plexus; (4) by the distribution to the eyeball-short ciliary 
nerves. The nasal nerve element in the ciliary ganglion confers trophicity and common sen- 
sation on the eyeball. Branches of the ganglion derived from the third nerve are motor to 
the ciliary muscle and sphincter of the iris. Branches of the ganglion derived from the 
sympathetic produce dilatation of the iris. 
Short Ciliary Nerves. Identify (1) by the origin from the ciliary ganglion and their course 
to the posterior part of the eyeball, which they pierce; (2) by uniting with the long ciliary 
branches of the nasal nerve on piercing the sclerotic coat. (Study with the dissecting micro- 
scope.) 
Long Ciliary Nerves. Identify (1) by the derivation from the nasal nerve; (2) by the 
course along the inner side of the optic nerve to the back of the globe; (3) by union with the 
filaments from the ciliary ganglion-the short ciliary nerves. (Study with the dissecting 
microscope.) 
Short Ciliary Arteries. Identify (1) by their large number (twelve to fifteen) and their loca- 
tion about the optic nerve ; (2) by piercing the sclerotic coat to supply the choroid and iris; 
(3) by attending the ciliary nerves-long and short. (Study with the dissecting microscope.) 
THE OPHTHALMIC ARTERY. 
The Ophthalmic Artery arises from the internal carotid, near the anterior clinoid process. 
It passes through the optic foramen with the optic nerve, and, at times, through the sphenoidal 
fissure. Its branches are to be studied from the following table : 
Branch. 
Course. 
Distribution. 
Lacrymal. 
Above the external rectus on the outer 
wall of the orbit with the lacrymal 
nerve. 
Lacrymal gland, lids, conjunctiva, malar 
branch to the temporal fossae; anasto- 
motic branch, through the sphenoidal 
fissure to the middle meningeal artery. 
Supra-orbital. 
Forward beneath the roof of the orbit 
on the levator palpebrte, and onto the 
face through the supra-orbital foramen 
with the supra-orbital nerve. 
Communicates with the frontal, angular, 
and superficial temporal arteries, and 
shares their distribution. 
Arteria 
Enters the optic nerve on the outer side 
To the retina, in which no anastomosis be- 
centralis 
retinse. 
near the optic foramen. 
tween this and other arteries - occurs. 
(See Gray and Gerrish.) 
Short ciliary, 
twenty in 
number. 
Travel forward with the optic nerve, 
piercing the sclerotic coat. 
To the choroid and iris. 
Long ciliary. 
One on each side of the optic nerve, 
pierces the sclerotic coat, and passes 
between the sclerotic and the choroid 
coats. 
They pass nearly to the iris, anastomose 
with the short ciliary, and form the cir- 
culus major at the circumference of the 
iris, and the circulus minor at the free 
margin of the iris. 
Anterior 
They are derived from the muscular 
They supply the conjunctiva covering the 
ciliary. 
branches and follow the tendons to 
near the corneal margin. 
sclerotic coat, pierce the sclerotica, and 
join the circulus major. 
Anterior 
Through the anterior ethmoidal foramen 
Branches: to the frontal and the anterior 
ethmoidal. 
in company with the nasal nerve. 
ethmoidal cells ; an anterior meningeal 
branch and a nasal branch. 
Posterior 
Through the posterior ethmoidal fora- 
To the posterior ethmoidal cells, upper 
ethmoidal. 
men. 
part of the nose, and a branch to the 
Muscular. 
Pass to the upper and lower muscles of 
the eyeball. 
meninges. 
Supply the muscles of the eyeball. 
Superior pal- 
pebral. 
Forms an arch near the margin of the 
lid, between the tarsal cartilage and 
the orbicularis palpebrarum. 
To the superior lid. 
Branches of the Ophthalmic Artery. THE EYE. 
93 
Branch. 
Course. 
distribution. 
Inferior pal- 
pebral. 
Arches between the tarsal cartilage and 
the orbicularis palpebrarum. 
To the inferior lid. 
Nasal. 
Leaves the orbit above the tendon of the 
orbicularis and inosculates with the 
nasal and angular arteries. 
Supplies the side of the nose and the lac- 
rymal sac. 
Frontal. 
Passes upward at the inner angle of the 
eye and inosculates with the supra- 
orbital. 
Inosculates with the supra-orbital artery 
and distributed to the skin of the inner 
canthus and vicinity. 
NERVES OF THE EYE. 
The following nerves enter the orbit through the optic foramen and sphenoidal 
fissure, and supply the contents of the same with motion, special and common 
sensation, and trophic influence : 
1. The optic passes through the optic foramen with the ophthalmic artery and 
is distributed to the retina. 2. The oculomotor (third cranial) is distributed to 
the levator palpebrse, superior, inferior, internal recti, and inferior oblique. 
3. The trochlearis (fourth cranial) is distributed to the superior oblique. 4. The 
abducens (sixth cranial) is distributed to the internal rectus. 5. The ophthalmic 
division of the trifacial (fifth cranial) is distributed (a) to the skin of the scalp as 
far as the lambdoid suture; (6) to the conjunctiva, lacrymal sac, and caruncle; 
(c) to the skin of the eyelids and nose; (cZ) to the mucous membrane of the upper 
part of the nasal fosste. (For ciliary ganglion and nerves, see " dissection.") 
EYEBALL. 
Ox eyes in large numbers should be used in identification of the following structures. Use 
variety of lines of incision with very small saw, the eyes being frozen. Study with a dissect- 
ing microscope. 
Vitreous Humor. Identify (1) by the transparency and gelatinous appearance; (2) by the 
occupancy of the posterior four-fifths of the interior of the globe; (3) by a depression in front 
containing the lens; (4) by a structureless hyaloid membrane, which invests the vitreous 
(except in front), and passes from this to the margin of the lens, forming its suspensory liga- 
ment ; (5) by the easy detachment from the retina, except at the optic disk. 
Retina. Identify (1) by the location immediately in contact with the vitreous humor ; (2) 
by the transparency when fresh, and the pink, milky color when not fresh ; (3) by ending as 
a transparent structure (in the region of the posterior part of the ciliary processes) in a wavy, 
saw-like margin-ora serrata; (4) by the continuation forward on the ciliary processes and 
iris as black pigment cells, called respectively pars ciliaris retinee and pars iridica retinse. 
Choroid. Identify (1) by the dark-brown color and the great vascularity ; (2) by the loca- 
tion between the retina and slerotica; (3) by the continuation forward as ciliary processes and 
iris ; (4) by investing the posterior five-sixths of the eyeball and ending near the ora serrata 
of the retina in the ciliary processes (plicse ciliares). 
Ciliary Processes (about seventy in number). Identify (1) as a rich, brown, circular, plaited 
frill around and resting on the circumference of the lens; (2) by the continuity with the iris 
in front, with the choroid behind, as indistinct folds (plicae ciliares) in the region of the ora 
serrata of the retina; (3) by interdigitation of its folds with those of the suspensory ligament 
of the lens. (Note. - When the vitreous is turned out a pigment impress around the lens-cup 
in the vitreous humor will show this interdigitation.) 
Iris. Identify on the living (1) as a thin, circular, multicolored, contractile curtain sur- 
rounding the pupil and suspended in the aqueous humor between the cornea and the lens; 
(2) by the continuity of the circumference with the ciliary body and the connection with the 
posterior elastic lamina of the cornea by the pectinate ligament (ligamentum pectinatum); 
(3) by the presence on the anterior surface of lines converging toward the pupil; (4) by the 
deep purplish tint of the posterior surface, due to the pigmented epithelium of the pars 
iridica retinae. 
Ciliary Muscle. Identify (1) by the location on the outer surface of the forepart of the 
choroid near the junction of the cornea and sclerotica; (2) by the grayish, semitransparent 
appearance, and being one-eighth inch broad; (3) by the origin from the sclerocorneal junc- 
tion and ligamentum pectinatum iridis; (4) by the backward direction and insertion into the 
choroid opposite the ciliary processes. 
Crystalline Lens. Identify (1) by the location behind the pupil (in contact with the free 
margin of the iris) and in the fossa patellaris of the vitreous body; (2) by the circumference 94 
A MANUAL OF DISSECTION. 
being surrounded and partly overlapped by the ciliary processes ; (3) by the convex anterior and 
posterior surfaces; (4) by being retained in position chiefly by a suspensory ligament derived 
from the hyaloid investment of the vitreous body. 
Aqueous Humor. Identify by the location in the anterior and posterior chambers, commu- 
nicating through the pupil. 
Ciliary Nerves. Identify (1) by the location in the delicate connective tissue (lamina 
fusca) between the sclerotic and choroid coats, or in the.small grooves on the inner surface of 
the sclerotica; (2) by the derivation from the ciliary ganglion and nasal nerve; (3) by the 
distribution to the ciliary muscle, iris, and cornea; (4) by being accompanied by long and 
short ciliary arteries. 
Fig. 51. 
A horizontal section of the eyeball. (Gray.) 
Sclerotic Coat. Identify (1) as a white, tough, fibrous structure covering the posterior 
five-sixths of the globe; (2) by the insertions of the tendons of the four recti and two oblique 
muscles ; (3) by the perforations for the optic and ciliary nerves, and ciliary vessels ; (4) by 
the relation internally with the lamina fusca, a delicate connective tissue containing long and 
short ciliary vessels and nerves, and binding the sclerotic coat to the choroid ; (5) by the rela- 
tion with the cornea in front. 
Cornea. Identify (1) as a brilliant, translucent coat forming the anterior sixth of the 
globe; (2) by the relation marginally with the sclerotic coat; (3) by contact of the posterior 
surface with the aqueous humor of the eye in the anterior chamber. CHAPTER VI. 
THE ORGANS OF HEARING. 
These consist of (a) the auricle, or external ear ; (6) the external auditory 
canal; (c) the middle ear, or tympanum; (cZ) the Eustachian tube ; (e) the 
internal ear, or labyrinth. 
Dissection and Identification. After the parts of the external ear have been learned, 
remove integument and study the cartilages. Cut through the lobule one-half inch from the 
end, and lastly, trace out the arteries and nerves. 
The External Ear, for purposes of dissecting-room study, presents the following points for 
identification. Here, as in many other regions, but little cutting is necessary: 
Pinna (auricle). Identify (1) by its location on the side of the head leading into the middle 
ear through the external auditory canal; (2) by the irregularly concave interior and uneven 
oval form ; (3) by the composition: skin, connective tissue, and yellow fibrocartilage. 
Helix. Identify (1) as a folded, circumferential border; (2) by its great prominence and 
graceful curve. 
Antihelix. Identify (1) by its location in front of and parallel with helix ; (2) by the presence 
of a depression between this and the helix; (3) by its bifurcation above to enclose a triangular 
fossa. 
Fig. 52. 
The pinna, or auricle. Outer surfaces. (Gray.) 
Fossa of Helix. Identify (1) by its location between the helix and the antihelix; (2) as a 
narrow, curved depression. 
Fossa of Antihelix. Identify by its location near the upper and inner part of the auricle, 
in the bifurcation of the antihelix. 
Concha. Identify by its location as the capacious cavity in the concavity of the antihelix. 
Commencement of the helix divides the concha into an upper part (cymba conchae) and a 
lower part (cavum conchae). 
Tragus. Identify (1) by its location in front of the concha and backward projection over 
the external auditory meatus; (2) by the tuft of hair on its under surface, resembling a goat's 
beard ; hence the name. 
Antitragus. Identify (1) by its location opposite the tragus; (2) by the presence between 
this and the tragus of a deep notch-incisura intertragica. 
Incisura Intertragica. Identify (1) as a deep notch between the tragus and antitragus; 
(2) by its course leading into the concha and the external auditory canal. 96 
A MANUAL OF DISSECTION. 
Lobule. Identify (1) by its location at the lowest part of the auricle; (2) by the absence 
of firmness and elasticity; (3) by its composition of areolar and adipose tissue and a great 
tendency to enlarge with age. 
External Auditory Meatus. Identify (1) by its location, extending from the bottom of the 
concha to the membrana tympani; (2) by the length (one and a quarter inch) measured from 
the tragus; (3) by its oval cylindrical form and S-shaped canal which it forms; (4) by its 
composition: bone cartilage and skin. 
Muscles. The muscles of the external ear are nine in number. They are quite 
small and unimportant in man. For details the student is referred to Gray's 
Anatomy. 
Arteries. The arteries of the external ear are (a) posterior auricular, from the 
external carotid ; (6) anterior auricular, a branch of the temporal ; (c) the auricular 
branch of the occipital. These are small, but may be seen in well-injected mate- 
rial. Each artery is surrounded by sympathetic nerves and accompanied by cor- 
responding veins. 
Nerves. 1. The facial supplies the muscles of the external ear through its tem- 
poral and auricular branches. 2. The auricularis magnus (second and third of 
cervical plexus) supplies the skin of back of pinna and communicates with auric- 
ular branches of seventh and tenth. 3. The auricularis minor (second of cervical 
plexus) supplies skin of upper and back part of external ear. 4. The occipitalis 
major (internal branch of posterior primary division of second cervical nerve) 
supplies skin of back part of external ear. 5. Arnold's nerve (auricular branch 
of vagus) supplies (a) posterior part of auditory canal ; (6) skin of back part of 
pinna. 6. The auriculotemporal (from third division of trifacial) supplies front 
of the upper part of the pinna. 
THE TYMPANUM, OR MIDDLE EAR. 
The following five structures should be identified before any attempt is made to 
dissect this region : 
The Petrosa. Identify (1) by its great size and its location between the middle and pos- 
terior fosste at base of the skull; (2) by meeting of its anterior and posterior surfaces at the 
superior border of the petrosa. 
Internal Auditory Meatus. Identify (1) by its location near the middle of the posterior 
surface of the petrosa; (2) by the size of the opening (one-fourth inch in diameter) and very 
smooth edges; (3) by the contained structures-seventh nerve, eighth nerve, and auditory 
artery. 
Carotid Canal. Identify (1) by its location near apex of the petrosa and appearing on its 
anterior surface; (2) by the presence of the internal carotid artery (as large as a lead-pencil) 
in its canal. 
Hiatus Fallopii. Identify (1) by its location near the middle of the anterior surface of the 
petrosa, about one-half an inch external to the carotid canal; (2) by its very small size and 
oblique direction ; (3) by the emergence of a nerve (great superficial petrosal). 
Tegmen Tympani. Identify (1) by its location on the anterior surface of the petrosa near 
the anterior border; (2) by its very frail, thin structure, and being the only part of this sur- 
face that yields to gentle tapping. 
Dissection. Remove the tegmen, or roof, of the middle ear by gentle use of a chisel, taking 
care not to injure the petrosal nerves on the anterior surface of the petrosa. Now study in 
situ the following structures, preferably with a reading-glass: (a) the bones of the tympanum ; 
(i) the chorda tympani nerve crossing the upper segment of the membrana tympani; (n) the 
membrana tympani forming the greater part of the outer wall of the middle ear; (d) the 
seventh nerve in the aquaeductus Fallopii; (e) the opening in the posterior wall leading into 
the mastoid antrum, and the opening for the Eustachian tube in the anterior wall. 
The tympanum is about one-half inch in height and one-sixth in width. It 
is prolonged forward as Eustachian tube, backward as mastoid antrum, and its 
length is, for practical purposes, one-half inch. The subdivisions are attic and 
tympanic cavity proper. The latter is quite narrow, and has the membrana tym- 
pani, or drum, as its outer wall. The former is broader, contains most of the 
bones of hearing, and has a part of the temporal bone as its outer wall. The 
tympanum is not horizontal, but its anterior end, as previously stated, slopes THE ORGANS OF HEARING 
97 
downward, forward, and inward to the Eustachian tube; its posterior end upward, 
backward, and outward to the mastoid antrum. 
The Roof is a thin plate of bone (tegmen tympani) separating the tympanum 
from the middle fossa at the base of the skull. It contains the foramina that 
transmit the petrosal branches of the seventh nerve. 
The Floor separates the tympanum from the jugular fossa, in which are the in- 
ternal jugular vein, and the ninth, tenth, and eleventh cranial nerves. In this 
floor is an aperture through which Jacobson's nerve (tympanic branch of the 
glossopharyngeal) passes to form the tympanic plexus. 
The Outer Wall is formed by the drum below and squamosa above, these two 
structures corresponding to the tympanum proper and attic, respectively. Open- 
ings : the iter chordae posterius, by which the chorda tympani nerve, a branch 
of the seventh cranial, enters the tympanum; the iter chordae anterius, by which 
the chorda tympani leaves the tympanum; Glaserian fissure, through which passes 
the tympanic branch of the internal maxillary artery; the processus gracilis of 
the malleus and the laxator tympani muscle. 
The Inner Wall contains (1) a ridge of bone covering the seventh nerve in its 
passage through the tympanum ; (2) the fenestra ovalis leading into the vestibule, 
and to which is attached the base of the stapes by a periosteal membrane; (3) the 
Fig. 53. 
View of inner wall of tympanum, enlarged. (Gkay.) 
promontory formed by a turn of the cochlea, covered by the tympanic plexus and 
located below and in front of the fenestra ovalis; (4) the fenestra rotunda 
(covered by the membrana secundaria) communicating with the scala tympani of 
the cochlea ; (5) the pyramid, from whose summit emerges the tendon of the 
stapedius. A branch of the seventh nerve pierces the pyramid for supply of the 
stapedius muscle. 
The Posterior Wall communicates with the mastoid antrum through one large 
and several small openings. As indicated in a previous paragraph, the mastoid 
antrum is the backward continuation of the attic or upper part of the tympanic 
cavity. 
The Anterior Wall presents for examination the canalis musculo-tubarius. This 
canal is divided into an upper and a lower compartment by a horizontal lamina 
of bone-the processus cochleariformis. The upper compartment lodges the 
tensor tympani muscle ; the lower is the osseous part of the Eustachian tube. 
Contents : the tympanum contains (1) a chain of small bones extending from 
the drum to the fenestra ovalis ; (2) the chorda tympani nerve, a branch of the 
facial; (3) mucous membrane, continuous in front with that of the Eustachian 
tube and behind with that of the mastoid antrum ; (4) nerves and vessels; (5) the 
facial nerve in a bony canal, the aquseductus Fallopii. 98 
71 MANUAL OF DISSECTION. 
Course of Facial Nerve. 1. Nerve enters the internal auditory canal with the 
auditory nerve and auditory artery-a branch of the basilar. 2. Nerve passes 
into aquseductus Fallopii, or facial canal, through an opening in anterior superior 
cribriform area of lamina cribrosa, or fundus of auditory canal. 3. Nerve 
develops ganglion (intumescentia gangliformis) and makes a bend outward and 
backward along inner wall of tympanum. 4. Nerve makes bend downward 
between inner and posterior walls of tympanum and passes vertically downward 
through the petrosa and emerges through the stylomastoid foramen. 
Branches of Facial Nerve in the course through the petrosa. From the geniculate 
ganglion (1) the large superficial petrosal, to Meckel's ganglion; (2) the small, 
superficial petrosal, to the otic ganglion ; (3) the external, superficial petrosal, to 
Fig. 54. 
The tympanum or middle represented as a box, with roof, floor, outer and inner walls, anterior and posterior ends. 
The seventh or facial nerve passes in its bony canal along the inner and posterior walls. 
a. First division of the fifth nerve, b. Second division of the fifth nerve, c. Third division of the fifth nerve. 
d. Gasserian ganglion, e. Small petrosal, f. Great petrosal, g. Eustachian tube. h. Fenestrse ovale and rotunda. 
i. Facial nerve, j. Floor, k. Middle meningeal artery. I. External petrosal, m. Anterior wall. n. Outer wall 
(drum), o. Canal for Jacobson's nerve. 
the sympathetic on the middle meningeal artery ; (4) communicating, to auricular 
branch of the vagus (Arnold's) ; (5) the tympanic, to the stapedius muscle; (6) 
the chorda tympani, to the submaxillary and sublingual glands, and anterior two- 
thirds of tongue. 
The accompanying illustration will aid the memory in fixing the location of 
roof, floor, and walls of the tympanum and their most important points of interest. 
The right tympanum is represented by a box, viewed from above and behind. 
The front of the box, with an aperture divided into two parts, represents the an- 
terior wall of the tympanum, with the canal occupied by the tensor tympani 
above and Eustachian tube below. The rear end of the box represents the pos- THE ORGANS OF HEARING. 
99 
terior wall of the tympanum, with an opening into the mastoid antrum. The 
outer wall of the box represents the external wall of the tympanum, formed by 
the membrana tympani. The inner wall represents the internal wall of the tym- 
panum, in which are the fenestrse ovalis and rotunda. The floor of the box 
represents the floor of the tympanum, in which is Jacobson's canal, giving pas- 
sage to the tympanic branch of the glossopharyngeal nerve (Jacobson's). The 
facial nerve passes backward between inner wall and roof, then downward, 
between inner and posterior walls. 
Relations. (1) The temporosphenoidal lobe of the brain lies on its roof ; (2) the 
floor of the tympanum lies on the jugular fossa ; (3) the drum of ear and chorda 
tympani are on external wall ; (4) the mastoid antrum and cells are behind ; (5) 
the internal carotid artery is in front; (6) the facial nerve skirts two sides; (7) 
the internal ear is in close relation. 
Clinical Imparlance. (1) The drum of the ear may become ruptured; (2) the 
interossicular joints may become ankylosed; (3) pus may form in tympanum; 
(4) in suppuration of the middle ear, the nerve of Jacobson and the chorda 
tympani are liable to damage. They are, according to Gowers, the two chief 
paths of taste-fibres. 
Ossicles of Tympanum. There are three bones forming a movable chain between 
membrana tympani and fenestra ovalis (malleus, incus, and stapes). The malleus 
consists of (1) an oval head articulating with the incus ; (2) a neck ; (3) a manu- 
brium, giving attachment to the tensor tympani muscle ; (4) a short process in 
contact with the membrana tympani ; (5) a processus gracilis, lodged in Glaserian 
fissure and giving attachment to laxator tympani. The incus or anvil has (1) a 
body articulating with the malleus ; (2) a long process terminating in the os orbic- 
ulare, which articulates with the head of the stapes ; (3) a short process attached 
to the margin of the opening into the mastoid cells. The stapes or stirrup has 
(1) a head, articulating with the os orbiculare; (2) a neck, receiving insertion of 
the stapedius ; (3) two branches or crura joining the base, which is connected with 
the margins of the fenestra ovalis. 
Muscles of the Tympanum. 1. Tensor tympani, arising from (a) under surface 
of petrosa; (6) cartilage and bone of Eustachian tube and inserted into handle of 
malleus near root. Its nerve is from the otic ganglion, and by drawing down in- 
ward it increases tension thereof and makes hearing more acute. 2. Laxator 
tympani (anterior ligament of malleus) arises from (a) spine of sphenoid ; (6) car- 
tilage of Eustachian tube, and is inserted into neck of malleus above processus 
gracilis. Its nerve is from the facial (tympanic branch), and its action is to relax 
the drum. 3. Stapedius. Origin: Interior of pyramid on inner wall of tympanum. 
Insertion: Neck of stapes. Nerve: Facial. Action: To compress fluid contents 
of vestibule. 
Nerves of Tympanum. 1. Jacobson's (tympanic branch of glossopharyngeal J 
passes through floor of tympanum and forms tympanic plexus on promontory 
of inner wall. 2. Small, deep petrosal, a branch of tympanic plexus, passes to 
carotid plexus of the sympathetic. 3. Small superficial petrosal, a branch of the 
geniculate ganglion, is joined by twig of tympanic plexus for supply of parotid 
gland. 4. Tympanic plexus. (See Jacobson's nerve.) 5. Facial nerve, passes 
through tympanum beneath a ridge of bone along inner and posterior walls. 
6. Chorda tympani, a branch of the facial, crosses drum of ear between handle of 
malleus and long process of incus. 7. The nerve (a branch of the facial) to the 
stapedius muscle passes through a small canal connecting the aquseductus Fallopii 
and the interior of the pyramid. 
Arteries of the Tympanum. 1. Tympanic branch of internal maxillary, passes 
through Glaserian fissure and supplies the mucous membrane. 2. Stylomastoid 
branch of posterior auricular enters through stylomastoid foramen and facial 
canal and supplies (a) mastoid cells ; (6) back part of tympanum. 3. Petrosal 
branch of middle meningeal artery, enters through hiatus Fallopii, and supplies 
petrosa, geniculate ganglion, seventh and petrosal nerves. 4. Tympanic branch 100 
A MANUAL OF DISSECTION. 
of internal carotid artery, pierces anterior wall and supplies raucous membrane. 
5. Tympanic branch of ascending pharyngeal artery enters through Eustachian 
tube. 6. Tympanic branch of Vidian passes through Eustachian tube. 
EUSTACHIAN TUBE. 
Dimensions. The Eustachian tube is an inch and a half long and extends 
downward, forward, and inward from the anterior wall of the tympanum to the 
pharynx. The narrowest part is in the middle, and here its walls are in con- 
tact. The anterior part is fibrocartilaginous, the posterior part osseous. 
Fig. 55. 
Eustachian tube, laid open by a cut in its long axis. (Gerrish after Testut.) 
The cartilaginous end is about one inch long and passes between the origins of 
the levator and tensor palati, giving attachment to some fibres of these muscles. 
It is situated in a groove between the petrosa and greater wing of the sphenoid. 
The pharyngeal opening is a vertical slit one-half inch long and on a line poste- 
riorly with the inferior turbinated bone. 
The bony part of the Eustachian tube is about one-half inch long and con- 
tinuous with the anterior part of the tympanum. It is lined by mucous mem- 
brane continuous with that of the pharynx and middle ear. 
INTERNAL EAR; LABYRINTH. 
The study of the labyrinth includes (1) the fundus of the internal auditory 
canal; (2) the vestibule; (3) the semicircular canals; (4) the cochlea; (5) the 
membranous labyrinth; (6) the vestibular and spiral ganglia of the auditory 
nerve ; (7) the primitive otic vesical, its secretory and neuro-epithelia. No one 
should attempt a dissection of this region until he has made himself thoroughly 
familiar with the brief outline here given and the embryology of the labyrinth. 
Dissection. Study carefufiy the internal ear in the following table and in Gray's Anatomy. 
Then immerse temporal bone (recent) in dilute muriatic acid for forty-eight hours, after which 
time the soft structures may be very satisfactorily studied with a dissecting microscope. THE ORGANS OF HEARING. 
101 
Fig. 56. 
Diagrammatic view of the fundus of the internal auditory meatus (Testut): 1. Falciform crest. 2. Anterior 
superior cribriform area. 2'. Internal opening of the aquaeductus Fallopii. 8. Vertical crest which separates the 
anterior and posterior superior cribriform areas. 4. Posterior superior cribriform area, with (4'1 openings for nerve- 
fllaments. 5. Anterior inferior cribriform area. 5'. Spirally arranged, sieve-like openings for the nerves to the 
cochlea. 5". Opening of the central canal of the cochlea. 6. Crest which separates the anterior and posterior in- 
ferior cribriform areas. 7. Posterior inferior cribriform area. 7'. Orifices for the branches of the nerve to the saccule. 
8. Foramen singulare of Morgagni, with the anterior portion of the canal which gives passage to the nerve to the 
posterior semicircular canal. (Gray.) 
LAMINA CRIBROSA. 
Fundus of the Internal Auditory Canal; Lamina Cribrosa. The lamina cribrosa 
has three crests which divide its surface into four perforated areas. The crests are 
called falciform, superior vertical and inferior vertical. The perforated areas 
are called anterior superior, posterior superior, anterior inferior, posterior inferior. 
These cribriform or perforated areas transmit the facial and auditory nerves to 
their respective canals in the petrous part of the temporal bone. 
Falciform Crest; Crista Falciformis. Located horizontally across lamina crib- 
rosa, dividing this into a superior and an inferior cribriform area. 
Superior Vertical Crest; Crista Verticalis Superior. Located vertically on lamina 
cribrosa, dividing superior cribriform area into anterior and posterior cribriform 
areas. 
Inferior Vertical Crest; Crista Verticalis Inferior. Located vertically on lamina 
cribrosa, dividing inferior cribriform area into anterior and posterior cribriform 
areas. 
The Aquseductus Fallopii, Commencement of, in Anterior Superior Cribriform Area, 
is located in the anterior and upper part of the lamina cribrosa, for the transmission 
of the facial nerve. The aquseductus Fallopii ends at the stylomastoid foramen, 
having made a tortuous course through the petrosa. 
The Area Cribrosa Superior (in posterior superior cribriform area) is located in the 
upper and back parts of lamina cribrosa behind beginning of aqmeductus Fallopii. 
This perforated space transmits filaments of auditory nerve to macula acustica of 
utricle and to cristse acusticse of superior and inferior semicircular canals. 
The Area Cribrosa Media (in posterior inferior cribriform area) is located below 
posterior part of falciform crest. It transmits filaments of auditory nerve to 
macula acustica of saccule. 
The Foramen Singulare (in the posterior inferior cribriform area) is located be- 
low and posterior to area cribrosa media. It transmits filaments of auditory 
nerve to crista acustica of posterior semicircular canal. 
The Tractus Spiralis Foraminosus (in the anterior inferior cribriform area) is 
located in anterior and lower part of lamina cribrosa, and consists of spirally 
arranged openings which end in central canal of cochlea and transmit the auditory 
nerve. 102 
A MANUAL OF DISSECTION. 
THE VESTIBULE. 
The Vestibule is located on the inner side of tympanum, behind cochlea and in 
front of semicircular canals. It is about one-fifth inch in diameter and has the 
following points of importance : 
The Fenestra Ovalis. Covered by base of stapes and its annular ligament. It 
separates tympanum from scala vestibuli of cochlea. 
Fovea Hemispherica ; Recessus Sphericus. Inner wall of vestibule (a depression). 
It is perforated in front and below by numerous foramina for branches of auditory 
nerve to saccule. 
The Macula Cribrosa. Anterior and inferior parts of fovea hemispherica. It 
consists of foramina transmitting branches of auditory nerve to saccule. 
The Crista Vestibuli is a vertical ridge located behind macula cribrosa and fovea 
hemispherica. It bifurcates to form the fossa cochlearis. 
The Fossa Cochlearis is embraced by bifurcation of crista vestibuli. It is per- 
forated by foramina for passage of filaments of auditory nerve to posterior end of 
cochlear duct. 
The Aquaeductus Vestibuli. Hind part of inner wall of vestibule. It extends to 
posterior surface of petrous part of temporal bone, and transmits a small vein and 
ductus endolymphaticus. Ductus endolymphaticus ends in cul-de sac between 
layers of dura mater. 
The Semicircular Canals, Openings of, is posterior wall of vestibule. They are 
five in number. Each canal has a dilated end, the ampulla. 
Fovea Semi-elliptica. Upper wall of vestibule separated from fovea hemispherica 
by crista vestibuli. It lodges the utricle of the membranous labyrinth. 
The Apertura Scalae Vestibuli Cochleae. Front wall of vestibule, an elliptical 
opening. It communicates with scala vestibuli of cochlea. 
The Semicircular Canals are three bony tables-superior, external, and posterior- 
each describing more than a half-circle and lying at right angles to the other two 
canals. Each presents atone end a dilatation called an ampulla, twice the diameter 
of the canal. The superior semicircular canal is vertical and forms a prominence 
on anterior surface of petrosa, and has an outer and an inner end. The outer end 
opens separately, the inner conjointly with that of posterior semicircular canal into 
vestibule. The posterior canal is parallel to posterior surface of petrosa, and its 
dilated extremity opens into back part of vestibule. The external canal is the 
shortest and opens into vestibule above fenestra ovalis and by a separate orifice 
into back part of vestibule. The semicircular canals are occupied by the mem- 
branous semicircular canals containing endolymph, and between them and bony 
canals in which they are contained is the perilymphatic space containing perilymph. 
The Cochlea is conical and located in front of vestibule. Apex looks forward, 
outward, and downward in front of inner wall of tympanum. Base corresponds 
with anterior depression at bottom of internal auditory canal, and has foramina 
for cochlear branch of auditory nerve. 
The Modiolus, or Columella, is the conical central axis or pillar of cochlea extend- 
ing from base to apex of same, perforated by cochlear nerves, which form the 
ganglion spirale in attached margin of lamina spiralis ossea. 
The Tractus Spinalis Foraminosus is located in the cochlear area (anterior inferior 
cribriform area) at bottom of internal auditory canal, corresponding to base of 
modiolus. Nerves traversing tractus pass through canals in modiolus, and, bend- 
ing outward, reach attached margin of lamina spiralis ossea, where ganglion spirale 
is developed. 
The Canalis Spiralis Modioli is a spiral canal in attached margin of lamina spi- 
ralis area, lodging ganglion spirale, the true origin of the cochlear nerve. 
The Central Canal of Modiolus extends from base to apex of modiolus, trans- 
mitting branches of cochlear division of auditory nerve to apical coil of scala 
media. THE ORGANS OF HEARING. 
103 
The Cupola, Cul-de-sac, is termination of bony canal of cochlea after two turns 
and three quarters around modiolus. It forms apex of bony cochlea. 
The Bony Canal of Cochlea is a little over one inch long, one-tenth inch in diameter 
at commencement, and becomes progressively smaller from base to apex of cochlea. 
The Fenestra Rotunda is covered by the membrana tympani secundaria ; it 
separates tympanum and scala tympani of bone cochlea. 
The Apertura Scalae Vestibuli Cochleae is front wall of vestibule, and communi- 
cates with scala vestibuli of cochlea. 
The Membrana Tympani Secundaria is a membrane covering fenestra rotunda and 
separating scala tympani of cochlea and tympanum. 
The Aquseductus Cochlea is an aperture leading from cochlea to inferior surface 
of petrosa, transmitting a small vein and forming a communication between sub- 
arachnoid space of skull and perilymph in scala tympani of cochlea. 
The Lamina Spiralis Ossea is a bony shelf projecting outward from modiolus into 
interior of spiral canal, making two and three-quarter turns about modiolus. 
The Scala Vestibuli is the upper and smaller of two perilymph spaces of cochlea. 
It communicates above with scala tympani through helicotrema, below with vesti- 
bule. 
The Scala Tympani is the lower and larger of the two perilymph spaces in the 
cochlea. It communicates above with scala vestibuli through helicotrema and 
below with tympanum, but for membrane covering fenestra rotunda. 
Fig. 57. 
Membranous labyrinth of the right ear, viewed from the right side. (Gerrish after Testut.) 
The Helicotrema is a small opening near summit of cochlea, through which scalae 
vestibuli and tympani communicate. 
The Lamina Spiralis Secundaria is a bony lamina projecting inward from outer 
wall in lower part of first turn of bony canal of cochlea. 
Fissura Vestibuli is a narrow fissure between primary lamina spiralis ossea and 
lamina spiralis secundaria. 
The Membranous Labyrinth is the oldest part of the organs of hearing, originating 
from ectoderm on dorsolateral surface of head region of embryo, near dorsal end 
of first outer visceral cleft. The thickened patch of ectoderm becomes an auditory 
pit ; edges of auditory pit meet and form otic vesicle. The vesicle recedes from 
ectodermic surface and takes position near after-brain in relation with and behind 
acustico-facial ganglion. From primitive vesicle is evolved the entire complex 
membranous labyrinth, the endolymph and organ of Corti. These are represented 
in the adult by endothelium of membranous labyrinth, neuro-epithelial cells, and 
endolymph. 
The Utricle (Utriculus) is the upper and larger of the two parts formed by con- 
striction of otic vesicle. It communicates with semicircular canals directly and 
with the saccule indirectly through ductus endolymphaticus. The macula acustica 
has same significance here as in the saccule. 104 
A MANUAL OF DISSECTION. 
The Semicircular Canals (membranous) are three in number and correspond to the 
osseous canals in which located, except in size. They open by five orifices into 
the utricle. Each membranous canal is about one-third the diameter of the 
osseous canal, and has at one end an enlargement-the ampulla. The walls of 
ampullae are thickened in middle, forming the septum transversum. The lining 
of ampullae is specialized neuro-epithelial cells (cristae acusticae), and receives a 
partial distribution of auditory nerve. 
The Sacculus is the lower and smaller of the two parts into which the otic vesicle 
divides. It communicates with cochlear duct through canalis reunions and with 
utricle through ductus endolymphaticus. The macula acustica is composed of 
highly specialized neuro-epithelial cells (of ectodermic origin), and is located where 
branches of eighth nerve enter saccule to arborize around its hair cells. • 
The Cochlear Duct, Scala Media. That part of membranous labyrinth contained 
in bony cochlea is scala media. It communicates with saccule through canalis 
reuniens. Its interior is an endolymph space like that of utricle, saccule, and 
semicircular canals. The scala media is between two perilymph spaces-the scala 
vestibuli and the scala tympani. 
The Endolymph Spaces and Endolymph. They are the following, and are all 
derived from an original otic vesicle of ectodermic origin : (1) Scala media, or 
cochlear duct in the bony cochlea ; (2) saccule and utricle in bony vestibule ; (3) 
membranous semicircular canals in the osseous semicircular canals. They all 
contain a fluid called endolymph. 
The Perilymph Spaces and Perilymph. These are between the membranous and 
osseous labyrinths, and are named as follows : (1) The scala vestibuli and scala 
tympani are in the bony cochlea with the scala media ; (2) all spaces in vestibule 
and bony semicircular canals external to membranous labyrinth. 
GANGLIA OF AUDITORY NERVE. 
The Ganglion Spirale (on the cochlear division of the eighth nerve). This occu- 
pies spiral canal of modiolus, and is made up of bipolar cells, which constitute the 
true origin of the cochlear division of the auditory nerve. These cells, by their 
dendrites, are in relation peripherally with specialized neuro-epithelial cells of the 
organ of Corti ; centrally, axonic processes reach auditory nucleus in medulla. 
Ganglion of Scarpa; Vestibular Ganglion; Intumescentia Gangliformis. This is 
composed of cells forming the true origin of the vestibular division of the eighth 
nerve. It lies on vestibular nerve in internal auditory canal. Its cells are in 
relation with neuro-epithelial cells of utricle, saccule, and ampullae of semicircular 
canals. Axonic processes reach vestibular origin of auditory nerve in medulla. 
OTIC VESICLE AND NEURO-EPITHELIA. 
Cells of Otic Vesicle. The majority are arranged as flattened, polyhedral, serous 
cells in a single layer, forming secretory and protective structures. Some, 
however, are specialized neuro-epithelial cells, as follows, and form the cristae 
acusticae in the semicircular canals, the maculae acusticae in the utricle and sac- 
cule and the organ of Corti in the scala media. 
The Neuro-epithelia. These cells are found on floor of scala media (membrana 
basilaris), forming organ of Corti ; in utricle, forming macula acustica ; in sac- 
cule, forming macula acustica ; in ampullated ends of semicircular canals, form- 
ing cristae acusticae. These cells form peripheral end organs in the mechanism of 
hearing. Impulses originate in rods and hair cells of Corti, are transmitted by 
dendrites to spiral and vestibular ganglia, thence by axonic processes to nucleus of 
eighth nerve in medulla. THE ORGANS OF HEARING. 
105 
The Macula Acustica of Utricle, A specialization of neuro-epithelial cells 
marking place where branches of eighth nerve enter utricle to arborize around its 
cells. 
The Macula Acustica of Saccule. An area of neuro-epithelial cells where 
branches of auditory nerve enter saccule to arborize around its cells. 
The Cristse Acusticae. An area of neuro-epithelial cells where branches of 
auditory nerve enter ampullae of semicircular canals to arborize around its cells. 
The Organ of Corti, the most highly specialized neuro-epithelial area, is located 
on floor of scala media, and is the most important part concerned in hearing. 
(See Gray and Gerrish.) 
The internal ear (labyrinth) is where the end organs of hearing are located. 
The sensitive agents concerned, as previously stated, are neuro-epithelial cells of 
ectodermic origin, derived from the lining of the primitive otic vesicle. Dendritic 
processes from these several sensitive areas in utricle, saccule, semicircular canals 
and scala media reach the spiral and vestibular ganglia, whence axons of cells 
located in these ganglia proceed to the nuclei of the auditory nerve in the medulla. CHAPTER VII. 
THE NECK. 
Dissection and Identification. Remove the integument according to the incisions indicated 
in Fig. 1. Then consult the illustrations and find the structures on the cadaver corresponding 
thereto in the order in which they are here given. The scalpel should be sparingly used after 
the skin has been removed. Blunt dissecting with forceps attains far better results. 
Fig. 58. 
Veins of the head and neck. (Gray.) 
Superficial Fascia. Identify (1) as a thin, fatty layer, especially pronounced in the upper 
part of the neqk, where it forms the double chin ; (2) by the location between the platysma 
myoides muscle and the integument; (3) by containing the platysma myoides, superficial 
jugular veins, and the superficial branches of the cervical plexus. 
Platysma Myoides Muscle. Identify (1) by the location beneath the skin in the deep part 
of the superficial fascia; (2) by composition of muscular fibres extending from the region THE NECK. 
107 
of the clavicle to the lower jaw. Detach the muscle along the mandible and turn it aside 
to expose the jugular veins. 
Anterior Jugular Vein. Identify (1) by the location in the superficial fascia in front of 
the sternocleidomastoid muscle beneath the platysma; (2) by the origin from small veins in 
the submaxillary region. 
Posterior Jugular Vein. Identify (1) by the location behind the sternocleidomastoid 
muscle; (2) by the origin in the occipital region; (3) by ending in the external jugular 
beneath the platysma. 
External Jugular Vein. Identify (1) by the vertical course from the parotid region to the 
clavicle, crossing some of the superficial branches of the cervical plexus ; (2) by the course 
across the sternocleidomastoid muscle from before backward ; (3) by ending in the subclavian 
vein anterior or posterior to the scalenus anticus muscle. 
Superficialis Colli Nerve. Identify (1) by the course across the centre of the sternocleido- 
mastoid muscle and the distribution to the skin of the front and sides of the neck ; (2) by the 
location beneath the external jugular vein; (3) by consulting the illustration of the super- 
ficial branches of the cervical plexus; (4) by the derivation from the cervical plexus and the 
emergence behind the sternomastoid. 
Auricularis Magnus Nerve. Identify (1) by the course upward and forward across the 
sternocleidomastoid muscle and the distribution to the skin in the parotid region ; (2) by the 
derivation from the cervical plexus and the emergence at the posterior margin of the sterno- 
mastoid muscle. 
Lesser Occipital. Identify (1) by the location behind the sternomastoid and the distribu- 
tion to the ear and the side of the head; (2) by the derivation from the cervical plexus. 
Small Occipital Nerve. Identify (1) by the location along the posterior margin of the 
sternomastoid muscle and the distribution to the skin covering the mastoid process. 
Supraclavicular Nerve. Identify (1) by the location along the posterior margin of the 
sternomastoid muscle; (2) by the course across the clavicle and the distribution to the skin 
covering the pectoralis major muscle; (3) by the derivation from the cervical plexus with the 
suprasternal nerve. 
Suprasternal Nerve. Identify (1) by the location along the posterior border of the sterno- 
mastoid and the derivation from the cervical plexus with the supraclavicular; (2) by the 
course across the sternomastoid and the distribution to the skin covering the manubrium of 
the sternum. 
Supra-acromial Nerve. Identify (1) by the location behind the sternomastoid and the 
derivation from the cervical plexus; (2) by the course across the acromion process to the 
integument in this region. 
Deep Cervical Fascia. Identify (1) by the location immediately beneath the superficial 
fascia, forming an investment for the entire neck; (2) by forming the sheaths for all vessels, 
glands, and muscles of the neck. Study the description of the deep cervical fascia with its 
superior and inferior attachments on page 123. 
Sternum. Identify (1) by the location in the mid-line of the anterior thoracic wall; (2) by 
the articulation of the clavicles with its upper piece. 
Clavicle. Identify (1) by the location along the lower border of the neck (forming part 
thereof); (2) by the articulation with the sternum and acromion, forming the sternoclavicular 
and acromioclavicular joints, respectively. 
Mastoid Process. Identity (1) by the location behind and below the ear; (2) by the inser- 
tion of the sternomastoid muscle in part. 
Hyoid Bone. Identify (1) by the location about one inch above Adam's apple (thyroid 
cartilage) and two or three inches below and behind the symphysis menti. 
Sternocleidomastoid Muscle. Identify (1) by the location on the front and side of the neck, 
extending from the sternum and clavicle diagonally across the neck to the mastoid process and 
occipital bone; (2) by the location on its surface of the external jugular vein and the 
branches of the cervical nerves. 
Sternohyoid Muscle. Identify (1) by the extent from the sternum to the body of the 
hyoid; (2) by the location near the mid-line of the neck and the insertion with the omohyoid 
muscle into the hyoid bone. 
Omohyoid Muscle. Identify (1) by the oblique course from the shoulder region to the body 
of the hyoid bone, where it is inserted with the sternohyoid ; (2) by the deep relation with the 
carotid sheath and the location beneath the sternomastoid muscle. 
Sternothyroid Muscle Identify (1) by the extent from the sternum to the thyroid carti- 
lage; (2) by the location beneath the sternohyoid on the thyroid body. The sternothyroid 
must be cut and turned aside to expose this muscle. 
Thyrohyoid Muscle. Identify (1) by the upward continuation of the sternothyroid to the 
body of the hyoid bone; (2) by the location beneath the sternohyoid and omohyoid muscles 
on the superior laryngeal nerve and the thyrohyoid membrane. 
Ansa Hypoglossi. Identify (1) by the location on the carotid sheath and the distri- 
bution to the depressor muscles of the hyoid bone; (2) by the derivation from the hypoglossal 
nerve and cervical plexus through the descendens and communicantes hypoglossi, respec- 
tively. 
Stylohyoid Muscle. Identify (1) by the extent below and behind the jaw from the styloid 
process to the hyoid bone; (2) by being perforated by the intermediary tendon of the 108 
J MANUAL OF DISSECTION. 
digastric muscle; (3) by the location above (and in intimate relation with) the posterior 
bellv of the digastric. 
Mylohyoid Nerve. Identify (1) by the distribution to the mylohyoid muscle and the ante- 
rior belly of the digastric; (2) by the location in the mylohyoid groove of the mandible with 
the mylohyoid artery. 
Hypoglossal Nerve. Identify (1) by the location below the posterior belly of the digastric 
muscle in front of the carotid vessels ; (2) by the course across the hyoglossus and beneath 
the mylohyoid muscle to the tongue. 
Spinal Accessory Nerve. Identify (1) by the location beneath the digastric and stylohyoid 
muscles; (2) by piercing the upper part of the sternomastoid muscle and appearing in the 
occipital triangle; (3) by crossing the occipital triangle and entering the trapezius muscle. 
Fig. 59. 
Nerves of the tongue. (Gerrish after Testut.) 
Facial Artery and Vein. Identify (1) by the location on the mandible in front of the 
masseter muscle, the artery in front of the vein ; (2) by the location in the digastric and supe- 
rior carotid triangles, the vein superficial to the submaxillary gland, stylohyoid, and digastric 
muscles, and hypoglossal nerve ; and the artery beneath these ; (3) the artery, a branch of the 
external carotid ; tbe vein, tributary to the internal jugular in the superior carotid triangle. 
Superior Thyroid Artery and Vein. Identify (1) by the location beneath the depressor 
muscles of the hyoid bone and the distribution to the thyroid gland; (2) artery, the first 
branch of the external carotid; the vein crosses the common carotid artery to reach the 
internal jugular vein; (3) by the location of the artery and vein one-half inch below the 
greater horn of the hyoid bone. THE NECK. 
109 
Lingual Artery and Vein. Identify (1) by the location in the superior carotid and digas- 
tric triangles ; (2) by the course beneath the digastric, stylohyoid, and hyoglossus muscles to the 
tongue; (3) by the origin of the artery from the external carotid; (4) by the termination of 
the vein in the internal jugular; (5) by the location one-half inch above the greater horn of 
the hyoid bone where they pass beneath the hyoglossus muscle. 
Thyroid Body. Identify (1) by the location on the side and front of the larynx and 
adjacent part of the trachea beneath the sternohyoid and sternothyroid muscles; (2) by the 
large size and bluish color. 
Submaxillary Gland. Identify (1) by the location in the submaxillary triangle; (2) by the 
presence of the facial artery on lower surface; (3) by contact of the internal surface with the 
hyoglossus, mylohyoid, and styloglossus muscles. 
Sublingual Gland. Identify (1) by the location immediately beneath the tongue on the 
mylohyoid muscle; (2) by the sublingual ridge, extending outward and backward from the 
fraenum linguae when the tongue is elevated (on the living.) 
Trachea Identify (1) by the continuity with the larynx above and the bronchi below; 
(2) by the relation to the spinal column (from the fifth cervical to the fifth thoracic); (3) by 
its imperfect cartilaginous ring-structure. 
Larynx. Identify (1) by the location below the hyoid bone and above the trachea ; (2) by 
the characteristic prominence produced by the thyroid cartilage-Adam's apple. 
Thyrohyoid Membrane. Identify (1) by the location between the thyroid cartilage and 
the hyoid bone; (2) by the location beneath the sternohyoid and thyrohyoid muscles; (3) by 
being pierced by the superior laryngeal nerve and vessels. 
Line of Carotid Vessels. This line extends from the sternoclavicular joint to a point mid- 
way between the angle of the jaw and the mastoid process. In this line are the carotid 
arteries (common, external, and internal), internal jugular vein, vagus nerve, and the cervical 
sympathetic cord. 
Carotid Sheath. Identify (1) by the location beneath the sternomastoid and omohyoid 
muscles along the neck in the line of the carotid vessels; (2) by the presence of the ansahypo- 
glossal loop on the anterior surface; (3) by the transparent fibrous nature of the structure. 
Internal Jugular Vein. Identify (1) by the location in the carotid sheath external to the 
carotid arteries and vagus nerve; (2) by the union with the subclavian to form the innominate 
vein; (3) by its tributaries-facial, lingual, pharyngeal, occipital, superior and middle thyroid 
veins. (See Dr. Shaw's table of veins.) 
Common Carotid Artery. Identify (1) by the location in the carotid sheath near the 
trachea, internal to the vagus and jugular vein ; (2) by the division into the internal and external 
carotids, opposite the upper margin of the thyroid cartilage; (3) by the origin, on the right side 
from the innominate, on the left from the aortic arch. (See Dr. Shaw's table of arteries.) 
External Carotid Artery. Identify (1) by the extent in the carotid sheath from the bifur- 
cation of the common carotid to a point behind the neck of the mandible; (2) by its branches: 
superior thyroid, lingual, facial, occipital, posterior auricular, internal maxillary, temporal 
and ascending pharyngeal. (See Dr. Shaw's table of arteries.) 
Internal Carotid Artery. Identify (1) by the origin from the common carotid opposite the 
upper border of the thyroid cartilage with the external carotid artery; (2) by the deep loca- 
tion behind the external carotid and absence of branches in the cervical stage. (See Dr. 
Shaw's table of arteries.) 
Pneumogastric or Vagus Nerve. Identify (1) by the location in the carotid sheath between 
the internal jugular vein and carotid artery; (2) by entering the thorax (on the right side) 
between the subclavian artery (which it crosses) and the right innominate vein ; on the left 
side between the common carotid and the subclavian arteries beneath the innominate vein. 
Superior Laryngeal Nerve. Identify (1) by the location beneath the thyrohyoid and 
sternohyoid muscles on the thyrohyoid membrane with the superior laryngeal artery, a branch 
of the superior thyroid ; (2) by perforating the thyrohyoid membrane; (3) by the origin from 
the ganglion of the trunk of the vagus, and the course behind the common carotid artery and 
along the pharynx. 
Right Recurrent Laryngeal Nerve. Identify (1) by the origin from the vagus in front of 
the right subclavian artery; (2) by the course behind the subclavian and common carotid 
arteries to the side of the trachea; (3) by the location in the groove between the trachea and 
oesophagus, and the further course behind the articulation of the inferior horn of the thyroid 
cartilage and the cricoid cartilage to the larynx. 
Left Recurrent Laryngeal Nerve. Identify (1) by the origin from the vagus in front of 
the arch of the aorta; (2) by the course around the aortic arch internal to the ductus arte- 
riosus, and to the groove between the trachea and oeophagus; (3) the further course, the same 
as the right recurrent. 
Phrenic Nerve. Identify (1) by the location on the scalenus anticus muscle; (2) by 
entering the thorax between the subclavian artery and vein internal to the scalenus anticus. 
Glandulae Concatenatse. Identify (1) as the deep cervical lymphatic glands in company 
with the carotid arteries and internal jugular vein; (2) by the extent from the base of the 
skull to the root of the neck, where they enter the mediastinum. 
Cervical Plexus. Identify (1) by the superficial branches in the superficial fascia as pre- 
viously identified. They emerge through the deep fascia along the posterior border of the sterno- 
mastoid muscle; (2) by the location opposite the four upper vertebrse resting on the levator 110 
A MANUAL OF DISSECTION. 
anguli scapulae and scalenus medius muscles; (3) by the location beneath the sternomastoid 
muscle; (4) deep branches are to be identified by making a study of the text and illustrations. 
Scalenus Anticus. Identify (1) by the insertion into the scalene tubercle of the first rib ; 
(2) by the presence of the phrenic nerve and subclavian vein on its anterior surface. 
Scalenus Medius Identify (1) by the insertion into the first rib behind the groove for the 
subclavian artery; (2) by the presence of nerves forming the cervical and brachial plexuses 
on its anterior surface. 
Fig. 60. 
Deep lateral and prevertebral muscles of the neck. (Gerrish after Testut.) 
Scalenus Posticus. Identify (1) by the attachment to the second rib; (2) by attachment to 
the posterior tubercles of the lower three or four cervical vertebrae. 
Brachial Plexus. Identify (1) by the location between the scalenus anticus and medius 
muscles in the subclavian triangle beneath the clavicle and pectoral muscles; (2) turn to the 
" Brachial Plexus" in the text and read carefully. 
MUSCLES OF THE NECK. 
The Platysma Myoides. The platysma myoides is a broad, thin layer of muscular 
fibre in the superficial fascia. It arises a variable distance below the clavicle from 
the deep fascia, covering the deltoid and pectoralis major muscles. The fibres 
extend upward and inward to the corner of the mouth. On the upper boundary 
line of the neck the muscle extends backward to near the angle of the jaw, 
covering the facial vessels. The platysma, acting with the hyoid group of 
muscles, depresses the mandible. Nerve: The facial. THE NECK. 
111 
The Sternocleidomastoid. Location : The neck, extending from the sternum 
and clavicle to the mastoid and occipital. Fascial sheath ; First layer of the deep 
cervical fascia. Origin : (1) Manubrium of the sternum, anterior surface ; (2) 
inner third of the clavicle, anterior surface. Insertion: (1) Mastoid process of 
the temporal bone, anterior border and outer surface ; (2) superior nuchal line of 
the occipital bone, outer third. Nerve-supply: (1) Spinal accessory ; (2) muscular 
branches of the cervical plexus. Blood-supply: (1) Upper mastoid, a branch of 
the occipital artery ; (2) middle mastoid, a branch of the superior thyroid artery; 
(3) lower mastoid artery, a branch of the suprascapular. The occipital and supe- 
rior thyroid are branches of the external carotid artery; the suprascapular is a 
branch of the subclavian. Deep relations : (1) Omohyoid muscle; (2) anterior 
jugular vein passes behind the external head of the muscle; (3) lower part of 
the sternohyoid and sternothyroid muscles; (4) ansa hypoglossi; (5) carotid sheath, 
containing the common artery, vagus nerve, and internal jugular vein; (6) poste- 
rior belly of the digastric; (7) splenitis capitis, levator anguli scapulse, scaleni, 
posticus, medius, and anticus; (8) bifurcation of the common carotid into the 
internal and external carotid arteries; (9) occipital, subclavian, suprascapular, and 
transversalis colli arteries; (10) a part of the parotid gland; (11) cervical plexus. 
Depressors of the Hyoid Bone. The sternohyoid, omohyoid, sternothyroid, and 
thyrohyoid. Nerve-supply: The ansa hypoglossi. This nerve loop usually lies 
on the carotid sheath. It is formed by the descendens hypoglossi, communicating 
with the two branches from the second and third nerves of the cervical plexus- 
the communicantes hypoglossi. 
Sternohyoid. Origin: (1) Posterior surface of the manubrium; (2) posterior 
sternoclavicular ligament; (3) clavicle. Insertion: Lower border of the body of the 
hyoid bone, with the omohyoid. Fascial sheath: Second layer of the deep cervical 
fascia. Blood-supply: Lingual, inferior, and superior thyroid arteries. Superficial 
relations: Skin, fascia, platysma, sternomastoid, sternum, clavicle. Deep relations : 
Sternothyroid, thyrohyoid, cricothyroid muscles, cricothyroid and thyrohyoid mem- 
branes, superior thyroid vessels, thyroid gland, and cartilages of the larynx. 
Omohyoid Muscle. Origin : Superior border of the scapula, internal to the 
suprascapular foramen. Insertion: Lower border of the body of the hyoid bone 
with the sternohyoid. Fascial sheath: Second layer of the deep cervical fascia. 
Blood-supply: Lingual, inferior and superior thyroids. Superficial relations : 
Anterior belly has the same relations as the contiguous part of the sternohyoid. 
The sudden deflection of the muscle toward the shoulder makes the deep relations 
of the intermediary tendon and posterior belly complicated: sternomastoid, 
platysma, clavicle, and trapezius. Deep relations : Sternothyroid and thyrohyoid 
muscles; common carotid artery, vagus nerve, internal jugular vein, and descen- 
dens hypoglossi; scalenus medius and anticus and phrenic nerve. 
Sternothyroid Muscle. Synonym: Sternocleidothyroid. Origin: (1) Back and 
side of the lower part of the manubrium; (2) cartilage of the first rib; (3) back 
of the clavicle. Insertion : Oblique line of the thyroid cartilage. Nerve-supply : 
Ansa hypoglossi. General action : To depress the hyoid bone. Specific action : 
To depress the thyroid cartilage. Fascial sheath: Second layer of the deep 
cervical fascia. Blood-supply : Lingual, superior and inferior thyroids. Super- 
ficial relations: Sternomastoid, sternohyoid, omohyoid, and anterior jugular veins. 
Deep relations: (1) Trachea and larynx; (2) common carotid and innominate 
arteries, thyroid gland and vessels, middle thyroid vein. 
The Thyrohyoid. Origin: Oblique line of the thyroid cartilage. Insertion: 
Body of the hyoid and greater cornu. Nerve-supply: Special branch of the hypo- 
glossal. Blood-supply: Lingual and superior thyroid arteries. Superficial rela- 
tions : Sternohyoid and omohyoid muscles. Deep relations: Superior laryngeal 
nerve and vessels, thyroid cartilage, and thyrohyoid membrane. This muscle 
seems to be an upward continuation of the sternothyroid. 
The Digastric Muscle. Origin of the anterior belly: Digastric fossa of the man- 
dible. Origin of the posterior belly: Digastric groove of the mastoid process. 112 
A MANUAL OF DISSECTION. 
Attachment of the digastric tendon : Body and greater cornu of the hyoid. Grand, 
divisions: Anterior belly, posterior belly, digastric tendon. Insertions of bellies : 
Tendon. Nerve-supply of the anterior belly: Mylohyoid; of the posterior belly: 
Facial. Action of the anterior belly: To depress the mandible; of the digastric 
muscle: To elevate the hyoid and tongue. Blood-supply of the posterior belly : 
Occipital. Blood-supply of the anterior belly: Submental branch of the facial 
artery. Mesial connection: With its fellow of the opposite side. Superficial 
relations: Parotid gland, stylohyoid, splenius, and trachelomastoid muscles, skin 
fasciae, platysma and sternomastoid musclesand facial vein. Deep relations: Mylo- 
hyoid, styloglossus, stylopharyngeus, hypoglossus muscles, external carotid, internal 
carotid, lingual and facial arteries, internal jugular vein, and hypoglossal nerve. 
fig. 61. 
Muscles of the neck and boundaries of the triangles. (Gray.) 
The Stylohyoid Muscle. Origin: Back and outer surface of the styloid process 
near the base. Insertion: Junction of the body and the greater cornu of the 
hyoid bone perforated near the insertion by the tendon of the digastric. Nerve- 
supply : Special branch of the facial. Blood-supply: Occipital artery. Action : 
To elevate the hyoid bone. Synergist: Posterior belly of the digastric muscle. 
Antagonists: Depressors of the hyoid bone. 
The Mylohyoid Muscle. Origin: Mylohyoid ridge. Extent of origin: Sym- 
physis menti to the last molar tooth. Insertion: Posterior fibres into the body of 
the hyoid bone, anterior and middle, into the fibrous raphe, extending from the 
symphysis menti to the body of the hyoid. Fibrous raphe may be wanting. 
Nerve-supply : Mylohyoid branch of the inferior dental nerve. Blood-supply: 
Submental and mylohyoid arteries. Action : To carry the hyoid bone and tongue 
forward and form the floor of the mouth. 
The Geniohyoid Muscle. Origin: Inferior genial tubercle of the mandible. In- 
sertion : Anterior surface of the body of the hyoid bone. Situation : Above the THE NECK. 
113 
inner border of the mylohyoid muscle. Nerve-supply: Hypoglossal. Action : 
To carry the hyoid bone forward; and depress the jaw. Blood-supply: Sublingual 
branch of the lingual artery. 
The Mylohyoid Nerve. The mylohyoid nerve is a branch of the inferior dental. 
It is given off just before this nerve enters the inferior dental foramen in the 
mandible. It perforates the sphenomandibular ligament and runs in the mylo- 
hyoid groove with the vessels of like name. 
The Scalenus Anticus. Origin: Scalene tubercle of the first rib. Insertion: 
Anterior tubercles of the third, fourth, fifth, and sixth cervical vertebrae. Action : 
Flexion of the neck and elevation of first rib. Synergists: Scalenus medius, 
scalenus posticus, and longus colli. Antagonists; Semispinalis colli. Rela- 
tions : Anterior, sternomastoid, omohyoid, subclavius muscles, phrenic nerve, 
internal jugular, and subclavian veins. Internal: Vertebral vessels and sympa- 
thetic cord, longus colli and rectus capitis anticus major. External: Pleura, 
subclavian artery, and cervical nerves. 
The Scalenus Medius. Origin ; First rib, behind the groove for the subclavian 
artery. Insertion : Posterior tubercles of the six lower cervical vertebrae. Action : 
Flexion of the neck and elevation of first rib. Synergists: Scalenus anticus, 
posticus, and longus colli. Antagonists: Same as scalenus anticus. Anterior 
relations: Subclavian artery, cervical and brachial plexuses, trapezius, sterno- 
mastoid and omohyoid muscles. Posterior relations: Levator anguli, scapulae, 
and scalenus posticus. 
The Scalenus Posticus. Origin : Second rib. Insertion : Posterior tubercle of the 
lower cervical vertebrae. Action: Flexion of the neck and elevation of second rib. 
The Rectus Capitis Lateralis. Origin: Front of the upper surface of the lateral 
mass of the atlas. Insertion : Under surface of the jugular process of the occip- 
ital bone. Nerve-supply; Anterior branch of the first cervical nerve. Action : 
To flex the head laterally. 
The Rectus Capitis Anticus Minor. Origin : Lateral mass of the atlas. Inser- 
tion: Under surface of the basilar process of the occipital bone in front of the 
foramen magnum. Action: Flexion of the head. Synergists: Pectus capitis 
anticus major. Antagonists : Rectus capitis posticus, major and minor, superior 
oblique, trachelomastoid, splenitis capitis, complexus, biventer cervicis and 
trapezius. Nerve-supply: First cervical. 
The Rectus Capitis Anticus Major. Origin: From the front of the anterior 
tubercles of the third, fourth, fifth, and sixth cervical vertebrae. Insertion: Under 
surface of the basilar process of the occipital bone. Action: Flexion of the head. 
Synergists: Rectus capitis anticus minor. Antagonists: Same as those that 
antagonize the preceding muscle. Nerve-supply: First and second cervical. 
The Longus Colli Muscle. The longus colli muscle is in front of the cervical 
and upper thoracic vertebrae, and has: 1. A vertical division. 2. A lower 
oblique division. 3. An upper oblique division. Origin of the vertical division : 
1. Bodies of the sixth and seventh cervical vertebrae. 2. Bodies of the first, 
second, and third thoracic vertebrae. 3. Transverse processes of the fourth, fifth, 
sixth, and seventh cervical vertebrae. Insertion: Bodies of the second, third, and 
fourth cervical vertebrae. Origin of the lower oblique portion: Bodies of the first, 
second, and third thoracic vertebrae. Insertion : Anterior tubercles of the trans- 
verse processes of the fifth and sixth cervical vertebrae. Origin of the upper oblique 
portion : Anterior tubercles of the transverse processes of the third, fourth, and fifth 
cervical vertebrae. Insertion : Anterior tubercle of the atlas. Nerve: Cervical. 
BOUNDARIES AND TRIANGLES OF THE NECK. 
Anterior Boundary. The mentosternal line extending from the mid-line of the 
chin to the middle of the suprasternal notch. In this line are (1) the hyoid bone; 
(2) the hyothyroid membrane; (3) the progressive angle of the thyroid cartilage; 114 
A MANUAL OF DISSECTION. 
(4) the thyrocricoid membrane; (5) the cricoid cartilage; (6) the isthmus of the 
thyroid gland; (7) the inferior thyroid veins, resting on the trachea; (8) the 
trachea. 
Posterior Boundary. The anterior border of the trapezius muscle. It requires 
some practice on the part of the student to locate this border. This muscle 
extends almost to the junction of the middle and outer thirds of the clavicle. 
Inferior Boundary. The clavicle and manubrium. The clavicle articulates 
internally with the manubrium of the sternum; externally, with the acromion 
process of the scapula. The inner third of the bone is occupied by the clavicular 
attachment of the sternocleidomastoid muscle. 
Superior Boundary. The lower border of the mandible and mastomandibular 
line. The latter extends from the mastoid process to the angle of the mandible. 
This boundary is crossed by the facial artery and vein, external jugular vein, and 
great auricular nerve. 
The Triangles of the Neck. The general shape of the neck on each side of 
the mid-line is that of a parallelogram. The sternocleidomastoid, extending 
diagonally from the posterior superior angle to the anterior inferior angle, divides 
this space into two large triangles-one in front of and the other behind the 
sternocleidomastoid muscle. 
The Anterior Triangle has its base up, its apex down, and is bounded in front by 
the mentosternal line; behind, by the sternomastoid muscle; above, by the man- 
dible and mastomandibular line. This triangle encloses three smaller triangles : 
1. The submaxillary. 2. The superior carotid. 3. The inferior carotid. 
The Posterior Triangle has its base down, its apex up, and is bounded in front by 
the sternocleidomastoid; behind, by the trapezius muscle; below, by the middle 
third of the clavicle. This triangle encloses two smaller triangles : 1. The occip- 
ital. 2. The supraclavicular or subclavian. Names: The names of the five 
smaller triangles of the neck are : the submaxillary, superior carotid, inferior 
carotid, occipital, and subclavian or supraclavicular. 
The Submaxillary Triangle is bounded above by the mandible and mastomandib- 
ular line; below, by the digastric and stylohyoid muscles; in front, by the ante- 
rior belly of the digastric. The floor is formed by the anterior belly of the digas- 
tric, the mylohyoid, and hyoglossus muscles. Contents: The hypoglossal nerve, 
mylohyoid nerve and vessels, submaxillary gland, facial artery and vein, ascend- 
ing palatine artery, tonsillar artery, submaxillary artery, submental artery, parotid 
gland in part, external carotid artery, the posterior auricular artery, and cervical 
lymphatic glands. 
The Superior Carotid. Triangle is bounded posteriorly by the sternocleidomastoid 
muscle; inferiorly, by the anterior belly of the omohyoid; superiorly, by the 
posterior belly of the digastric muscle. The floor is formed by the thyrohyoid, 
hyoglossus, and inferior and middle constrictors of the pharynx. 
The contents of the superior carotid triangle are : 1. The bifurcation of the 
common carotid, internal carotid artery, external carotid artery, and internal 
jugular vein. 2. Branches of the external carotid : Superior thyroid artery, 
lingual artery, facial artery, occipital artery, and ascending pharyngeal artery. 
3. Branches of the superior thyroid: Hyoid artery, sternomastoid artery, 
superior laryngeal artery, sternomastoid branch of the occipital artery, and the 
internal jugular vein. 4. Tributaries of the internal jugular : Facial, temporo- 
maxillary, lingual, superior thyroid and middle thyroid veins. 5. Hypoglossal 
nerve: Descendens hypoglossi nerve, to the thyrohyoid muscle; internal laryngeal 
nerve, external laryngeal nerve, spinal accessory nerve, pneumogastric nerve, 
sympathetic nerve, larynx and pharynx in part, greater cornu of the hyoid 
bone, intercarotid body, lymphatic vessels and nerves. 
The Inferior Carotid Triangle is bounded in front by the mid-line»of the neck; 
behind, by the sternomastoid muscle; above, by the omohyoid muscle. The floor 
is formed by the longus colli, scalenus anticus, and rectus capitis anticus muscles. 
The contents of the inferior carotid triangle are the sternohyoid and sternothyroid THE NECK. 
115 
muscles, branches of the ansa hypoglossi, superior thyroid artery and external 
laryngeal nerve, thyroid body, larynx and trachea, recurrent laryngeal nerve and 
vessels, oesophagus (on the left side), and common carotid sheath and its contents. 
The Occipital Triangle is bounded in front by the sternomastoid; behind, by the 
trapezius; below, by the omohyoid. The floor is formed by the splenius capitis, 
levator anguli scapulae, scalenus medius, and scalenus posticus muscles. Contents 
of the occipital triangle are the spinal accessory nerve, upper part of the brachial 
plexus, branches of the third and fourth cervical nerves to the trapezius, super- 
ficial branches of the cervical plexus, transversalis colli artery and vein, and 
branches of the third and fourth cervical nerves, to the levator anguli scapulae. 
The Subclavian Triangle is bounded above by the omohyoid muscle; below, by 
the clavicle; in front, by the sternomastoid. The floor is formed by the scalenus 
medius, the scalenus posticus, a portion of the first rib, and the serratus magnus. 
Contents of the subclavian triangle are the subclavian artery and vein, transver- 
salis colli artery and vein, suprascapular artery and vein, external jugular vein, 
trunks of the brachial plexus, and certain cervical lymphatic glands. 
Common Roof Structures. The skin, superficial fascia, and the first layer of the 
deep fascia of the neck form a common roof for all the cervical triangles. 
Transitory Nature of Contents. Very few structures of the neck may be located 
exclusively in a given triangle. The submaxillary gland is wholly in a triangle 
of the same name, but the facial artery begins in the superior carotid triangle, 
passes through the submaxillary triangle, and ends on the face. Rather, then, 
look upon the triangles as areas traversed by nerves and conduits. The nature 
of the contents of the triangles, then, is rather transitory than resident. 
Structures in the Mid-line of the Neck. On either side of the symphysis menti 
are the two anterior bellies of the digastric muscle. Between the bellies is the 
fibrous raphe, into which the mylohyoids are inserted. The hyoid bone is easily 
found at the base of the tongue, while below this is the prominence of the 
thyroid cartilage known as the " pomum Adami," the cricothyroid membrane and 
cricoid cartilage, on which latter the cricoid artery rests. Below the cricoid car- 
tilage, in the mid-line of the neck, is the trachea. Superficial to the trachea, in 
the lower part of the neck, are: 1. The isthmus of the thyroid. 2. The inferior 
thyroid veins. 3. The innominate artery. 4. The left innominate vein. 5. Re- 
mains of the thymus. 6. The thyroid artery. 
CAROTID ARTERIES-RIGHT AND LEFT. 
These arteries, above the sternoclavicular articulations, are practically alike in 
course and relations. The left arises in the thorax from the arch of the aorta; 
the right from the innominate. We must speak, therefore, of the left artery as 
having a certain length in the thorax not possessed by the right; the left artery 
exceeds the right in-length about two inches. 
By the thoracic part of the left common carotid artery is meant that part 
between the arch of the aorta and the left sternoclavicular articulation. Each 
artery has a cervical part, which extends from behind the sternoclavicular articu- 
lation to the upper border of the thyroid cartilage, where each divides into an 
internal and an external carotid.1 
Relation of the thoracic part of the left common carotid artery: 1. Anterior : 
manubrium, sternohyoid, sternothyroid, the thymus or its remains, and the left 
innominate vein. 2. Posterior: trachea, oesophagus, thoracic duct, and left recur- 
rent laryngeal nerve. 3. Inner : innominate artery, trachea, inferior thyroid vein. 
4. Outer and posterior: left subclavian artery, left vagus nerve, left pleura, left lung. 
Common Carotid Arteries. Origin of right: innominate, behind the sternoclav- 
icular articulation. Termination of each : opposite upper border of the thyroid 
1 Experience shows this bifurcation occurring on a level with the hyoid bone in the majority of cases. 116 
A MANUAL OF DISSECTION. 
cartilage. Mode of termination of each : in the internal and external carotids. Origin 
of left: aortic arch, to the left and behind the innominate. Relation to each other 
as they ascend: they diverge. Carotids are separated three-quarters of an inch 
at the top of the manubrium by the trachea. Distance between the carotids at 
bifurcation ; 2.25 inches. Fascial sheath : third layer of the deep cervical fascia. 
Contents of sheath: internal jugular, vagus, common carotid. Contents of sheath 
are separated by fibrous septa. Relation : vein external, artery internal, nerve in 
middle. Length of arteries: right, 3.75 inches; left, 4.75 inches. Lying on the 
carotid sheath : ansa hypoglossi. The sympathetic cord of the neck lies behind 
the sheath. 
Internal Carotid Artery. The internal carotid artery begins at the bifurcation 
of the common carotid, at the level of the upper border of the thyroid cartilage, 
Fig. 62. 
Superficial arteries oi the head. (Gerrish after Testut.) 
and ends near the optic chiasm, where it breaks up into branches for the supply 
of the orbit, nose, and brain. The artery has the following stages : cervical, 
petrosal, cavernous, and terminal. 
The cervical stage extends from the bifurcation of the common carotid to the 
carotid foramen in the petrosa. The artery in this stage rests on (1) the vagus; 
(2) the superior cervical ganglion; (3) the rectus capitis anticus major; (4) the 
three upper cervical-vertebrae. Near the base of the skull the artery is separated 
from the internal jugular vein by the ninth, tenth, eleventh, and twelfth nerves. 
The vagus and internal jugular vein are external, the pharynx and tonsil internal 
to the artery. No branches are given off in this stage. THE NECK. 
117 
The petrosal stage is in the carotid canal. In this stage the artery gives off 
(1) a tympanic branch to the middle ear; (2) a Vidian branch, which anastomoses 
with the Vidian branch of the internal maxillary. 
The cavernous stage is in the cavernous sinus of the dura mater. Branches: 
(«) To the walls of the cavernous sinus; (6) to the Gasserian ganglion; (c) to the 
pituitary body; (d) the anterior meningeal. 
The terminal stage begins where the artery, emerging from the cavernous sinus, 
pierces the dura internal to the anterior clinoid process in close relation with the 
optic nerve and ends in the following branches : (a) The ophthalmic enters the 
orbit through the optic foramen; (6) anterior cerebral; (c) middle cerebral; (d) 
posterior communicating. 
External Carotid Artery. Origin: Bifurcation of the common carotid opposite 
the thyroid. Termination: Behind the neck of the condylar process of the 
mandible. Relation of the external to the internal carotid artery behind the neck of 
the mandible: Superficial to; the external is separated from the internal behind 
the neck of the jaw by the parotid; covered at the origin by the skin, fascia, and 
platysma myoides. Relation to the stylohyoid, digastric, and hypoglossal nerve: 
Behind; divides into the temporal and internal maxillary in the parotid gland. Struct- 
ures between the external and the internal carotids: (1) Stylopharyngeus, stylo- 
glossus muscle; (2) glossopharyngeal nerve and pharyngeal branch of the vagus; 
(3) a part of the parotid gland ; (4) styloid process ; (5) stylohyoid ligament. 
Comparative size of carotids: External smaller. Beneath the ninth nerve and the 
temporomaxillary vein is in the parotid. Branches : Superior thyroid, lingual, 
facial, occipital, posterior auricular, internal maxillary, temporal, ascending 
pharyngeal. 
Superior Thyroid Artery. Origin : In the superior carotid triangle from the 
external carotid. Location : Below and external to the greater horn of the hyoid 
bone. Course: Downward to the thyroid gland and the hyoid depressors. Termi- 
nation : In the upper and front surface of the thyroid gland. Passes beneath the 
omohyoid, sternohyoid, and the thyrohyoid muscles. Important anastomoses cere : 
(1) With the opposite superior thyroid on the upper border of the isthmus; (2) 
with the inferior thyroid on the lateral lobe of the thyroid. Secondary func- 
tion of the superior thyroid artery: To supply the sternomastoid and depressors of 
the hyoid bone. Branches: Hyoid, sternomastoid, cricothyroid, superior laryn- 
geal. The hyoid branch is below the greater horn of the hyoid bone; the middle 
sternomastoid supplies the sternomastoid muscle; the cricothyroid lies on the crico- 
thyroid membrane; the superior laryngeal perforates the thyrohyoid membrane and 
is attended by the superior laryngeal branch of the vagus. It supplies the crico- 
thyroid muscle and mucous membrane of the larynx. Surgical importance of the 
cricothyroid branch, in laryngotomy : The artery may be very large and extended 
upward. The main branch of the superior thyroid artery may cross the crico- 
thyroid membrane. The membrane should be fully exposed in laryngotomy before 
a cut into the larynx is made. Make the incision transversely and close to the 
cricoid cartilage to avoid unnecessary bleeding. 
The Lingual Artery. Origin: Superior carotid triangle from the external carotid. 
Termination: Apex of the tongue as the ranine artery. Ijocation : One-half inch 
above the greater horn of the hyoid bone. Course: Beneath the digastric, stylo- 
hyoid, and hyoglossus; crossed by the twelfth nerve at the posterior margin of the 
hyoglossus muscle; beneath (he hyoglossus on the middle constrictor of the pharynx; 
in the tongue between the inferior lingualis and geniohyoglossus; curved to permit 
elongation of the tongue. The lingual triangle is a space in which the lingual 
artery may be ligated preparatory to amputation of the tongue as a palliative 
measure in malignant diseases of this organ. The triangle is bounded (1) inter- 
nally, by the mylohyoid muscle; (2) below and externally, by the digastric tendon; 
(3) above, by the hypoglossal nerve. The floor of this space is formed by the 
hyoglossus muscle, beneath which the artery may be found. Hyoid bone as a 
guide : About one-half inch above the greater horn of the hyoid bone demonstrate 118 
A MANUAL OF DISSECTION. 
the lingual artery passing beneath and the hypoglossal nerve lying on the hyo- 
glossus muscle; one-half inch below the greater horn the superior laryngeal nerve 
and artery penetrate the thyrohyoid membrane to gain the interior of the larynx. 
The Facial Artery. Origin: Superior carotid triangle, branch of the external 
carotid. Termination: Inner canthus of the eye, as angular artery. Synonym: 
External maxillary artery. Location: Superior carotid and digastric triangles, 
and face. Grand divisions: Cervical and facial parts. Cervical part: From 
its origin to front of the masseter on the mandible. Facial part; From front 
of the masseter to the inner canthus. Attended by : Sympathetic nerves called 
nervi molies. (Function of nervi molies: To produce blushing and pallor.) Course 
of cervical part: Beneath the digastric, stylohyoid, twelfth, or hypoglossal nerve 
and submaxillary gland; rests on the mylohyoid muscle; passes behind or through 
the submaxillary gland; crosses the mandible in front of the masseter muscle; 
anterior to the facial vein on the mandible; general character of the facial artery: 
is very tortuous; may be compressed in front of the masseter muscle. Branches 
of the cervical stage: 1. Ascending palatine. Course: (a) Passes between the 
styloglossus and stylopharyngeus; (6) between the superior constrictor of the 
Fig. 63. 
Arteries and veins of the tongue, viewed from the right side. (Gerrish after Testut.) 
pharynx and the internal pterygoid muscle; (c) at the level of the levator palati 
divides into the palatine and tonsillar branches. In the tonsil the artery anasto- 
moses with the descending palatine branch of the internal maxillary, tonsillar 
branches of the ascending pharyngeal, and the tonsillar branch of the dorsalis 
linguae artery. 2. The tonsillar branch ascends between the internal pterygoid 
and styloglossus. It passes through the superior constrictor of the pharynx and 
supplies the tonsil and root of the tongue. 3. Submaxillary, glandular branches, 
numerous and small, supply the submaxillary gland. 4. Submental, given off 
behind the submaxillary gland. It lies on the mylohyoid muscle, and gives 
branches to the submaxillary gland and muscles under the jaw; it supplied the 
lower lip through a superficial branch. The facial stage passes benealh the 
platysma, risorius, zygomatics, levator labii superioris alseque nasi, and the infra- 
orbital branches of the seventh nerve; it lies on the levator aoguli oris and infra- 
orbital plexus of the fifth cranial nerve. Branches : (1) Inferior labial; (2) 
inferior coronary; (3) superior coronary; (4) lateralis nasi; (5) angular; (6) mas- 
seter and buccinator on the face. 
The Occipital Artery. The occipital artery begins in the superior carotid triangle 
as a branch of the external carotid, and ends in the skin of the posterior part of the THE NECK. 
119 
scalp. The sternomastoid muscle crosses the artery and determines its stages-the 
first is anterior, the second beneath, and the third posterior to the muscle. In its first 
stage the occipital crosses the internal carotid artery, internal jugular vein, vagus 
nerve, and is itself crossed by the twelfth nerve. The second stage of the artery is 
deep. It lies between the transverse process of the atlas and the mastoid process, 
where it changes its course-backward in the occipital groove, beneath the sterno- 
mastoid, splenitis capitis, trachelomastoid, and digastric muscles, and later becoming 
superficial and resting on the complexes muscle. Branches: (1) Auricular, to 
the cranial part of the concha; (2) muscular, to the digastric, stylomastoid, 
splenitis, trachelomastoid; (3) the posterior meningeal enters the cranium through 
the jugular foramen and supplies the dura mater of the posterior fossa; (4) arteria 
princeps cervicis is a short branch and its course is downward. It divides 
into (u) a superficial branch, which lies beneath the splenitis capitis, which, 
together with the trapezius, it supplies; (6) a deep branch, which lies beneath the 
complexus and anastomoses with the deep cervical branch of the superior intercostal 
artery, a branch of the subclavian. This anastomotic arch lies on the semi- 
spinalis colli muscle, and is an important collateral route after ligation of the 
common carotid artery. 
The Posterior Auricular Artery. The posterior auricular artery arises from the 
external carotid above the digastric muscle, and lies on the styloid process 
beneath the parotid gland. It lies in a groove between the cartilage of the ear 
and the mastoid process. The artery lies just above the spinal accessory nerve and 
gives off the following branches : (a) To the digastric and stylohyoid muscles, and 
parotid gland; (6) stylomastoid artery, which, passing through the stylomastoid 
foramen, supplies the mastoid cells, vestibule, and membrana tympani; (c) auric- 
ular branches, to the external ear; (d) mastoid branches, to the mastoid region. 
The Ascending Pharyngeal. The ascending pharyngeal artery arises either from 
the bifurcation of the common carotid or half an inch above the same from the 
external carotid. Branches: (1) Muscular, to the rectus capitis anticus major 
and minor; (2) prevertebral, to the vagus and hypoglossal nerves and superior 
cervical ganglion; (3) pharyngeal to Eustachian tube, soft palate, stylopharyngeus, 
superior and middle constrictor muscles of the pharynx; (4) meningeal, to the 
dura mater; (5) tympanic, to the middle ear. 
The Superficial Temporal Artery. The superficial temporal artery is one of the 
terminals of the external carotid. It arises in the parotid gland behind the neck 
of the condylar process and crosses the root of the zygoma near the external audi- 
tory meatus. About two inches above the zygoma it divides into an anterior and 
a posterior branch. The artery is attended (1) by sympathetic nerves from 
the superior cervical ganglion; (2) by the temporal branches of the facial nerve; 
(3) by the auriculotemporal branch of the inferior maxillary division of the tri- 
geminus; (4) by the temporal veins which lie superficial to the artery. Branches : 
(1) Transverse facial, which crosses and gives branches to the masseter muscle 
and glandula socia parotidis; (2) anterior auricular, to the front of the external 
ear; (3) middle temporal, which, piercing the temporal fascia, communicates with 
the deep temporal branches of the internal maxillary artery, another terminal 
of the external carotid. 
The Internal Maxillary Artery. This artery arises from the external carotid in 
the substance of the parotid gland behind the neck of the jaw. It transverses the 
zygomatic fossa, passes between the upper and lower heads of the external pterygoid 
muscle, and enters and gives off its terminal branches in the sphenomaxillary 
fossa. The portions of the artery and their branches are as follows : 1. The 
maxillary portion is between the neck of the jaw and the internal lateral ligament. 
Branches: (a) deep auricular, to the external auditory meatus and drum; (6) 
tympanic, passes through the Gasserian fissure to the middle ear; (c) middle 
meningeal, given off between the neck of the jaw and the internal lateral liga- 
ment, passes between the two roots of the auriculotemporal nerve through the 
foramen spinosum into the middle fossa, and is distributed to the dura mater; (d) 120 
A MANUAL OF DISSECTION. 
small meningeal, enters the skull through the foramen ovale and supplies the 
Gasserian ganglion and dura; (e) inferior dental, with a nerve of the same name, 
enters the mandibular canal, and is distributed to the teeth and gums of the man- 
dible and to the skin of the chin. 2. The pterygoid portion is between the 
external pterygoid muscle and the insertion of the temporal. Branches: (a) 
Masseteric, which supplies the masseter muscle and anastomoses with the facial 
artery and transverse facial branch of the superficial temporal. It gains the under 
surface of the muscle through the sigmoid notch, and is accompanied by a nerve 
and veins of like name; (6) deep temporal, attended by a nerve and veins of 
like name to the deep surface of the temporal muscle; (c) pterygoid, to the ptery- 
goid muscles. These branches are all attended by nerves (branches of the tri- 
geminus) and veins of like name; (d) buccal, attended by the long buccal branch 
of the inferior maxillary division of the fifth cranial nerve, passes forward to the 
buccinator muscle, and anastomoses with the facial artery. 3. The spheno- 
maxillary portion is in the sphenomaxillary fossa. 
Branches: (1) Alveolar or posterior superior dental, given off with the infra- 
orbital as this artery enters the sphenomaxillary fossa; (a) gingival branches, 
to the gums; (6) antral branches to the antrum of Highmore. (2) The infra-orbital 
arises with the inferior dental, passes along the infra-orbital canal with the supe- 
rior maxillary nerve, and appears on the face through the infra-orbital foramen 
between the levator labii superioris and levator anguli oris. Branches; (a) To 
the lacrymal gland; (6) to the inferior rectus and inferior oblique muscles; (c) 
to the mucous membrane of the antrum of Highmore; (d) to the incisor and 
cuspid teeth; (e) on the face, to the nose, lip, and eyelid. (3) The Vidian, a 
small branch, passes through the Vidian canal to the Eustachian tube, middle 
ear, pharynx, and is attended by the Vidian nerve and veins. (4) The pterygo- 
palatine branch passes through a canal of like name with the pharyngeal branch 
of Meckel's ganglion to the pharynx and Eustachian tube. (5) The nasopalatine 
or sphenopalatine branch enters the nose through a foramen of like name, with 
the sphenopalatine branches of Meckel's ganglion. This artery supplies the 
ethmoid cells and mucous membrane of the antrum of Highmore. (6) The 
descending or posterior palatine passes through the posterior palatine canal 
with the palatine nerves from Meckel's ganglion, thence along the roof of the 
mouth to the anterior palatine canals, in which they inosculate on the septum with 
branches of the nasopalatine artery. They supply the gums, glands, mucous 
membrane, and soft palate. 
VEINS OF THE NECK. 
Superficial Jugular Veins. The jugular veins are four in number on each side of 
the mid-line of the neck. Of these, one, the internal, is a deep structure in the 
carotid sheath, and made up at the base of the cranium at the jugular foramen, 
conveying blood from the sinuses of the dura mater. The veins for our study 
now are the jugulars found in the superficial fascia and properly called superficial 
jugulars when spoken of collectively. From their position with reference to the 
sternocleidomastoid muscle they are called anterior, external, and posterior, and 
located as follows: (1) The anterior, in front of the sternomastoid muscle; (2) 
the external, crosses the sternomastoid muscle; (3) the posterior lies behind the 
sternomastoid muscle. 
The anterior jugular vein begins in the submaxillary region by the confluence of 
small veins; it ends either in the external jugular or subclavian in the region of 
the clavicle. It descends vertically to within about one inch of the suprasternal 
notch, and then turns behind the sternomastoid muscle. There may be two anterior 
jugular veins on each side. This vein communicates with its fellow of the oppo- 
site side, and receives tributaries from the inferior thyroid veins. The anterior 
jugular vein communicates with the internal and has no valves. THE NECK. 
121 
The posterior jugular vein begins in the occipital region, is tributary to the 
external jugular vein, and has no valves. 
The external jugular vein is made up in the parotid gland, behind the angle of 
the jaw by the confluence of the temporal and internal maxillary veins. It 
descends vertically, crosses the sternomastoid muscle and superficial cervical 
nerves, opens into the subclavian vein in front of or to the outer side of the 
scalenus anticus muscle and may be double. It has two pairs of valves-one at 
its termination, another about two inches above the clavicle. 
Internal Jugular Vein. Inception: Jugular foramen, between the occipital and 
petrosa. Formation: Confluence of lateral and inferior petrosal sinuses. Termi- 
nation : Root of the neck in the innominate vein. Special dilatation : At origin, 
called gulf or sinus. General direction : Vertically down the neck. Relation to 
the carotids: External to both common and internal. It unites with the sub- 
clavian to form the innominate vein. The right is larger than the left internal 
jugular. Valves: One pair at or near the termination of the vein. The fascial 
sheath is derived from the third layer of the cervical fascia. Function: To col- 
lect blood from the face, neck, and brain. The vein is crossed by the omohyoid 
muscle and communicantes hypoglossi. Surgical importance: Ligated for septic 
thrombosis of the lateral sinus. Vein lies on the rectus capitis lateralis; and is 
behind the ninth, tenth, and eleventh cranial nerves. Tributaries: Facial, 
lingual, pharyngeal, occipital, superior and middle thyroid, and may receive a 
communicating branch from the external jugular vein. 
Facial Vein. Location: Face, submaxillary, and carotid triangles. Inception: 
Angular vein at the side of the root of the nose. Termination: Internal jugular 
in the superior carotid triangle. Vein descends along the anterior border of the 
masseter muscle; vein lies beneath the platysma myoides on the face; vein lies 
posterior to the facial artery on the mandible; vein is superficial to the twelfth 
nerve, digastric, stylohyoid muscles, and submaxillary glands; vein crosses the 
carotid artery in the superior carotid triangle. Course in the neck : Straight, but 
does not accompany the facial artery. Vein receives the anterior pterygoid at the 
angle of the mouth; vein less flaccid than other superficial veins and has no 
valves. This vein remains open when divided by a knife. 
Lingual Vein. Location: Dorsum, sides, and under surface of the tongue. 
Vein is located in the submaxillary and superior carotid triangles; vein follows the 
course of the lingual artery and ends in the internal jugular. 
Pharyngeal Vein. Origin: Plexiform in the back and sides of the pharynx. 
Common termination: Internal jugular vein. Occasional termination: Facial, 
lingual, superior thyroid. Tributaries: Meningeal, Vidian, and sphenopalatine. 
Union of tributaries forms the pharyngeal plexus of the veins. 
Occipital Veins. Origin: Plexiform on the back part of the skull. Common 
termination: Internal jugular vein. Occasional termination: External jugular 
vein. General course: Same as that of the artery. Vein communicates with the 
lateral sinus by an emissary vein; vein lies on complexes and superior oblique 
muscles of the neck; vein is beneath the sternomastoid, digastric, splenius, trachelo- 
mastoid; vein pierces the attachment of the trapezius muscle; vein is crossed 
by the hypoglossal nerve, and itself crosses the tenth and eleventh cranial nerves. 
Superior Thyroid Vein. Origin: In substance of the thyroid gland. Vein 
terminates in the internal jugular; vein crosses the common carotid artery; vein 
ends occasionally in the facial vein; vein is below the greater cornu of the hyoid 
bone; vein is located in the superior carotid triangle; vein lies below the depres- 
sors of the hyoid bone; vein anastomoses with the inferior thyroid and fellow of 
the opposite side; vein returns blood from the depressors of the hyoid bone and 
thyroid gland; vein has general upward and outward direction and receives tribu- 
tary the superior laryngeal, hyoid, and mastoid. 
Middle Thyroid Vein. Origin: Lower and lateral part of the thyroid gland. 
Vein terminates in the internal jugular; vein crosses the common carotid and 
vagus; vein is located in the superior carotid triangle. 122 
A MANUAL OF DISSECTION. 
DEEP CERVICAL FASCIA. 
The Deep Cervical Fascia forms a strong investment for the entire neck. It divides 
in various places to form sheaths for muscles, vessels, and glands. It is attached 
above to the bones of the head; below, to the apex of the thorax ; behind, to the 
ligamentum nuchee and vertebrae; in front, to the hyoid bone. By means of these 
several attachments the deep fascia holds the structures of the neck in position. 
Dissection. Transverse sections of this as of all other regions of the body should be studied 
from specimens prepared especially and kept on hand in the dissecting-room for this purpose. 
Divisions of the Deep Cervical Fascia. 1. Anterior. 2. Posterior. The anterior 
division includes the fascia in front of the bodies and transverse processes of the 
cervical vertebrae. The posterior division includes the fascia behind the cervical 
Fig. 64. 
The cervical fascia, as seen in a horizontal section of the neck at the level ot the sixth cervical vertebra. 
(Gerrish after Testut.) 
vertebrae and their transverse processes. Each division consists of four layers and 
four interfascial spaces. The first layer of the deep cervical fascia is in both the 
anterior and posterior divisions-that is, it is continuous around the neck. 
Anterior Division. The first layer is a continuation of the first layer of the 
back of the neck. At the posterior border of the sternomastoid it divides to 
enclose this muscle. 
The second layer encloses the depressor muscles of the hyoid bone: omohyoid, 
sternohyoid, sternothyroid, and thyrohyoid. It is derived from the first layer in 
the region of the internal part of the sternomastoid muscle. 
The third layer forms a common sheath for the carotid artery, vagus nerve, in- 
ternal jugular vein, trachea, thyroid gland, and oesophagus. This layer is derived 
from the first layer in the region of the posterior margin of the sternomastoid 
muscle. 
The fourth layer continues behind the pharynx as the prevertebral fascia, and 
forms a covering for the longus colli muscle. THE NECK. 
123 
Attachments. The first or outei' layer is attached above to the superior curved 
line of the occipital bone, mastoid and styloid processes of the temporal bone, and 
hyoid bone. At the hyoid bone it divides, one layer covering the under surface 
of the mylohyoid muscle, the other becoming attached to the lower border of the 
mandible. In the interfascial space between these two layers is the submaxillary 
gland. Below, the first layer splits, one part being inserted into the anterior, 
the other into the posterior part of the superior border of the manubrium, forming 
in this region Burns' space between the two insertions. 
The second layer is attached above to the hyoid bone; below, to the sternum, 
clavicle, scapula, and first rib. 
The third layer is attached above to the hyoid bone and styloid process; 
below, it encloses the subclavius and the minor pectoral muscles, and sub- 
clavian vessels, forms the clavipectoral fascia and costo-coracoid ligament, and 
sends off two prolongations: (1) into the thorax, where it is continuous with the 
pericardium; (2) into the axilla, about the vessels and nerves. 
The fourth layer is attached above to the basi-occipital; below, to the bodies of 
the cervical vertebrae. 
Pus in the region of the internal jugular vein may point (1) into the axilla; 
(2) into the middle mediastinum. 
Posterior Division. The muscles of the back of the neck are ensheathed by the 
deep fascia, extending in an archiform manner from the cervical spines and liga- 
mentum nuchae to the articular and transverse processes laterally. There are four 
layers of the fascia and four spaces containing the muscles, as follows : 
Interfascial Spaces. The first space, located between the first and second layers 
of fascia, contains (1) the trapezius; (2) the levator anguli scapulae, scalenus 
posticus, medius, and anticus. 
The second space, located between the second and third layers of fascia, 
contains the splenius capitis et colli. 
The third space, located between the third and fourth layers of fascia, contains 
the complexus muscle. 
The fourth space, located between the fourth layer of fascia and the spines and 
laminae of the cervical vertebrae, contains the semispinalis colli muscle. 
Attachments of the Posterior Division of the Cervical Fascia. This fascia is 
attached above to the occipital bone; below, to the ribs and vertebral column cor- 
responding to the origin of the several muscles. In the posterior mid-line of the 
neck the fascia is attached to the ligamentum nuchae and cervical spines. 
THYROID BODY. 
The Thyroid Body, common to all vertebrates, consists genetically of two lobes 
connected by an isthmus or median lobe. The isthmus varies in size in different 
persons, is located just below the cricoid cartilage, and may even be absent. 
Just above the isthmus is the locality for high tracheotomy. A prolongation of 
the isthmus-the pyramid-may be attached to the body of the hyoid bone. Mus- 
cular fibres occasionally develop in this prolongation, and constitute the levator 
glandulae thyroideae. The capsule of the thyroid is derived from the third layer 
of the deep cervical fascia. 
The thyroid body has an apex near the side of the thyroid cartilage; a base, 
on a level with the fifth ring of the trachea; a convex anterior surface, covered 
by the depressor muscles of the hyoid bone; a deep or posterior concave surface, 
which embraces the side of the trachea and larynx, and an external border, which 
may completely overlap the common carotid artery. 
The Blood-supply of the thyroid is from the superior and inferior thyroid arteries 
and an occasional middle thyroid. The superior thyroid artery is the first branch 
of the external carotid. It descends beneath the depressor muscles of the hyoid 
bone to the upper part of the front surface of the thyroid body. The superior 124 
A MANUAL OF DISSECTION. 
thyroid artery anastomoses across the upper border of the isthmus with the artery 
of the opposite side, and also with the inferior thyroid artery. The inferior 
thyroid is a branch of the thyroid axis of the subclavian artery. It passes 
beneath the carotid sheath and sympathetic nerve to the posterior surface of the 
thyroid body. This artery anastomoses freely with the artery of the opposite side 
and also with the superior thyroid artery. The middle thyroid artery (arteria thy- 
roidea ima) when present is a branch either of the aortic arch or the innominate artery. 
The Thyroid Veins form a considerable plexus on the thyroid body. They are 
quite large, and occasion troublesome bleeding in operations on the thyroid 
body. The thyroid veins are (1) superior and middle, which cross the common 
carotid artery and discharge into the internal jugular vein; (2) an inferior thyroid, 
which emerges from the base of the lobes, descends on the front of the trachea, 
and ends in the left innominate vein. These latter veins are in a quantity of fat 
and connective tissue, and their chief surgical interest is in cases of low tracheotomy. 
Fig. 6.\ 
The thyroid body and the related bloodvessels. (Gerrisk after Testut.) 
Embryology. The median lobe of the thyroid originates by evagination from 
the ventral wall of the pharynx. The tube formed by evagination is the thyro- 
glossal duct or canal of His. As a rule, the duct becomes obliterated by the 
eighth week of foetal life. The foramen caecum at the base of the tongue is a 
remnant of this duct. The duct may persist in the adult. As previously 
remarked, the middle lobe of the thyroid body may be absent in man. Its absence 
is the rule in vertebrates below man, in which the lateral lobes do not unite. 
The thyroid body is relatively larger in women and children than in adult males. 
SUBMAXILLARY GLAND. 
The Submaxillary Gland is in the digastric or submaxillary triangle of the neck. 
The gland, except the part next to the jaw, has (1) capsule of the deep cervical 
fascia; (2) two extremities, an anterior and posterior; (3) and three surfaces- 
external, lower, and internal. THE NECK. 
125 
The anterior extremity touches the anterior belly of the digastric muscle; the 
posterior touches the posterior belly of the digastric and stylomaxillary ligament, 
and is grooved for the facial artery. 
The external surface rests in the submaxillary fossa on the inner surface of the 
body of the mandible and on the internal pterygoid muscle. The lower surface 
is crossed by the facial vein and the inframandibular branch of the facial nerve. 
The internal surface rests on the hyoglossus, mylohyoid, and styloglossus muscles. 
The deep portion of the gland is anterior to the posterior margin of the mylo- 
hyoid muscle; the remainder is superficial. Wharton's duct is a forward contin- 
uation of the deep portion of the gland, and opens on the summit of a papilla 
near the frsenum lingua;. The duct passes above the gustatory nerve. 
The Blood-supply of the submaxillary gland is from the lingual artery and sub- 
mental branches of the facial. All branches of the external carotid artery are 
accompanied by sympathetic nerves, derived from the superior cervical ganglion 
of the gangliated cord; hence any territory receiving its blood from the external 
carotid artery receives sympathetic nerve impulse from the superior cervical 
ganglion. (See page 19 for parotid gland.) 
SUBLINGUAL GLAND. 
The Sublingual Gland rests in the sublingual fossa of the mandible on the mylo- 
hyoid muscle. It is immediately beneath the mucous membrane of the mouth, and 
produces the sublingual ridge, which may be seen extending outward and backward 
from the fraenum linguae when the patient's tongue is elevated. It is in relation 
internally with the geniohyoglossus and styloglossus, and its fellow of the opposite 
side, and Wharton's duct. Posteriorly it is near the deep portion of the submaxillary 
gland. Its duct (Rivinus or Bartholin), which is the excretory for the main por- 
tion of the gland, opens with Wharton's duct on a papilla near the fraenum linguae; 
the ducts of Walther are excretories for a minor part of the gland, situated well 
in front. The sublingual gland derives its blood from the sublingual branch of 
the lingual artery, and the submental branch of the facial artery. Its nerves are 
from the submaxillary ganglion and sympathetic. 
Nerves. The submaxillary and sublingual glands receive nerves from two 
sources : (1) From the facial through the chorda tympani; (2) from the superior 
cervical ganglion. The chorda tympani leaves the tympanum through the canal 
of Huguier and joins the lingual. There is a small ganglion (submaxillary) 
where the chorda tympani fibres leave the lingual nerve. 
Embryology. The salivary glands, which in mammals consist of three pairs- 
parotid, submaxillary, and sublingual-develop as outgrowths of the epithelium 
from the mucous membrane of the mouth. The epithelial elements of the glands 
are therefore of ectodermic origin. (See Gerrish.) 
THE LARYNX. 
Dissection. The student should dissect thoroughly the larynx of the ox before the human 
is undertaken. This possesses all the features of the human larynx, and its great size leads to 
a clearer conception. Directions: (1) Fasten the larynx to a board (by small nails), putting 
same on the stretch to its fullest extent. (2) Remove all soft structures, leaving only the 
cartilages and the crico-thyroid membrane. (3) Cut away the right ala of the thyroid as in 
Fig. 67, and expose the intrinsic muscles. (4) Remove the thyro-arytenoid muscle and 
expose the vocal cords. (5) Separate the arytenoid cartilage from the cricoid and study its 
articulation, borders (three), surfaces (three), muscles, and vocal cords attached. (6) Remove all 
soft coverings and develop the cartilages until they look like Fig. 66. 
The larynx is situated between the hyoid bone and the trachea. It is a highly 
specialized part of the air passages for the discharge of the following functions : 
1. It permits easy passage of air to the lungs. 2. It is the organ of voice, its 126 
A MANUAL OF DISSECTION. 
construction being such that expired air may produce vibration of the vocal cords. 
3. By means of the epiglottis it prevents during deglutition entrance of food into 
the trachea. 4. It may close the chink of the glottis when the lungs are full of 
air, and thereby favor fixation of the diaphragm. When the diaphragm is fixed 
the abdominal muscles stimulate the intestines, urinary bladder, gall-bladder, and 
the gravid uterus to contraction. In a secondary way, therefore, the larynx aids 
urination, defecation, parturition, and the discharge of bile. 
Fig. 66. 
The cartilages of the larynx. Posterior view. (Gray.) 
Cartilages of the Larynx. Thyroid (one) shield-like; hyaline cartilage. Cricoid 
(one) finger-ring-like; hyaline cartilage. Arytenoid (two) pitcher-like; hyaline 
cartilage. Epiglottis (one) over the glottis; yellow elastic tissue. Cornicula 
laryngis (two) little horns; yellow elastic tissue. Cuneiform (two) wedge-like; 
yellow elastic tissue. The tip of the arytenoid is yellow elastic tissue. 
The Thyroid Cartilage. The thyroid cartilage is the largest. It consists of two 
lateral, four-sided plates called wings. These wings meet in the mid-line of the 
neck below the hyoid bone, and form a prominence-Adam's apple. Each wing THE NECK. 
127 
of the thyroid cartilage has two surfaces-an outer and an inner, and four 
borders-anterior, posterior, superior, and inferior. 
The outer surface has an oblique line, limited above and below by two tubercles. 
To this surface the sternothyroid and thyrohyoid muscles and inferior constrictor 
of the pharynx are attached. 
The inner surface is smooth and in contact with the vessels and nerves of the 
larynx, the mucous membrane, and two muscles, thyro-arytenoid and crico-aryte- 
noid lateralis. 
The anterior borders form by their union the pomum Adami, in front; behind, 
they give attachment to (1) the epiglottis ; (2) the true and false vocal cords ; (3) 
the thyro-arytenoid and thyro-epiglottidean muscles. (See Fig. 66.) 
The posterior border gives partial attachment to the stylopharyngeus and palato- 
pharyngeus muscles. This border is continued downward as the inferior cornu, 
Fig. 67. 
Muscles of larynx, right side. The right ala of the thyroid cartilage has been cut through and turned down. 
(Gerrish after Testut.) 
which articulates with the cricoid cartilage ; it is continued upward as the supe- 
rior cornu, to which the posterior thyrohoid ligaments are attached. 
The inferior border gives attachment to the crico-thyroid muscle and crico- 
thyroid membrane. The superior border gives attachment to the thyrohyoid 
membrane, and forms in the centre the median notch in front. 
The Cricoid Cartilage. The cricoid cartilage resembles a ring with a very large 
setting behind. The front part is one-quarter inch, the back part one inch wide. 
The front part gives attachment to the crico-thyroid muscles and the inferior con- 
strictor of the pharynx. The posterior part gives attachment to the posterior 
crico-arytenoid muscles and oesophagus, and articulates with the arytenoid cartilage. 
The inferior border is attached to the trachea by the crico-tracheal membrane, 
and has (1) an articular surface for the inferior horn of the thyroid cartilage; 
(2) origin of the crico-thyroid membrane and the lateral crico-arytenoid muscle. 128 
A MANUAL OF DISSECTION. 
The Arytenoid Cartilage. The arytenoid cartilages are two in number, and give 
attachment to the true and false vocal cords and insertion to all the intrinsic muscles 
of the larynx except the crico-thyroid. Analysis. The apex terminates in the cor- 
niculum laryngis, and points inward and backward. The base is irregularly 
saucer-shaped, and articulates with the cricoid, forming the crico-arytenoid joint. 
The anterior angle, called the vocal process, gives attachment to the true vocal 
cord. The external angle, called the muscular process, gives attachment to (1) 
the lateral crico-arytenoid muscle in front; (2) the posterior crico-arytenoid 
muscle behind. The internal angle gives attachment to a ligament which binds 
this angle to the corresponding one of the opposite side and Io the cricoid cartilage. 
The internal surface is covered by mucous membrane. The posterior surface 
gives attachment to the arytenoid muscle. The cornicula laryngis form the 
summits of the arytenoid cartilages. The cuneiform cartilages are in front of 
these in the aryteno-epiglottidean fold of mucous membrane. 
The Epiglottis. The epiglottis is attached by its stalk to the retiring angle of 
the thyroid cartilage. (Fig. 66.) It has lingual and laryngeal surfaces covered by 
mucous membrane. On the laryngeal surface is an elevation called the cushion. 
The lateral margins are free above, below they give attachment to the aryteno- 
epiglottidean folds by which the superior opening of the larynx is bounded. The 
mucous membrane of the lingual surface is reflected onto the tongue in three 
folds, one median and two lateral, called the glosso-epiglottidean. 
The Thyrohyoid Membrane. The thyrohyoid membrane occupies the space 
between the thyroid cartilage and the hyoid bone. The central part, quite strong, 
corresponds to the body of the hyoid bone above and the thyroid notch below. 
The lateral part is pierced by the superior laryngeal nerve and vessels. The 
posterior part, cord-like and strong, extends from the tip of the superior cornu of 
the thyroid cartilage to the tip of the greater horn of the hyoid bone. 
The Crico-thyroid Membrane fills the space between the cricoid and thyroid 
cartilages. The membrane is quite elastic and supports the crico-thyroid artery, 
a small vessel to be avoided in laryngotomy. 
Intrinsic Muscles of the Larynx. 
Name. 
Origin. Insertion. 
Function. 
1. Cricothyroideus. 
Front and lateral part of Lower border of the thyroid 
the cricoid cartilage. cartilage. 
Tension and elongation 
of the vocal cord*. 
2. Crico-arytenoideus 
posticus. 
Posterior surface of the Muscular process of the base 
cricoid cartilage. of the arytenoid. 
Dilates the rima glot- 
tidis by rotating the 
arytenoid outward. 
3. Crico-arytenoideus 
lateralis. 
Upper border of the Forepart of the base of the 
cricoid cartilage. muscular process of the 
arytenoid. 
Narrows the rima glot- 
tidis by rotating the 
arytenoid inward 
4. Thyro- 
arytenoideus. 
Near retiring angle of Anterior surface and base of 
the thyroid cartilage. the arytenoid. 
Draws the arytenoid 
forward and relaxes 
the vocal cords. 
5. Arytenoideus. 
Posterior surface of the Posterior surface of the aryte- 
arytenoid. noid. 
Approximates the vocal 
cords and depresses 
the arytenoid. 
6. Aryteno-epiglot- 
tideus. 
Apex of the arytenoid Into the epiglottis, 
cartilage. 
Contracts superior aper- 
ture of the larynx. 
7. Thyro-epiglot- 
tideus. 
Thyroid cartilage. Epiglottis. 
Depresses the epiglottis 
and compresses the 
sacculus laryngis. 
Interior of the Larynx. The cavity of the larynx is limited above, by the 
superior opening, below by the lower border of the cricoid cartilage. It is lined 
by mucous membrane and divided by the space between the true vocal cords- 
the rima glottidis-into a superior and an inferior part, and has the general 
appearance of an hour-glass. 
The True Vocal Cords are remotely derived from the crico-thyroid membrane, and 
extend from the retiring angle of the thyroid cartilage to the vocal processes or 
anterior angles of the arytenoid cartilages. They are concerned in the production THE NECK. 
129 
of the voice. The two cords face each other, and have free, sharp, chisel-like 
edges above, which vibrates during phonation. They are about one inch long. 
The False Vocal Cords are not concerned in phonation. They are about one- 
quarter of an inch above the true cord. They are composed of fibrous tissue covered 
by mucous membrane, and cannot be made tense. They extend from the retiring 
angle of the thyroid cartilage to the anterior surface of the arytenoid cartilage. 
The Ventricle of the larynx is a depression limited above by the false, below 
by the true vocal cords, and externally by the thyro-arytenoid muscle. 
The Laryngeal Pouch is a small, blind sac, about one-half inch long, leading 
upward from the front of the ventricle to the upper border of the thyroid car- 
tilage. The pouch is guarded by two folds of mucous membrane. The fossa 
innominata is between the false vocal cord and the aryteno-epiglottidean fold, and 
should not be mistaken for the laryngeal pouch. 
The Rima Glottidis is limited laterally (1) by the true vocal cords ; (2) by the 
vocal processes and arytenoid cartilages. The part of the chink between the cords 
is the glottis vocalis; that between the arytenoids is the respiratory portion. 
The Sinus Pyriformis is limited internally by the aryteno-epiglottidean fold and 
externally by the ala of the thyroid cartilage. 
The Superior Laryngeal Nerve, a branch of the vagus, supplies the crico-thyroid 
muscle and mucous membrane of the larynx as far as the true vocal cords. It 
perforates the thyrohyoid membrane. (See Vagus Nerve.) 
The Recurrent Laryngeal Nerve, a branch of the vagus, supplies all the intrinsic 
muscles of the larynx except the crico-thyroid. On the right side this nerve is 
given off from the vagus at the lower part of the subclavian artery, whence it 
ascends behind the right common carotid artery to the side of the trachea. On 
the left side the nerve arises in front of the aortic arch, winds inward around 
and below the ductus arteriosus, and ascends to the side of the trachea. 
The Blood-supply is from the superior and inferior laryngeal arteries, derived 
from the superior and inferior thyroids, respectively. Veins corresponding in 
name and location accompany the arteries. 
THE TRACHEA. 
The trachea is a conduit conveying air to and from the lungs. Location: Mid-line 
of the neck, and extending from the cricoid cartilage of the larynx to the bifurcation 
at the fifth thoracic vertebra. Fascial sheath : Third layer of the deep cervical 
fascia. Continuous above with the larynx, below with the bronchi. Relation to 
the vertebrce: In front, from the fifth cervical to the fifth thoracic. Size: Nearly 
an inch wide and nearly five inches long. Chara.cteristic feature: Imperfect car- 
tilaginous rings, from sixteen to twenty. Trachea divides into: Right and left 
bronchi. Function of the rings of cartilage: To keep the trachea open. Func- 
tion of deficiency of the rings: To permit expansion of trachea. Lining ; Mucous 
membrane. Grand divisions: Cervical and thoracic parts. Relations of the trachea 
in the neck: Posteriorly, oesophagus passing to the left; laterally, common carotid 
artery, thyroid lobes, inferior thyroid arteries, and recurrent laryngeal nerves, 
which latter lie in a fatty groove between the trachea and oesophagus; ante- 
riorly, isthmus of the thyroid, inferior thyroid veins, middle thyroid artery, 
sternohyoid, and sternothyroid muscles, and two layers of the deep cervical 
fascia. Relations of the trachea in the thorax : On the right side, pleura and pneu- 
mogastric nerve; on the left side, pleura, left common carotid artery, pneumo- 
gastric nerve, cardiac and recurrent laryngeal nerves; anteriorly, manubrium of 
the sternum, origins of the sternohyoid and sternothyroid muscles, left innominate 
vein, left common carotid artery, transverse part of the aortic arch, and the deep 
cardiac plexus. The blood-supply is from the tracheal branches of the inferior 
thyroid artery. The veins join the thyroid plexus. Nerves: Vagus, sympa- 
thetic, recurrent laryngeal. 130 
A MANUAL OF DISSECTION. 
CERVICAL PLEXUS. 
Location. Opposite the four upper cervical vertebrae. It is covered by the 
sternomastoid muscle. It rests on the levator anguli scapulae and scalenus medius 
muscles. Its superficial branches emerge behind the posterior border of the 
sternomastoid. This plexus is called cervical on account of its derivation from 
cervical nerves and its major distribution to the neck. 
Fig. 68. 
Plan of the cervical plexus. (Gray.) 
Formation. The plexus is formed by the union of the anterior primary divi- 
sions of the first, second, third, and fourth cervical nerves. The fourth cervical 
nerve is connected by a descending twig to the brachial plexus. 
Table of Branches of Cervical Plexus. (Gray.) 
Superficialis colli. 
Auricularis magnus. 
Occipitalis minor. 
Supraclavicular. 
Suprasternal. 
Supra-acromial. 
Communicating. 
Communicantes hypoglossi. 
Muscular branches. 
Phrenic nerve. 
Communicating branches. 
Muscular. 
Ascending 
Descending 
Superficial 
Deep 
f Internal 
L External THE NECK. 
131 
Communicating Branches extend to the auriculotemporal, facial, hypoglossal, 
pneumogastric, spinal accessory, cervical sympathetic, and brachial plexus. 
Superficial Branches. The superficialis colli crosses the sternomastoid muscle, 
and passes beneath the external jugular vein. The nerve perforates the deep 
fascia near the anterior border of the sternomastoid muscle, and has ascending 
and descending branches from which the antero-lateral part of the neck is supplied 
with sensation. 
The auricularis magnus crosses the sternomastoid muscle to the ear and face. 
The nerve is derived from the second and third cervical. Branches: Facial, dis- 
tributed to the skin covering the parotid gland; auricular, to the skin of the back 
of the ear; mastoid, to the skin over the mastoid process. 
The occipitalis minor is behind the sternomastoid muscle, and perforates the deep 
fascia near the cranium. The nerve arises from the second and third cervical and 
supplies the side of the head and a part of the ear. 
The supraclavicular branches cross the clavicle and supply the skin over a part 
of the pectoralis major and deltoid muscles. 
The suprasternal branches cross the sternomastoid muscle at its origin, and 
supply the skin covering the manubrium. This nerve crosses the external jugular 
vein. 
The supra-acromial branches supply the skin of the back of the shoulder. 
Deep Branches. Communicating branches extend to the cervical sympathetic, 
pneumogastric, and hypoglossal nerves. 
Muscular Branches. They extend to the rectus capitis anticus major (first cer- 
vical nerve); to the rectus capitis lateralis (first cervical nerve); to the sterno- 
mastoid (second cervical nerve); to the scalenus medius (third and fourth cervical 
nerves); to the levator anguli scapulae (third and fourth cervical nerves); to the 
trapezius (third and fourth cervical nerves); to the longus colli (second, third, 
fourth, fifth, and sixth cervical nerves); to the diaphragm (third, fourth, and 
fifth cervical nerves). 
The Phrenic Nerve arises from the third, fourth, and fifth cervical. The nerve 
is beneath the sternomastoid and crosses obliquely inward the scalenus anticus 
muscle. It is crossed by the suprascapular and transverse cervical arteries and 
omohyoid muscle. On each side of the neck the nerve passes behind the sub- 
clavian vein. In the thorax the right phrenic is to the outer side of the innomi- 
nate vein and superior vena cava; on the left it passes between the arch of the 
aorta and lung. On either side the phrenic nerve is closely bound to the peri- 
cardium by connective tissue and attended by a small artery (arteria comes nervi 
phrenici), a branch of the internal mammary. 
The phrenic nerve pierces and is distributed to the under surface of the 
diaphragm, and sends small twigs to the pleura, pericardium, and diaphragmatic 
peritoneum. 
BRACHIAL PLEXUS. 
Location of Stages. The first stage is on the scalenus medius muscle, in the 
posterior triangle of the neck; the second stage is in the subclavian triangle; the 
third stage is beneath the clavicle and subclavius muscle; the fourth stage is 
beneath the pectoral muscles. 
Names of Stages. Stage of Emergence. The five component nerves form- 
ing the plexus emerge through the intervertebral foramina, lie on the scalenus 
medius muscle, and are separate from each other. 
Stage of Trunks. The five component nerves now unite to form the three 
trunks-upper, middle, and lower ; the lower trunk is behind the subclavian 
artery, the other two above and posterior to it. 
Stage of Divisions. Each trunk divides into anterior and posterior divi- 
sions; the plexus lies beneath the clavicle and subclavius muscle, and is above, 
external, and posterior to the axillary artery. 132 
A MANUAL OF DISSECTION. 
Stage of Cords. The six divisions of the trunk are collected into three 
cords-posterior, inner, and outer. The plexus lies under the pectoral muscles 
in the axilla, and its three cords surround the axillary artery. 
Formation of Plexus. The brachial plexus is formed by the union of the 
anterior primary divisions of the fifth, sixth, seventh, and eighth cervical nerves, 
and the greater part of the first thoracic nerve. The lesser part of the first 
thoracic forms the first intercostal nerve. The brachial plexus communicates 
above with the fourth cervical, and below with the second thoracic nerve. The 
nerves forming the plexus emerge through the intervertebral foramina. 
Formation of Trunks. The fifth and sixth fuse to form the upper trunk, the 
seventh forms the middle trunk, and the eighth cervical and first thoracic (greater 
part of) fuse to form the lower trunk. 
Division of Trunks. Each trunk (upper, middle, and lower) divides into ante- 
rior and posterior parts, making six strands in all, three of which are anterior 
and three posterior. 
Fig. 69. 
Plan of the brachial plexus. (Gerrish.) 
Formation of Cords. The posterior cord is formed by the union of the three 
posterior divisions of the three trunks; the outer cord by the union of the anterior 
divisions of the upper and middle trunks; the inner cord by the anterior division 
of the lower trunk. 
Classification of Branches of Distribution. 1. Branches above the clavicle. 
2. Branches below the clavicle. 
Branches above the Clavicle. 1. The posterior thoracic arises from the 
fifth, sixth, and seventh cervical nerves, passes behind the brachial plexus, and 
is distributed to the serratus magnus muscle. 2. The suprascapular nerve 
arises from the fifth and sixth cervical nerves. It passes beneath the trapezius, 
and, crossing the suprascapular artery, enters the suprascapular foramen beneath 
the superior transverse scapular ligament. It gives (a) an articular branch to 
the shoulder-joint; (6) a branch to the supraspinatus muscle; (c) a branch to the 
infraspinatus muscle. These branches are accompanied by vessels of like name. 
The muscular branches enter their respective muscles on the deep surface, near 
the apex. Gray rami communicantes attend these branches for the supply of THE NECK. 
133 
bone, cartilage, fasciae, and vessels. 3. The nerve to rhomboidei, major and minor, 
arises from the fifth cervical, near the intervertebral foramen. This nerve is in 
the space between the minor rhomboid and levator anguli scapulae. It also con- 
tains gray rami for bone, fasciae, ligament, and vessels. 4. The nerve to the 
subclavius muscle arises from the fifth cervical, near the intervertebral foramen, 
or a little lower from the upper trunk of the plexus. It crosses the third stage 
of the subclavian artery, and gives (a) a muscular branch to the subclavius 
muscle; (6) a communicating branch to the phrenic nerve; (c) gray rami for the 
supply of bone fasciae and vessels. 5. The nerves to the longus colli, scalenus 
anticus, medius and posticus, arise from the sixth, seventh, and eighth cervical, 
near the exit of these nerves from the intervertebral foramina. They convey 
gray rami for bone, fascia, and vessels. 6. The communicating branch to the 
phrenic nerve arises from the fifth cervical. It conveys gray rami for fasciae, 
vessels, and bone. (See Sympathetic for Gray Rami.) 
Branches below the Clavicle. From the outer cord: 1. The outer head of 
the median. 2. The external anterior thoracic. 3. The musculocutaneous. 
From the inner cord: 1. The inner head of the median. 2. The internal anterior 
thoracic. 3. The internal cutaneous. 4. The lesser internal cutaneous. 5. The 
ulnar. From the posterior cord: 1. The subscapular nerves (short, long, lower). 
2. The circumflex. 3. The musculospiral. 
The Median Nerve arises by two heads-an outer and an inner-from the outer 
and inner cords of the brachial plexus, respectively. It accompanies the axillary 
artery and its prolongation, the brachial, to the elbow. It gains the forearm 
between the condylar and the coronoid heads of the pronator radii teres. It is, 
in rare cases, fused with the musculocutaneous nerve. It is said to give 
off two articular branches to the elbow-joint. It supplies all the muscles on the 
anterior surface of the forearm except the flexor carpi ulnaris and one-half of the 
flexor profundus digitorum. It supplies the outer (radial) three and one-half 
fingers (palmar surface) with sensation. In the hand it supplies the two radial 
lumbricales and all the muscles of the thenar eminence except the adductor 
pollicis and the inner head of the flexor brevis pollicis. It is accompanied by a 
small artery below the elbow, which occasionally is as large as the radial artery, 
and passes beneath the anterior annular ligament. In the forearm the median 
nerve lies beneath the flexor sublimis digitorum. The digital branches of this 
nerve supply the joints of the thumb, index, and middle fingers and radial half 
of the ring finger. This nerve conveys gray rami communicantes for bone, 
fasciae, ligament, and bloodvessels in its course. 
The External Anterior Thoracic Nerve arises from the outer cord. It communi- 
cates with the internal anterior thoracic, a branch of the inner cord, pierces the 
clavi pectoral fascia, and supplies the pectoralis major muscle. 
The Musculocutaneous Nerve is a branch of the outer cord of the brachial plexus. 
It perforates, as a rule, the coracobrachialis muscle, and gains the intermuscular 
space between the biceps and brachial is anticus. It supplies the coracobrachialis, 
biceps, and brachialis anticus, that is, the muscles that flex the forearm on the 
arm ; the cutaneous part is distributed (1) to the skin over the outer and posterior 
part of the forearm as low as the wrist; (2) to the integument of the outer and 
anterior parts of the forearm and thenar eminence. The musculocutaneous nerve 
contains gray rami for bone, fascise, and vessels. 
The Internal Anterior Thoracic Nerve arises from the inner cord of the brachial 
plexus, and passes between the (first stage of) axillary artery and vein. It com- 
municates with the external anterior thoracic nerve and supplies the pectoralis 
minor and major muscles. It conveys gray rami for bone, fasciae, and vessels. 
The Ulnar Nerve is a branch of the inner cord of the brachial plexus. It is 
attended by the inferior profunda artery above the elbow, by the ulnar below. It 
gains the forearm between the two heads (olecranon and condylar) of the flexor 
carpi ulnaris. It supplies the flexor carpi ulnaris and the ulnar half of the flexor 
profundus digitorum. It supplies the little finger and the ulnar half of the ring 134 
A MANUAL OF DISSECTION. 
finger dorsally and palmarly. It supplies in the hand all the muscles not 
innervated by the median nerve : the palmaris brevis, abductor minimi digiti, 
flexor brevis minimi digiti, opponens minimi digiti, adductor transversus pollicis, 
adductor obliquus pollicis, inner head of flexor brevis pollicis, the two ulnar lum- 
bricales, and all the interossei of the hand. It gives articular branches to elbow 
and wrist, and all other joints moved by the muscles which it supplies. This 
nerve conveys gray rami for bone, fasciae, and vessels. 
The Internal Cutaneous Nerve is a branch of the inner cord of the brachial 
plexus. It lies on the inner side of the axillary artery at its origin; a little lower 
it lies between the artery and vein. In the upper two-thirds of the arm it is in 
front and internal to the brachial vessels. It accompanies the basilic vein. It 
supplies (1) the integument of the upper and inner part of the arm; (2) the 
integument of the anterior and postero-internal parts of the forearm. The nerve 
conveys gray rami for fasciae and vessels. 
The Lesser Internal Cutaneous Nerve (Wrisberg) is a branch of the inner cord 
of the brachial plexus. It supplies the integument on inner part of arm and ole- 
cranon process. In the axilla the nerve communicates with the intercostohumeral. 
The Subscapular Nerves arise from the posterior cord of the brachial plexus. 
They are named short, long, and lower. The short supplies the subscapularis 
muscle; the long accompanies the subscapular artery and supplies the latissimus 
dorsi; the lower supplies the teres major and gives filaments to the subscapularis 
muscle. The nerves convey gray rami communicantes. 
The Circumflex Nerve is a branch of the posterior cord of the brachial plexus. 
It accompanies the posterior circumflex vessels through the quadrilateral space. 
Branches: (1) Articular, to the shoulder; (2) muscular, to the teres minor; (3) 
muscular, to the deltoid; (4) cutaneous, to the skin over the middle and lower 
thirds of the deltoid muscle. This also contains gray rami communicantes. 
The Quadrilateral Space, through which the circumflex nerve and posterior 
circumflex vessels pass from the axilla to the back of the shoulder, is bounded 
above by the teres minor; below, by the teres major and latissimus dorsi; inter- 
nally, by the scapular or long head of the triceps ; externally, by the surgical 
neck of the humerus. 
The Musculospiral Nerve is a branch of the posterior cord of the brachial plexus. 
It is between the two humeral heads of the triceps muscle, in the musculospiral 
groove, with the superior profunda artery. In the lower third of the arm it lies 
between the brachialis anticus and supinator longus. In this space it gives 
branches to the radial group of muscles (supinator longus and extensors carpi 
radialis longior and brevior). It divides, here, into the radial and posterior 
interosseous. The posterior interosseous passes through the supinator brevis and 
supplies all the muscles on the posterior part of the forearm. The radial branch 
becomes cutaneous by piercing the deep fascia in the lower third of the forearm 
between the supinator longus and the extensor carpi radialis. In the hand, the 
radial nerve supplies with sensation the ball of the thumb and adjacent three and 
one-half fingers, dorsally. The musculospiral nerve gives off two cutaneous 
branches to the skin over the insertion of the triceps and anconeus. 
Communications. The brachial plexus communicates (1) above with the cervi- 
cal plexus; (2) below, with the first intercostal nerve, while one part of the first 
thoracic enters into the formation of the plexus; (3) internally, with the sympa- 
thetic vertebral ganglia, by means of gray rami communicantes. 
Gray Rami Communicantes. It is an established fact in physiology and anatomy 
that the bones, fasciae, and vessels of the trunk and extremities receive their 
sympathetic nerves through branches called gray rami communicantes. These 
nerves originate in cells of the vertebral ganglia, and reach the parts they supply 
with the spinal nerves. Throughout this book the student will be constantly 
reminded of the nerve-supply to such structures as bones, fasciae, and unstriped 
muscle-fibre of vessels; not that he is expected to find gray rami in the coats of 
an artery, but by constant repetition it is hoped to impress the fact that there is a THE NECK. 
135 
definite origin, course, and distribution for the gray rami communicantes. The gray 
rami are indigenous in every region of the spinal cord. Their trophic cells are in 
the vertebral ganglia of the sympathetic nerve. In descriptive texts on anatomy, 
students will have occasion to read that certain nerves give branches to certain 
arteries. For example, the femoral artery receives branches from the obturator 
and anterior crural nerves. These are the gray rami, departing from their 
escorts, to accompany the artery to bone, fascia, and vessel. (See Gerrish.) 
The Subclavian Artery is (1) below the brachial plexus, on the upper surface of 
the first rib, between the scalenus anticus and medius, in the first stage of the 
brachial plexus-the stage of emergence; (2) the artery is in front of the lower 
trunk and below and anterior to the middle and upper trunks, in the second stage 
of the plexus-the stage of trunks; (3) the artery is below, internal and anterior 
to the plexus, beneath the clavicle and subclavius muscle, in the third stage of 
the plexus-the stage of division of trunks; (4) the artery is surrounded by the 
outer, inner, and posterior cords, beneath the pectoral muscles, in the fourth 
stage of the plexus-the stage of cords. 
HYPOGLOSSAL NERVE. 
The Hypoglossal Nerve. The deep origin is from the whole length of the me- 
dulla oblongata by multipolar cells resembling those of the anterior horn of 
the spinal nerves. Its nucleus lies in line with that of the third, fourth, and sixth 
cranial nerves. The superficial origin is from a groove between the olivary 
body and anterior pyramid. In mode of origin it is identical with that of the 
motor roots of the spinal nerves. 
Roots. The hypoglossal nerve roots cross the vertebral artery and pierce the 
dura in two places. They unite to form one trunk in the anterior condylar fora- 
men, through which the nerve escapes from the cranium. At the base of the 
skull the nerve is between the internal carotid artery and the internal jugular 
vein. It passes below the posterior belly of the digastric muscle and around the 
occipital artery. After leaving the occipital artery, the nerve passes in front of 
the carotid vessels below the digastric and stylohyoid, lies on the hyoglossus 
muscle, and disappears behind the mylohyoid muscle to the tongue. 
Composite Character. 1. The hypoglossal is purely motor at its origin. 2. 
Sensory filaments from the first and second cervical nerves. 3. Sensory filaments 
from the pneumogastric. 4. Vasomotor fibres from the superior cervical ganglion. 
5. Motor fibres from the cervical plexus. 
Distribution. 1. A meningeal branch to the dura mater and occipital bone. 2. 
Vasomotor fibres to the tongue, derived from the superior cervical ganglion. 3. 
Sensory filaments to the tongue, derived from the second cervical nerve. 4. Sensory 
filaments to the tongue, derived from the vagus. 5. Motor branches to the hyo- 
glossus. 6. Motor branches to the styloglossus. 7. Motor branches to the genio- 
hyoglossus. 8. Motor branches to the superior lingualis. 9. Motor branches 
to the inferior lingualis. 10. Motor branches to the transverse lingualis. 11. 
Motor branches to the vertical lingualis. 
Communications. 1. With the trunk-ganglion of the vagus. 2. With the supe- 
rior cervical ganglion. 3. With the second and third cervical nerves. 4. With 
the lingual branch of the trifacial. 5. With the pharyngeal plexus. 6. According 
to Gerrish, the nerve to the sternohyoid and the sternothyroid muscles may give a 
communicating branch to the phrenic nerve. 
The Ansa Hypoglossi is formed by the union of a branch of the hypoglossal nerve 
(descendens hypoglossi) and two branches from the second and third nerves of the 
cervical plexus (communicantes hypoglossi). These branches meet on the carotid 
sheath and form a loop, from which branches are given off to the sternohyoid, 
sternothyroid, omohyoid, and thyrohyoid muscles. In other words, the depressor 
muscles of the hyoid bone derive their nerve-supply from the ansa hypoglossi. 136 
A MANUAL OF DISSECTION. 
SPINAL ACCESSORY NERVE. 
The Spinal Accessory Nerve emerges higher than the cervical nerves. It pierces 
the sternocleidomastoid muscle, crosses the occipital triangle, and enters and sup- 
plies the trapezius muscle. 
Subdivisions. 1. Spinal, which arises from the lateral columns of the spinal 
cord as low as the sixth cervical nerve. 2. Accessory, which arises from the me- 
dulla. This part joins the vagus, and is distributed with the pharyngeal and 
laryngeal branches of the same. 
The Spinal Part of the Nerve passes either anterior or posterior to the internal jug- 
ular vein and behind the digastric and stylohyoid muscles, having left the cranium 
through the jugular foramen. The nerve pierces the sternomastoid muscle, and, 
in company with the superior sternomastoid branch of the occipital artery, crosses 
the occipital triangle and enters the trapezius muscle. The nerve unites with 
branches of the third and fourth cervical nerves beneath the trapezius muscle to 
form a plexus. 
VAGUS OR PNEUMOGASTRIC NERVE. 
To make the identification of certain structures in the neck easier, the follow- 
ing abstract and table of the vagus nerve are appended : 
The vagus or pneumogastric nerve has a superficial and a deep origin. The 
superficial origin is by eight or ten filaments from a groove between the olivary 
and restiform bodies. The deep origin is from the nucleus vagi in the lower 
part of the floor of the fourth ventricle, beneath the ala cinerea and continuous 
with the nucleus of the ninth nerve. The sensory fibres arise in the cells in the 
ganglia of the root and trunk. Course: The vagus nerve escapes from the 
cranium through the jugular foramen with the ninth and eleventh nerves and the 
internal jugular vein. It passes vertically down the neck in the carotid sheath, 
between the internal jugular vein and the internal and common carotid arteries. 
Thence the courses of the two nerves are different. On the right side, the 
vagus crosses the subclavian artery (lying between this and the innominate 
vein) and descends by the side of the trachea to the back part of the root of 
the lung, where it forms the posterior pulmonary plexus ; whence two cords 
descend on the oesophagus, forming, with the branches of the opposite side, the 
plexus guise. From here, the nerve passes along the oesophagus to the posterior 
surface of the stomach. On the left side, the vagus enters the thorax between 
the left common carotid and the subclavian arteries, beneath the left innominate 
vein. It crosses the arch of the aorta, passes behind the root of the lung along 
the anterior surface of the oesophagus, and through the diaphragm to the anterior 
surface of the stomach. 
Ganglia. The vagus nerve has two ganglia (one of the root and one of the 
trunk), which contain the cells from which the sensory fibres of the vagus arise. 
These ganglia are derived from the fourth cephalic ganglion of the embryo. 
Ganglion of the Root. This is circular in form, grayish in color, about 
two lines in diameter, and located in the jugular foramen. To it is connected (1) 
the accessory portion of the spinal accessory nerve; (2) the petrous ganglion of 
the ninth nerve; (3) the facial nerve, through the auricular branch ; (4) the supe- 
rior cervical ganglion of the sympathetic, through ascending filaments of this 
latter. 
Ganglion of the Trunk. This is about an inch long, cylindrical in form, 
involving all the fibres of the nerve. The accessory portion of the eleventh 
nerve passes through this ganglion. It is connected to (1) the twelfth nerve; 
(2) the superior cervical ganglion; (3) the loop between the first and second 
cervical nerves. 137 
THE NECK. 
Fig. 70. 
Distribution of the right pneumogastric nerve. (W. Keiller, in Gerrish's Anatomy.) 138 
A MANUAL OF DISSECTION 
Table of Branches of the Vagus. 
Name. 
Source and Course. 
Distribution. 
Meningeal 
Ganglion of the root in the jugular fora- 
Sensory to the dura mater in the posterior 
nerve. 
men ; it runs backward into the cranial 
cavity. 
fossa at the base of the skull. 
Auricular 
Ganglion of the root in the j ugular fora- 
1. A branch to the facial nerve, where the 
(Arnold's) 
men ; is joined here by the nerve from 
auricular crosses this (the seventh) about 
nerve. 
the petrous ganglion of the glosso- 
pharyngeal ; enters Arnold's canal on 
the outer' wall of the jugular fossa, 
traverses petrosa, to the auricular 
fissure, between the mastoid process 
and the external auditory meatus. It 
crosses the facial nerve about two lines 
above the stylomastoid foramen. 
two lines above the stylomastoid foramen. 
2. At the auricular fissure the nerve divides 
into two branches and supplies the pos- 
terior part of the pinna and the posterior 
part of the external auditory meatus ; 
the other communicates with the poste- 
rior auricular branch of the facial nerve. 
Romberg relates the case of cough and 
vomiting due to hypersesthesia of the 
auricular branch of the vagus. 
Superior 
Inferior ganglion of the vagus, and con- 
1. The external laryngeal branch passes 
laryngeal 
sists principally of fibres from the ac- 
beneath the sternothyroid to the crico- 
nerve. 
cessory part of the spinal accessory 
nerve (since this passes through the 
ganglion). It receives a branch from 
the superior cervical ganglion, and 
passes along the pharynx to the side of 
the larynx, behind the internal carotid 
artery. It divides into internal and 
external laryngeal branches. 
thyroid muscle, pharyngeal plexus, in- 
ferior constrictor of the pharynx, and 
communicates with the superior cardiac 
nerve. 
2. The internal laryngeal branch perforates 
the thyrohyoid membrane, supplies the 
epiglottis, base of the tongue, mucous 
membrane of the larynx (as low as the 
true vocal cords), and gives a communi- 
cating branch to the recurrent laryngeal 
nerve on the inner surface of the thyroid 
cartilage, beneath the mucous membrane. 
Inferior or 
On the right side the nerve arises from 
(1) A communicating twig to the internal 
recurrent 
the vagus in front of the subclavian 
branch of the superior laryngeal nerve, 
which gives a few filaments to the lower 
laryngeal 
artery, winds around this vessel, and 
ascends to the side of the trachea, be- 
hind the common carotid and inferior 
thyroid arteries. (It may pass in front 
of the inferior thyroid artery.) It now 
ascends in the groove between the 
trachea and oesophagus, and beneath 
lower border of the inferior constrictor 
of the pharynx, enters the larynx 
behind the crico-tbyroid articulation. 
nerve. 
part of the larynx; (2) to all intrinsic 
muscles of the larynx except the crico- 
thyroid ; (3) cardiac filaments unite with 
similar branches from the sympathetic 
and vagus; (4) oesophageal branches; 
(5) tracheal branches to the trachea and 
pharyngeal branches to the inferior con- 
strictor of the pharynx. 
On the left side the nerve arises from the 
vagus in front of the aortic arch, 
passes around the arch internal to the 
remains of the ductus arteriosus and 
ascends to the side of the trachea, 
whence its course is the same as that 
of the right nerve. 
(Same as nerves on the right side.) 
Cervical car- 
Arise from the vagus at the upper and 
Superior to deep cardiac plexus with the 
diac nerves. 1 
back part of the neck-are called supe- 
rior and inferior. On the right side 
the inferior branch accompanies the 
cardiac branches of the sympathetic, 
with which they communicate. The in- 
ferior branches arise just above the first 
Thoracic car- 
innominate artery ; on the left it crosses 
the arch of the aorta. 
rib. and are distributed on the right side 
to the deep cardiac plexus with the car- 
diac sympathetic ; on the left side to the 
superficial cardiac plexus. 
On the right side from the trunk of the 
They pass inward and end in the deep 
diac nerves. 
vagus by the side of the trachea and 
recurrent laryngeal. On the left side 
from the recurrent laryngeal. 
cardiac plexus. 
Anterior pul- 
From vagus ; are small and two or three 
Join the filaments of the sympathetic from 
monary 
nerves. 
in number. 
the superior cervical ganglion and glosso- 
pharyngeal, and form the anterior pul- 
monary plexus distributed to the surface 
of the root of the lung. 
(Esophageal 
Vagus both above and below, pulmonary 
Branches of the two sides unite to form the 
nerves. 
branches ; lower more numerous than 
upper. 
plexus gulae or oesophageal plexus, from 
which the branches are distributed to 
the pericardium and oesophagus. 
Gastric 
nerves. 
The vagus ends in the gastric branches. 
The right gastric branch is distributed to 
the posterior surface of the stomach ; the 
left, to the anterior. CHAPTER VIII. 
THE THORACIC AND SHOULDER REGIONS. 
Dissection and Identification. Remove integument, as indicated in Figs. 74 and 76. 
Consult accompanying illustrations and find structures on cadaver in the order in which they 
are here given. 
Sternum. Identify (1) by its location in the mid-line of the front of the thorax ; (2) by its 
articulation with the inner end of the clavicle and the true ribs; (3) by a pronounced notch 
between the inner ends of the clavicles above and a prominent, movable, xiphoid or ensi- 
form cartilage below. 
Clavicle. Identify (1) by its location at the junction of the neck and thorax, extending 
from the upper end of the sternum outward to the acromion process of the scapula near the 
tip of the shoulder; (2) by its characteristic shape (italic f) and subcutaneous situation ; (3) 
by its attachment to the sternum, acromion, and first rib. 
Acromion Process. Identify (1) by its location at the tip of the shoulder; (2) by its con- 
tinuity with the spine of the scapula; (3) by its articulation with the outer end of the clavicle 
(acromioclavicular); (4) by its situation at the apex of a V, the limbs of which are formed by 
the clavicle and scapular spine. 
Coracoid Process. Identify (1) by its location under cover of the deltoid beneath the 
middle third of the clavicle; (2) by its attachment to the upper surface and inner border of 
the pectoralis minor, its outer border to the coraco-acromial ligament, its apex to the short 
head of the biceps and coracobrachialis muscles. 
Arm-pit. Identify, when arm is at right angles to the thorax, as a depression (covered by 
hair), limited in front by the pectoralis major, behind by the latissimus dorsi, teres major, and 
scapula, internally by the ribs and serratus magnus muscle, externally by the humerus. 
Superficial Fascia. Identify (1) by its location immediately beneath the skin ; (2) by its 
loose cellulo fibrous structure enclosing fat in its spaces ; (3) by its continuity with the superficial 
fascia of the neck, shoulder, arm, and abdomen ; (4) by its non-attachment to bony emi- 
nences; (5) bvits division into two lamellae, between which are located the mammary glands. 
Cephalic Vein. Identify by location in a groove between the pectoralis major and deltoid 
muscles with the descending branch of the acromial-thoracic artery. (See table, and illustra- 
tion of cutaneous veins.) 
Deep Fascia. Identify (1) by its location beneath the superficial fascia; (2) by its attach- 
ment to the sternum, clavicle, acromion, and scapular spine; (3) by its continuity with the 
deep fascia of the axilla, thorax, and back; (4) by perforations for transmission of nerves and 
vessels to skin, and superficial fascia. 
Pectoralis Major Muscle. Identify (1) by its location at the upper and forepart of the 
chest in front of the axilla; (2) by its origin from the inner half of the clavicle, sternum, 
cartilages of true ribs, and aponeurosis of external oblique muscle. 
Pectoralis Minor Muscle. Identify (1) by its location beneath the pectoralis major and its 
triangular shape; (2) by its origin from the upper margins and outer surfaces of the third, fourth, 
and fifth ribs near their cartilages, and insertion into the inner border and upper surface of 
the coracoid process of the scapula ; (3) by the attachment of the costo coracoid membrane to 
its upper border; (4) by the relation of its posterior surface to the axillary vessels and 
brachial plexus. 
Deltoid Muscle. Identify (1) by its triangular shape (apex down) and the rounded outline 
it confers on the shoulder; (2) by its origin from the outer third of the anterior border and 
upper surface of the clavicle, from the outer margin and upper surface of the acromion 
process, and from the lower lip and posterior border of the spine of the scapula; (3) by its 
insertion into the middle of the outer surface of the humerus; (4) by its extent, covering the 
anterior, outer, and posterior sides of the shoulder-joint. 
Biceps Muscle. Identify (1) by its fusiform shape and location on the whole anterior 
surface of the arm; (2) by the two heads of origin-a short from the apex of the coracoid 
process (in common with the coracobrachialis), a long from the upper margin of the glenoid 
cavity of the scapula; (3) by its insertion into the bicipital tuberosity of the radius. 
Brachial Artery. Identify (1) by its origin (as a continuation of the axillary) at the 
tendon of the teres major, and termination on the flexor surface, at the bend of the elbow, in the 
radial and ulnar; (2) by its location internal to the biceps, coracobrachialis, and median nerve. 
Coracobrachialis Muscle. Identify (1) by its origin from the apex of the coracoid process 
of the scapula with the short head of the biceps ; (2) by its insertion into the middle of the 
internal surface and internal border of the humerus; (3) by being perforated by the musculo- 
cutaneous nerve ; (4) by the relation of its anterior surface with the pectoralis major muscle, 140 
A MANUAL OF DISSECTION 
median nerve, and brachial vessels ; (5) by the relation of its posterior surface with the anterior 
circumflex vessels, humerus, inner head of the triceps, teres major, latissimus dorsi, and 
subscapularis muscles. 
Brachialis Anticus Muscle. Identify (1) by its origin from the lower half of the outer 
and inner surfaces of the humerus; (2) by its insertion into the coronoid process of the ulna; 
(8) by the relation of its anterior surface with the biceps muscle, brachial vessels, median and 
musculocutaneous nerves; (4) by the relation of the posterior surface with the humerus and 
elbow-joint. 
Fig. 71. 
Deep nerves of the front of the right arm. (Gerrish after Testut.) 
Musculocutaneous Nerve. Identify (1) by its location between the biceps and brachialis 
anticus muscles; (2) by passing through the coracobrachialis muscle (usually); (3) by dis- 
tribution to biceps, coracobrachialis, brachialis anticus, humerus, elbow, and skin of anterior- 
part of forearm. 
Circumflex Nerve and Posterior Circumflex Vessels. Cut the deltoid near insertion, turn 
same upward over the shoulder, and identify the nerve and the vessels emerging from the 
quadrilateral space and entering the deep surface of the deltoid muscle. (See Fig. 74.) THE THORACIC AND SHOULDER REGIONS. 
141 
INTERMUSCULAR SEPTA. 
The External Intermuscular Septum, derived from the deep fascia, is attached to 
the outer lip of the bicipital groove, external condylar ridge of humerus, and 
outer humeral condyle, and gives attachment to the triceps, brachialis anticus, and 
supinator longus muscles. It is blended with the tendon of the deltoid muscle 
and is perforated by the musculospiral nerve and superior profunda artery. 
jt^The Internal Intermuscular Septum, a derivative of the deep fascia, is attached to 
the internal lip of the bicipital groove, internal condylar ridge, internal condyle, 
and gives attachment to the triceps and brachialis anticus muscles. It blends with 
the tendon of the coracobrachialis, and is perforated by the ulnar nerve, inferior 
profunda artery, and certain anastomotic arterial branches. 
THE MUSCLES. 
The Pectoralis Major Muscle. Origin: (1) Inner half of clavicle ; (2) anterior 
surface of sternum ; (3) cartilages of second, third, fourth, fifth, aud sixth ribs ; 
(4) sheath of rectus muscle. Insertion: External lip of bicipital groove, deltoid 
Fig. 72. 
Pectoralis minor ot right side. (Gebkish alter Testut.) 
tendon, and adjacent septa. Action: Adduction, flexion, and inward rotation of 
arm. Synergist: Subscapularis. Antagonists: Deltoid, supraspinatus, teres 
major, teres minor, latissimus dorsi. Nerves: External and internal anterior 
thoracic from outer and inner cords of brachial plexus. Arteries: Internal mam- 
mary, long thoracic, acromial-thoracic. The external anterior thoracic nerve from 
the outer cord of the brachial plexus (fifth, sixth, and seventh cervical nerves) 
crosses the axillary vessels, pierces the costo-coracoid membrane, and communicates 
with the internal anterior thoracic nerve. 142 
J. MANUAL OF DISSECTION. 
The Pectoralis Minor muscle arises from the third, fourth, and fifth true ribs, 
and is inserted into the anterior border of the coracoid process of the scapula. Its 
nerve is the internal anterior thoracic, a branch of the inner cord of the brachial 
plexus. The internal anterior thoracic nerve sends filaments to the major pec- 
toral muscle and passes between the axillary artery and vein. 
The Subclavius Muscle. Origin: Junction of first rib and its cartilage. Inser- 
tion: Groove on under surface of middle third of clavicle. Action: To depress 
shoulder by drawing clavicle downward and forward. Nerve : Prom upper trunk 
of brachial plexus. Synergist: Serratus magnus. Antagonist: Trapezius. The 
subclavius muscle, brachial plexus, and subclavian vessels are beneath the clavicle. 
Fig. 73. 
Serratus magnus of right side. The scapula has been turned backward and drawn outward. (Modified from 
Gerrish after Testut.) 
The Costo-coracoid Membrane fills the space between the clavicle and pectoralis 
minor muscle and covers the axillary vessels and nerves. The membrane is 
attached to clavicle, sheath of subclavius muscle, first rib, coracoid process, and 
minor pectoral muscle. It is pierced by the cephalic vein, anterior thoracic nerves, 
and acromial thoracic vessels. The part of the membrane extending from the first 
rib to the coracoid process is called the costo-coracoidjigament. 
The Serratus Magnus Muscle. Origin: Outer surface of eight or nine ribs. 
Insertion: Anterior lip of vertebral border of scapula. Action: To draw verte- 
bral border of scapula forward. Synergist: Pectoralis minor. Antagonist: Tra- 
pezius. Nerve: Posterior thoracic, from brachial plexus above clavicle. Arteries : THE THORACIC AND SHOULDER REGIONS. 
143 
Intercostals. Nerve: The posterior thoracic from fifth, sixth, and seventh cervi- 
cal nerves, at their emergence from the intervertebral foramina. The nerve passes 
behind the brachial plexus and axillary vessels, and as it lies on the serratus 
magnus muscle, gives branches to each digitation thereof. 
The Biceps Muscle has two heads (short and long). Origin of short head: Apex 
of coracoid process, with coracobrachialis. Origin of long head: Supraglenoid 
tubercle above glenoid cavity. Insertion: Bicipital tuberosity of radius and deep 
fascia of forearm. Action: Flexion of forearm. Synergists: Brachialis anticus 
and supinator longus. Antagonist: Triceps. Nerve: Musculocutaneous. Artery: 
Brachial. The bicipital fascia, extending from the inner side of the tendon of 
biceps, opposite bend of elbow, crosses brachial vessels and blends with the deep 
fascia of upper and inner forearm region. 
The Coracobrachialis Muscle. Origin: Apex of coracoid process. Insertion : 
Middle third of humerus, inner border. Action: Adduction and flexion of 
humerus. Synergist: Pectoralis major. Antagonists : Infraspinatus and teres major. 
Nerve : Musculocutaneous, from outer cord of brachial plexus. Artery : Acromial- 
thoracic and brachial. This muscle is pierced by the musculocutaneous nerve. 
Brachialis Anticus Muscle. Origin : Lower half of internal and external sur- 
faces of humerus. Insertion: Coronoid process of ulna. Action : Flexion of 
forearm. Nerve : Musculocutaneous, from outer cord of brachial plexus. Artery : 
Brachial. Synergists : Biceps and brachio-radialis. Antagonist: Triceps. 
The Deltoid Muscle. Origin: (1) Outer third of clavicle ; (2) outer border of 
acromion process ; (3) lower lip of scapular spine. Insertion: Outer surface of 
humerus in lower part of upper third. Action: Abduction, extension, and exter- 
nal rotation of humerus. Synergists: Supraspinatus, infraspinatus, teres minor. 
Antagonists: Pectoralis major, subscapularis. Nerve: Circumflex, from pos- 
terior cord of brachial plexus. Arteries : Acromial-thoracic, anterior and posterior 
circumflex. 
The Teres Minor Muscle. Origin : (1) Upper two-thirds of axillary border of 
scapula ; (2) adjacent intermuscular septa. Insertion : Greater tuberosity of hu- 
merus and capsule of shoulder-joint. Action: External rotation. Synergist: 
Infraspinatus. Antagonists: Subscapularis and pectoralis major. Nerve: Cir- 
cumflex. Artery: Posterior circumflex. 
(The Quadrilateral Space is bounded externally by neck of humerus ; internally 
by long head of triceps ; above by teres major behind and subscapularis in front; 
below by teres major and latissimus dorsi. See page 134.) 
The Supraspinatus Muscle. Origin: (1) Inner two-thirds of supraspinous fossa; 
(2) spine of scapula and supraspinous fascia. Insertion: Greater tuberosity of 
humerus and capsule of shoulder-joint. Action: Abduction. Synergist: Del- 
toid. Antagonists : Pectoralis major and subscapularis. Nerve: Suprascapular, 
from brachial plexus (above the clavicle). Artery : Suprascapular. 
The Infraspinatus. Origin: (1) Infraspinous fossa, inner two-thirds ; (2) spine 
of scapula ; (3) fascia and intermuscular septum, between it and tereal muscles. 
Insertion : Greater tuberosity of humerus. Action : External rotation. Syner- 
gist: Teres minor. Antagonists: Subscapularis and pectoralis major. Nerve: 
Suprascapular. Artery: Suprascapular. 
The Suprascapular Nerve arises from the upper trunk of the brachial plexus and 
passes beneath the trapezius muscle through the suprascapular notch. Distribu- 
tion : To supraspinatus and infraspinatus muscles, to shoulder-joint; gray rami 
communican tes. 
The Suprascapular Artery arises from thyroid axis of the subclavian, passes 
behind and parallel to the clavicle, beneath the omohyoid muscle to the supra- 
spinous fossa. It does not pass through the suprascapular notch with the supra- 
scapular nerve, but crosses the transverse scapular ligament. The suprascapular 
artery anastomoses with the acromial-thoracic, posterior circumflex, subscapular, 
and posterior scapular arteries, and is attended by one or two veins, whose tribu- 
taries correspond to branches of the artery, in number and location. 144 
A MANUAL OF DISSECTION. 
THE NERVES. 
The Musculocutaneous Nerve is a branch of the outer cord of the brachial plexus. 
It pierces coracobrachialis, lies between biceps and brachialis anticus, and becomes 
cutaneous above elbow to outer side of biceps tendon. There are two nerves for 
biceps, one for each head. The nerve to coracobrachialis muscle is given off near 
origin of this muscle. The cutaneous branch is distributed to skin of front and 
outer part of forearm. The humerus, elbow, and greater part of the brachialis 
anticus are supplied by this nerve. 
The Circumflex Nerve, a branch of the posterior cord of brachial plexus, supplies 
deltoid, teres minor, shoulder-joint, and integument over lower two-thirds of del- 
toid. It gains posterior part of arm through quadrilateral space with posterior 
circumflex vessels. The posterior circumflex artery is a branch of the axillary and 
Fig. 74. 
Suprascapular and circumflex nerves of right side, seen from behind. (Gerrish after Testut.) 
lias two venae comites. The anterior circumflex artery, smaller than the posterior, 
is a branch of the axillary ; it passes beneath the coracobrachialis and the short 
head of biceps to the bicipital groove, whence its branches proceed to the shoulder- 
joint and head of the humerus. 
AXILLARY SPACE. 
The Axillary Space (analysis, Fig. 75). The apex, the highest part of the space, 
is bounded by the first rib, clavicle, and superior border of the scapula. The 
axillary vessels and brachial plexus of nerves pass through it. The apex is a 
passage connecting root of neck with axillary space. The base of axillary space 
is the lowest part. It corresponds to the hollow under the arm. The base is 
composed of hairy skin, superficial and deep fasciae. The deep fascia of the 
base is the axillary fascia. The structures forming axillary base extend from 
lower margin of pectoralis major to latissimus dorsi and teres major muscles. 
The anterior boundary is formed by skin, superficial fascia, pectoral fascia, 
pectoralis major muscle, pectoralis minor muscle, costo-coracoid membrane, and THE THORACIC AND SHOULDER REGIONS. 
145 
subclavius muscle. The posterior boundary is formed by the subscapularis, latis- 
simus dorsi, and teres major muscles. The inner boundary is formed by first 
four ribs, their intercostal muscles, and a portion of the serratus magnus muscle. 
The external boundary is narrow and formed by the humerus, biceps, and coraco- 
brachialis muscles. Contents : (1) Axillary artery and its branches ; (2) axillary 
vein and its tributaries; (3) brachial plexus and its branches ; (4) intercosto- 
humeral nerve (the lateral cutaneous branch of second intercostal) distributed to 
skin of arm ; (5) ten or twelve lymphatic glands, which surround the axillary 
vessels. These vessels, nerves, and glands are bound together by connective 
tissue, within which is more or less fat. (See Gray's Anatomy.) 
AXILLARY ARTERY. 
The Axillary Artery, a continuation of the subclavian, begins at the outer 
border of the first rib and ends at the base of the axillary space. The artery has 
Fig. 75. 
Axillary and subclavian arteries. (Gerrish after Testut.) 
three stages-first, second, and third. The first stage extends from the outer 
border of the first rib to the upper border of the pectoralis minor muscle. The 
second stage is beneath the pectoralis minor. The third stage extends from the 
lower border of the pectoralis minor to the base of the axillary space. 
The Axillary Vein has the same course and stages as the artery. It lies internal 
to and partially obscures the artery. It begins at the base of the axillary space 
as a continuation of the basilic vein and ends in the subclavian vein. Its tribu- 
taries correspond in the main to the branches of the artery. (See Gerrish.) 
Relations of Axillary Artery (superficial, internal, external, and posterior). 1. 
Superficial : Skin, superficial and deep fasciae, pectoral muscles, costo-coracoid 146 
A MANUAL OF DISSECTION. 
membrane, clavicle, subclavius muscle, external anterior thoracic nerve, cephalic 
vein, acromial-thoracic vessels, and inner head of median nerve. 2. Internal : 
Axillary vein, inner cord of brachial plexus, ulnar, and internal cutaneous 
nerves. 3. External: Coracobrachialis muscle, brachial plexus, median and 
musculocutaneous nerves. 4. Posterior: Subscapularis, teres major, latissimus 
dorsi, first intercostal space, second and third serrations of serratus magnus, 
posterior thoracic nerve, internal anterior thoracic nerve, musculospiral and 
circumflex nerves. 
The branches of the axillary artery are: 1. The superior thoracic (from first 
portion), which passes between the pectoral muscles (to side of the chest), to both 
of which it is distributed. 
2. Acromial thoracic (from first portion), which courses to upper border of the 
minor pectoral muscle, dividing into acromial, thoracic, and humeral branches for 
distribution in these respective regions. 
3. Long thoracic (from second portion), which courses along the lower border 
of the minor pectoral muscle to axillary and mammary glands and contiguous 
regions. 
4. Alar thoracic (from second portion), which pass to the axillary space for the 
supply of the axillary connective tissue and axillary glands. 
5. Subscapular (from third portion), which passes along the subscapularis 
muscle to the posterior wall of the axilla, deltoid, triceps, infraspinatus, and latis- 
simus dorsi. 
6. Anterior circumflex (from third portion), which passes beneath the coraco- 
brachialis and short head of the biceps muscle to the head of the humerus and 
shoulder-joint. 
7. Posterior circumflex (from third portion), which, passing through quadrilat- 
eral space with the circumflex nerve, is distributed to the deltoid muscle. (See 
p. 134.) 
BRANCHES OF BRACHIAL PLEXUS. 
Dissection. The brachial plexus has been described on page 131. It now becomes neces- 
sary to dissect its branches of distribution. The following order is advised : 1. Consult 
Fig. 76 and find the name and location of the particular nerve. 2. Dissect the nerves in the 
order given below; first, those derived from the outer cord (three) ; second, those derived 
from the inner cord (five); third, those derived from the posterior cord (three). 3. Study the 
relation of median, ulnar, circumflex, and musculospiral to the axillary artery. 4. Trace 
the musculocutaneous through the coracobrachialis muscle and the circumflex through the 
quadrilateral space. 5. Associate nerves and arteries in the following cases : (a) The median, 
with the brachial; (6) the ulnar (above the elbow), with the inferior profunda; (c) the mus- 
culospiral, with the superior profunda; (cZ) the radial, with the radise; (e) the ulnar (below 
the elbow), with the ulnar; (/) the circumflex, with the posterior circumflex. 
The three cords of the brachial plexus give off the following branches below the 
clavicle : 
The outer cord. 1. External anterior thoracic, which crosses the axillary ves- 
sels, pierces the costo-coracoid membrane, and supplies the pectoralis major, form- 
ing communication with the internal anterior thoracic nerve. 
2. Musculocutaneous, which perforates the coracobrachialis, passes between the 
biceps and brachialis anticus to the muscles of the front of the arm, humerus, 
elbow-joint, and skin of the anterior part of the forearm. 
3. Outer head of the median nerve, which unites with the inner head (from 
inner cord) for the supply of («) all muscles of front of forearm, except flexor 
carpi ulnaris and inner half of flexor profundus digitorum) ; (6) all muscles of 
ball of thumb (except adductor pollicis and inner head of flexor brevis pollicis) ; 
(c) the two outer lumbrical muscles ; (d) skin of palmar surface of thumb, index, 
middle, ami radial half of ring finger ; (e) articular branches to certain joints. 
The inner cord. 1. Inner head of the median nerve, which unites with the 
outer head. (See above.) THE THORACIC AND SHOULDER REGIONS. 
147 
Fig. 76. 
Nerves of the left upper extremity. (Gray.) 148 
A MANUAL OF DISSECTION. 
2. Internal anterior thoracic, which passes (between axillary artery and vein) 
(a) to the under surface of the pectoralis minor ; (6) through the costo-coracoicl 
membrane to the pectoralis major muscle. 
3. Internal cutaneous, which passes downward (internal to brachial artery), 
pierces the deep fascia, with basilic vein, in middle third of arm, and is distrib- 
uted (a) to the skin covering the biceps; (6) to the skin of the anterior and poste- 
rior surfaces of the forearm on the ulnar side. 
4. Lesser internal cutaneous (Wrisberg), which passes behind and internal to 
the axillary vein, and along brachial artery to the middle of the forearm, where 
it pierces the deep fascia and is distributed (a) to the skin of the back of the 
lower third of the arm ; (6) to the skin over the olecranon process and inner 
condyle. 
5. Ulnar, which passes along the inner side of the axillary and brachial arteries 
to the middle of the arm, where it crosses the inner head of the triceps and pierces 
the internal intermuscular septum; thence it descends between the olecranon 
process and internal condyle (with the inferior profunda artery), passes between 
the two heads of the flexor carpi ulnaris to the forearm, and is distributed (a) to 
the flexor carpi ulnaris and ulnar half of the flexor digitorum profundus ; (6) to 
the adductor pollicis and ulnar head of the flexor brevis pollicis; (c) to the 
adductor trans versus and obliquus pollicis ; (d) to the two ulnar lumbricals ; (e) 
to all the interossei muscles of the hand ; (/) to the integument of the little 
finger and ulnar side of the ring finger, dorsally and palmarly. 
The posterior cord. 1. Three subscapular nerves (upper, lower, and middle), 
distributed as follows : (a) the upper, to the subscapularis muscle; (6) the lower, 
to the teres major ; (c) the middle, to the latissimus dorsi. 
2. Circumflex nerve, which passes through the quadrilateral space (with the 
posterior circumflex artery) to (a) deltoid and teres minor muscles; (6) skin cover- 
ing the lower two-thirds of the deltoid muscle ; (c) skin covering the long head 
of the triceps. 
3. Musculospiral, which passes behind the axillary and upper part of the bra- 
chial arteries, thence through the musculospiral groove (on the posterior surface 
of the humerus) with the superior profunda artery to the following distribution : 
(a) triceps ; (6) muscles of radial and posterior parts of the forearm ; (c) skin 
of posterior part of the arm, forearm, and hand. 
BRACHIAL ARTERY. 
The Brachial Artery begins at the lower border of the tendon of the teres major 
(as a continuation of the axillary) and ends at the bend of the elbow in the radial 
and ulnar. The artery is attended by two veins, which lie one on each side 
of the artery, and unite just above the lower margin of the tendon of the latis- 
simus dorsi to form the axillary vein. With the exception of the nutrient, 
branches of the axillary vein correspond in number and location to those of the 
artery. 
Relations : The brachial artery (with its two venae comites) has the following rela- 
tions : Anterior : Integument, superficial fascia, deep fascia. Posterior : Triceps 
muscle, musculospiral nerve, superior profunda artery, coracobrachialis insertion, 
brachialis anticus muscle. External : Median nerve, coracobrachialis and biceps 
muscles. Internal: Internal cutaneous nerve, ulnar nerve, median nerve, below, 
and basilic vein in the upper half. 
The brachial artery has the following branches : 
1. Superior profunda (from the inner and back part), which passes between the 
inner and outer heads of the triceps with the musculospiral nerve, to the fol- 
lowing distribution : (a) anterior and posterior articular ; (6) nutrient to humerus ; 
(c) muscular branches to triceps. THE THORACIC AND SHOULDER REGIONS. 
149 
2. Nutrient (middle of arm), which passes through the nutrient canal of the 
humerus to the medulla of the shaft of this bone, anastomosing with the periosteal 
arteries. 
3. Inferior profunda (below middle of arm), which accompanies ulnar nerve, and 
anastomoses with the anterior and posterior ulnar recurrent arteries. 
4. Anastomotica magna (two inches above elbow), which crosses the brachialis 
anticus and is distributed to the triceps, and anastomoses with the anterior and 
posterior ulnar recurrent, superior, and inferior profundae. 
5. Muscular branches (three or four) are given off in its course to the biceps, 
coracobrachialis, and brachialis anticus. CHAPTER IX. 
CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY-ANTERIOR 
REGION OF FOREARM. 
Dissection, Identification. Remove the integument, as indicated in Fig. 77. Be guided by 
the illustrations and text in identifying the structures found. When dissecting the nerves and 
vessels, divide the connective tissue surrounding the same in the direction of the main trunk 
and its branches. Do not use the scalpel in developing the branches of vessels and nerves. 
Superficial Fascia. Identify (1) by its location immediately beneath the integument and 
a variable amount of fat in its meshes; (2) by the free mobility it confers on the skin (except 
in the soles and palms); (3) by the presence of a large number of cutaneous arteries, veins, and 
nerves. 
Fig. 77. 
Dissection of upper extremity. (Gray.) 
Deep Fascia. Identify (1) by its location beneath the superficial fascia; (2) by its attach- 
ment to the bony eminences about the elbow and wrist, and formation of the septa and sheaths; 
(3) by the aponeurotic expansion it receives from biceps, triceps, and brachialis anticus; (4) 
by continuity with the anterior annular ligament at the wrist. 
Cutaneous Veins. Identify by its location in the superficial fascia. To make a thorough 
study of these structures on the cadaver, turn to the proper illustration (Fig. 80) and seek the 
name of a given vein; then find this name in the first column of the table of cutaneous veins 
on page 155. In the second, third, and fourth columns study their source, course, and distri- 
bution, respectively. CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
151 
Cutaneous Nerves. Identify (1) by their distribution to skin ; (2) by their passage through 
perforations in the deep fascia and their location in the deep layer of the superficial fascia. 
Study their source, course, and distribution by the illustrations and the table of cutaneous 
nerves (Figs. 81, 82), the same as the veins are studied. 
Fig. 78. 
Fig. 79. 
Ulnar and radial arteries. Deep view. (Gray.) 
The radial and ulnar arteries. (Gray.) 152 
A MANUAL OF DISSECTION. 
Anterior Annular Ligament. Identify (1) by its location on the front of the carpus, with 
firm attachments to the carpal bones; (2) by its continuity with the palmar fascia below and 
the deep fascia of the forearm above; (3) by the presence beneath it of the median nerve, 
flexor of thumb, and flexors of the fingers beneath. 
Fig. 80. 
The superficial veins of the upper extremity. (Gray.) CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
153 
Palmar Fascia. Identify (1) by its location on the palmar surface of the hand; (2) by its 
continuity with the anterior annular ligament above; (3) by its strong, glistening appearance, 
seen when the superficial fascia and granular fat are removed. 
Fig. 81. 
Cutaneous nerves of the upper limb, ventral aspect. (Gerrish after W. Keiller.) 
Fibrous Sheaths (ligamenta vaginalia). Identify (1) by the location on the flexor surface 
of the fingers ; (2) by the contents-the tendons of the flexors sublimis and profundus digi- 
torum inverted by a synovial membrane called the theca. (Fig. 84.) 154 
A MANUAL OF DISSECTION. 
The Common Tendon. This is identified by its attachment to the inner humeral condyle. 
It gives partial origin to the pronator radii teres, flexor carpi radialis, palmaris longus, flexor 
sublimis digitorum, and flexor carpi ulnaris. 
Fig. 82. 
Cutaneous nerves of the upper limb, dorsal aspect. (Gerrish after W. Keilleb.) 
Pronator Radii Teres. Identify (1) by its insertion into the middle of the outer surface of 
the radius; (2) by the two heads, between which the median nerve gains the forearm. 
Flexor Carpi Radialis. Identify (1) by its passage through a groove in the os trapezium 
and insertion into the bases of the second and third metacarpals; (2) by its adjacency to the 
radial artery. CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
155 
Palmaris Longus. Identify (1) by its insertion into the anterior annular ligament and 
palmar fascia;'(2) by its delicate tendon (sometimes absent) in the mid-line of the lower part 
of the forearm. 
Flexor Sublimis Digitorum. Identify (1) by its four terminal tendons slit and transmitting 
the four corresponding tendons of the flexor profundus digitorum ; (2) by its insertion into the 
sides of the second phalanges. 
Flexor Carpi Ulnaris Identify (1) by its location on the ulnar side of the forearm; (2) 
by its insertion into the pisiform and adjacent bones; (3) by the adjacency of the ulnar artery 
and nerve. 
Flexor Profundus Digitorum Identify (1) by its origin from the ulna and interosseous 
membrane; (2) by its division into four tendons, which passthrough the slits in the corre- 
sponding tendons of the flexor sublimis digitorum 
Flexor Longus Pollicis. Identify (1) by the origin from the anterior surface of the radius ; 
(2) by its insertion into the base of the distal phalanx of the thumb. 
Pronator Quadratus. Identify by its quadrate shape and its location on the anterior sur- 
face of the lower fourth of the radius and ulna. 
Supinator Brevis. Identify (1) by its extensive origin from the outer condyle of the hu- 
merus and adjacent structures; (2) by the posterior interosseous nerve passing to the back of 
the forearm between the upper and deep parts of the muscle. 
Cubital Fossa. Identify (1) by its location at the bend of the elbow ; (2) by the presence 
of the brachial, ulnar, radial arteries, median nerve, tendon of biceps, and cutaneous veins 
and nerves. (Figs. 79, 80, 81.) 
Median Nerve. Identify (1) by its location to the inner side of the brachial artery in the 
cubital fossa; (2) by its location beneath the flexor sublimis digitorum in the forearm; (3) by 
its location beneath the anterior annular ligament with the flexors of the thumb and fingers. 
Ulnar Nerve. Identify (1) by its location between the two heads of the flexor carpi ulnaris ; 
(2) by its location in the ulnar groove (with the ulnar vessels), between the flexor carpi ulnaris 
and the flexor sublimis digitorum. 
Radial Artery. Identify (1) by its origin in the cubital fossa (from the bifurcation of the 
brachial) with the ulnar ; (2) by its location in its course downward on the tendon of the biceps, 
supinator brevis, flexor sublimis digitorum, pronator radii teres, flexor longus pollicis, pronator 
quadratus, and radius. 
Ulnar Artery. Identify (1) by its origin in the cubital fossa from the brachial with the 
radial; (2) by its course in the upper third of the forearm beneath all the muscles arising 
from the inner humeral condyle (except the flexor carpi ulnaris); (3) by its course in the lower 
two-thirds of the forearm in the ulnar groove with the ulnar nerve. (See Ulnar Nerve, p. 164.) 
Superficial Palmar Arch. Identify (1) by its source from the ulnar artery near the pisi- 
form bone; (2) by its arched course across the palm and location beneath the skin, fascia, 
palmaris brevis, palmar fascia, and resting on the flexor tendon of the fingers (Fig. 78); (3) 
by its distribution to all the digits except the thumb and radial side of the index ; (4) by its 
anastomosis on the radial side of the anterior ligament, with the superficialis volte of the 
radial artery. 
Deep Palmar Arch. Identify (1) by its source from the radial artery and course between 
the heads of the first dorsal interosseous muscle, between the adductor and flexor brevis pol- 
licis ; across the bases of the metacarpal bones; (2) by the anastomosis with deep branch of 
the ulnar artery. (Fig. 79.) 
Table of Cutaneous Veins of the Upper Extremity. (Fig. 80.) 
Name. 
Source. 
Course and Location. 
Destination. 
Dorsal plexus of 
Formed by veins from 
Located on the dorsum of 
Terminates in the radial, 
veins. 
the fingers. 
the hand, on the radial 
and ulnar sides. 
median, and ulnar veins. 
Anterior plexus 
Veins from the palm 
Located on the anterior 
Terminates in the median 
of veins. 
and thumb. 
part of the wrist. 
and anterior ulnar veins. 
Radial vein. 
Radial side of the dor- 
sal plexus of veins. 
Along the radial side of the 
forearm to the outer side 
of the tendon of the 
biceps muscle. 
Joins the median cephalic 
vein to form the cephalic 
vein. 
Posterior ulnar 
The ulnar side of the 
Back part of the ulnar sur- 
Is joined by the anterior 
vein. 
dorsal plexus. 
face of the forearm to 
the inner side of the in- 
ternal condyle. 
ulnar vein at the inner 
side of the internal con- 
dyle, to form the com- 
mon median vein, which 
latter unites with the 
median basilic, to form 
the basilic vein. 
Anterior ulnar 
The anterior plexus of 
Anterior surface of the 
Joins the posterior ulnar 
vein. 
the veins. 
forearm, on the ulnar 
side. 
near the elbow, to form 
the common ulnar vein. 
Common ulnar 
Confluence of the ante- 
Upward on the inner and 
Joins the median basilic to 
vein. 
rior and posterior 
ulnar veins. 
flexor part of elbow. 
form the basilic vein. 156 
A MANUAL OF DISSECTION. 
Name. 
Source. 
Course and Location. 
Destination. 
Median vein. 
The anterior plexus of 
veins on the front of 
the wrist. 
Along the median front of 
the forearm to the bend 
of the elbow. 
Divides into the median 
cephalic and median 
basilic, which help form 
the cephalic and basilic 
veins respectively. 
Median basilic 
Bifurcation of median 
Crosses the brachial and bi- 
Joins the common median 
vein. 
vein opposite the 
elbow. 
cipital fasciae and in- 
ternal cutaneous nerves. 
vein to form the basilic. 
Median cephalic 
Bifurcation of median 
In the groove between the 
Joins the radial vein to 
vein. 
vein opposite the 
bend of the elbow. 
biceps and supinator 
longus muscles. 
form the cephalic vein. 
Basilic vein. 
Confluence of the com- 
mon, ulnar, and 
median basilic, near 
bend of the elbow. 
To the inner side of the 
biceps, internal to the 
brachial artery, and up 
to the middle third of 
the forearm. 
Perforates the deep fascia 
and joins the venae 
comites of the brachial 
artery, to form the axil- 
lary vein. 
Cephalic vein. 
Confluence of median 
cephalic and radial. 
A groove external to the 
biceps muscle; a second 
groove between the pec- 
toralis major and deltoid 
muscles, with the de- 
scending branch of the 
acromial thoracic artery. 
Crosses the first stage of 
the axillary artery and 
ends in the axillary vein. 
Table of Cutaneous Nerves of the Upper Extremity. (Figs. 81, 82.) 
Name. 
Spinal Source. 
Course. 
Distribution. 
Suprasternal 
3d and 4th cervical, 
Emerges between the sterno- 
To integument covering the 
nerve. 
cervical plexus. 
mastoid and trapezius and 
crosses the clavicle and 
sternum. 
upper half of the ster- 
num ; to the sternoclav- 
icular joint. 
Supraclavicular 
3d and 4th cervical, 
Emerges between the sterno- 
To the integument covering 
nerve. 
cervical plexus. 
mastoid and trapezius and 
crosses the clavicle. 
the pectoralis major as 
far down as the nipple. 
Supra-acromial 
3d and 4th cervical, 
Emerges between the sterno- 
To the integument of the 
nerve. 
cervical plexus. 
mastoid and trapezius and 
crosses the clavicle. 
upper and back part of 
the shoulder ; to the 
acromio-clavicular joint. 
Circumflex nerve. 
5th and 6th cervical, 
brachial plexus, 
from posterior 
cord. 
Passes through the quadri- 
lateral space and divides 
into anterior and posterior 
branches. 
To theintegument covering 
the lower two-thirds of 
the deltoid; to shoulder- 
joint; motor to deltoid and 
teres minor muscles; skin 
over long head of triceps. 
Internal cutan- 
8th cervical and 1st 
Pierces the deep fascia with 
To the integument of the 
eous nerve. 
dorsal, brachial 
plexus, inner 
cord. 
the basilic vein in the mid- 
dle third of the arm, and 
divides into anterior and 
posterior branches. 
inner part of the arm and 
forearm, as far as the 
carpus. 
Lesser internal 
1 st thoracic, brachial 
Descends on the inner side of 
To the integument of the 
cutaneous nerve. 
plexus, inner cord. 
the brachial artery and 
pierces the deep fascia in 
the middle third of the arm. 
back of the lower third 
of the arm; over the ole- 
cranon process ; in front 
of the internal condyle. 
Intercosto- 
Lateral cutaneous 
Perforates the external inter- 
To the integument of the 
humeral nerve. 
branch of second 
intercostal nerve. 
It does not divide 
as do the other cu- 
taneous branches 
into anterior and 
posterior divi- 
sions. 
costal muscle, crosses the 
base of the axillary space, 
and joins the lesser internal 
cutaneous. 
upper half of the inner 
and back part of the arm. 
Cutaneous branch 
5th, 6th and 7th cer- 
Perforates the coracobrach- 
To the integument over the 
of the musculo- 
vical, from outer 
ialis, lies between the bi- 
anterior and posterior 
cutaneous nerve. 
cord of brachial 
plexus. 
ceps and brachialis anticus, 
pierces the deep fascia ex- 
ternal to the tendon of the 
biceps. 
radial regions of the fore- 
arm and thenar emi- 
nence ; articular branch 
to the elbow; gray ramus 
to humerus; (motor to 
coraco-brachial, biceps, 
and brachialis anticus.) CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
157 
Name. 
Spinal Source. 
Course. 
Distribution. 
Cutaneous of the 
8th cervical and 1st 
Pierces the deep fascia near 
To the integument of the 
ulnar. 
thoracic. 
the wrist. 
forearm above the wrist. 
Cutaneous palmar 
of the ulnar. 
8th cervical and 1st 
thoracic. 
Lies on the ulnar artery. 
To the integument of the 
palm corresponding to 
one-and-a-half fingers. 
Cutaneous dorsal 
8th cervical and 1st 
Pierces the deep fascia about 
To the integument of the 
of the ulnar. 
thoracic. 
two inches above the wrist, 
passes beneath the flexor 
carpi ulnaris. 
dorsum of the hand, 
wrist, little finger, and 
the ulnar half of the 
ring finger. 
Cutaneous palmar 
6th, 7th, and 8th 
Pierces the deep fascia above 
Integument of the palm 
of the median. 
cervical and 1st 
thoracic ; brachial 
plexus. 
the annular ligament. 
corresponding to three- 
and-a-half fingers; to 
the skin over the ball of 
the thumb. 
Cutaneous digital 
6th, 7th, and 8th 
Emerge from beneath the an- 
To integument of radial 
of the median. 
cervical and 1st 
thoracic ; brachial 
plexus. 
terior annular ligament, in 
course of median nerve. 
three-and a-lialf fingers. 
Cutaneous, inter- 
6th, 7th, and 8th 
Passes through the axillary 
To integument of the pos- 
nal from the 
musculospiral. 
cervical from the 
brachial plexus ; 
posterior cord. 
space. 
terior part of the arm as 
far as the olecranon ; to 
the front of the elbow. 
Cutaneous, exter- 
6th, 7th, and 8th 
Pierce the outer head of the 
To the posterior surface of 
nal from the 
musculospiral. 
cervical from the 
brachial plexus; 
posterior cord. 
triceps. 
the radial side of the 
forearm ; outer and an- 
terior surface of lower 
half of the arm. 
Radial, a branch 
6th, 7th, and 8th 
To outer side of the radial 
To integument of the ball 
of the musculo- 
cervical from the 
artery beneath the supin- 
of the thumb ; to dor- 
spiral. 
brachial plexus ; 
posterior cord. 
ator longus. 
sum of the hand, and to 
three-and-a-half fingers 
dorsally. 
ANTERIOR ANNULAR LIGAMENT. (Figs. 83, 85.) 
The anterior annular ligament, a very strong, fibrous band, arches over the 
front of the carpus and aids this latter in forming an osseoliganientous canal for 
the median nerve and long flexor tendons of the thumb and fingers. It is 
attached on the ulnar side to the pisiform bone and unciform process of the unci- 
form bone; on the radial side to the trapezium and tuberosity of the scaphoid. 
On the ligament are the ulnar and median cutaneous nerve twigs, ulnar nerve, 
and vessels; beneath the same are two synovial bursae-one for the flexor tendon 
of the thumb, the other for the two digital flexors. (Fig. 84.) The palmaris 
longus and a part of the flexor carpi radial is are inserted into the outer surface, 
and the small muscles of the thumb and little finger arise therefrom. (Fig. 85.) 
The cavity beneath the anterior annular ligament consists of one compartment, and 
contains the following structures : flexor sublimis digitorum, flexor profundus 
digitorum, flexor longus pollicis, median nerve, and two synovial bursae, disposed 
as previously stated. 
DEEP PALMAR FASCIA. 
The deep palmar fascia consists of a strong fibrous tissue covering the palmar 
surface of the hand. It has (1) a central portion; (2) two lateral portions. The 
central portion is far more dense than the lateral. It is attached above to the 
anterior annular ligament; on the sides, to the lateral portions of the palmar fascia ; 
below, it divides into four slips for the fingers. Each slip gives fibres (1) to the 
skin of the palm and fingers, which confer stability; (2) to the sides of the 
glenoid ligaments, at the metacarpophalangeal joints; and from these offsets are 
so disposed as to form short channels for the flexor tendons in front of the lower' 
ends of the metacarpal bones, akin to fibrous sheaths that form channels for the 
same tendons in the fingers. The intervals between the digital slips transmit the 158 
A MANUAL OF DISSECTION. 
digital vessels, nerves, and lumbrical muscles to the fingers. The palmar fascia 
sends fibrous processes through the superficial fascia to the skin, and on this 
depends the immobility of the skin of the palm when the fingers are extended. 
The lateral portions of the palmar fascia are thin, and cover the muscles of the 
little finger and ball of the thumb. 
Fig. 83. 
Transverse section through the wrist, showing the annular ligaments and the canals for the passage of the 
tendons. (Gray.) 
LIGAMENTA VAGINALIA. 
Fibrous sheaths for the flexor tendons are so attached to the margins of 
the phalanges as to form osseo-aponeiirotic canals. These sheaths are very 
Fig. 84. 
Synovial membranes of tendons in the palm, artificially distended. (Gerrish after Testut.) 
strong opposite the middle of the first and second phalanges, but much thinner 
opposite the joints. Each sheath is lined by synovial membrane, which is CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
159 
reflected onto the tendons. The synovial sheaths for the tendons of the thumb 
and little finger are continuous with the two synovial bursse beneath the 
anterior annular ligament; those for the intervening digits terminate in blind 
sacs near the metacarpophalangeal articulations. (Fig- 84.) 
MUSCLES OF FRONT OF FOREARM (SUPERFICIAL GROUP). 
The Pronator Radii Teres. Origin of humeral head: Internal condyle by the 
common tendon and intermuscular septa. Origin of ulnar head: Coronoid 
Fig. 85. 
Fig. 86 
Fig. 85 -Superficial muscles of front of right forearm. (Gerrish after Testut.) 
Fig. 86 -Muscles in the right forearm, the deepest layer. (Gerrish after Testut.) 
process. Insertion: Middle of outer surface of radius. Action: Pronation of 
radius. Synergist: Pronator radii quadratus, located anteriorly just above- the 
wrist. Antagonists: Supinators, longus and brevis. Nerve: Median, from outer 
and inner cords of the brachial plexus. Arteries: Radial and ulnar. 160 
A MANUAL OF DISSECTION. 
The Flexor Carpi Radialis. Origin: Common tendon, from internal condyle of 
humerus, and deep fascia. Insertion: Bases of second and third metacarpal 
bones. This tendon passes through a groove in the os trapezium, external to 
the anterior annular ligament. Action: Flexion of carpus. Synergists : Flexor 
carpi ulnaris and palmaris longus. Antagonists: Extensor carpi radialis longior, 
extensor carpi radialis brevior, extensor carpi ulnaris. Nerve: Median. Artery : 
Radial artery, a branch of the brachial. 
The Palmaris Longus. Origin: Common tendon from the internal condyle of 
the humerus and intermuscular septa. Insertion : Anterior annular ligament and 
palmar fascia. Action: Flexion of carpus. Synergists: Flexor carpi radialis 
and flexor carpi ulnaris. Antagonists : Three extensors of carpus. Nerve : 
Median. Artery : Radial. 
The Flexor Sublimis Digitorum has two heads. Origin : (1) Internal condyle by 
the common tendon; (2) oblique line of the radius. Insertion: Sides of the 
second phalanges of the four fingers. These tendons are slit for the transmission 
of the tendons of the flexor profundus digitorum. Action: Flexion of the 
second phalanges. Synergists: Tendons of the flexor profundus. Antagonists: 
Extensor communis digitorum, extensor minimi digiti, extensor indicis. Nerve: 
Median, from outer and inner cords of the brachial plexus. Arteries: Radial 
and ulnar. 
The Flexor Carpi Ulnaris has two heads, humeral and ulnar. Origin: (1) Com- 
mon tendon, from the internal condyle of the humerus; (2) olecranon process and 
upper two-thirds of the posterior border of the ulna. The ulnar nerve passes 
between these two heads. Insertion : (1) Pisiform bone ; (2) unciform process of 
unciform bone; (3) base of fifth metacarpal bone. Action: Flexion of carpus. 
Synergists: Flexor carpi radialis and palmaris longus. Antagonists: Three 
carpal extensors. Nerve: Ulnar, from inner cord of brachial plexus. This 
nerve is accompanied by the inferior profunda above the elbow and by the ulnar 
artery below. Artery: Ulnar. 
Internal " Common Tendon." The preceding five muscles-pronator radii teres, 
flexor carpi radialis, palmaris longus, flexor sublimis digitorum, flexor carpi ulnaris 
-arise by a common tendon from the internal condyle of the humerus. The 
muscles are often fused near the condyle, so that to individualize is a very difficult 
task in dissecting. 
MUSCLES OF FRONT OF FOREARM (DEEP GROUP). 
Flexor Profundus Digitorum. Origin: (1) Upper three-fourths of the anterior 
and internal surfaces of the ulna and the interosseous membrane; (2) aponeurosis 
on the posterior border of the ulna, common to this muscle, the flexor carpi 
ulnaris and extensor carpi ulnaris. Action: Flexion of the third phalanges. 
Synergists: Tendons of the flexor sublimis digitorum. Antagonists : Extensor 
communis digitorum, extensor minimi digiti, and extensor indicis. Nerves: Ante- 
rior interosseous, a branch of the median (to the radial half); ulnar nerve to 
ulnar half of muscle. Artery: Ulnar. The four tendons of this muscle pass 
through slits in the four corresponding tendons of the flexor sublimis digi- 
torum. 
The Flexor Longus Pollicis. Origin : (1) Anterior surface of the radius below 
the oblique line; (2) occasionally from the coronoid process of the ulna. Inser- 
tion : Base of the distal phalanx of the thumb. Action: Flexion of the distal 
phalanx of the thumb. Synergist: Flexor brevis pollicis. Antagonists: Exten- 
sor longus pollicis, extensor brevis pollicis, extensor ossis metacarpi pollicis. 
Nerve: Anterior interosseous, a branch of the median. Arteries: Anterior 
interosseous and radial. 
The Pronator Quadratus. Origin: Anterior surface of the lower fourth of the 
ulna. Insertion : Anterior surface of the lower fourth of the radius. Action : 
Pronation of the radius. Synergist: Pronator radii teres. Antagonists : Supi- CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
161 
nator longus and supinator brevis. Nerve : Anterior interosseous, a branch of 
the median. Artery: Anterior interosseous. 
The Supinator Brevis. Origin: (]) External condyle of the humerus; (2) 
external lateral ligament; (3) orbicular ligament of the radius ; (4) oblique line 
of the ulna; (5) a triangular depression in front of the oblique line of the ulna ; 
(6) aponeurosis covering the muscle. Insertion: Oblique line, tuberosity and 
back of the inner part of the neck of the radius. Action : Supination of forearm. 
Synergist: Supinator longus. Antagonists: Pronator radii teres and pronator 
quadratus. Nerve: Posterior interosseous, a branch of the musculospiral, found 
between the superficial and deep layers of the supinator brevis muscle. 
SMALL MUSCLES OF THE HAND. 
Muscles of Radial Region. 
Adductor Pollicis. Origin: Anterior annular ligament, tuberosity of the scaph- 
oid bone, ridge of the trapezium. Insertion: Radial side of the base of the first 
phalanx of the thumb and tendon of the extensor longus pollicis. Nerve: Median. 
Action: Abduction of the metacarpal bone. 
Opponens Pollicis. Origin: Anterior annular ligament and the ridge on the 
trapezium. Insertion: Radial side of the metacarpal bone of the thumb. Nerve: 
Median. Action: Metacarpal flexor. 
Flexor Brevis Pollicis. Origin: Anterior annular ligament, first, metacarpal 
bone, and tendon of the extensor longuspollicis. Insertion: Base of first phalanx 
of the thumb, internal and external. Nerves: Median and ulnar for outer and 
inner heads, respectively. Action : Flexion and adduction of first phalanx. 
Adductor Obliquus Pollicis. Origin: Os magnum, bases of second and third 
metacarpals, anterior carpal ligament, sheath of the tendon of the flexor carpi 
radialis. Insertion : Base of first phalanx of the thumb and flexor brevis pollicis. 
Nerve: Ulnar. Action: Adduction of the metacarpal bone of the thumb. 
Adductor Transversus Pollicis. Origin: Lower two-thirds of the metacarpal 
bone of the middle finger. Insertion : Base of the first phalanx of the thumb with 
adductor and flexor brevis pollicis. Nerve: Ulnar. Action: Adduction of the 
metacarpal bone. 
Muscles of Ulnar Region, 
Palmaris Brevis. Origin: Anterior annular ligament and palmar fascia. Inser- 
tion : Skin of inner part of the palm. Nerve: Ulnar. Action: Adduction. 
Abductor Minimi Digiti. Origin: Pisiform bone and tendon of the flexor carpi 
ulnaris. Insertion: Base of the first phalanx of the little finger and extensor 
minimi digiti. Nerve: Ulnar. Action: Abduction of the little finger. 
Flexor Brevis Minimi Digiti. Origin : Anterior annular ligament and unciform 
process of unciform bone. Insertion : Base of the first phalanx of the little finger. 
Nerve: Ulnar. Action: Flexion of the little finger. 
Opponens Minimi Digiti. Origin: Anterior annular ligament and unciform 
process of unciform bone. Insertion: Metacarpal bone of the little finger. 
Nerve: Ulnar. Action: Flexion of the little finger and metacarpal bone. 
Muscles of Palmar Region. 
The Lumbrical Muscles are four in number. They arise from the tendons of the 
flexor profundus digitorum and are inserted into the tendons of the extensor com- 
munis digitorum. 
First and Second Lumbricals. Origin: Radial side and palmar surface of 
the flexor profundus digitorum tendons to the index and middle fingers. Inser- 162 
A MANUAL OF DISSECTION. 
tion: Extensor communis tendons of the index and middle fingers. Nerve: 
Median. 
Third and Fourth Lumbricals. Origin : Contiguous sides of the middle and ring 
and ring and little fingers, respectively. Insertion : Extensor communis tendons 
of the ring and little fingers. Nerve : Ulnar. 
The dorsal interossei are four in number : 
First Dorsal. Origin : Upper half of the ulnar border of the first metacarpal 
bone and radial border of the second metacarpal bone. Insertion: Radial side of 
the base of the first phalanx of the index finger and tendon of the extensor com- 
munis digitorum of the index finger. 
The Second, Third, and Fourth Dorsal Interossei arise from the adjacent sides of 
the second and third, third and fourth, fourth and fifth metacarpal bones, 
respectively, and are inserted into the corresponding tendons of the extensor 
communis digitorum. Nerve: Ulnar. 
Palmar Interossei. There are three palmar interossei muscles. The first arises 
from the ulnar side of the second metacarpal and is inserted into the base of the first 
phalanx of the index finger and extensor communis digitorum. The second arises 
from the radial side of the fourth metacarpal bone, and is inserted into the base of 
the first phalanx of the ring finger and extensor communis digitorum. The thiid 
arises from the radial side of the fifth metacarpal bone, and is inserted into the 
radial side of the base of the first phalanx of the little finger. 
Action of the Lnmbrical and Interossei Muscles. " The palmar interossei adduct 
the fingers to an imaginary line drawn longitudinally through the centre of the 
middle finger. The dorsal interossei abduct the fingers from that line. In ad- 
dition to this the interossei, in conjunction with the lumbricals, flex the first 
phalanges at the metacarpophalangeal joints, and extend the second and third 
phalanges, in consequence of this insertion, into the expansion of the extensor 
tendons. The extensor communis digitorum is believed to act almost entirely on 
the first phalanges."-Gray's Anatomy. 
CUBITAL FOSSA. 
The cubital fossa is a depression on the flexor surface of the elbow ; its analysis 
is given below, as follows : Roof, formed by skin and fascia ; floor, formed by 
brachialis anticus and supinator brevis ; superior border, formed by an imaginary 
line extending from condyle to condyle ; outer border, formed by brachio- 
radialis (supinator longus) ; inner border, formed by pronator radii teres. Con- 
tents : (1) Brachial artery and veins ; (2) radial artery ; (3) ulnar artery ; (4) 
tendon of biceps ; (5) median nerve ; (6) musculospiral nerve ; (7) radial 
recurrent artery ; (8) ulnar recurrent artery ; (9) common interosseous artery. 
Order of contents: (1) Brachial artery ; (2) to inner side of artery, the median 
nerve; (3) to outer side of artery, the tendon of the biceps ; (4) to outer side of 
tendon of biceps, the musculospiral nerve (deeply located between the brachialis 
anticus and supinator longus), dividing into the radial and posterior interosseous 
nerves. Also muscular branches are given off to the pronator radii teres and 
supinator longus by the median and musculospiral nerves, respectively. 
MEDIAN NERVE. 
The median nerve arises by an inner and an outer head from the inner ,and 
outer cords of the brachial plexus, respectively. The main course of the nerve 
is with the brachial artery and its venre comites. In the upper part of its course 
the nerve is external ; in the middle, on ; and in the lower, internal to the artery. 
The nerve passes into the forearm between the two heads of the pronator radii 
teres, and gives off the following branches: CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
163 
(1) Muscular (near elbow) (a) to pronator radii teres, flexor carpi radialis, pal- 
maris longus, and flexor sublimis digitorum ; (2) muscular (6) (anterior interos- 
seous) to flexor longus pollicis, pronator quadratus, and radial half of the flexor 
profundus digitorum ; (3) muscular (c) to first and second lumbricals, abductor 
pollicis, opponens pollicis, and outer head of the flexor brevis pollicis ; (4) palmar 
Fig. 87. 
Deep nerves of the front of the right forearm (Gerrish after Testut.) 
cutaneous to skin of ball of the thumb and of the palm, corresponding to three and 
one-half fingers on radial side of the hand ; (5) digital cutaneous to integument of 
palmar surface (and also about the nails) of the thumb, index, middle and radial 
half of ring finger ; (6) (d) articular, to elbow, radio-ulnar, radiocarpal, carpal, 
carpo-metacarpal, metacarpophalangeal and interphalangeal articulations. 164 
A MANUAL OF DISSECTION. 
ULNAR NERVE. 
The ulnar nerve is from the inner cord of the brachial plexus. It lies to the 
ulnar side of the brachial artery, but in the middle of the arm it diverges from 
this vessel to reach the interval between the olecranon process and the internal 
condyle. It reaches the forearm between the two heads of the flexor carpi 
Fig. 88. 
Superficial palmar nerves. (Gerrish after Testut.) 
ulnaris, and in the upper third joins the ulnar artery, lying to its ulnar side. 
The nerve crosses the anterior annular ligament, internal to the pisiform bone, 
and divides into superficial and deep palmar branches. 
Branches of the Ulnar Nerve. (1) Muscular (near elbow) to (a) flexor carpi 
ulnaris, (6) ulnar half of flexor profundus digitorum ; (2) muscular (deep palmar) 
to abductor minimi digiti, flexor brevis minimi digiti, opponens minimi digiti, 
abductor transversus and obliquus pollicis, inner head of flexor brevis pollicis, 
the two ulnar lumbricales, and all the interosseous muscles of the hand ; (3) cuta- CUTANEOUS VEINS AND NERVES OF UPPER EXTREMITY. 
165 
neous (middle third of forearm) to skin of lower and anterior third of forearm 
and wrist ; (4) cutaneous (lower third of forearm) to wrist and palm, correspond- 
ing to the little finger and ulnar half of the ring finger ; (5) cutaneous (digital) to 
skin of little finger and ulnar half of the ring finger ; (6) cutaneous (dorsal) to 
skin of dorsal surface of the little finger and adjacent part of the ring finger ; (7) 
articular, to elbow, medio-carpal, radiocarpal, carpo-metacarpal, metacarpophal- 
angeal, and inter phalangeal articulations. 
RADIAL ARTERY. 
The radial artery begins just below the bend of the elbow, at the bifurcation 
of brachial, and ends in the deep palmar arch in the palm of the hand. It is accom- 
panied by two venae comites. The radial artery is found, then, in the forearm, 
wrist, and hand, and has the following relations in the forearm : Internally, 
the pronator radii teresand flexor carpi radialis; externally, the supinator longus 
and middle third of radial nerve; anteriorly, the integument, superficial fascia, 
deep fascia, and supinator longus; posteriorly, the tendon of the biceps, the 
supinator brevis, flexor sublimis digitorum, pronator radii teres, flexor longus 
pollicis, pronator quadratus, and radius. At the wrist, the radial artery lies on 
the scaphoid, trapezium, and external lateral ligament, and is beneath the 
extensor tendons of the thumb, branches of the radial nerve, and certain 
cutaneous veins. In the hand, the artery passes (1) between the heads of the 
first interosseous muscle; (2) across the palm to the base of the fifth metacarpal 
bone, where, by inosculating with a communicating branch of the ulnar artery, 
it forms the deep palmar arch. The deep arch lies on the proximal ends of the 
metacarpal bones and interossei muscles, and is covered by integument, superficial 
fascia, palmar fascia, flexor sublimis digitorum, flexor profundus digitorum, 
lumbricales, flexor brevis minimi digiti, opponens minimi digiti, and adductor 
obliquus pollicis. 
Branches of Radial Artery. Radial recurrent; muscular; anterior carpal; 
superficialis volae ; posterior carpal; metacarpal or first dorsal interosseous ; dor- 
salis pollicis; dorsalis indicis; princeps pollicis; radialis indicis ; superior per- 
forating; palmar interosseous, three or four in number; palmar recurrent ; deep 
palmar arch. (See Dr. Shaw's table of arteries.) 
ULNAR ARTERY. 
The ulnar artery arises at the bifurcation of the brachial, a little below the 
bend of the elbow, and ends on the anterior annular ligament (just internal to the 
pisiform bone), in superficial and deep palmar branches. Between these two 
points the artery has the following relations : Anteriorly, the superficial flexor 
muscles, median nerve, superficial fascia, deep fascia; posteriorly, the brachialis 
anticus and flexor profundus digitorum ; internally, the flexor carpi ulnaris and 
lower two-thirds of the ulnar nerve; externally, the flexor sublimis digitorum. The 
ulnar artery is attended by two veins having tributaries corresponding to the 
branches of the artery. 
Branches of the Ulnar Artery. Anterior ulnar recurrent; posterior ulnar recur- 
rent; common interosseous; anterior interosseous; posterior interosseous; muscu- 
lar; anterior carpal; posterior carpal; deep palmar or communicating; superficial 
palmar arch. CHAPTER X. 
THE POSTERIOR REGION OF ARM AND FOREARM AND RADIAL REGION 
OF FOREARM. 
IDENTIFICATION AND DISSECTION. 
Cutaneous Nerves and Vessels. Consult the illustrations to find the names of cutaneous 
structures ; determine the source, course, and distribution of the same by the tables on the 
cutaneous nerves and veins of the upper extremity in Chapter IX. (pp. 155-157). 
Superficial Fascia. Identify (1) by its location beneath the skin and the fat contained in 
its meshes of cellulo-fibrous structure; (2) by its free mobility and the presence of the 
cutaneous nerves and vessels; (3) by its non-attachment to bone. 
Fig. 89. 
Cutaneous nerves of the dorsum of the hand. (Gerrish after Testut.) 
Deep Fascia. Identify (1) by its location beneath the superficial fascia, attachment to 
bone, and immobility; (2) by its perforations for the cutaneous nerves and vessels; (3) by its 
great strength on the back part of the forearm and its continuity with the posterior annular 
ligament. 
Radial Nerve. Identify (1) by its emergence through the deep fascia on the radial side of 
the forearm between the supinator longus and extensor carpi radialis longior muscles ; (2) by 
its distribution to the skin of the ball of the thumb, and the dorsal surface of the thumb, index 
and middle fingers, and radial half of the ring finger. POSTERIOR REGION OF ARM AND FOREARM. 
167 
Posterior Annular Ligament. Identify (I) by its location on the back of the wrrist and 
firm attachments to the bony eminences; (2) by its continuity with the dorsal fascia of the 
hand below and the deep fascia of the forearm above; (3) by the formation of six compart- 
ments for the transmission of all the tendons on the posterior and radial regions except the 
supinator longus. (Fig. 83.) 
Teres Major. Identify (1) by its extent from the axillary border of the scapula to the inner 
lip of the bicipital groove of the humerus, with the tendon of the latissimus dorsi; (2) by its 
Fig. 90. 
Musculospiral and circumflex nerves of right side. (Gerrish after Testut.) 
location below the circumflex structures emerging from the quadrilateral space; (3) by its 
attachment to the latissimus dorsi. 
Quadrilateral Space. Identify (1) by its boundaries-neck of the humerus, long head of 
the triceps, teres minor, teres major, and latissimus dorsi; (2) by its contents-posterior cir- 
cumflex vessels and circumflex nerve. 
Musculospiral Nerve. Identify (1) by its location in the spiral groove on the posterior 
surface of the humerus between the two humeral heads of the triceps muscle with the superior 
profunda vessels; (2) by its location (in the lower third of the arm on the outer side) between 
the brachialis anticus and supinator longus. 168 
A MANUAL OF DISSECTION. 
Posterior Interosseous Nerve. Identify (1) by its derivation from the musculospiral (with 
the radial); (2) by its course through the supinator brevis muscle; (3) by its distribution to 
the posterior part of the forearm ; (4) by its location between the superficial and deep groups 
of muscles. 
Triceps Muscle. Identify (1) by its location on the posterior surface of the humerus and 
insertion into the olecranon process of the ulna; (2) by its three heads of origin-from scapula, 
below glenoid ; from humerus, above and below the musculospiral groove. 
Suprascapular Nerve and Vessels. Identify (1) by their location on the superior border of 
the scapula; (2) the nerve passes through the suprascapular foramen, the vessels cross the 
superior transverse scapular ligament. These structures are exposed on turning aside the 
supraspinatus muscle. (Fig. 90 ) 
Extensor Carpi Radialis Longior and Extensor Carpi Radialis Brevior Muscles. 
Identify (1) by their location on the radial side of the forearm ; (2) by their location in one 
compartment of the posterior annular ligament; (3) by their course beneath the three ex- 
tensor muscles of the thumb ; (4) by their insertion into the bases of the second and third 
metacarpal bones on the radial side. (Fig. 93.) 
Extensors of Thumb. Identify (1) the extensor longus pollicis inserted into the base of 
the distal phalanx; (2) the extensor brevis pollicis into the base of the proximal phalanx; (3) 
the extensor ossis metacarpi pollicis into the base of the metacarpal bone of the thumb; (4) 
these three tendons cross the radial artery where this vessel passes to the back of the hand 
to gain the first interosseous space; (5) the extensor longus pollicis is in a separate compart- 
ment; the other two in same compartment. (Fig. 93.) 
Extensor Communis Digitorum. Identify (1) by the distribution of its four tendons to 
the four fingers; (2) by its location in a compartment of the posterior annular ligament with 
the extensor indicis; (3) by the insertion of each tendon into the bases of the second and third 
phalanges. (Fig. 92.) 
Extensor Indicis. Identify (1) by its location in a compartment of the posterior annular 
ligament with the extensor communis digitorum; (2) by its insertion, with the tendon of the 
extensor communis digitorum, into the second and third phalanges of the index finger. (Fig. 93 ) 
Extensor Minimi Digiti. Identify (1) by its location in a separate compartment of the 
posterior annular ligament; (2) by its insertion with the tendon of the extensor communis 
digitorum, into the second and third phalanges of the little finger. (Fig. 91.) 
Extensor Carpi Ulnaris. Identify (1) by its location on the ulnar side of the forearm, and 
by its passage through a separate compartment of the posterior annular ligament; (2) by its 
insertion into the ulnar side of the base of the fifth metatarsal bone. (Fig. 92.) 
The Teres Major. Origin: (1) Lower third of the axillary border of the scap- 
ula ; (2) deep fascia and adjacent intermuscular septa. Insertion: Inner lip of the 
bicipital groove. Action: Abductor of arm. Synergist: Latissimus dorsi. An- 
tagonist: Deltoid. Nerve: Subscapular from posterior cord of the brachial plexus. 
Artery: Subscapular. 
The Subscapularis. (Figs. 72, 73.) Origin : Subscapular fossa. Insertion: Lesser 
tuberosity of the humerus and capsule of the joint. Action: Internal rotation and 
adduction. Synergist: Pectoralis major. Antagonists: Teres minor and infra- 
spinatus. Nerve: Subscapular, from posterior cord of the brachial plexus. 
Artery: Subscapular. 
The Latissimus Dorsi. Origin: (1) Spinous processes of the six inferior thoracic 
vertebrae ; (2) spines of the lumbar and sacral vertebrae ; (3) posterior layer of the 
lumbar fascia ; (4) external lip of the iliac crest, posterior to the attachment of the 
external oblique muscle ; (5) from three or four lower ribs. Insertion: Bottom 
of the bicipital groove, higher on the humerus than insertion of the pectoralis 
major. Its tendon, about three inches long, is in front of the tendon of the teres 
major, and separated therefrom by a bursa. Nerve: Long subscapular, from 
posterior cord of the brachial plexus. 
The Subscapular Nerves (upper, lower, and middle, or long). The upper sup- 
plies the subscapularis ; the lower supplies the subscapularis and teres major; the 
middle, or long, accompanies the subscapular artery and supplies the latissimus 
dorsi. The subscapular artery is the largest branch of the axillary. It is given 
off opposite the lower border of the subscapularis muscle, passes along its lower 
margin to the inferior angle of the scapula, and anastomoses with the long tho- 
racic, intercostals, and posterior scapular. (Fig. 75.) 
The Triceps (three heads-long, external, and internal). Origin of Long Head: 
Below glenoid cavity. Origin of External Head: Above musculospiral groove 
on the posterior surface of the humerus. Origin of Internal Head: Below mus- POSTERIOR REGION OF ARM AND FOREARM. 
169 
culospiral groove. Insertion: Olecranon process and deep fascia contiguous 
thereto. Action: Extension of forearm. Synergist: Anconeus. Antagonists : 
Biceps, brachialis anticus, supinator longus. Nerve: Musculospiral. Artery : 
Superior profunda. (Fig. 90.) 
The Anconeus. Origin: External condyle of humerus and posterior ligament 
of the elbow-joint. Insertion: Olecranon and upper third of ulna. Action: 
Extension of forearm. Synergist: Triceps. Antagonists: Biceps, brachialis 
anticus, and supinator longus. Nerve: Musculospiral, from posterior cord of 
brachial plexus. Artery: Superior profunda. (Fig. 92.) 
The Supinator Longus (brachio-radialis). Origin: Upper two-thirds of the 
external condylar ridge of the humerus and the external intermuscular septum. 
Insertion : Base of the styloid process of the radius. This muscle conceals the 
radial nerve. Action: Flexion and supination of the forearm. Synergist: 
Supinator radii brevis. Antagonists: Pronator radii teres and pronator radii 
quadratus. Nerve: Musculospiral from posterior cord of the brachial plexus. 
Arteries: Radial and brachial. (Figs. 85, 93.) 
The Musculospiral Nerve arises from the posterior cord of the brachial plexus 
(sixth, seventh, and eighth cervical and first thoracic). Course : (1) Behind the 
axillary and the upper part of the brachial artery ; (2) in front of the tendons of the 
latissimus dorsi and teres major ; (3) in the musculospiral groove on the posterior 
surface of the humerus (with the superior profunda artery) between the two 
humeral heads of the triceps muscle ; (4) it pierces the external intermuscular sep- 
tum and lies between the brachialis anticus and the supinator longus; (5) in front 
of the external condyle of the humerus it divides into the radial and posterior 
interosseous nerves. Branches: Cutaneous, radial, muscular, and posterior 
interosseous. The radial and other cutaneous branches are described in the 
table of cutaneous nerves of the upper extremity (p. 156). Muscular branches 
supply the triceps, anconeus, supinator longus, supinator brevis, extensor carpi 
radialis longior, extensor carpi radialis brevior, and, usually, the brachialis 
anticus. The posterior interosseous nerve supplies all the muscles on the posterior 
part of the forearm. (Figs. 69, 90.) 
The Superior Profunda Artery is a branch of the brachial. It accompanies the 
musculospiral nerve, supplies the triceps and humerus, and anastomoses with the 
radial recurrent, posterior ulnar recurrent, interosseous recurrent, anastomotica 
magna, and inferior profunda. (Fig. 90.) 
POSTERIOR ANNULAR LIGAMENT. 
The Posterior Annular Ligament (Figs. 91, -92, 93) is a strong, fibrous structure 
at the back of the wrist, so attached as to form six compartments for the passage 
of tendons. It is attached internally to the cuneiform and pisiform bones, and 
styloid process of the ulna; externally, to the margin of the radius; dorsally, 
to the small elevations on the posterior part of the lower end of the radius. 
The six compartments are : 
J For the tendon of the extensor ossis metacarpi pollicis muscle. 
[ For the tendon of the extensor brevis pollicis muscle. 
n f For the tendon of the extensor carpi radialis longior muscle. 
[ For the tendon of the extensor carpi radialis brevior muscle, 
o f For the tendons of the extensor communis digitorum muscle. 
' | For the tendons of the extensor indicis muscle. 
4. For the tendon of the extensor longus pollicis muscle. 
5. For the tendon of the extensor minimi digiti muscle. 
6. For the tendon of the extensor carpi ulnaris muscle. 
These six compartments are lined by a synovial membrane extending from 
above the annular ligament to the dorsum of the hand. (Figs. 83, 84.) 170 
A MANUAL OF DISSECTION. 
POSTERIOR PART OF FOREARM (SUPERFICIAL GROUP OF 
MUSCLES). 
The Extensor Communis Digitorum. (Fig. 92.) Origin: (1) External condyle of 
the humerus, by the common tendon ; (2) adjacent intermuscular septa and deep 
fascia. Insertion: Second and third phalanges of the fingers, by four aponeuroses, 
as follows : The aponeuroses of insertion on the back of the first phalanx are joined 
by the lumbrical and interossei tendons of insertion. Each aponeurosis breaks 
up into a central and two lateral parts, opposite the first phalanx. The central 
part is inserted into the dorsal base of the second phalanx ; the lateral parts are in- 
serted into and cover the dorsal surface of the third phalanx. Action: Extension 
of fingers. Synergists: Dorsal and palmar interossei and lumbricals. Antago- 
Fig. 91. 
Synovial membranes of tendons in the dorsum of the forearm and hand, artificially distended. (Gerrish 
after Testut.) 
nists: Flexor sublimis digitorum and flexor profundus digitorum. Nerve: Poste- 
rior interosseous, a branch of the musculospiral. Artery: A branch of the ulnar. 
The Extensor Minimi Digiti. Origin: Common tendon and adjacent intermus- 
cular septa. Insertion: Second and third phalanges, with tendon of extensor 
communis digitorum. Action: Extension of little finger. Synergists: Extensor 
communis digitorum, lumbricals, and interossei. Antagonists: Flexor brevis 
minimi digiti, flexor sublimis digitorum, and flexor profundus digitorum. Nerve: 
Posterior interosseous, a branch of the musculospiral. Artery: Posterior inter-' 
osseous. 
The Extensor Carpi Ulnaris. Origin: (1) Outer condyle, by the common tendon, 
adjacent intermuscular septa, and deep fascia; (2) middle third of the posterior 
surface of the ulna; (3) posterior border of the ulna with the flexor carpi ulnaris POSTERIOR REGION OF ARM AND FOREARM. 
171 
and flexor profundus digitorum. Insertion: Ulnar side of the base of the fifth 
metacarpal bone. Action: Extension of carpus. Synergists: Extensor carpi 
radialis longior and extensor carpi radialis brevior. Antagonists: Flexor carpi 
radialis, flexor carpi ulnaris, and pahnaris longus. Nerve: Posterior interosseous. 
Artery; Ulnar. 
The Anconeus. Origin: Back of outer condyle. Insertion: (1) Side of 
olecranon process of ulna; (2) upper fourth of posterior surface of ulna. Action : 
Extension of forearm. Synergist: Triceps. Antagonists: Biceps, brachialis 
anticus, and brachio-radialis. Nerve: Musculospiral. Arteries: Anastomotica 
magna and radial recurrent. This muscle seems to be a semidismembered part 
of the triceps. (Fig. 92.) 
POSTERIOR PART OF FOREARM (DEEP GROUP OF MUSCLES). 
The Supinator Brevis (Fig. 93) is concealed by the supinator longus, extensor 
carpi radialis longior, and extensor carpi radialis brevior. Origins: (1) External 
condyle of humerus and external lateral ligament; (2) orbicular ligament of 
radius; (3) a ridge on ulna, extending downward from sigmoid cavity. Insertion: 
(1) Oblique line of radius; (2) external and posterior surfaces of the radius 
between oblique line and head. Action: Supination of radius. Synergist: 
Supinator longus. Antagonists: Pronator radii teres and pronator quadratus. 
Nerve: Posterior interosseous, a branch of the musculospiral. Artery : Radial 
recurrent. 
Extensor Ossis Metacarpi Pollicis (the strong extensor muscle of the thumb). 
Origin: Posterior surfaces of the radius, ulna, and interosseous membrane. 
Insertion : Dorsal base of the metacarpal bone of the thumb. Action : Extension 
of thumb and metacarpal bone. Synergists : Long and short extensors of the 
thumb. Antagonists : Long and short flexors of the thumb. Nerve: Posterior 
interosseous. Artery : Posterior interosseous. 
The Extensor Brevis Pollicis. Synonym: Extensor primi internodii pollicis. 
Origin: Posterior surface of the radius and interosseous membrane. Insertion: 
Dorsal base of first phalanx. Action; Extension of first phalanx of thumb. Has 
no synergists. Antagonists : Flexor brevis pollicis. Nerve : Posterior interosse- 
ous. Artery: Posterior interosseous. 
The Extensor Longus Pollicis. Synonym : Extensor secundi internodii pollicis. 
Origin : Posterior surface of the ulna and interosseous membrane. Insertion : 
Base of distal phalanx of thumb. Action : Extension of thumb. Has no syner- 
gists. Antagonists: Flexor longus pollicis. Nerve: Posterior interosseous. 
Artery : Posterior interosseous. 
The Extensor Indicis. Origin: (1) Posterior surface of the ulna below the 
extensor longus pollicis. Insertion: With extensor communis digitorum, into 
second and third phalanges. Its tendon joins that of the extensor communis 
digitorum opposite the lower end of the second metacarpal bone, and lies to the 
ulnar side of this tendon. Action : Extension of the index finger. Synergists : 
Extensor communis digitorum, first lumbrical, first dorsal interosseous, and first 
palmar interossei muscles. Antagonists : Flexor sublimis and flexor profundus 
digitorum. Nerve: Posterior interosseous. Arteries: Anterior and posterior 
interosseous. 
The Posterior Interosseous Nerve (Figs. 76, 87) is given off by the musculospiral 
(with the radial) between the brachialis anticus and supinator longus, in front of the 
external condyle of the humerus. It passes through the supinator brevis muscle to 
the back of the forearm, and is distributed to all the muscles of the radial and pos- 
terior regions of the forearm, except the anconeus, supinator longus, and extensor 
carpi radialis longior, which three muscles derive their nerve-supply from the 
musculospiral, prior to its division into the radial and posterior interosseous 
branches. Course: (1) Between the superficial and deep groups of muscles; (2) 
beneath the extensor longus pollicis on the interosseous membrane. 172 
A MANUAL OF DISSECTION. 
Fig. 92. 
Fig. 93. 
Fig. 92.-Muscles in the dorsum of the right forearm and hand. (Gerrish after Testut.) 
Fig. 93.-Muscles in radial region of right forearm, and deep muscles in its dorsum. (Gerrish after Testut.) POSTERIOR REGION OF ARM AND FOREARM. 
173 
The Posterior Interosseous Artery (Fig. 79) is a branch of the common interosseous 
of the ulnar artery. It passes to the back of the forearm between the oblique 
ligament and interosseous membrane. Posteriorly, it is between the supinator brevis 
and extensor ossis metacarpi pollicis. In the upper third of the forearm the 
artery is separated from the posterior interosseous nerve by the radius and 
supinator brevis; in the middle third the nerve and artery are together; in 
the lower third they are separated by the extensor longus pollicis and extensor 
indicis. 
RADIAL GROUP OF MUSCLES. (Fig. 93.) 
The Brachio-radialis (supinator longus). Origin : Upper two-thirds of external 
condylar ridge of the humerus. Insertion : Base of the styloid process of the 
radius. Arteries : Radial recurrent and radial. Nerve : Musculospiral. 
The Extensor Carpi Radialis Longior. Origin : Lower third of the external con- 
dylar ridge and external intermuscular septum. Insertion : Base of the index 
metacarpal bone on the radial side. Action : Extension of carpus. Synergists : 
Extensor carpi radialis brevior and extensor carpi ulnaris. Antagonists : Flexor 
carpi radialis, flexor carpi ulnaris, and palmaris longus. Nerve : Musculospiral, 
from posterior cord of brachial plexus. Artery : Radial. 
The External " Common Tendon " gives origin to the extensor carpi radialis 
brevior, extensor communis digitorum, extensor minimi digiti, and extensor carpi 
ulnaris, and is attached to the outer humeral condyle. 
The Extensor Carpi Radialis Brevior. Origin : By the common tendon from the 
external condyle of the humerus. Insertion : Base of the third metacarpal bone 
on the radial side. Action: Extension of the carpus. Synergists: Extensor 
carpi radialis longior and extensor carpi ulnaris. Antagonists: Flexor carpi 
radialis, flexor carpi ulnaris, and palmaris longus. Nerve : Posterior interosseous, 
a branch of the musculospiral. Artery: Radial. 
Table of Muscles of the Upper Extremity. 
(Names in parentheses in first column are new nomenclature ; m. should be read musculus a muscle.) 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Pectoralis major 
1. Anterior surface of the 
Into the outer bi- 
Filaments1 from 
Internal 
(m. pectoralis 
pectoral half of clavicle. 
cipital ridge of 
all nerves 
mammary 
major). 
2. One-half the breadth 
of the anterior surface of 
the sternum and cartil- 
ages of all the true ribs. 
the humerus by 
a flat tendon 
about two inches 
in width. 
forming 
brachial 
plexus 
through the 
anterior 
thoracic 
nerves. 
intercostals, 
superior 
thoracic, 
acromial 
thoracic, and 
long thoracic. 
Pectoralis minor 
1. By three tendinous digi- 
Inner border and 
Filaments from 
Internal 
(m. pectoralis 
tations from the upper 
upper surface of 
all nerves 
mammary 
minor). 
margin and outer surfaces 
of tlie 3d, 4th, and Sth 
ribs near their cartilages. 
2. From the aponeurosis 
covering the intercostal 
muscles. 
the coracoid 
. process of 
scapula. 
forming 
brachial 
plexus 
through the 
anterior 
thoracic 
nerves. 
intercostals, 
superior 
thoracic, 
acromial 
thoracic, and 
long thoracic. 
Subclavius (m. 
From the 1st rib and its 
Into a groove on 
Fifth cervical 
First intercostal 
subclavius). 
cartilage by a short, 
thick tendon. 
the under sur- 
face of clavicle. 
nerve. 
and short 
thoracic. 
Serratos magnus 
Outer surfaces and upper 
Ventral part of 
Posterior 
Intercostals, 
(m. serrafus 
borders of eight upper 
the vertebral 
thoracic 
long and short 
anterior). 
ribs, by nine digitations, 
the 1st rib having two 
digitations. 
border of the 
scapula. 
from the 
5th, 6th, 
and usually 
the 7th cer- 
vical nerves. 
thoracic 
arteries. 
1 The pectoralis major is a polymeric muscle, hence its nerve filaments are from more than one neural segment. 
(See Barker.) 174 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Deltoid (m. del- 
1. Outer one-third of the 
Deltoid ridge on 
Circumflex, 
Posterior, 
toideus). 
anterior border and upper 
surface of the clavicle. 
2. Outer margin and 
upper surface of the acro- 
mial process of scapula. 
the middle of 
the outer surface 
of the humerus. 
from poste- 
rior cord of 
brachial 
plexus. 
circumflex, 
and acromial 
thoracic 
arteries. 
Subscapularis 
1. Internal two-thirds of 
1. Lesser tuberos- 
Upper and 
Subscapular 
(m. subscapu- 
laris). 
the subscapular fossa. 2. 
Lower two-thirds of the 
groove on the axillary 
border of the scapula. 
ity of humerus. 
2. Neck of hu- 
merus to within 
one inch below 
lesser tuberosity. 
lower sub- 
scapular. 
artery. 
Supraspinatus 
(m. supra- 
spinatus). 
1. Inner two-thirds of the 
supraspinous fossa. 2. 
supraspinous fascia. 
Highest of the 
three facets of 
greater tuberos- 
ity of humerus. 
Suprascapular. 
Suprascapular. 
Infraspinatus m. 
infraspinatus). 
Internal two-thirds of the 
infraspinous fossa and 
fascia covering the same. 
Middle facet of the 
greater tuber- 
osity of humerus. 
Suprascapular. 
Suprascapular. 
Teres minor (m. 
teres minor). 
1. Dorsal surface of the 
upper two-thirds of the 
axillary border of the 
scapula. 2. Aponeurotic 
laminae. 
Lower facet of the 
greater tuberos- 
ity of the 
humerus. 
Circumflex. 
Infrascapular, 
circumflex. 
Teres major (m. 
teres major). 
Oval surface on the dorsal 
aspect of the inferior 
angle of the scapula. 
Inner bicipital 
ridge of the 
humerus. 
Lower sub- 
scapular. 
Subscapular. 
Coracobrachialis 
Apex of the coracoid pro- 
Middle of the in- 
Musculo- 
Brachial, 
(m. coraco- 
brachialis). 
cess with short head of 
the biceps muscle. 
ternal surface 
and border of 
the shaft of the 
humerus. 
cutaneous. 
muscular 
branches. 
Biceps (m. biceps 
1. Short head from apex 
1. Back of tuber- 
Musculo- 
Brachial artery, 
brachii), caput 
longum, and 
caput breve. 
of the coracoid process 
with coracobrachialis. 
2. Long head from the 
upper margin of the 
glenoid cavity. 
osity of radius. 
2. Deep fascia 
of forearm 
through bicip- 
ital fascia. 
cutaneous. 
muscular 
branches. 
Brachialis anti- 
Lower one-half of the outer 
Anterior surface 
Musculo- 
Brachial artery. 
cus (m. brach- 
ialis). 
and inner surfaces of the 
shaft of the humerus. 
of the coronoid 
process of ulna. 
cutaneous. 
Triceps (m. tri- 
1. Middle, scapular, or 
The three heads 
Musculo- 
Brachial and 
ceps brachii, 
caput longum, 
laterale and 
mediale). 
Subanconeus (m. 
epitrochleo- 
anconeus). 
long head from depres- 
sion below the glenoid 
cavity. 2. The external 
or long humeral head 
from the posterior surface 
of the shaft of the hum- 
erus above the musculo- 
spiral groove. 3. The 
internal or short humeral 
head from the posterior 
surface below the mus- 
culospiral groove. 
Under surface of triceps. 
unite and are in- 
serted conjointly 
into the back of 
the olecranon 
process of the 
ulna. 
Capsular ligament 
of the elbow- 
joint. 
spiral. 
superior pro- 
funda. 
Brachial artery. 
Pronator radii 
teres (m. pro- 
nator teres; 
caput humerale 
et caput 
ulnare). 
1. Humerus, above internal 
condyle. 2. Common ten- 
don. 3. Deep fascia of 
the forearm and inter- 
muscular septum. 4. 
Inner side of the coronoid 
process of the ulna. 
Middle of the 
outer surface of 
the radius. 
Median. 
Radial. 
Flexor carpi ra- 
dialis (m. flexor 
carpi radialis). 
1. Internal condyle by the 
common tendon. 2. Deep 
fascia. 3. Intermuscular 
septa. 
Bases of the meta- 
carpal bones of 
index and mid- 
dle fingers. 
Median. 
Radial. 
Palmaris longus 
(m. palmaris 
longus). 
1. Internal condyle. 2. 
Deep fascia and inter- 
muscular septa. 
Central part of the 
palmar fascia 
and lower part 
of the annular 
ligament. 
Median. 
Radial and 
ulnar. POSTERIOR REGION OF ARM AND FOREARM. 
175 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Flexor carpi ul- 
naris (m. flexor 
carpi ulnaris ; 
caput humerale 
et caput 
ulnare). 
1. Internal condyle of the 
humerus by the common 
tendon. 2. Inner margin 
of the olecranon. 3. 
Upper two-thirds of the 
posterior border of the 
ulna by an aponeurosis 
common to it, the exten- 
sor carpi ulnaris, and 
flexor profundus digi- 
torum. 4. Intermuscu- 
lar septum. 
1. Pisiform bone. 
2. Base of 5th 
metacarpal and 
unciform bones. 
3. Annular lig- 
ament. 
Ulnar. 
Ulnar. 
Flexor sublimis 
digitorum (m. 
flexor digi- 
torum sub- 
limis ; caput 
humerale et 
caput radiale). 
1. Internal condyle of the 
humerus by the common 
tendon, internal lateral 
ligament of the elbow- 
joint, and intermuscular 
septum. 2. Inner side 
of the coronoid process of 
the ulna. 3. Oblique line 
of the radius. 
Side and middle of 
second pha- 
langes of four 
inner digits, by 
four tendons 
which are per- 
forated by cor- 
responding ten- 
dons of flexor 
profundus. 
Median. 
Radial and 
ulnar. 
Flexor profundus 
digitorum (m. 
flexor digi- 
torum pro- 
fundus). 
1. Upper three-fourths of 
the anterior and inner 
surface of the ulna. 2. 
Inner side of the coro- 
noid process. 3. By 
aponeurosis in common 
with the flexor and 
extensor carpi ulnaris. 
4. Ulnar one-half of 
the interosseous mem- 
brane. 
Divides into four 
tendons, which 
are inserted into 
the bases of the 
last phalanges 
of the four 
inner digits. 
Median and 
ulnar. 
Ulnar. 
Flexor longus 
pollicis (m. 
flexor pollicis 
longus). 
1. Anterior surface of the 
shaft of the radius. 2. 
Interosseous membrane. 
3. Inner border of the 
coronoid process. 
Base of the last 
phalanx of the 
thumb. 
Median. 
Radial. 
Pronator quad- 
1. Lower part of the ante- 
Anterior surface 
Anterior 
Radial and 
ratus (m. pro- 
nator quad- 
ratus). 
rior surface of the shaft 
of the ulna. 2. Anterior 
border of the lower one- 
fourth of the ulnar. 
(lower one- 
fourth) and the 
anterior border 
of the shaft of 
the radius. 
interosseous. 
ulnar. 
Supinator longus 
1. Upper two-thirds of the 
Base of the styloid 
Musculo- 
Brachial and 
(m. brachio- 
radialis). 
external supracondylar 
ridge of the humerus. 2. 
External intermuscular 
septum. 
process of the 
radius. 
spiral. 
radial. 
Extensor carpi 
radialis longior 
(m. extensor 
carpi radialis 
longior). 
1. Lower one-third of the 
external supracondylar 
ridge of the humerus. 2. 
External intermuscular 
septum. 
Base of the meta7 
carpal bone of 
the index finger 
on radial side. 
Musculo- 
spiral. 
Radial. 
Extensor carpi 
radialis brevior 
(m. extensor 
carpi radialis 
brevior). 
1. External condyle of the 
humerus by the common 
tendon. 2. External 
lateral ligament of the 
elbow joint. 3. Inter- 
muscular septa and deep 
fascia. 
Base of the meta- 
carpal bone of 
middle fingeron 
the radial side. 
Posterior 
interosseous. 
Radial. 
Extensor com- 
1. External condyle of the 
Second and third 
Posterior 
Posterior 
munis digi- 
torum (m. 
extensor digi- 
torum corfl- 
munis). 
humerus by the common 
tendon. 2. Deep fascia 
and intermuscular septa. 
phalangesof the 
four inner 
digits. 
(For mode of 
insertion, see 
text.) 
interosseous. 
interosseous. 
Extensor minimi 
1. External condyle by the 
Second and third 
Posterior 
Posterior 
digiti (m. ex- 
tensor digiti 
quinti pro- 
pri us). 
common tendon. 2. Deep 
fascia and intermuscular 
septa. 
phalangesof the 
little finger. 
interosseous. 
interosseous. 176 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion. 
Nerve. Blood-supply, 
Extensor carpi 
1. External condyle of the 
Base of the meta- 
Posterior Posterior 
ulnaris (m. ex- 
humerus by the common 
carpal bone of 
interosseous. interosseous 
tensor carpi 
ulnaris). 
tendon. 2. Posterior 
border of the ulna by 
aponeurosis common to 
it, flexor carpi ulnaris, 
and flexor profundus 
digitorum. 
the little finger 
on the ulnar 
side. 
and radial. 
Anconeus (m. 
1. Continuation of the ex- 
Side of olecranon 
Musculo- Radial and 
ancomeus). 
ternal part of the triceps. 
2. Separate tendon from 
the back of the outer 
condyle of the humerus. 
and upper one- 
fourth of the 
posteriorsurface 
of the shaft of 
the ulna. 
spiral. superior 
profunda. 
Supinatoi' brevis 
1. External condyle of the 
1. Outer edge of 
Posterior Posterior 
(m. supinator). 
humerus. 2. External 
lateral ligament of the 
elbow. 3. Orbicular liga- 
ment of the radius. 4. 
Ridge of the ulna ex- 
tending from the lesser 
sigmoid. 5. Depression 
in front of the ridge. G. 
Deep fascia. 
the bicipital tu- 
berosity. 2. Ob- 
lique line of the 
radius. 
interosseous. interosseous 
and radial. 
Extensor ossis 
1. Outer part of the poste- 
Base of the meta- 
Posterior Posterior 
metacarpi pol- 
licis (m. ab- 
ductor pollicis 
longus). 
rior surface of the ulna. 
2. Interosseous mem- 
brane. 3. Middle one 
third of the posterior 
surface of the radius. 
carpal bone of 
the thumb. 
interosseous. interosseous. 
Extensor brevis 
1. Posterior surface of the 
Base of the first 
Posterior Posterior 
pollicis ; ex- 
tensor primi 
shaft of the radius. 2. 
Interosseous membrane. 
phalanx of the 
thumb. 
interosseous. interosseous. 
internodii pol- 
licis (m. ex- 
tensor pollicis 
brevis). 
Extensor longus 
1. Outer part of the poste- 
Base of the last 
Posterior Posterior 
pollicis; ex- 
tensor secundi 
internodii pol- 
licis (m. ex- 
rior surface of the ulna. 
2. Interosseous mem- 
brane. 
phalanx of the 
thumb. 
interosseous. interosseous. 
tensor pollicis 
longus). 
Extensor indicis 
1. Posterior surface of the 
Second and third 
Posterior Posterior 
(m. extensor 
indicis pro- 
prius). 
shaft of the ulna below 
the extensor longus pol- 
licis. 2. Interosseous 
membrane. 
phalanges of the 
index finger 
with corre- 
sponding part 
of the extensor 
communis 
digitorum. 
interosseous. interosseous. CHAPTER XI. 
THE THORACIC WALLS. 
DISSECTION AND IDENTIFICATION. 
Remove integument according to incisions in Figs. 77 and 94, study illustration of cutaneous 
nerves, and remember each is attended by cutaneous vessels of like name, although not shown 
in the accompanying illustration. 
Anterior Cutaneous Nerves. Identify (1) by their location near sternum and distribution 
to integument; (2) by their serial continuity with the anterior cutaneous nerves of abdomen ; 
(3) by their accompanying perforating branches of the internal mammary artery; (4) by their 
derivation from the intercostal nerves (Fig. 96): (5) by their communications with the lateral 
cutaneous branches of the intercostal nerves. (Fig. 94.) 
Lateral Cutaneous Nerves. Identify (1) by their location in intercostal spaces in a line 
slightly behind the anterior axillary fold; (2) by their accompanying the lateral cutaneous 
branches of the intercostal arteries; (3) by their derivation from the intercostal nerves and 
distribution to the integument; (4) by their communication with the anterior cutaneous nerves 
and the posterior primary divisions of the spinal nerves; (5) by their serial continuity with 
the lateral cutaneous nerves of the abdominal walls. (Fig. 94.) 
Internal Mammary Arteries. Identify (1) by their course along the anterior thoracic walls, 
one-half inch to outer side of sternum; (2) by their derivation from the first stage of the sub- 
clavian artery, and anastomosis (in sheath of rectus abdominis muscle) of its superior epigastric 
branch with the deep epigastric branch of the external iliac artery; (3) by their furnishing two 
anterior intercostal arteries to each of the six intercostal spaces; (4) by their termination behind 
the cartilage of the seventh rib in the superior epigastric and musculophrenic arteries; (6) by 
being accompanied by two veins. (Fig. 95.) 
External Intercostal Muscle. Identify (1) by its location in an intercostal space and 
attachment to the ribs; (2) by the downward and forward direction of its fibres; (3) by its extent, 
from the tubercle of the rib to the costo-chrondral articulation ; (4) by the continuance of the 
anterior intercostal membrane from the end of the muscle forward to the sternum; (5) by 
eleven muscles on each side of the thorax. 
Internal Intercostal Muscle. Identify (1) by its location in an intercostal space and 
attachment to ribs; (2) by the downward and backward direction of its fibres; (3) by its extent 
from the angle of the ribs to the margin of the sternum; (4) by continuance of the posterior 
intercostal membrane backward from the angle to the tubercle of the rib ; (5) by its eleven 
muscles on each side. Remove the external intercostal muscles to expose the internal inter- 
costal muscle and the intercostal nerves and vessels. 
Intercostal Artery. (Fig. 95.) Identify (1) by its location in an intercostal space with a 
nerve of like name; (2) by its derivation from subclavian, internal mammary, and aorta. 
The intercostal arteries are derived from (1) the subclavian, which furnishes the superior 
intercostal artery by which the first and second spaces are supplied; (2) the internal mam- 
mary ; (3) the thoracic aorta. The aorta gives off ten intercostal arteries. Each, after a short 
course, divides into an upper and a lower branch. These anastomose with corresponding 
branches of the internal mammary. The intercostal branches from the aorta are called 
posterior intercostals; those from the internal mammary artery, anterior intercostals. The 
twelfth is called subcostal. 
The Intercostal Veins are twelve in number on each side. They accompany the arteries, 
and correspond therewith in course and distribution. The last thoracic vein is called the 
subcostal. Tributaries are dorsal, from muscles of back; spinal, from neural canal and spinal 
meninges. 
Intercostal Nerves. Identify (1) by its location in the intercostal spaces (except twelfth) 
with the intercostal vessels; (2) by their derivation from the thoracic nerves; (3) by their 
extensive distribution. 
Superficial Fascia. Identify (1) by its location beneath the skin ; (2) by its continuity with 
the superficial fascia of the neck, abdomen, and back; (3) by its contents : mammary glands, 
fat, and cutaneous vessels and nerves. 
" INTERNAL MAMMARY ARTERY. (Fig. 95.) 
This is a branch of the first part of the subclavian artery. The artery, accom- 
panied by two veins, passes behind the inner end of the clavicle and the costal 178 
A MANUAL OF DISSECTION. 
cartilages to the sixth intercostal space, where it divides intojthe superior 
epigastric and musculophrenic. In its course the artery lies one-half inch to 
the outer border of the sternum. From without, the artery is covered by skin, 
Fig. 9-1. 
Cutaneous distribution of thoracic nerves. (Gerrish after Testut.) 
superficial fascia, aponeurotic origin of pectoralis major, costal cartilages, anterior 
intercostal membrane, and external intercostal muscles. The artery is crossed by 
terminal branches of intercostal nerves. Branches: (1) The arteria comes nervi 
phrenici, accompanies the phrenic nerve ; (2) the perforating, accompany the THE THORACIC WALLS. 
179 
anterior cutaneous nerves; (3) the mediastinal, supply the thymus and mediastinal 
lymphatics; (4) the anterior intercostals, accompany the intercostal nerves; (5) the 
Fig. 95. 
The internal mammary artery and its branches. (Gray.) 
superior epigastric, enters the sheath of the rectus muscle ; 6) the musculo- 
phrenic, supplies the diaphragm and lower intercostal spaces ; (7) the pericardiac, 
supplies the pericardium. In the female the perforating branches form the prin- 180 
A MANUAL OF DISSECTION. 
cipal blood-supply of the mammary glands. The superficial epigastric branch 
anastomoses with the deep epigastric of the external iliac in sheath of the rectus 
muscle. 
Internal Mammary Veins. Two veins accompany each internal mammary 
artery, and are fed by tributaries corresponding to the branches of the artery. 
The veins have numerous valves. Behind the first intercostal space the four 
internal mammary veins form two main trunks, which open into the innominate 
veins of their respective sides. 
THORACIC OR DORSAL NERVES. 
The walls of the thorax and abdomen are supplied by the dorsal or thoracic 
nerves. These nerves do not form plexuses, as do those in the cervical, lumbar, and 
sacral regions. Their number is twelve on each side. The first dorsal emerges 
between the first and second dorsal vertebrae, the twelfth, between the last thor- 
acic and first lumbar. Each nerve arises by an interior motor and a posterior 
sensory root, which leave the neural canal and unite in the intervertebral fora- 
men, forming a mixed trunk. On emerging from the intervertebral foramen the 
mixed trunk divides into anterior and posterior primary divisions to supply pre- 
axial and post-axial parts of the body, respectively. 
Posterior Primary Divisions. The posterior primary division (smaller than the 
anterior), in company with the corresponding dorsal branch of the intercostal ves- 
sel, reaches the back through 1 a space bounded by the transverse process of the 
vertebra, neck of rib, body of vertebra, and superior costo-transverse ligament, 
and divides into internal and external branches. The internal branch, accom- 
panied by corresponding vessels, passes between the semispinalis dorsi and multi- 
fidus spinse. It supplies the multifidus spina?, semispinalis dorsi and integument 
of the back, out to the angles of the ribs, in the upper half of the thorax. The 
externa] branch, accompanied by corresponding vessels, emerges between the lon- 
gissimus dorsi and iliocostalis, supplying these and the musculus accessorius, leva- 
tores costarum, and integument of the lower half of the thorax as far outward as the 
angles of the ribs. The posterior primary divisions also supply the costo-transverse 
articulations. It will be seen, then, that the posterior primary divisions of the 
spinal nerves supply the erector spinse and its divisions, the costo-transverse ar- 
ticulations, and the skin of the back externally to the angle of the ribs, where 
their cutaneous branches communicate with the lateral cutaneous branches of the 
anterior primary divisions. (See dissection of the back.) 
INTERCOSTAL NERVES. (Fig. 96.) 
Intercostal Nerves. The anterior primary divisions of the dorsal nerves are 
called the intercostals, of which the six upper supply the thoracic and the six 
lower the abdominal walls. Each intercostal nerve is connected to a vertebral 
ganglion of the sympathetic, by both gray and white rami communicantes, and 
is accompanied by intercostal vessels. (See sympathetic nerve.) 
An intercostal nerve has three stages : (1) from intervertebral foramen to angle 
of rib ; (2) from angle of rib to costo-chondral articulation; (3) from costo- 
chondral articulation to sternum. In the first stage the nerve is beneath the 
artery, under cover of the parietal pleura and posterior intercostal membrane, 
resting on the external intercostal levator, costarum muscles, and superior costo- 
transverse ligament. In the second stage the nerve is between the internal and 
external intercostal muscles. In the third stage the nerve passes inward through 
the internal intercostal muscle (and lies on this latter) under cover of the 
triangularis sterni muscle, internal mammary vessels, and costal pleura. (Inter- 
costal vessels have the same course and stages). THE THORACIC WALLS. 
181 
Branches of an Intercostal Nerve. 1. Anterior cutaneous : one in each inter- 
costal space pierces the pectoralis major muscle near the sternum, and is attended 
by the perforating branches of the internal mammary vessels. (Below the dia- 
phragm these nerves and vessels are serially continuous with the anterior cutaneous 
nerves and vessels of the abdominal walls.) 2. Lateral cutaneous: one in each 
intercostal space, attended by similar vessels. These pierce the thoracic wall, a 
little behind the anterior axillary fold, between the tooth-like processes of the ser- 
ratus magnus muscle (Fig. 94), and are serially continuous below the diaphragm 
with the lateral cutaneous branches of the abdominal walls. Each lateral cutaneous 
nerve divides into a posterior branch (which communicates with cutaneous branches 
of the posterior primary division), and an anterior branch, which communicates with 
the anterior cutaneous branch. (Figs. 94, 96.) 3. Articular branches, to costo- 
vertebral and chondrosternal articulations. (The nerve that supplies a muscle, 
Fig. 96. 
Plan of a typical intercostal nerve. (Gerrish after W. Keiller.) 
supplies the joint moved and the integument covering the insertion of the muscle.) 
4. Muscular branches, to external and internal intercostals, infracostals, trian- 
gularis sterni, and levatores costarum. 5. Sympathetic branches: "Fine 
sternal branches are given off at the anterior ends of the intercostal spaces to 
the back of the sternum." (Luschka and Quain.) 11 Minute subcostal branches 
perforate the internal intercostal muscles, to reach the inner surface of the ribs, 
where they are distributed to the periosteum and bone, as well as probably to the 
costal pleura." (Testut.) 11 The gray rami communicantes commence as axis- 
cylinder processes of the ganglion cells, are distributed to spinal nerves, and in 
them reach the vessels, fascite, bones, etc., for which they are destined. The white 
rami communicantes are derived probably from the motor roots of the spinal and cra- 
nial nerves. In man they are derived from the thoracic, and the first (and perhaps 
the second) lumbar nerves, and furnished to the sympathetic cords." (Gerrish.) 182 
A At AN UAL OF DISSECTION. 
MUSCLES OF THE THORAX. 
The External Intercostal Muscles are twenty-two in number, eleven on each 
side. The fibres of these muscles pass downward and forward, reminding one of 
the direction of the fibres of the external oblique muscles of the abdominal walls. 
The muscular fibre of the external intercostal muscles extends from the tubercle 
of the rib to the costo-chondral articulation. From this point to the sternum, the 
anterior intercostal membrane is projected, its fibres taking the same direction as the 
fibre of the muscle. (Fig. 96.) Origin : Lower borders of the ribs. Insertion : 
Upper borders of lower eleven ribs, extending from tubercle of rib to costo- 
chondral junction. Nerve: Intercostals, by numerous small branches which 
enter the inner surfaces of the muscles. The anterior and posterior intercostal 
membranes are parts of a general subpleural endothoracic fascia. 
The Internal Intercostal Muscles are twenty-two in number, eleven on each side. 
The fibres run downward and backward, reminding one of the internal oblique 
muscles of the abdominal walls. The muscular fibre extends from the margin 
of the sternum to the angles of the ribs, thence the posterior intercostal membrane 
is extended backward. Fibres of the tenth and eleventh intercostal muscles are 
continuous with the internal oblique muscle. 
The Triangularis Sterni Muscle rests on the inner surface of the sternum aud 
costal cartilages. It represents the transversalis abdominis muscle, and is con- 
tinuous with it. Origin : (1) Ensiform cartilage; (2) body of sternum; (3) fifth, 
sixth, and seventh costal cartilages. Insertion : Second, third, fourth, fifth, and 
sixth costal cartilages. Between this muscle and the bones on which it rests are 
the internal mammary vessels and intercostal nerves. (Fig. 96.) 
Serratus Posticus Superior Muscle. Direction of fibre, downward and outward. 
Origin : (1) Ligamentum nuchae ; (2) spines of seventh cervical, and first and 
second thoracic vertebrae. Insertion : Outer surfaces of second, third, fourth, and 
fifth ribs. Action: Elevation of ribs. Synergists: External oblique and internal 
•oblique. Nerve: Second and third intercostals-posterior primary division. 
The Serratus Posticus Inferior Muscle. Direction of fibres, upward and out- 
ward. Origin : Spines of eleventh and twelfth thoracic, and first and second 
lumbar vertebrae. Insertion : Lower borders of eighth, ninth, tenth, eleventh, 
and twelfth ribs. Synergists: Infracostals. Nerves: Tenthand eleventh inter- 
costals-posterior primary divisions. 
The Levatores Costaruni are twelve in number on each side, and are continuous 
with the external intercostals. Origin : Tips of transverse processes of last cervical 
and eleven upper thoracic vertebrae. Insertion: Outer surfaces of ribs from 
tubercles to angles. Action : Elevation of ribs. Nerves : Intercostals. 
The Infracostals are eleven in number on each side. Direction: Upward 
and outward. Origin : Inner surfaces of lateral walls of thorax, external to 
angles of ribs. Insertion: Inner surface of first, second, or third ribs below their 
origin. Action: Depresses ribs. Nerves: Intercostals. 
THE DIAPHRAGM. 
Location. The diaphragm forms the floor of the thorax and the roof of the abdo- 
men, has a very complicated attachment to the abdomino-thoracic walls, and bears 
important relations to pleura, pericardium, peritoneum, oesophagus, aorta, inferior 
vena cava, and thoracic duct. It has a central tendon corresponding to the base 
of the pericardium, and muscular fibres that radiate outward from this to the 
inferior aperture of the thorax. Origin: (1) Back of ensiform; (2) bodies of 
first, second, and third thoracic vertebrae; (3) anterior lamella of lumbar fascia; 
(4) ligamenta arcuata externa, extending from the twelfth rib to the transverse 
process of the first lumbar vertebra; (5) the six lower ribs interdigitating with the 
transversalis muscle. THE THORACIC WALLS. 
183 
The Crura of the Diaphragm (right and left). They descend from the back of 
the diaphragm to the upper lumbar vertebrae. The right is larger than the left, 
and attached to the first, second, and third lumbar vertebrae; the left to the first 
and second vertebrae only. The aorta passes between the crura. Opposite the 
twelfth thoracic vertebra the two crura are bound together by a fibrous arch from 
which muscular fibres arise. Openings in the diaphragm ; (1) The aortic opening 
in front of the first lumbar vertebra is limited latterly by the crura, in front and 
behind by a fibrous arch. It gives passage to the aorta, thoracic duct, and vena 
azygos major. (2) The caval opening, in posterior part of central tendon, is 
situated opposite the cartilages of the eighth and ninth vertebrae, and gives pas- 
sage to the ascending vena cava and filaments of the right phrenic nerve. (3) The 
oesophageal opening lies to the left and in front of the aortic opening, and gives 
Fig* 97. 
Diaphragm viewed from below. (Gerrish after Testut.) 
passage to the oesophagus and pneumogastric nerves. Small openings transmit 
the vena azygos minor and the three splanchnic nerves (great, small, and smallest). 
The superior epigastric artery passes between the sternal and costal attachments 
of the diaphragm. Nerves: Two phrenics and phrenic plexus of sympathetic 
(branches that accompany the phrenic arteries). Arteries: Phrenic branches of 
aorta, musculophrenic branches of internal mammary, and arteria comes nervi 
phrenici. Action : (1) Respiratory; (2) expulsive on abdominal hollow organs. 
Relations. To aid the memory and gain a clear idea of the subject examine your 
dissection and demonstrate the following relations of the diaphragm: Above, lungs 
and heart, with bases of pleural and pericardiac sacs, respectively; below, liver 
(with coronary, falciform and lateral ligaments), stomach, pancreas, kidneys, 
suprarenal capsules, and spleen. Demonstrate the aorta, oesophagus, vena cava, 
thoracic duct, and splanchnic nerves passing through the diaphragm to the 
abdomen. CHAPTER XII. 
THORAX-SUBDIVISIONS AND CONTENTS. 
The pulmonary part of the thorax contains the lungs and pleural sacs. The 
space not occupied by the lungs and pleural sacs is called the mediastinum; hence, 
the thorax consists of two grand divisions, pulmonary and mediastinal, and each 
has definite contents. 
The general mediastinal space is divided into (a) superior mediastinum ; (6) 
anterior mediastinum ; (c) middle medias'tinum ; (d) posterior mediastinum. 
The Superior Mediastinum is bounded above by a plane passing through the 
upper border of the first piece of the sternum and the first dorsal vertebra ; below, 
by a plane passing through the upper border of the second piece of the sternum 
and the fourth dorsal vertebra; laterally by the pleurse. This space contains: the 
sternohyoid, sternothyroid and longus colli muscles; the arch of the aorta and its 
three large branches; the descending vena cava (upper half), innominate and left 
superior intercostal veins ; the vagus, cardiac, phrenic, and left recurrent laryngeal 
nerves; the trachea, oesophagus, thoracic duct, thymus and lymphatic glands. 
The Anterior Mediastinum is bounded, anteriorly, by the sternum and cartil- 
ages of the fourth, fifth, sixth, and seventh ribs of the left side ; posteriorly, by 
the pericardium, and laterally, by the pleurse. This space contains connective tis- 
sue, lymphatics from the convex surface of the liver, anterior mediastinal glands, 
and branches of the internal mammary artery. 
The Middle Mediastinum is bounded in front and behind by the anterior and 
posterior mediastina, respectively, laterally by the pleurse. This space contains 
the heart and pericardium, ascending aorta, superior vena cava (lower half), vena 
azygos major, bifurcation of trachea, bronchi, pulmonary arteries and veins, 
phrenic nerves and bronchial lymph glands. 
The Posterior Mediastinum is bounded in front by the pericardium, behind by 
the vertebral column, laterally by the pleurse. This space contains the thoracic 
aorta, the azygos veins, the vagus and splanchnic nerves, the oesophagus, thoracic 
duct, and lymph glands. 
Our study of the contents of the thorax will consist (a) of identification of struc- 
tures in situ, (b) of dissection of organs. 
Identification of Collective Structures in Situ. 
The Diaphragm. Identify (1) by its location below the lungs and heart and above the 
stomach and liver; (2) by its attachment to the sternum, costal cartilages, and vertebral 
column. These two statements regarding location and attachment apply to no other structure. 
There are many points that might be cited, but these two are sufficient for identification. 
Lungs. Identify (1) by their location on each side of the heart, extending up into the 
lateral parts of the root of the neck above the level of the first rib and resting on the upper 
surface of the diaphragm below; (2) by their spongy feel and dark spots. 
Parietal Pleura. Identify (1) by its location on and attachment to the ribs and dia- 
phragm ; (2) by its reflection onto the lungs and lateral part of mediastinum. Diaphragmatic, 
cervical, costal, and mediastinal are parts of the parietal pleura in these several regions. 
Visceral Pleura. Identify (1) by its location on and firm attachment to the lungs; (2) by 
its reflection onto the thoracic walls; (3) by the glistening appearance it confers on the lungs; 
(4) by its great elasticity seen when the lungs are passively inflated. The black spots on the 
lungs are beneath the visceral pleura; hence this latter is transparent. 
Pleural Cavity. Identify (1) by its location between the parietal and visceral layers of the 
pleura; (2) by the small amount of serum contained; (3) by its extent from the root of the 
neck to the diaphragm and from the ribs to the mediastinal pleura. 
Thymus G-land. Identify in the very young (1) by its two lateral lobes in close contact, 
near mid-line, extending from the thyroid gland in the neck to the fourth costal cartilage, and TH OH AX-SUB DI VISIONS AND CONTENTS. 
185 
resting on the pericardium; (2) by its location on the front and sides of the trachea. Lobes 
are sometimes separated by intermediary lobules, and occasionally fused in one mass. The 
glands are formed by evaginalion from the third pharyngeal pocket, are soft, lobulated, of 
pinkish-gray color, and at birth weigh about one-half ounce. The thymus is a ductless 
blood gland, and in the adult obtains as a connective tissue remnant on the upper part of 
the pericardium, separated from the arch of the aorta and other great bloodvessels by a layer 
of fascia. 
Parietal Pericardium. Identify (1) by its sac-like shape and conical form, attached by its 
base to the diaphragm, by its truncate apex to the great vessels below the central part of the 
root of the neck, behind the first piece of the sternum ; (2) by its being covered almost 
completely by the anterior margins of the lungs. (Fig. 98.) 
The Visceral Pericardium invests the heart, and cannot be seen until the parietal peri- 
cardium has been incised and turned aside. The pericardial cavity is identified as a space 
between the visceral and parietal layers of the pericardium. 
Fig. 93. 
Front view of the heart and lungs. (Gray.) 
Internal Mammary Artery. Identify (1) by its location (one on each side) on the ante- 
rior wall of the thorax, about one half inch external to the margin of the sternum ; (2) by its 
origin from the first portion of the subclavian artery; (3) by its two accompanying veins, 
which unite behind the first intercostal space and form its two common trunks (right and left), 
and discharge into the corresponding innominate veins. (Fig. 95.) 
Phrenic Nerve. Identify (1) by its location beneath the mediastinal pleura, on lateral 
aspect of the pericardium; (2) by its location anterior to the root of the lungs; (3) by its 
accompanying artery, a branch of the internal mammary, the arteria comes nervi phrenici. 
Root-structures of Lungs. Identify as a constriction or neck connecting the heart and 
lungs. Develop by dividing the connective tissue along the vessels and bring into view by 
gently turning the anterior margins of the lungs outward. Root of the lung consists of the 
bronchus, pulmonary artery, pulmonary vein, pulmonary vessels, and nerves. (Fig. 98.) 
Aortic Arch. Identify (1) by its central location between the descending vena cava on the 
right and the pulmonary artery on the left; (2) by its graceful curve backward and to the left, 
across the root of the left lung; (3) by the three large arteries (innominate, left common carotid, 
and left subclavian) arising from the highest part of the arch; (4) by its origin from the left 
ventricle of the heart. 186 
A MANUAL OF DISSECTION. 
Descending or Superior Vena Cava. Identify (1) by its location to the right of the aorta 
and by its blue color (generally) ; (2) by the adjacency of the phrenic nerve to its outer side; 
(3) by its formation, the confluence of the right and left innominate veins, beneath the car- 
tilage of the first rib, near the sternum on the right side; (4) by its termination in the upper 
part of the right auricle of the heart. 
Vena Azygos Major. (Fig. 107.) Identify (1) by its arching from behind forward, across 
the root of the right lung, opposite the fourth dorsal vertebra; (2) by its termination in the 
descending vena cava, just before this latter pierces the pericardium. 
Ascending or Inferior Vena Cava. Identify (1) by its passage through the caval opening- 
in the diaphragm and base of the pericardium; (2) by its termination in the lower part of the 
right auricle of the heart. 
Pulmonary Artery. Identify (1) by its location to the left of the aorta ; (2) by its division 
into the right and left pulmonary arteries. The left pulmonary artery passes directly to the 
lung above the bronchus; the right, beneath the aorta, vena cava, and right phrenic nerve, to 
the right lung and below the bronchus. 
Pulmonary Veins. Identify (1) by their termination in the posterior wall of the left 
auricle; (2) by their position as the lowest of the root structures of the lungs. 
Apex of Heart. Identify by its characteristic pointed shape and location near the fifth 
intercostal space of the anterior wall of the thorax, one and a half inches below the nipple, 
and three and a half inches to the left of mid-sternal line. 
The Base of Heart. Identify (1) by its logical remoteness from the apex ; (2) by the large 
vessels arising therefrom ; (3) by its relation to the vertebrae-four thoracic vertebrae lie above, 
four below, and four behind it. 
The Posterior Surface of Heart. Identify (I) by its location on the floor of the pericar- 
dium on the diaphragm ; (2) by its flattened appearance. 
The Anterior Surface. Identify (1) by its location behind the gladiolus; (2) by the pres- 
ence of the third, fourth, and fifth costal cartilages on each side. 
Auricular Part of Heart. Identify (1) by its thin, flaccid, collapsed walls; (2) by its 
characteristic posterior location; (3) by two forward-projecting, ear-like processes-the 
auricular appendices; (4) by a deep hollow between the two auricular parts, from which the 
aorta and pulmonary artery spring, behind and in front, respectively; (5) by its receiving 
tributary the venae cavee and pulmonary veins. (Fig. 98.) 
Ventricular Part of Heart. Identify (1) by its conical form and firm, fleshy walls; (2) by 
its giving origin to the aorta and pulmonary artery; (3) by connection with the auricles of 
the heart; (4) by its apex, base, and right and left borders, anterior and posterior surfaces. 
Right Border of the Ventricle is long and sharp, readily identified, and extends from base 
to apex and from right to left. It separates the surfaces and is called the margo acutus. 
The Left Border is short and round, extends from base to apex, and is called margo obtusus. 
The Right Ventricle includes superficially (1) right border; (2) about two-thirds of ante- 
rior surface ; (3) about one-third of posterior surface, thus making the "right heart" anterior. 
The Left Ventricle includes superficially (1) left border; (2) about one-third of anterior sur- 
face; (3) about two-thirds of posterior surface; (4) apex. This makes the major part of the 
so-called left heart posterior. 
The Auriculo-ventricular Groove. Identify by its location around the circumference of 
the organ in a transverse direction nearer the base than the apex, and at a place where the 
auricular and ventricular parts of the heart are joined. This groove contains the right and left 
coronary arteries. 
The Anterior Interventricular Groove begins in the auriculo-ventricular groove to the left 
of the pulmonary artery, and may be traced along the anterior surface of the heart downward 
a little to the right of the apex. This groove is occupied by the descending branch of the left 
coronary artery. 
The Posterior Interventricular Groove traverses the posterior surface of the heart, origi- 
nates above in the auriculo-ventricular groove, and contains the descending branch of the 
right coronary artery. 
Inverse Relation of Borders and Interventricular Grooves of Heart. The anterior inter- 
ventricular groove, occupied by the descending branch of the left coronary artery, and on the 
anterior surface of the heart, is nearer the left than the right border. The posterior interven- 
tricular groove, occupied by the descending branch of the right coronary artery and on the 
posterior surface of heart, is nearer the right than the left border of the heart. 
Correspondences. The anterior and posterior interventricular grooves correspond to the 
interventricular septum, by which the two ventricles are completely separated from each other. 
The auriculo-ventricular groove corresponds to the attachment of the valves in the openings 
between the auricles and ventricles of the heart (right and left auriculo-ventricular valves). 
The Left Coronary Artery arises from the left posterior sinus of Valsalva, passes behind the 
pulmonary artery to the left in the auriculo-ventricular groove to the posterior surface. In 
its course it gives left auricularand ventricular branches and a large descending branch, which 
passes along the anterior interventricular groove to the apex of the heart. 
The Right Coronary Artery arises from the anterior sinus of Valsalva, traverses the auriculo- 
ventricular groove to the right until it reaches the posterior surface of the heart. In its course 
it gives auricular and ventricular branches to the right auricle and ventricle, a large branch to 
the right margin, and a descending branch in the posterior interventricular groove. THORA X-S UBDI VISIONS A ND C ONT ENTS. 
187 
The Superficial Cardiac Plexus, situated in the concavity of the aortic arch, on the bifur- 
cation of the pulmonary artery, gives off the right coronary plexus which accompanies the 
right coronary artery. The deep cardiac plexus, situated behind the arch of aorta, gives off 
the left coronary plexus to the left coronary artery. 
The Cardiac Veins. The veins of Thebesius are small vessels which return blood from the 
deep substance of the heart. They open into the right auricle through the minute foramina 
Thebesii. The anterior cardiac veins are on the front surface of the right ventricle, and open 
directly into the right auricle of the heart. The coronary sinus is in the groove between the 
left auricle and left ventricle, and may be identified in this place in fresh bodies by its large 
size and blue appearance. It opens into the right auricle between the vena cava and the 
auriculo-ventricular opening, and is guarded by the coronary valve. Tributaries of the coro 
nary sinus: Great cardiac vein in interventricular groove, with descending branch of left 
coronary artery; middle cardiac vein (a branch of posterior cardiac) in posterior interven- 
tricular groove, with descending branch of right coronary artery; right cardiac and oblique 
vein of Marshall. 
Fig. 99. 
The heart in situ. The pericardium has been cut open in front, and reflected. (Gebrish after Testut.) 
THE PERICARDIUM. 
Dissection. (Fig. 99.) Cut through the visceral layer from diaphragm to arch of aorta. 
Locate phrenic nerves (on side of pericardium) and trace same to upper surface of the dia- 
phragm. Turn apex of heart upward and examine visceral layer of pericardium (investing 
the heart). Locate base of pericardium and find ascending vena cava piercing the same. 
Place borders of lungs in normal position and estimate how much of pericardium is not 
covered by lung tissue-the area of pericardia.1 dulness. 
The Pericardium is a fibroserous sac surrounding the heart. Its base is attached to the 
central tendon of the diaphragm and perforated by the ascending vena cava. The apex sur- 
rounds the descending vena cava, aorta, and pulmonary vessels, and has the following pouches : 
(1) One between the inferior vena cava and lower pulmonary vein of right si^e; (2) one 
between the superior vena cava and upper pulmonary vein of right side; (3) one between the 
left pulmonary artery and left pulmonary vein. (See Gerrish.) 
Tubular Prolongations. The ascending aorta and common pulmonary artery are sur- 
rounded in common by a tubular prolongation, their adjacent surfaces only remaining uncov- 
ered by pericardium. Between these two vessels and the auricular part of the heart is a space 
(sinus transversus). The inferior vena cava receives a small investment of pericardium. The 
superior vena cava is invested in part. The pulmonary veins are invested on the front and sides. 
Surfaces and Relations. The anterior surface of the pericardium is in relation with the 
sternum, internal mammary vessels, connective tissue, triangularis sterni, and thymus; the 188 
A MANUAL OF DISSECTION. 
posterior surface with the oesophagus, aorta, vagus nerves, thoracic duct, vena azygos major; 
the lateral surface with the anterior margins and inner surface of the lungs and mediastinal 
pleurae. The pericardium consists of (1) a parietal layer; (2) a reflected or visceral layer; (3) 
a potential space between the two layers, called the pericardiac cavity. Each layer of the 
pericardium consists of a fibrous, non-elastic outer part, and a smooth, moist, glistening, 
secretory inner part. Arteries: Internal mammary, arteria comes nervi phrenici, bronchial, 
oesophageal, pericardiac. Nerves : Vagus, phrenic, sympathetic. 
THE HEART. 
Dissection. (1) Cut directly downward through the superior vena cava, atrium of right 
ventricle, and inferior vena cava as far as the diaphragm ; (2) cut through the auricular appen- 
dix in a line at right angles to first incision. These two incisions will permit the right auricle 
to be studied after having been thoroughly cleansed. (Fig. 100.) (3) Cut about one inch of 
apex of heart off and pass director downward through the auriculo-ventricular opening into 
the right ventricle. Now pass a director from right ventricle into pulmonary artery and cut 
Fig. 100. 
Right auricle and part of right ventricle, the front wall having been removed. (Gerkish after Testut.) 
down on same. This will afford an opportunity to study the interior of the right ventricle 
and the pulmonary semilunar valves. Pass director from apex of heart upward into aorta and 
cut down on same. This will expose the left ventricle and aortic semilunar valves. Trace 
pulmonary veins into left auricle and open same. Bullocks' hearts should be dissected to give 
a clear idea of valves, chordae tendineae, and columnae carneae. 
The adult heart has two compartments, right and left, separated by a septum in such a 
manner that no direct communication exists. Each compartment has an auricle and a ven- 
tricle. There are, then, two auricles and two ventricles, which collectively constitute the heart. 
The heart is lined by endothelium continuous with that of all vessels that enter or depart. 
Right Auricle. (Figs. 98, 100.) The right auricle has (1) a small, forward-projecting, ear- 
shaped, auricular process; (2) an atrium, into which a number of vessels discharge venous 
blood derived from the substance of the heart and from the regions both above and below the 
diaphragm. The atrium of the right auricle communicates with the right ventricle through 
the auriculo-ventricular opening. Tributaries of right auricle: (1) Foramina of Thebesius are 
openings of small veins (some are blind pouches) which return the blood from the substance 
of the heart. The largest is the cardiac vein of Galen. (2) The orifices of the anterior car- 
diac veins, three or four in number, which return the blood from the right ventricle of the 
heart. (3) The orifice of the ascending or inferior vena cava. This vessel perforates base of 
the pericardium and the diaphragm, opens into the lower part of the atrium, and returns prac- THORAX-SUBDIVISIONS AND CONTENTS. 
189 
tically all the venous blood from below the diaphragm. As it passes through the caval open- 
ing the hepatic veins become tributary to it. (4) The orifice of the descending vena cava. 
This vessel opens into the upper part of the atrium. It is formed by the confluence of the 
two innominate veins, and receives the vena azygos major. 
Direction of Currents. The current of blood in the descending vena cava is directed into 
the auriculo-ventricular opening; that of the ascending vena cava, against the fossa ovalis in 
the posterior wall of the auricle. The currents are not opposed to each other. In the foetus 
the same directions obtained, and blood in the ascending vena cava passed through the 
foramen ovale to the left auricle. 
The Eustachian Valve is a fold of endocardium extending from the orifice of the ascending 
vena cava to the foramen ovale in the foetal heart. It directs the blood-stream through the 
foramen ovale into the left auricle. In the adult heart the Eustachian valve (often feebly 
marked) guards the opening of the ascending vena cava. 
The Orifice of the Coronary Sinus is between the opening for the ascending vena cava and 
the auriculo-ventricular opening. It is guarded by a fold of endocardium called the valve of 
Thebesius. The valve is imperfect. 
The Fossa Ovalis, the remains of the foramen ovale of the foetal heart, is in the posterior 
wall of the right auricle. It is surrounded by a margin called the annulus ovalis, and is seen 
by cleaning the wall (with gauze) and putting same on the stretch. 
The Musculi Pectinati and Crista Terminalis. The inner surface of the auricles has a 
number of parallel ridges called musculi pectinati. They end in a smooth, vertical ridge, 
the crista terminalis. The whole has, in fancy, the appearance of a comb, and is to the 
auricles what the column® carne® are to the ventricles of the heart, like mechanical devices 
for increasing the strength. 
Fig. 101. 
Valves ot the heart and great arteries viewed from above, the auricles having been removed. (Gerrish after 
Testut.) 
Function of Right Auricle. This chamber of the heart collects the blood during ventricular 
systole, and discharges same through the auriculo-ventricular opening into the right ventricle 
during ventricular diastole. 
Right Ventricle. (Fig. 100.) The right ventricle is triangular in shape and its base is at 
the auriculo-ventricular groove. Its apex does not occupy the apex of the heart, but corre- 
sponds to the intersection of the anterior and posterior interventricular grooves in the margo 
acutus, about one inch above the apex of the heart. Orifices of right ventricle : (1) auriculo- 
ventricular (guarded by the auriculo-ventricular valve), by which the blood reaches the ven- 
tricle from the auricle; (2) pulmonary, by which the blood leaves the ventricle. This orifice 
is guarded by the pulmonary semilunar valves. The interior surface of the conus arteriosus 
(see p. 198) is smooth; that of the remainder of the ventricle is made irregular by column® 
carne®, of which three varieties are recognized. 
Variety of Column® Carne®. (Fig. 102.) (1) Slightly elevated and elongated ridges of 
muscular tissue covered by endocardium; (2) fleshy bands of muscular tissue covered by endo- 
cardium and attached by two ends to the walls of the ventricle, but free in the rest of their 
extent; (3) fleshy conical masses, musculi papillares, attached by their bases to the ventricular 
walls, covered, by endocardium and ending in delicate tendons, chord® tendine®, which are 
attached to the auriculo-ventricular valves and arranged into anterior and posterior sets. The 
so-called moderator band is a muscular structure which stretches across the ventricle from 
anterior papillary muscle to ventricular substance. Its use is to prevent overdistention of the 
ventricular cavity of the heart by fixing the anterior walls of the ventricle to a firm septum. 
Tricuspid Valve. The right auriculo-ventricular or tricuspid valve consists of three trian- 
gular cusps, the base of each of which is attached to the margin of the auriculo-ventricular 190 
A MANUAL OF DISSECTION. 
opening. At their bases the three cusps are united in a continuous ring. Histologically these 
cusps consist of two layers of endocardium united by connective tissue. Each cusp has 
attachments (1) to the margin of the auriculo-ventricular orifice; (2) to the chordae tendineae. 
Location and Names of Cusps of Right Auriculo-ventricular Valve. (1) The central 
cusp, behind the auriculo ventricular opening, is closely related to the septum; (2) the marginal 
cusp, to the right of the auriculo-ventricular opening, is near the right border of the heart; 
(3) the infundibular cusp, the largest of the three, is between the auriculo-ventricular opening 
and the pulmonary orifice. When the left ventricle of the heart contracts and forces blood 
into the aorta these cusps prevent regurgitation into the right auricle. 
Semilunar Valve of Pulmonary Artery. (Fig. 101.) This has three segments, and each 
segment has two layers of endocardium connected by fibrous tissue. Each segment has an 
attached and a free margin. The free margins occlude in such a manner as to prevent regur- 
gitation, and occlusion is made more effective by the presence of a nodule of cartilage in the 
centre of the free margin of each segment (corpus Arantii). The semilunar valve is placed at 
the beginning of the pulmonary artery, which is slightly dilated above the segments to form 
Fig. 102. 
Left auricle and ventricle, the hind wall of each having been removed. (Gerrish after Testut.) 
the sinuses of Valsalva. The arrangement of the segments is as follows: two are in front and 
one behind the opening of the pulmonary artery. 
Left Auricle. The left auricle of the heart, like the right, consists of (1) an auricular 
appendix (that points forward), and is the only part of the auricle that can be seen from in front 
(Fig. 98); (2) an atrium, or principal cavity, into which the pulmonary veins discharge. (Fig. 
102.) The interior of the left auricle is smooth everywhere except in the auricular appendix, 
where the musculi pectinati give it a roughened appearance. 
Openings in Left Auricle. (1) On posterior wall are openings for the pulmonary veins un- 
guarded by valves. (Fig. 102.) Two pulmonary veins on each side may discharge by a com- 
mon opening; (2) the auriculo-ventricular opening, guarded by the auriculo-ventricular valve, 
is in the floor of the auricle and opens into the left ventricle; (3) the remains of the foetal 
foramen ovale (fossa ovalis) is in the septum between the auricles. (Fig. 100.) 
Left Ventricle (Fig. 102.) The left ventricle has stronger walls than the right and includes 
the apex of the heart. The ventricular septum and upper part of the anterior wall of the 
ventricle are smooth; the apex and upper part of the anterior wall have a complex network 
of columnse carnese. The papillary muscles and chordae tendineae are larger and stronger in 
the left than in the right ventricle. THORAX-SUBDIVISIONS AND CONTENTS. 
191 
Openings in Left Ventricle. (1) The aortic opening, guarded by the aortic semilunar 
valve; (2) the left auriculo-ventricular opening, guarded by bicuspid or mitral valves, is 
between the left auricle and the left ventricle. These two openings are close together, near 
the base of the heart; that for the aorta is in front and to the right. 
The Aortic Valve has three semilunar segments attached to the margins of the aortic open- 
ing. (Fig. 101.) Each segment has a free or occlusal margin, in the centre of which is a 
nodule of cartilage (corpus Arantii). Each segment is composed of two layers of endocardium 
and connective tissue. Segments are similar in structure, but stronger than segments of the 
semilunar pulmonary valve. The aorta is dilated in the neighborhood of the semilunar valve 
(above) to form the sinuses of Valsalva. One lies in front and two behind the opening. The 
right coronary artery originates in the anterior sinus of Valsalva; the left, in the posterior sinus. 
The Bicuspid, or left auriculo-ventricular valve, is composed of two layers of endocardium 
and connective tissue, and attached to the auriculo-ventricular opening and to the chordee 
tendinese of the papillary muscles. The anterior cusp is larger, and located between the aortic 
and the auriculo-ventricular openings. The function of the bicuspid valve is to prevent 
regurgitation of blood into the auricle during systole of the left ventricle. 
Fig. 103. 
Pulmonar.v veins, seen in a dorsal view of the heart and lungs. (Gerrish after Testut.) 
TRACHEA AND BRONCHI. 
Dissection. Locate the bifurcation of the trachea opposite the fourth dorsal vertebra. Cut 
longitudinally through its walls at this point, and extend the incision two inches into each 
bronchial tube. Notice the angle of departure of the bronchi from the trachea, and study the 
imperfect cartilaginous rings of each. Trace the bronchi into the lungs and identify their 
relation by comparison with the table, on a subsequent page, of root-structures of the lungs 
(p. 194). Identify the relations of the trachea by comparison with the table on page 192. 
The Trachea and bronchial tubes convey air to and from the lungs. The trachea extends 
from the sixth cervical vertebra to the fourth dorsal, where it divides into the right and left 
bronchial tuhgs. The trachea is nearly an inch in diameter, and about five inches in length. 
The upper part of the trachea is in the neck; the lower, in the superior mediastinal space. 
Arteries: Inferior thyroids. Nerves: Vagus, recurrent laryngeal, and sympathetic. 
The Bronchial Tubes begin at the bifurcation of the trachea, opposite the fourth dorsal ver- 
tebra, and terminate in the lung. (Fig. 103.) The right bronchus is about one inch, the left 
about two inches in length. The right bronchus is larger and more vertical in direction than 
the left; hence the greater liability of foreign bodies lodging in this one. 192 
A MANUAL OF DISSECTION. 
Relations of the Trachea. (Fig. 103.) 
Posteriorly, the trachea lies on the oesophagus. 
Isthmus of thyroid gland. 
Inferior thyroid veins. 
Arteria thyroidea ima. 
Sternohyoid muscle. 
Sternothyroid muscle. 
Cervical fascia. 
Superficial jugular veins. 
In neck. 
Anterior relations. 
Manubrium of the sternum. 
Remains of the thymus gland. 
Left innominate vein. 
Arch of the aorta. 
Innominate artery. 
Left common carotid artery. 
Deep cardiac plexus. 
In thorax. 
In neck. 
Common carotid arteries. 
Lateral lobes of the thyroid. 
Inferior thyroid arteries. 
Recurrent laryngeal nerves. 
Lateral relations. 
Pleura. 
Vagus nerve. 
Innominate artery. 
Right side. 
In thorax. 
Recurrent laryngeal nerve. 
Aortic arch. 
Left common carotid artery. 
Left subclavian artery. 
Left side. 
THE PLEURA. 
Dissection. Trace the pleura over the outer surface of the mediastinal space, diaphragm, 
ribs, and lungs. Strip same from ribs and study the intercostal vessels and nerves near the 
vertebral column. Tear the pleura from the vertebral column and gain a view of the contents 
of the posterior mediastinum. Strip the pleura from the dome of the thorax and study the 
subclavian artery in its relation to the apex of the lung. 
The Pleura is a serous membrane investing the lungs and lining the walls of the 
pulmonary compartment of the thorax. The pleura consists of (1) a visceral 
layer (pleura pulmoualis) investing the lungs; (2) a parietal layer investing the 
walls; (3) a potential space between the visceral and parietal layers, called the 
pleural cavity. The visceral pleura is identified by its smooth, moist, glistening 
appearance and location on the lungs. It is inseparably attached to the lungs, 
and dips down into their fissures; it is transparent, since black, carbonaceous spots 
on the lungs may be seen through it. 
Special Names. The pleura that covers the inner surfaces of the ribs and inter- 
costal spaces is called the costal pleura; that covering the upper surface of the 
diaphragm, diaphragmatic pleura; that investing the dome of the thoracic cavity 
(extending from one to two inches above the first rib), cervical pleura; that 
reflected from the back of the sternum to the spine, interrupted only where it 
invests the lungs and their root-structures, mediastinal pleura; this latter sepa- 
rates the pleural from the mediastinal parts of the thoracic cavity. The liga- 
mentum latum pulmonis is a triangular fold of the pleura, extending from the 
root of each lung to the diaphragm, and is shown by drawing the lung outward 
and upward. 
The Pleural Cavity is a potential, not an actual space, situated between the vis- 
ceral and parietal layers. It is occupied normally by a small amount of serum, 
which lubricates the opposed surfaces of the pleura. An oversecretion of this 
serum, is hydrothorax. Pus in the pleural cavity, is pyothorax; air in the pleural 
cavity, is pneumothorax; the presence of pus and air in the pleural cavity, consti- 
tutes pyopneumothorax. THORAX-SUBDIVISIONS AND CONTENTS. 
193 
General Characters. Pleura is smooth, strong, polished, moist, elastic, glisten- 
ing, transparent, secretory, absorptive, retentive, laxly attached to walls and firmly 
attached to the lungs. .Removed from its environment, the pleura cannot be 
distinguished from the peritoneum. 
Retentive Medium. The pleura covering the thoracic walls is held in position 
by subpleural connective tissue, just as peritoneum is retained by subperitoneal 
connective tissue, to the abdominal walls. The special name for this connective 
tissue is endothoracic fascia. Arteries that supply the lungs and bronchial tubes 
supply the visceral pleura; those that supply the walls (intercostals and internal 
mammary) supply the parietal pleura. Nerves: Visceral pleura is supplied by 
the sympathetic and vagus, the same nerves that supply the lungs. Parietal 
pleura is supplied by gray rami communicantes of sympathetic origin; these 
originate in the vertebral ganglia and reach the body walls with the intercostal 
nerves. (See sympathetic.) 
Functions. Pleura strengthens the parts it invests and retains the lungs in 
position. It secretes a lubricating fluid called serum, it limits the extent of 
inflammatory products, and, by its high degree of elasticity, confers resiliency on 
the lungs. 
THE LUNGS. 
Dissection. Locate the phrenic nerve on the anterior part of the root of the lungs 
(attached to pericardium) and liberate same by blunt dissection in direction of nerve. Trace 
pulmonary vessels and bronchial tubes (through the slit-like passage) into the lungs. Examine 
base of the lung and find same resting on the diaphragm. Find ligamentum latum pulmonis, 
extending from root of lung to diaphragm. (See p. 192.) Demonstrate two large lobes in the 
left lung separated by an oblique fissure. Find two fissures and three lobes in the right lung. 
(Fig. 98.) Identify apex of lung passing through apex of bony thorax. Cut through the vis- 
ceral pleura and study the interior of the lung. Demonstrate (a) parietal and visceral pleura; 
(6) the pleural cavity. Study the relation of the bronchus to the pulmonary vessels on right 
and left sides and compare dissection with illustration and table on pages 185 and 194, respec- 
tively. Cut through root and turn over the lung and gain view of the posterior mediastinum. 
The lungs are the major organs of respiration. They are located in the pul- 
monary subdivision of the thoracic cavity and are firmly bound to the base of the 
heart by the pulmonary arteries and veins. By means of the bronchial tubes 
they are in communication with the trachea, and bound thereto. Analysis: The 
apex of the lung is blunt and rounded, and rises from one to two inches above 
the first rib into the root of the neck, where it is protected by the cervical pleura 
and fascia. The subclavian artery crosses the front and inner part of the apex of 
the lung. The base of the lung is in apposition with the upper surface of the 
diaphragm and diaphragmatic pleura. With the intervention of the diaphragm, 
the base of the right lung is in relation with the liver; likewise the base of the left, 
with the liver, stomach, and spleen. The outer surface of the lung is convex, in 
relation with the ribs and intercostal spaces; the inner is concave and in relation 
with the pericardium. Between the inner surface of the lung and pericardium is 
the phrenic nerve with its accompanying artery, descending to the diaphragm in 
front of the root of the lung, along the mediastinal pleura. The posterior border 
of the lung rests in a broad groove on each side of the vertebral column, and is 
long, thick, and rounded. The anterior border is sharp, short, thin, and lies 
between the pericardium and sternum behind and costal cartilages in front. The 
anterior border of the left lung is notched, leaving a space called the incisura car- 
diaca. The left lung is divided by an oblique fissure into two lobes, superior and 
inferior; the right, by two fissures into superior, inferior, and middle lobes. 
(Fig. 98.) 
Root-structures of Lungs. This is a collective noun by which all structures that 
enter or depart from the lungs, for carrying on functional and nutritive activities 
of these organs, are designated. These structures are bound together by connec- 
tive tissue, and invested by pleura. By means of the root-structures the lungs are 
held in proper position. The root of the lung is composed of bronchial tubes, 194 
A MANUAL OF DISSECTION. 
bronchial arteries and veins, pulmonary arteries, pulmonary veins, pulmonary 
nerves (vagus and sympathetic), pulmonary lymphatic vessels and glands, connec- 
tive tissue, and investing pleura. 
Relations of Root-structures of the Lungs. 
From before, backward . 
Pulmonary vein. 
Pulmonary artery. 
Bronchus. 
Both sides. 
From above, downward . 
Bronchus. 
Pulmonary artery. 
Pulmonary vein. 
Right side. 
Pulmonary artery. 
Bronchus. 
Pulmonary vein. 
From above, downward . 
Left side. 
The Bronchial Arteries nourish the lungs and bronchial tubes. They lie on the posterior 
part of the bronchial tubes, and are three in number-one on the right, and two on the left 
side. These arteries are small and variable in origin and course. Both the right and left 
bronchial arteries may arise by a common trunk from the aorta. The left bronchial arteries 
usually arise from the aorta; the right, either from the aorta or first intercostal artery. The 
bronchial veins correspond to the bronchial arteries in distribution, and return the greater 
part of the blood from the substance of the lung and bronchial tubes, and discharge as 
follows: The right, into the vena azygos major; the left, into the vena azygos minor supe- 
rior, or left superior intercostal. (Fig. 104.) 
THE GREAT BLOODVESSELS. 
Dissection. Dissect down on the ascending aorta until the coronary arteries are reached. 
Cut through the aorta one inch above the coronary arteries, and study the aortic semilunar 
valves. Dissect between the arch of the aorta and pulmonary artery, and find the remains 
of the ductus arteriosus. (Fig. 98.) Study the three large branches given off from the arch 
of the aorta. Identify the relations of the aorta by comparison with the following tables and 
illustrations on pages 185 and 191. Divide the connective tissue (blunt dissection) and identify 
all structures entering both heart and lungs. 
Ascending Aorta. 
The ascending aorta (Fig. 98) arises from the left ventricle of the heart, where it 
is guarded by the aortic, semilunar valves, and ends at the beginning of the aortic 
arch, opposite the upper border of the second sternochondral joint on the right 
side. The right and left coronary arteries, given off above the free margin of the 
semilunar valves, are its only branches. The following are its relations : 
Anterior. 
Pulmonary artery. 
Right auricular appendix. 
Pericardium. 
Right pleura and right lung. 
Remains of the thymus gland. 
Right side. / \ r .± ., 
„ . I . Left side. 
Superior vena cava. Ascending J 
Right auricle. \ Aorta- Pulmonary artery. 
Posterior. 
Right pulmonary artery. 
Left auricle. 
Arch of the Aorta. 
The Arch of the Aorta (transverse aorta) extends from the upper border of the 
second sternochondral joint on the right side to the left side of the lower border 
of the fourth dorsal vertebra, and lies about one inch below the upper margin of THORA X-S FBI) I] AS IO NS A ND CONTENTS. 
195 
the sternum. Its branches are the innominate, left common carotid, and left 
subclavian arteries. (Fig. 98.) 
Relations of the Arch of the Aorta. 
Above. 
Left innominate vein. 
Innominate artery. 
Left common carotid artery. 
Left subclavian artery. 
In front. s Behind. 
Pleurae and lungs. \ Trachea. 
Remains of the thymus gland. Arch of j Deep cardiac plexus. 
Left vagus nerve. ( Aorta. I Thoracic duct. 
Left phrenic nerve. Left recurrent nerve. 
Superficial cardiac nerves. (Esophagus. 
Left superior intercostal vein. 
Below. 
Bifurcation of the pulmonary artery. 
Remains of the ductus arteriosus. 
Superficial cardiac plexus. 
Left recurrent laryngeal nerve. 
Left bronchus. 
Innominate Artery. 
The innominate artery arises from the arch of the aorta in front of the left 
common carotid. It is about two inches long, and divides opposite the upper 
border of the right sternoclavicular joint into the right subclavian and right 
common carotid arteries. The following are its relations : 
In Front. 
Sternum. 
Sternohyoid and sternothyroid muscles. 
Remains of the thymus gland. 
Left innominate vein. 
Right inferior thyroid vein. 
Inferior cervical cardiac branch of right vagus. 
Right side. / \ Left side. 
Right innominate vein. , Innominate | Remains of the thymus. 
Right vagus nerve. \ Artery. ] Left common carotid. 
Pleura. \ / Left inferior thyroid vein. 
Trachea. 
Behind. 
Trachea. 
Left Common Carotid Artery. 
The left common carotid artery arises from the arch of the aorta between the 
innominate and left subclavian. Its relations in the thoracic portion are as 
follows: 
In Front. 
Sternum. 
Sternohyoid and sternothyroid muscles. 
Left innominate vein. 
Remains of the thymus gland. 
Internally. / y Externally. 
Innominate artery. Common \ Left vagus nerve. 
Inferior thyroid veins. \ \rter^ / Left Pleura anddung. 
Remains of the thymus gland. \ / e ft subclavian artery. 
Behind. 
Trachea. 
(Esophagus. 
Thoracic duct. 
Left subclavian artery. 196 
A MANUAL OF DISSECTION. 
Left Subclavian Artery. 
The left subclavian artery arises from the left end of the arch of the aorta. 
Study its relations in the following plan : 
In Front. 
Vagus, cardiac, and phrenic nerves. 
Left common carotid artery. 
Thoracic duct. 
Left internal jugular vein. 
Left vertebral vein. 
Left innominate vein. 
Sternohyoid, sternothyroid, and sternomastoid muscles. 
Inner side. / \ Outer side. 
Trachea. ( Subclavian • Pleura. 
(Esophagus. \ Artery. ; Left lung. 
Thoracic duct. \ / 
Behind. 
(Esophagus. 
Thoracic duct. 
Inferior cervical ganglion. 
Longus colli. 
Thoracic Aorta. 
The thoracic aorta begins opposite the fourth thoracic vertebra as a continuation 
of the aortic arch, and ends at the aortic opening in the diaphragm at the 
twelfth dorsal vertebra, and traverses the posterior mediastinal space. In the 
upper part of its course the artery is to the left of the mid-line of the body. 
Between the two extreme points it lies on the vertebrae and shares the curves of 
the spine. Relations : 
In Front. 
Root of the left lung. 
Pericardium. 
(Esophagus. 
Diaphragm. 
Right side. \ Left side. 
(Esophagus. I Thoracic | Pleura. 
Vena azygos major. \ Aorta. I Left }ung. 
Thoracic duct. \ / (Esophagus (below.) 
Behind. 
Vertebral column. 
. Vena azygos minor superior. 
Vena azygos minor inferior. 
Branches of Thoracic Aorta. (1) Bronchial, three in number, accompany the 
bronchial tubes and supply the lung substance and bronchi; (2) pericardiac, to the 
pericardium; (3) oesophageal, to the oesophagus; (4) posterior mediastinal, to the 
lymphatic glands; (5) the posterior intercostal arteries are described in the dissec- 
tion of the thoracic walls. 
SUPERIOR VENA CAVA. 
The Superior Vena Cava (Fig. 104) is three inches long, and extends from the 
point of confluence of the innominate veins (behind cartilage of first rib on right 
side) to the right auricle of the heart, opposite the third costal cartilage. Exter- 
nally it is covered by mediastinal pleura, and is in relation with the right phrenic 
nerve. The upper half is in the superior mediastinal space; the lower half, 
enclosed by the pericardium, is in the middle mediastinal space. This vein has THORAX-SUBDIVISIONS AND CONTENTS. 
197 
no valves. Tributaries: Right innominate, left innominate, vena azygos major, 
pericardiac and mediastinal veins. 
Right Innominate Vein. (Fig. 98.) This vein, about one inch long, runs verti- 
cally downward and meets the left innominate below the cartilage of the first rib 
on the right side to form the superior vena cava. Tributaries : Right vertebral, 
right internal mammary, right inferior thyroid and right superior intercostal. It 
lies in front of and external to the right innominate artery; the phrenic nerve is 
to its outer side. 
Fig. 104. 
Azygos and intercostal veins. (Ger risk after Testut.) 
Left Innominate Vein. (Figs. 98, 104.) The left innominate vein is about two 
and a half inches long. It begins behind the sternal end of the clavicle on 
the left side by the confluence of the subclavian and internal jugular veins, and 
ends in the superior vena cava on the right side, behind the cartilage of the first 
rib. It lies beneath the manubrium, sternohyoid, sternothyroid, thymus or its 
remains, and crosses the trachea, left subclavian, left common carotid and innomi- 
nate arteries. Tributaries: Left internal mammary, left vertebral, left inferior 
thyroid, and left superior intercostal veins. 
The Vena Azygos Major (Fig. 104) arises in the ascending lumbar vein on the 
right side, passes through the aortic opening in the diaphragm to the right of the 
aorta and thoracic duct. In the thorax it lies on the thoracic vertebrae, crossing 198 
A MANUAL OF DISSECTION. 
the intercostal arteries. At the root of the right lung, opposite the fourth thoracic 
vertebra, it curves above the bronchus and opens into the superior vena cava just 
before this vessel perforates the pericardium. Tributaries: (1) The right superior 
intercostal vein; (2) veins of the ten lower intercostal spaces; (3) vena azygos 
minor superior; (4) vena azygos minor inferior; (5) pericardiac veins; (6) bronchial 
veins of the right lung; (7) oesophageal veins. 
The Vena Azygos Minor Superior (Fig. 104) is formed by the union of the 
fourth, fifth, sixth, seventh, and eighth intercostal and left bronchial veins. It 
communicates with the left superior intercostal vein, crosses the aorta and thoracic 
duct at the eighth dorsal vertebra, and joins the vena azygos major. The vena 
azygos minor inferior begins in the left ascending lumbar vein, pierces the left 
crus of the diaphragm and passes behind the aorta and thoracic duct at the ninth 
thoracic vertebra and opens into the vena azygos major. Its tributaries are the 
ninth, tenth, and eleventh intercostal veins. 
Pulmonary Vessels. 
The Pulmonary Artery (Figs. 98, 103), about two inches long, arises from the 
base of the right ventricle (conus arteriosus). It is at first in front of, later to 
the left of, the ascending aorta. The artery divides into right and left branches, 
which convey blood to the lungs for aeration. The right pulmonary artery passes 
behind the ascending aorta, superior vena cava, and right phrenic nerve to the 
right lung; the left passes in front of the descending aorta and left bronchus to 
the left lung. The beginning of the left pulmonary artery is connected to the 
under surface of the aortic arch, in the embryo, by the ductus arteriosus; in adult 
life a remnant of this obtains, as the ligamentum arteriosum. 
The Pulmonary Veins (Fig. 102), four in number (two for each lung), return 
blood from the lungs to the left auricle. They have no valves, are but little 
larger than the pulmonary arteries, and accompany these latter singly. In the 
lungs the veins lie in front of the pulmonary arteries. 
PHRENIC AND VAGUS NERVES. 
The Phrenic Nerves. These are right and left, and supply the diaphragm, peri- 
cardium, pleura, peritoneum (in part). The phrenic, on either side, in the neck, 
lies on the scalenus anticus muscle, and passes into the thorax beneath the sub- 
clavian vein (crossing the internal mammary artery from without inward, in front 
of the root of the lung), is covered by mediastinal pleura; it is seen beneath the 
inner border of the lung on the pericardium. In the superior mediastinal space 
the left phrenic nerve crosses the arch of the aorta. The right phrenic lies to the 
outer side of the descending vena cava and innominate vein. Each phrenic nerve 
is accompanied by an artery, arteria comes nervi phrenici (a branch of the internal 
mammary), which is distributed coextensively with the nerve. 
Vagus, or Pneumogastric Nerves. The left vagus nerve enters the thorax be- 
tween the left subclavian and the left common carotid arteries. It crosses the 
aortic arch to the left of and behind the phrenic nerve, and gives off the recurrent 
laryngeal nerve, passes behind the root of the lung and breaks up into branches 
which form, with filaments from the third and fourth thoracic ganglia of the sym- 
pathetic, the posterior pulmonary plexus. It leaves this plexus (in two strands), 
and soon gains the front of the oesophagus and unites with similar branches of the 
right vagus to form the plexus guise. The nerve leaves this plexus, passes through 
the diaphragm with the oesophagus and is distributed to the stomach, liver, 
and intestines. The right vagus nerve enters the thorax between the right in- 
nominate vein and the right subclavian artery, and descends with the trachea to 
the posterior part of the root of the right lung, where it forms with filaments from THORAX-SUBDIVISIONS AND CONTENTS. 
199 
the third and fourth thoracic ganglia of the sympathetic, the posterior pulmonary 
plexus. The nerve leaves this plexus as two cords, forms the plexus guise and 
passes through the oesophageal opening in the diaphragm into the abdominal cavity. 
Branches in Thorax : (1) (Esophageal, in the superior and posterior mediastinal 
spaces to oesophagus; (2) pulmonary, to the anterior and posterior pulmonary 
plexuses ; (3) pericardiac, from the plexus guise and the posterior pulmonary 
plexus to pericardium ; (4) thoracic cardiac (from vagus and recurrent laryn- 
geal), to cardiac plexus ; (5) recurrent laryngeal, to larynx, trachea and oesoph- 
agus. 
The Left Recurrent Laryngeal is given off below the arch of the aorta, and 
loops around the ductus arteriosus to gain the space between the trachea and 
(esophagus, whence it proceeds to the larynx ; the right nerve is given off at the 
lower border of the subclavian artery, and after winding backward and inward 
beneath the subclavian artery, pursues a similar course between the trachea and 
(esophagus. 
THORACIC DUCT. 
The Thoracic Duct begins on the second lumbar vertebra in the receptaculum chyli. 
Excepting lymphatic vessels from a part of the convex surface of the liver, the 
thoracic duct receives all the lymphatic vessels below the diaphragm; above the 
diaphragm it receives the lymphatic vessels from the left side of the heart, left 
lung, left side of the head and neck and left upper extremity. Course : The 
thoracic duct passes from the abdomen to the thorax on the right side of the aorta 
through the aortic opening in the diaphragm. In the posterior mediastinum it 
lies in front of the vertebral column, between the aorta and the vena azygos major. 
Opposite the fourth dorsal vertebra the duct passes behind the oesophagus and 
the aortic arch, ascends to the neck between the oesophagus and the left pleura, 
ending at the junction of the left subclavian and internal jugular veins. 
THE (ESOPHAGUS. 
The (Esophagus begins at the level of the thyroid cartilage as a downward contin- 
uation of the pharynx ; at the base of the thorax it passes through the oesophageal 
opening in the diaphragm, and ends in the cardiac extremity of the stomach. It is 
the narrowest and most muscular part of the alimentary canal. It lies in the 
neck, superior and posterior mediastinal spaces. Behind the oesophagus are the 
thoracic duct, vertebral column and longus colli muscles. In front of the oesoph- 
agus are the trachea, left bronchus, and diaphragm. 
MEDIASTINAL GLANDS. 
Superior Mediastinal Lymphatic Glands. There are, in relation with the arch 
of the aorta, eight or ten lymphatic- glands, which collect lymph from the heart, 
pericardium, and thymus. Lymph vessels leaving these glands are as follows : 
Those from the right side of the heart discharge into the right lymphatic duct ; 
those from the left into the thoracic duct. The posterior mediastinal lymphatic 
glands follow the aorta, and are joined by the lymphatic vessels from the oesoph- 
agus, heart, and diaphragm. The bronchial lymphatic glands are continuous above 
with the superior mediastinal glands. They are located principally near the bi- 
furcation of'- the trachea, and extend into the root of the lungs. They receive 
lymphatic vessels from the lungs, and the fluid they contain is often black. It 
will be noticed that the lungs of any adult are very dark; this discoloration is due 
to atmospheric impurities inhaled, and the peculiar color is carbonaceous. CHAPTER XIII. 
THE ABDOMINAL WALLS. 
Dissection. Remove the integument as indicated by the incisions in Fig. 105. Observe the 
fat, cutaneous vessels, and nerves in the superficial fascia beneath the skin. Be guided by the 
illustrations, and identify the structures in the order given in the text. 
Superficial Fascia. The superficial fascia of the abdominal walls consists of two layers: 
1. An upper, containing a variable amount of fat (panniculus adiposus), called Camper's fascia. 
2. A lower, free from fat, quite elastic, a rudimentary representative of the elastic abdominal 
tunic in the horse, and called Scarpa's fascia. 
Camper's Fascia is continuous over Poupart's ligament with the superficial fascia of the 
thigh, and has no deep fascial attachments. Scarpa's fascia, in the region of the pubes, 
extends over the penis, spermatic cord, and scrotum to the perineum, where it is continuous 
with Colle's fascia. On either side it blends with the fascia lata, immediately below Poupart's 
ligament. 
Fig. 105. 
Fig. 106. 
Dissection of abdomen. (Gray.) 
External abdominal ring of right side. 
(Gerrish after Testut.) 
Anterior Cutaneous Nerves. (Fig. 109.) Identify (I) by the distribution to the skin 
covering the rectus muscle; (2) by the fact of piercing the sheath of the rectus muscle and 
serially continuous with similar structures of the thoracic walls ; (3) by the derivation from 
the iliohypogastric and six lower thoracic nerves; (4) by the derivation of attending arteries 
from the deep and superior epigastric. 
Lateral Cutaneous Nerves. Identify (1) by the derivation from the iliohypogastric and 
six lower thoracic nerves ; (2) by serial continuity with similar structures of the thoracic 
region; (3) by the derivation of attending arteries from four intercostals and lumbars. 
Spermatic Cord and Two Nerves. (Fig. 109.) Locate emerging from the external 
abdominal ring, (a) The ilio inguinal nerve is in front of the cord (sensory nerve to the skin 
of the scrotum and thigh); (6) the genito-crural (sensory to the skin of the thigh and motor 
to the cremaster muscle) lies behind the cord. 
External Abdominal Ring. (Fig. 106.) Identify (1) by the location, external to and above 
the pubic crest between two strong lateral fibrous pillars, and in the aponeurosis of the exter- 
nal oblique muscle; (2) by the length, about one inch, extending in an inward and downward 
direction; (3) by the contents: male, the spermatic cord, ilio-inguinal and genito-crural 
nerves; female, the same two nerves as in the male, and round ligament of the uterus; (4) by 77TE J B I) OM INA L W L LS. 
201 
the boundaries : pubic crest below, intercolumnar fibres above, pillars internal and external, 
laterally. 
Linea Alba. The linea alba extends from the ensiform or xiphoid cartilage of the sternum 
to the symphysis pubis. It is formed by the junction of the aponeuroses of the external 
oblique, internal oblique, and transversalis muscles, and is situated between the recti muscles 
of the abdominal walls. The linea alba is narrow below, broad above the umbilicus, and has 
apertures for vessels and nerves. Externally, it is related to the integument; internally, to 
the transversalis fascia, urachus, and bladder. 
Umbilicus and. Semilunar Lines. (Fig. 107 ) The umbilicus is the largest aperture in the 
linea alba. In the foetus it transmits the umbilical vein and hypogastric arteries, structures 
concerned in aeration of the blood; in the adult the umbilical aperture is represented by a 
strong scar. The linese semilunares correspond to the outer margins of the recti muscles, and 
extend from the ninth rib to the spine of the pubic bone. Each is formed by the tendons or 
aponeuroses of the oblique and transversalis muscles. 
Osteological Points. The symphysis pubis is in the mid-line, and formed by the junction 
of the pubic bones. The pubic crest extends from the angle to the spine of the pubic bone, 
and gives attachment to the rectus abdom:nis, pyramidalis, and conjoined tendon of the in- 
ternal oblique and transversalis muscles. The pubic spine is situated at the outer end of the 
pubic crest, and gives attachment to the inner extremity of Poupart's ligament. The pectineal 
line extends from the pubic spine to the iliopectineal eminence, and gives attachment to the 
pectineus muscle and Gimbernat's ligament. The anterior superior iliac spine is at the ante- 
rior end of the iliac crest, and gives attachment to the outer extremity of Poupart's ligament. 
The crest of the ilium is limited by the anterior and posterior superior spinous processes of 
the ilium. It has three lips (external, middle, and internal), to which are attached, respec- 
tively, the external oblique (into the anterior one-half) ; internal oblique (into the anterior 
two-thirds); transversalis (into the anterior three-fourths). 
Dissection of Inguinal Canal and Contents. (Fig. 110.) To expose the contents and 
demonstrate the parts of the inguinal canal (roof, floor, inner wall, outer wall, internal and 
external rings) but little dissecting is required. Introduce a pair of forceps or a director 
through the external ring and cut the aponeurosis in the direction of the fibres. Now gently 
dissect the upper part of the aponeurosis and turn it back; pull the lower part down. The 
muscular structure now exposed is the arch of the internal oblique and the transversalis-the 
roof of the canal. Fibres given off from this arch to the spermatic cord constitute the cre- 
master muscle. The spermatic cord may now be lifted from the floor of the canal-Poupart's 
ligament. Carefully elevate the arched fibres, and the inner wall will come into view. The 
deep epigastric vessels are on this (the inner) wall, passing inward and upward ; and external 
to these the internal abdominal ring is seen, producing the spermatic cord. 
The ilio-inguinal nerve emerges from the inguinal canal, anterior to the spermatic cord, 
through the external abdominal ring, and supplies the skin of the scrotum and the upper inner 
part of the thigh. The hypogastric branch of the iliohypogastric nerve pierces the aponeu- 
rosis of the external oblique muscle above the external abdominal ring, and is distributed to 
the integument in the hypogastric region. 
ABDOMINAL MUSCLES IN GENERAL. 
The abdominal muscles are called external, or descending oblique; internal, or 
ascending oblique; transversalis, rectus abdominis, and pyramidalis. The fibres 
of the external oblique run downward and inward; those of the internal oblique 
in an opposite direction ; those of the transversalis in a horizontal direction. Each 
muscle consists of (1) an outer muscular part, and (2) an inner tendinous or 
aponeurotic part; each contributes to the formation of the sheath of the rectus 
muscle, linea alba, umbilicus, and linete semilunares; each has a polymeric inner- 
vation and blood-supply, since each arises from more than one myotome. The 
rectus muscle gives evidences of segmentation in its transverse lines, and has a 
distinct sheath in the upper three-fourths of its course. The pyramidalis is a 
small vertical muscle, a tensor of the linea alba. 
The External Oblique. (Fig. 107.) The external or descending oblique muscle 
has its origin in the outer surfaces and lower borders of the eight lower ribs, by 
fleshy processes, the five upper of which interdigitate with the serratus magnus, 
the three lower with the latissimus dorsi. Insertion: (1) The fibres from the 
lowest ribs into the anterior half of the outer lip of the iliac crest; (2) the middle 
and upper fibres into the linea alba, pubic spine, iliopectineal line, forming Pou- 
part's ligament, Gimbernat's ligament, triangular ligament of the abdomen, 
external abdominal ring, external pillar, internal pillar, and intercolumnar fascia. 
Each of these will now be described as a part of this muscle. 202 
A MANUAL OF DISSECTION. 
Poupart's Ligament or Crural Arch. (Fig. 110.) Poupart's ligament is the lower 
border of the aponeurosis of the external oblique muscle. It extends in an arch- 
ing, downward direction from the anterior superior iliac spine to the spine of the 
pubic bone. A part is reflected onto the iliopectineal line for one-half inch 
(Gimbernat's ligament.) The part reflected from Gimbernat's ligament, beneath 
the spermatic cord anterior to the conjoined tendon and behind the inner pillar of 
the external abdominal ring to the linea alba, is the 
triangular ligament of the abdominal walls. Pou- 
part's ligament is continuous with the fascia lata of 
the thigh. 
The External Abdominal Ring (Figs. 106, 110) is 
an interval in the aponeurosis of the external oblique 
muscle and to the outer side of and above the pubic 
crest. The ring is triangular, about one inch long, and 
is bounded below by the pubic crest; above, by the inter- 
columnar fibres; laterally, by the pillars of the ring. 
The general direction of the ring corresponds to the 
direction of the fibres of the aponeurosis-downward 
and inward. The ring is larger in males than in 
females, and gives passage to the spermatic cord or its 
homologue. 
Pillars or Columns of the External Abdominal Ring. 
(Fig. 106.) The external and internal pillars are the 
margins of the external abdominal ring. The external, 
or inferior pillar, is that part of Poupart's ligament 
which is inserted into the pubic spine. It is grooved 
for the lodgement of the spermatic cord or round liga- 
ment. The internal or superior pillar is inserted into 
the front of the symphysis pubis, and interlaces with 
the one of the opposite side. 
The Intercolumnar Fibres (Fig. 106) prevent diver- 
gence of the pillars from one another. They are much 
stronger in the male than in the female. They extend 
across the external ring, are bound together by connec- 
tive tissue, and form the intercolumnar or external sper- 
matic fascia-a covering of the testicle and inguinal 
hernia. 
Internal Oblique Muscle. (Fig. 110.) This muscle 
has its origin (1) in the anterior two-thirds of the middle lip of the crest of the 
ilium; (2) outer half of Poupart's ligament; (3) lumbar fascia. Insertion: (1) 
The fibres from Poupart's ligament unite with those of the transversalis muscle 
from the same source, form the conjoined tendon, and are inserted into the crest 
and iliopectineal line of the pubic bone; (2) into the lower border of the cartilages 
of the six lower ribs; (3) into the linea alba, extending from the symphysis pubis 
to the ensiform cartilage. The aponeurosis of this muscle, together with that of 
the internal oblique and transversalis, passes anterior to the rectus muscle below 
a point (the semilunar fold of Douglas) midway between the umbilicus and the 
crest of the pubic bone. Above this point it splits and forms a sheath for the 
rectus muscle. (Figs. 108, 109.) 
The Conjoined Tendon (Fig. 110) of the internal oblique and transversalis 
muscles is composed of fibres arising from Poupart's ligament. The tendon is 
inserted into the pubic crest and iliopectineal line behind the external abdominal 
ring, which latter it protects and strengthens. 
The Cremaster Muscle (cremasteric fascia), found in the male only, is derived from 
the internal oblique muscle by the descent of the testicle. It is attached (1) to 
the lower arched border of the internal oblique; (2) to the inner end of Poupart's 
ligament, and supports the testicle. Nerve: Genital branch of the genito-crural. 
Fig. 107. 
Obliquus externus abdominis ot 
the right side. (Gerrish after 
Testut.) THE ABDOMINAL WALLS. 
203 
Transversalis Muscle. (Fig. 109.) Origin: (1) Outer third of Poupart's ligament; 
(2) anterior three-fourths of the inner lip of the crest of the ilium; (3) inner sur- 
faces of the cartilages of the six lower ribs, interdigitating with the costal origin 
of the diaphragm; (4) middle layer of the lumbar fascia. Insertion: (1) Con- 
joined tendon; (2) lower part of the linea alba. 
Transversalis Fascia. The transversalis fascia is that part of the general fascia 
transversalis covering the inner surface of the transversalis muscle (see general 
fascia transversalis in the dissection of the iliac region). It is attached to the 
inner lip of the crest of the ilium; to Poupart's ligament, external to the femoral 
vessels; to the iliopectineal line, internal to the femoral vessels. It is related exter- 
nally to the deep epigastric vessels, transversalis muscle, and (below the semilunar 
fold of Douglas) to the rectus muscle; internally, to the peritoneum. The trans- 
versalis fascia is continuous with the iliac, and forms (1) the anterior part of the 
femoral sheath; (2) a diverticulum, the infundibuliform fascia, beginning at the in- 
ternal abdominal ring external to the deep epigastric artery and passing around the 
cord and testicle. (See inguinal hernia, inguinal canal, and femoral sheath, p. 206.) 
Fig. 108. 
Semidiagrammatic horizontal section of the trunk to show the lumbar fascia and the tendons of the lateral 
abdominal muscles. The upper figure shows the complete sheathing of the rectus in its superior portions; the 
lower shows the arrangement in its inferior fourth. (Gerrish after Testut.) 
The Lumbar Fascia. (Fig. 108.) The lumbar fascia extends from the posterior 
third of the crest of the ilium to the lower margin of the twelfth rib. It is com- 
posed of three lamellte-anterior, middle, and posterior. The anterior lamella is 
attached to the bodies of the lumbar vertebrae; the middle, to the tips of the lumbar 
transverse processes; the posterior, to the tips of the lumbar spinous processes. 
The posterior layer is the same as the aponeurosis of the latissimus dorsi and 
serratus posticus inferior, and gives attachment to the internal oblique muscle. 
The middle and anterior layers give attachment to the internal oblique and trans- 
versalis muscles. Three lamellae form two compartments for the erector spinae 
and quadratus lumborum. 
The Rectus Muscle (the rectus abdominis muscle). (Fig. 109.) Origin: (1) 
Crest of Ihe pubic bone between the conjoined tendon and the pyramidalis; (2) 
anterior pubic ligament. Insertion: Cartilages of the fifth, sixth, and seventh 
true ribs. Nerves: The lower intercostals. Arteries: Deep and superior epigas- 
trics, lumbars, and intercostals. Action: Flexion of thorax and pelvis on verte- 
bral column. The rectus has three tendinous bands-lineae transversae-which 204 
A MANUAL OF DISSECTION. 
give evidence of segmentation. "As is well known, man, in common with a 
large series of animals, is a segmented organism. Even in the adult the vertebral 
column, the roots of the spinal nerves, the ribs, and the transverse bands of con- 
nective tissue give evidence of this." (Barker.) The transverse lines in the rectus 
muscle are attached to the anterior, but not to the posterior part of the sheath. 
Sheath of the Rectus. (Fig. 108.) The rectus muscle has a sheath complete in 
the middle and incomplete, posteriorly, at each end. In the middle part the 
aponeurosis of the internal oblique muscle splits and lodges the rectus; this is 
further strengthened in front and behind by the aponeuroses of the external 
oblique and transversalis muscles, respectively. At its insertional end the muscle 
pierces the posterior part of the sheath, and is in contact with the cartilages of 
the fifth, sixth, and seventh ribs. The rectus also pierces the posterior part of its 
sheath, midway between the umbilicus and the pubic crest, lying posterior to the 
oblique and transversalis muscles, on the transversalis fascia. The cut margin of 
the sheath is the semilunar fold of Douglas. The sheath contains the rectus and 
pyramidalis muscles, the terminal branches of the seven lower thoracic nerves, 
and the anastomosis of the deep and superior epigastric arteries. Dissection : Cut 
longitudinally through the mid-line of the entire sheath of the rectus and turn the 
cut margins aside. 
The Pyramidalis Muscle is quite small and located in the sheath of the rectus 
muscle. Origin: Front of the pubic bone. Insertion: Linea alba. Function: 
Synergistic to the action of the rectus and tensor of the linea alba. Nerves : Ilio- 
hypogastric and the twelfth thoracic. 
VESSELS OF THE ABDOMINAL WALLS. 
Vessels. (1) Deep circumflex iliac; (2) intercostals; (3) lumbars; (4) deep epi- 
gastric; (5) superficial epigastric; (6) superior epigastric; (7) iliolumbar. In 
ligation of the external iliac above the circumflex and deep epigastric arteries, 
the blood reaches the lower extremity (a) via internal mammary and deep epigas- 
tric; (6) via lumbar and internal circumflex. 
NERVES OF THE ABDOMINAL WALLS. 
Nerves. The nerves supplying the abdominal walls (located between the internal 
oblique and transversalis muscles, Fig. 109) are the iliohypogastric, the ilio- 
inguinal, and the six lower intercostals. The iliohypogastric nerve gives off (1) a 
lateral cutaneous branch, which crosses the crest of the ilium and supplies the skin 
of the gluteal region; (2) a hypogastric branch, which becomes cutaneous above the 
external abdominal ring. The ilio-inguinal nerve gives off no lateral cutaneous 
branch. It lies anterior to the spermatic cord and escapes through the external 
abdominal ring to supply the scrotum and contiguous skin of the thigh. The six 
lower intercostal nerves supply all the muscles and the skin of the abdominal 
walls not supplied by the two preceding nerves-the iliohypogastric and ilio- 
inguinal. 
DESCENT OF THE TESTICLE. 
Development and Descent of the Testicle. The testicle is developed in the abdomen 
from the indifferent sexual gland behind the peritoneum, on the psoas magnus muscle, 
and below the kidney. It is nourished by the spermatic artery, a branch given off 
below the renal, of which latter, in rare cases, it may be a branch. The spermatic 
vein opens into the general venous circulation as follows : on the right, into the 
ascending vena cava; on the left side, into the renal vein. The mesorchium: The 
peritoneum invests the sides and front of the testicle and binds the organ to the THE ABDOMINAL WALLS. 
205 
posterior abdominal walls. In this latter capacity the fold of peritoneum consists 
of two layers resembling the intestinal mesentery, and is called the mesorchium. 
The space between the two layers of the mesorchium transmits vessels and nerves 
to the testicle, forming the root-structure of this organ. The gubernaculum testis 
is concerned in the migration of the testicle from the region of the kidney to the 
Fig. 109. 
Intercostal nerves, the superficial muscles having been removed. (Gerrish after Testut.) 
scrotum. It consists of unstriped muscular fibres, and is attached below to the 
pillars of the external abdominal ring and dartos in the bottom of the scrotum; 
above, to the testicle and to the peritoneum both below and above the testicle. 
The peritoneal attachments of the gubernaculum have important pathological 
interest in infantile hernia. Theory of migratory descent of testicle: (1) The 206 
J MANUAL OF DISSECTION 
testicle is fixed in position by the gubernaculum; meanwhile the pelvic and lum- 
bar regions grow upward; (2) the lower part of the gubernaculum shortens and 
lands the testicle in the scrotum via inguinal canal. Serial locations of testicle in 
its descent: third month, in false pelvis; fifth and sixth months, at internal 
abdominal ring; eighth month, in inguinal canal; ninth month, in scrotum. The 
processus vaginalis: that part of the gubernaculum inserted into the peritoneum 
below the testicle draws a process of peritoneum through the inguinal canal into 
the scrotum. This is the processus vaginalis. In those quadripeds in which the 
testicle reaches the scrotum, the processus vaginalis remains open and communi- 
cates freely with the abdominal cavity. In man the lower part of the processus 
vaginalis remains and retains the testicle; the upper part is closed. 
Tunica Vaginalis Testis. The part of the processus vaginalis which contains the 
testicle-that part which does not become obliterated-becomes the parietal por- 
tion of the tunica vaginalis testis ; the original peritoneal investment of the testicle 
becomes the visceral part of the tunica vaginalis ; the space between the parietal 
and visceral layers becomes the cavity of the tunica vaginalis testis. 
CONGENITAL AND INGUINAL HERNIM 
Congenital Inguinal Hernia. As previously stated, the upper part of the pro- 
cessus vaginalis becomes obliterated shortly after the testicle has reached the scro- 
tum, and thus the communication between the cavity of the peritoneum and the 
cavity of the tunica vaginalis testis is shut off. In some cases closure does not 
occur, and a loop of gut or omentum subsequently passing into the opening, is 
called a congenital hernia. 
Infantile Inguinal Hernia. The student will recall the manner in which the pro- 
cessus vaginalis was drawn down through the inguinal canal into the scrotum prior 
to the descent of the testicle. Now other fibres of the gubernaculum may in a 
similar manner draw down a second process of the peritoneum through the ingui- 
nal canal. This second process is called a hernial sac, and a viscus that enters it 
is an infantile hernia. 
The anatomical varieties of congenital hernia depend on four imperfect varieties 
of obliteration of the upper part of the processus vaginalis : 
1. The processus vaginalis remains open throughout its entire extent, and per- 
fect communication exists between the hernial sac and the cavity of the tunica 
vaginalis testis. 
2. The processus vaginalis is closed below only, and remains open in the rest 
of its extent; hence a very thin septum intervenes between the hernial sac and 
the cavity of the tunica vaginalis testis-funicular hernia. 
3. The processus vaginalis closes above, there being no communication between 
the hernial sac and the cavity of the tunica vaginalis testis. This variety is 
favorable to an encysted hernia. 
4. The processus vaginalis closes both above and below, cutting off communi- 
cation between the hernial sac and the cavity of the tuuica vaginalis testis. In 
this variety may be the seat of a hydrocele of the spermatic cord, and complicate 
diagnosis. (See Gray.) 
INGUINAL CANAL AND INGUINAL HERNIA. 
The inguinal canal is about one-and-a-half inches in length. It extends in an 
oblique direction inward, downward, and forward from the inlet (internal 
abdominal ring in the transversalis fascia) to the outlet (external abdominal ring) 
in the aponeurosis of the external oblique muscle. The internll abdominal ring 
(Fig. 110) is located one-half inch above Poupart's ligament, midway between the 
symphysis pubis and the anterior superior spine of the ilium. The external THE ABDOMINAL WALLS. 
207 
abdominal ring (Fig. 106) is located above the pubis in the aponeurosis of the 
external oblique muscle, between the inner and outer pillars of the external 
abdominal ring. The floor of the inguinal canal is formed by the upper concave 
part of Poupart's ligament, on which rests the spermatic cord in the male and 
the round ligament in the female. The roof (Fig. 110) is formed by the lower 
margin of the arched fibres of the internal oblique and transversalis muscles, ex- 
tending from the outer half of Poupart's ligament to their insertion into the 
crest of the pubis and iliopectineal line. The anterior wall of the inguinal canal 
is formed by (1) integument and superficial fascia; (2) aponeurosis of the external 
oblique muscle; (3) lower border of the internal oblique in the outer third of 
the canal. The posterior wall (Fig. 110) is formed by (1) the transversalis 
fascia; (2) conjoined tendon of the internal oblique and transversalis muscles: 
(3) triangular fascia. 
Fig. 110. 
Inguinal hernia. Dissection showing the transversalis muscle, the transversalis fascia, and the internal 
abdominal ring. (Gray.) 
Contents of the Inguinal Canal. The spermatic cord (male), round ligament of 
the uterus (female), inguinal branch of the ilio-inguinal nerve (male and female), 
genital branch of the genito-crural nerve (male and female), peritoneum, 
infundibulum, cremaster muscle investing cord, and testicle. 
Hesselbach's Triangle. This triangle is bounded internally by the outer margin 
of the rectus muscle; externally, by the deep epigastric artery; below, by Pou- 
part's ligament. The floor is formed by the posterior wall of the inguinal canal, 
and corresponds to the middle and internal inguinal fossae, by either of which a 
direct inguinal hernia may leave the abdominal cavity and reach the inner end 
of the inguinal canal. 
Deep Epigastric Artery. (Fig. 110.) This artery arises one-half inch above 
Poupart's ligament from the external iliac artery. It runs upward and inward, 
internal to the internal abdominal ring, and reaches the rectus muscle at the semi- 
lunar fold of Douglas, where it enters the sheath of this muscle and anastomoses 
with the superior epigastric branch of the internal mammary. The artery forms 208 
.1 MANUAL OF DISSECTION. 
the outer boundary of Hesselbach's triangle. (Fig. 110.) At first the artery is 
between the peritoneum and transversalis fascia, but subsequently penetrates the 
latter. Its relations are : 1. Artery is to the inner side of the internal abdominal 
ring. .2. Spermatic cord lies in front of the artery. 3. Vas deferens passes 
external to the artery. Branches: (1) Cremasteric, supplies the cremaster muscle 
and anastomoses with the spermatic; (2) pubic, supplies the periosteum back of the 
pubic bone; (3) muscular, to the rectus abdominis muscle; (4) cutaneous, pierces 
the abdominal walls and supplies the skin. 
Oblique or Indirect Inguinal Hernia is a protrusion of gut or omentum or both, 
following the course taken by the testicle in its descent through the inguinal 
canal, and acquiring investments from the successive structures of the abdominal 
walls. It leaves the abdominal cavity at the external inguinal fossa. (Fig. 112.) 
Coverings from within out : 1. Parietal peritoneum (hernial sac). 2. Extra- 
peritoneal fatty tissue (seat of lipomata of the cord). 3. Infundibulum, from 
the transversalis fascia (internal spermatic fascia). 4. Cremaster muscle, from the 
internal oblique (middle spermatic fascia). 5. Intercolumnar fascia, from the 
externa] oblique (external spermatic fascia). 6. Skin and superficial fascia form- 
ing the scrotal sac. 
Direct Inguinal Hernia. A direct inguinal hernia is one that passes through 
Hesselbach's triangle and leaves the abdominal cavity through either the middle 
or the internal inguinal fossa. (Fig. 112.) The coverings are different in the 
two, and are determined by the fossae. Coverings of a direct hernia, in which 
the protrusion leaves through the middle inguinal fossa: 1. Parietal peritoneum. 
2. Extraperitoneal fatty tissue. 3. Transversalis fascia. 4. Cremasteric muscle. 
5. Intercolumnar fascia. 6. Superficial fascia and skin. Coverings of a direct 
inguinal hernia, in which the protrusion leaves through the internal inguinal 
fossa : 1. Parietal peritoneum. 2. Extraperitoneal fatty tissue. 3. Transver- 
salis fascia. 4. Conjoined tendon. 5. Intercolumnar fascia. 6. Superficial fascia 
and skin. CHAPTER XIV. 
IDENTIFICATION OF ABDOMINAL ORGANS AND OTHER 
STRUCTURES IN SITU. 
Liver. (Fig. 111.) Identify (1) by the large size, characteristic dark, reddish-brown color; 
(2) by the location in the right hypochondrium and epigastrium in contact with the under 
surface of the diaphragm. Developed in the anterior mesogaster as an evagination of the 
duodenum. 
Gall-bladder. Identify (1) by the characteristic green color; (2) by the location in the 
fossa vesicalis on the under surface of the liver. Also identify the cystic artery, a branch of 
the hepatic, dividing on the neck of the gall-bladder into superficial and deep branches. 
Develop in the anterior mesogaster. 
Transverse Fissure of the Liver. Identify (1) by the transverse direction and location on 
the under surface of the liver; (2) by attachment of the lesser omentum to its margins; (3) 
by the hepatic root-structures (bile-ducts, hepatic artery, nerves, and portal vein) it transmits ; 
(4) by its location between the quadrate lobe in front, the caudate and Spigelian lobes behind. 
Left Longitudinal Fissure of the Liver. Identify by the presence of the umbilical vein 
or its remnant, the round ligament of the liver. The fissure is divided by a transverse fissure 
into an anterior part called the umbilical fissure, and a posterior part for the ductus venosus 
or its remains, and is sometimes closed in by liver substance called the pons hepatis. 
Bight Longitudinal Fissure of the Liver. This is parallel to the left, and obtains as (1) 
the fossa vesicalis for the gall-bladder; (2) the caval fossa for the ascending vena cava. These 
fossae are readily identified by their contents, and are on the inferior and posterior surfaces, 
respectively. 
Falciform Ligament of the Liver. Identify by the attachment of the margins (1) to the 
under surface of the diaphragm and posterior part of the sheath of the right rectus muscle as 
low as the umbilicus; (2) to the convex surface of the liver, extending from the notch on the 
anterior border (back between the right and left lobes) to the posterior surface. This liga- 
ment contains between its two layers (a) the round ligament of the liver; (6) branches of the 
epigastric veins which anastomose with the portal system; (c) branches of the phrenic nerve 
and phrenic arteries. 
Round Ligament of the Liver. Identify (1) by the location in the free margin of the fal- 
ciform ligament; (2) by the extent from the umbilicus to the notch in the anterior border of 
the liver; (3) by the location in the left longitudinal fissure on the under surface of the liver, 
and continuing on the posterior surface to the vena cava as the ductus venosus. The round 
ligament is the obliterated umbilical vein. 
Lateral Ligaments of the Liver. Identify by its triangular shape, peritoneal derivation, 
and attachment to the liver and diaphragm. The left is attached to the upper surface of the 
liver, and lies in front of the cesophageal opening in the diaphragm. The right is attached to 
the liver, between its lateral and inferior surfaces. 
The Coronary Ligament. Identify (1) when the liver is removed, by the reflection of the 
peritoneum from the diaphragm onto the upper and lower margins of the posterior surface of 
the liver ; (2) by the continuity with the right and left lateral ligaments. 
Stomach. (Fig. Ill ) Identify (1) by the large size and characteristic pyriform shape; (2) 
by the location in the left hypochondrium and epigastrium; (3) by its contact with the dia- 
phragm and anterior abdominal walls; (4) by the lesser omentum, connecting its lesser curva- 
ture to the margins of the transverse fissure of the liver; (5) by the great omentum, connecting 
the greater curvature to the transverse colon. 
Gastric Artery. Identify as a branch of the cceliac axis, in the lesser curvature of the 
stomach, anastomosing with the pyloric branch of the hepatic and giving branches to the 
anterior and posterior surfaces of the stomach and oesophagus. Artery is accompanied by 
corresponding veins, and nerves (from vagus and sympathetic). 
Great Omentum. (Fig. 111.) Identify (1) as a large fibroperitoneal apron consisting of 
four peritoneal layers fused, containing fat; (2) by attachment to the greater curvature of the 
stomach, superior portion of the duodenum, transverse colon, and hanging down over the 
small intestines, often into the true pelvis. In the region of the greater curvature of the 
stomach identify the anastomosis between the right and left gastro-epiploic arteries, branches 
of the gastro-duodenalis, and splenic, respectively. 
Lesser Omentum. Identify by the attachments to the lesser curvature of the stomach and 
transverse fissure of the liver. This is an exceedingly frail structure, and consists of two 
layers. The free right border forms the anterior boundary of the foramen of Winslow, con- 
tains the root-structures of the liver and the capsule of Glisson, and is called ligamentum 
hepatico-duodenale. 
Foramen of Winslow. Identify (1) by the location immediately beneath the free margin 
of the lesser omentum ; (2) by the boundary structures: lesser omentum in front, vena cava 210 
A MANUAL OF DISSECTION. 
behind, caudate and Spigelian lobes of the liver above, duodenum and hepatic artery below. 
This foramen connects the greater and lesser peritoneal sacs, and will admit one or two fingers 
into the lesser peritoneal sac. 
Distinction between Large and Small Intestines. Large intestine has three characters 
not possessed by the small. (1) Three bands of longitudinal muscular fibre radiating from 
the appendix; (2) sacculations produced by the longitudinal bands; (3) appendices epiploicae, 
small or large pouches of peritoneum filled with fat of unknown function. 
Iliocaecal Junction. Identify by the end of the ileum opening into the back and inner 
part of the large intestine at the junction of the caecum and ascending colon. This is 
usually found in the right iliac fossa. Also identify the ileocolic artery, a branch of the 
superior mesenteric, dividing into superior and inferior branches. 
Fig. 111. 
Arteries of the stomach, liver, and great omentum. (Gerrish after Testut.) 
Caecum, Identify by the location at the initial end of the ascending colon in the right 
iliac fossa (usually) and by the presence of an attached appendix vermiformis. It has, as a 
rule, a mesentery, and is freely movable. 
Appendix. Identify by the worm-like appearance and attachment to the caecum, where the 
three characteristic longitudinal bands of muscular fibre of the colon meet. Distal end is 
free; proximal end has mesentery in which may be identified the appendicular artery, a 
branch of the ileocolic. Locations of appendix : (1) Behind the caecum; (2) in the true 
pelvis ; (3) to the left, behind the ileum and mesentery. 
Ascending Colon. Identify (1) by the connection with the caecum and transverse colon; 
(2) by the location on the right kidney, transversalis and quadratus lumborum muscles; (3) 
by the absence of the mesocolon (generally). Also identify the colica dextra artery, a branch 
of the superior mesenteric, anastomosing with the colica media above and the ileocolic below. IDENTIFICATION OF ABDOMINAL ORGANS AND OTHER STRUCTURES. 
211 
Transverse Mesocolon. Turn the great omentum and transverse colon upward over the 
stomach. The broad fold of peritoneum connecting the transverse colon to the posterior wall 
of the abdomen is the transverse mesocolon. The transverse colon extends from the hepatic 
to the splenic flexure. Identify between its two layers, the colica media artery, a branch of 
the superior mesenteric. It supplies the transverse colon and anastomoses on the right with 
the colica dextra ; on the left with the colica sinistra. 
Transverse Colon. Identify (1) by the attachment to the great omentum and the greater 
curvature of the stomach; (2) by its limitations, hepatic and splenic flexures; (3) by the loca- 
tion transversely across the abdomen, at the junction of the epigastric and umbilical regions. 
Phrenocolic Ligament. Identity as a fold of peritoneum extending below the spleen 
from the splenic flexure of the colon to the diaphragm, opposite the tenth and eleventh ribs. 
It sustains the spleen as in a sling, and is called sustentaculum lienis. 
Descending Colon. Identify by the location on the left side on the posterior abdominal 
wall along the outer border of the left kidney. It ends at the crest of the ilium in the 
sigmoid. Sides and anterior surface are covered by peritoneum; the posterior surface is 
attached to the outer border of the kidney, quadratus lumborum and transversalis muscles. 
No mesocolon, hence no motion. Identify the colica sinistra, a branch of the inferior mesen- 
teric, supplying the descending colon. It divides into an ascending branch which anasto- 
moses with the colica media, and a descending one which anastomoses with the sigmoid 
artery. 
Sigmoid Flexure. Identify by the location in the left iliac fossa, commencing at the end 
of the descending colon at the iliac crest and ending at the left sacroiliac junction in the 
rectum. It forms a loop variable in length, and has a mesentery. Identify between the 
layers of the mesosigmoid, the sigmoid artery. It is a branch of the inferior mesenteric, 
and anastomoses with the colica sinistra and superior hemorrhoidal. 
Mesentery Proper. Identify by its two attachments (1) to the small intestine twenty feet 
long; (2) to the posterior abdominal wall in an oblique line, extending from the left side of 
the second lumbar vertebra to the right sacroiliac synchondrosis-six inches long. Distance 
from one attached margin to the other is about eight inches. Identify between the two layers 
of the mesentery proper, fat, mesenteric lymphatic vessels and glands, superior mesenteric 
arteries and veins. 
Small Intestine. Identify (1) by the absence of the three characteristics of the colon; (2) 
by the location, in the free margin of the mesentery proper; (3) by its subjacency to the 
transverse colon and great omentum. The jejunum is the upper two-filths of the small 
intestine below the duodenum ; the ileum the lower three-fifths. 
Large Intestine. Identify by its horse-shoe shape and relation to the jejunum and ileum. 
It consists of (1) an ascending colon extending from the right iliac fossa to the lower surface 
of the liver; (2) a transverse colon, extending in a sagging manner (near the junction of the 
umbilical and epigastric regions) from the hepatic flexure, across the abdomen, to the lower 
border of the spleen-splenic flexure; (3) a descending colon, extending from the splenic 
flexure along the outer border of the kidney and psoas magnus muscle to the crest of the 
ilium; (4) a sigmoid flexure, extending from the crest of the ilium, as a great or small loop to 
the left sacroiliac synchondrosis. The caecum, appendix, and sigmoid have mesenteries called 
mesocaecum, mesoappendix, and mesosigmoid, respectively. The transverse colon has an 
extensive mesentery called transverse mesocolon. The ascending and descending colon 
usually are covered by peritoneum on the sides and anterior surface only, hence in these cases 
there is no mesocolon. 
Lesser Sac of the Peritoneum. Identify by the boundaries : Right, foramen of Winslow; 
left, lieno-renal ligament; above, surface of the liver behind the transverse fissure; below, 
fusion-line between the anterior and posterior layers of the great omentum ; behind, the two 
posterior layers of the great omentum, transverse colon, ascending layer of the transverse 
mesocolon; in front, lesser omentum, stomach, and the two anterior layers of the great 
omentum. The finger passed through the foramen of Winslow reaches the lesser sac of the 
peritoneum. 
Greater Sac of the Peritoneum. Identification of this is easy. The greater sac is all the 
peritoneal cavity not included in the lesser. It communicates with the lesser sac through the 
foramen of Winslow. 
Spleen. Identify (1) by the location in the left hypochondriac and epigastric regions, between 
the fundus of the stomach and the diaphragm ; (2) by the dark, purplish color, oblong, flat- 
tened form, and absence of excretory duct. It was developed in the posterior mesogaster. 
Identify the splenic artery extending with its vein from the cceliac axis along the upper border 
of the pancreas to the spleen. 
Pancreas. Identify (1) by the location on the posterior abdominal walls in the epigastric 
and left hypochondriac regions, extending from the descending duodenum to the spleen, and 
crossing*the vena cava, aorta, and superior mesenteric vessels ; (2) by its long, prismatic shape, 
resembling a dog's tongue. It was developed, by evagination of the duodenum, in the posterior 
mesogaster. 
Right Kidney. (Fig. 112.) Identify (1) by the location in the right lumbar region near 
the vertebral column, extending from the upper border of the twelfth dorsal to the third 
lumbar vertebra; (2) by the relation of its anterior surface to the right lobe of the liver, 
second part of the duodenum, and hepatic flexure of the colon; (3) by its characteristic reni- 212 
A MANUAL OF DISSECTION. 
form shape and situation behind the peritoneum in a mass of fat and areolar tissue ; (4) by 
the ureter and large renal vessels entering at the hilum. 
Left Kidney. (Fig. 112.) Identify (1) by the location in the left lumbar region near the 
vertebral column, extending from the upper border of the twelfth dorsal to the third lumbar 
vertebra; (2) by the relation of its anterior surface to the stomach, pancreas, splenic vessels, 
small intestine, and (occasionally) the duodenum; (3) by the characteristic reniform shape 
and situation behind the peritoneum in a mass of fat and connective tissue; (4) by the ureter 
and large renal vessels entering at the hilum. 
Fig. 112. 
Abdominal aorta. (Gerrish after Testut.) 
Suprarenal Capsule. Identify (1) by the location above and in front of the upper end of 
each kidney; (2) by the yellow color and flattened appearance; (3) by their variable size, the 
average size being from one to two inches long; (4) by the absence of an excretory duct. Also 
identify numerous small-sized suprarenal arteries, from the aorta, renal, and phrenic arteries. 
Right and Left Ureters (Fig. 112.) Identify (1) the right ureter by the extent from the 
pelvis of the kidney to the bladder; (2) by adjacency to the outer side of the ascending vena 
cava; (3) by crossing the common or external iliac artery opposite the first piece of the sacrum; 
(4) by the location behind the ileum; (5) by the location on the psoas magnus muscle, where 
it is crossed by the spermatic and ovarian vessels. The left ureter has the same identification 
points, except instead of the ileum it is behind the sigmoid flexure of the colon. IDENTIFICATION OF ABDOMINAL ORGANS AND OTHER STRUCTURES. 
213 
Bladder. (Fig. 112.) Identify (1) by the location in the true pelvis behind the pubic bone 
and the flattened appearance when empty; (2) by the connection with the umbilicus through 
the urachus ; (3) it is anterior to the rectum in the male and to the uterus in the female. The 
false ligaments of the bladder are of peritoneal derivation and five in number: The superior is 
the peritoneum leaving the apex of the bladder with the urachus and obliterated hypogastric 
arteries. The synonym is plica urachi. The lateral, two in number, extend from the side of 
the base of the bladder along the hypogastric vestiges, to the iliac fossae and lateral pelvic 
walls. The plica hypogastrica is a synonym. The posterior, two in number, extend between 
the rectum and bladder, limiting, laterally, the rectovesical pouch. 
Spermatic Artery. (Fig. 112.) Identify (1) by the location behind the peritoneum on the 
psoas magnus; (2) the right artery crosses the ascending vena cava, the left passes behind the 
sigmoid flexure of the colon ; (3) by crossing in front of the ureter, from within out; (4) by 
leaving the abdominal cavity at the internal abdominal ring, in the transv^rsalis fascia, to the 
outer side of the deep epigastric artery and passing through the inguinal canal to the scrotum; 
(5) by the origin from the aorta below the renal artery. 
Fig. 113. 
Posterior view of the anterior abdominal wall in its lower half. The peritoneum is in place, and the 
various cords are shining through. (Gray after Joessel.) 
Spermatic Veins. (Fig. 112.) Identify by the blue color, quite marked, and in company 
with the spermatic artery; (2) the right vein is tributary to the ascending vena cava, the left 
to the renal vein; exceptionally, the right may open into the renal vein of the right side. 
The ovarian vessels are homologous and identified in the same way. 
Vas Deferens. (Figs. 112, 113.) Identify (1) as a small, white, round cord, emerging from 
the pelvis (behind the peritoneum) and crossing the obliterated hypogastric artery and 
external iliac vessels; (2) by passing to the outer side of the deep epigastric vessels, thence 
traversing the inguinal canal, and leaving the abdominal cavity through the external abdomi- 
nal ring with the spermatic vessels. 
Internal Abdominal Ring. Identify (1) by the location, in the transversalis fascia, to the 
outer side of the deep epigastric vessels; (2) by the meeting at the internal ring of the sper- 
matic vessels and vas deferens to form the spermatic cord. To aid in the identification, make 
firm, steady traction on the testicle, when a dimple in the peritoneum, corresponding to the 
location of the internal ring, will appear. 214 
A MANUAL OF DISSECTION. 
Plica Urachi. (Fig. 113.) Identify by the location in the mid-line of the anterior abdomi- 
nal wall and extending from the summit of the bladder to the umbilicus. The plica urachi is 
a fold of peritoneum covering the urachus, a remnant of the allantois. 
Plica Hypogastrica. (Fig. 113.) Identify by the location extending in an oblique direction 
from the side of the bladder to the umbilicus, external to the plica urachi. The plica is a fold 
of peritoneum covering the fibrous remnant of the hypogastric artery. 
Plica Epigastrica. (Fig. 113 ) Identify by the location extending from the external iliac 
artery beneath Poupart's ligament, obliquely upward and inward to the semilunar fold of 
Douglas. This plica covers the deep epigastric artery which (artery) forms the outer boundary 
of Hesselbach's triangle. 
Internal Inguinal Fossa. (Fig. 113.) Identify by the location between the plica urachi 
and plica hypogastrica above the level of Poupart's ligament. It corresponds to the inner 
part of Hesselbach's triangle, permits direct inguinal hernia, and is also called the fossa 
supravesicalis. 
Middle Inguinal Fossa. (Fig. 113.) Identify by the location between the plica hypogas- 
trica and the plica epigastrica above Poupart's ligament. It corresponds to the outer part 
of Hesselbach's triangle, permits direct inguinal hernia, and is called the fossa inguinalis 
mesialis. 
External Inguinal Fossa. (Fig. 113.) Identify by the location external to the deep epi- 
gastric artery above the level of Poupart's ligament. It permits indirect inguinal hernia, and 
corresponds to the internal abdominal ring. 
Hesselbach's Triangle (Fig. 110) includes the middle and internal inguinal fossae. It is 
bounded externally by the deep epigastric artery; internally, by the outer margin of the 
rectus abdominis muscle; below, by Poupart's ligament. The femoral fossa, below Poupart's 
ligament, is to the inner side of the femoral vein. (Fig. 113.) Its floor corresponds to the 
femoral ring, the beginning of the femoralcanal. This fossa permits femoral hernia. 
Poupart's Ligament, or superficial crural arch, extends in an archiform manner from the 
anterior superior iliac spine, externally, to the pubic bone internally, where it has two inser- 
tions: (1) Into the spine of the pubes; (2) into the iliopectineal line, as Gimbernat's liga- 
ment. Poupart's ligament is the lower thickened border of the aponeurosis of the external 
oblique muscle of the abdominal walls. The upper border is now exposed. (Fig. 110.) 
Gimbernat's Ligament is the reflected insertion of Poupart's ligament into the iliopectineal 
line. It has an apex inserted intothe pubic spine; a sharp, fine base toward the femoral 
sheath; an outer' margin attachedto Poupart's ligament; an inner margin attached to the 
iliopectineal line. This ligament forms the inner boundary of the femoral ring, and may be 
brought into view by pulling theperitoneum backward and inward, and breaking down the 
connective tissue internal to the femoral vessels. (Fig. 113.) 
The Triangular Ligament arises from the attachment of Gimbernat's ligament to the inner 
end of the iliopectineal line, passes upward behind the internal pillar of the external 
abdominal ring, and is inserted into the linea alba 
False Ligaments of the Uterus, two in number, is a term applied (a) to the uterovesical 
folds of peritoneum which extend from the uterus to the bladder, and limit the uterovesical 
pouch, laterally; (Z>) to the recto-uterine folds, extending from the rectum to the uterus, 
limiting; laterally the cul-de-sac of Douglas. 
The Peritoneum on the Posterior Wall of the Pelvis covers the first part of the rectum 
completely, and forms the mesorectum. A little lower the peritoneum disappears from the 
posterior part, then from the sides, and, finally, at the tip of the coccyx is reflected from the 
sacrum to the vagina and uterus. The peritoneum invests the uterus, connecting the same 
laterally with the iliac fossse and pelvic walls by the broad ligament, and is reflected to the 
bladder. The peritoneum leaves the bladder at the apex of the latter, with the urachus as 
the superior false ligament; laterally, it leaves hlong the line of the obliterated hypogastric 
arteries as the lateral false ligaments of the bladder. (Fig. 113.) 
The Uterovesical Pouch is bounded in front by the peritoneum covering the bladder; 
behind, by that covering the uterus; laterally, by the uterovesical folds of peritoneum, 
posterior false ligament of the bladder, extending from the uterus to the bladder. 
Douglas' Cul-de-sac (rectovaginal pouch) is bounded in front by the peritoneum covering 
the upper part of the vagina and uterus ; behind, by that covering the rectum ; laterally, by 
the recto-uterine ligaments, folds of peritoneum extending from the rectum to the cervix 
uteri and vagina. 
Distinction between the Abdominal and Peritoneal Cavity. Let a tin pint-cup repre- 
sent the abdominal cavity, and a hollow rubber ball, almost as large as the cup, the perito- 
neum. Place the ball in the cup and force a large marble into the cup with the ball. The 
part of the ball displaced by the marble represents the visceral peritoneum; the remainder 
of the ball represents the parietal peritoneum; the space be.ween the part of the ball dis- 
placed and the part not displaced represents the cavity of the peritoneum. Contents of the 
abdominal cavity: (1) Abdominal organs, with their nerve-supply and blood-supply; (2) 
peritoneum, with its visceral and parietal layers and cavity. The cavity of the peritoneum, 
represented in the simile by the cavity of the ball, contains only a small quantity of serum 
for lubricative purposes, secreted by the peritoneum. Serum secreted in an excessive amount 
is a diseased condition called abdominal dropsy or hydroperitoneum. This serum is clear 
and yellow; in abdominal dropsy (due to disease of the kidneys) it contains urea. IDENTIFICATION OF ABDOMINAL ORGANS AND OTHER STRUCTURES. 
215 
ABDOMINAL TOPOGRAPHY. 
Abdominal Regions. The abdomen consists of nine regions, in which are found collec- 
tively all the abdominal organs. There are but few organs confined to any one region ; still, 
certain ones belong more evidently to some regions than to others. Let the student map out 
nine regions by means of needle and thread, and then be guided by the following table in 
giving their contents. Directions for mapping regions : 1. Extend the thread from the tenth 
costal cartilage on the right to the tenth on the left, and secure it in position. 2. Extend the 
thread from the highest point of the iliac crest on the right to the corresponding point on the 
left. 3. Extend the thread vertically from the centre of Poupart's ligament on each side, and 
secure the same in position. This will divide the abdomen into nine regions, with contents, as 
shown in the table, and represented by Fig. 114. 
Fig. 114. 
Regions of the abdomen, delimited by Gerrish's method. (F. H. G.) 
Right Hypochondriac. 
Epigastric Region. 
Left Hypochondriac. 
1. Greater part of the right 1. 
lobe of the liver. 
Greater part of the stomach, including 
the cardiac and pyloric orifices. 
1. Fundus of the stomach 
2. Hepatic flexure of colon. 2. 
Left, and part of right lobe of liver. 
2. Spleen. 
3. Part of the right kidney. 3. 
4. 
5. 
6. 
Right Lumbar. 
Gall-bladder. 
Pancreas. 
Duodenum. 
Suprarenal capsules ; parts of kidneys. 
Umbilical Region. 
3. Tail of the pancreas. 
4. Splenic flexure of colon. 
5. Part of the left kidney. 
Left Lumbar. 
1. Ascending colon. 1. 
Transverse colon. 
1. Descending colon. 
2. Part of the right kidney. 2. 
Part of the great omentum. 
2. Part of the omentum. 
3. Convolutions of the small 3. 
intestine. 4. 
5. 
Right Inguinal. 
Part of the mesentery. 
Part of the transverse duodenum. 
Part of the small intestine; part of 
each kidney. 
Hypogastric. 
3. Part of the left kidney. 
4. Convolution of the small 
intestine. 
Left Inguinal. 
1. Csecum. 1. 
2. Vermiform appendix. 2. 
3. 
Small intestine. 
Bladder in children, and, when dis- 
tended, in the adult. 
Pregnant uterus. 
Sigmoid flexure of colon. 
Table of Abdomina^ Regions and Contents. CHAPTER XV. 
THE PERITONEUM. 
Dissection. Turn the abdominal wall (with the parietal peritoneum) aside so as to make 
the fullest exposure possible of organs in the abdominal cavity. Detach the diaphragm and 
push the liver upward so as to expose its under surface. Study illustration and text, and 
remember that the entire peritoneum may be studied without further cutting. 
Location and Distribution in the Abdominal Cavity. It covers the under surface 
of the diaphragm, anterior, posterior, and lateral walls of the abdomen, interior 
of pelvis, and all organs of pelvis and abdomen, partially or completely. 
Layers and Cavities. That part of the peritoneum that covers the walls is called 
the parietal layer ; that covering organs, the visceral layer ; the space between 
parietal and visceral layers is the peritoneal cavity. 
Characters. Peritoneum is a thin, translucent, smooth, strong, moist, elastic, 
serous membrane found in the abdominal cavity only. It differs structurally in 
nowise from pericardium and pleura. Removed from the abdominal cavity, its 
identity could not be established ; that is, no one could say whether it had once 
invested a liver or a lung. 
Retentive Medium. Peritoneum is held in place by subperitoneal connective 
tissue. The peritoneum investing the diaphragm adheres closely ; that investing 
the other abdominal walls, loosely, and may be easily removed. The peritoneum 
covering the stomach, liver, and intestines is firmly adherent. The common me- 
dium causing the peritoneum to adhere to walls and viscera is subperitoneal con- 
nective tissue. 
Blood-supply. Arteries that supply the abdominal walls (intercostals, phrenic, 
lumbar, circumflex iliac, and deep epigastric) supply the parietal peritoneum. 
Arteries that nourish organs (gastric, hepatic, splenic, renals, and mesenteries) 
supply visceral peritoneum. 
Nerve-supply. Peritoneum, like other secreting structures associated with vital 
or vegetative functions of the body, is supplied by the sympathetic nervous sys- 
tem ; but here, as with the blood-supply of peritoneum, we recognize a parietal 
and a visceral sympathetic nerve-distribution. Sympathetic nerves (from the solar 
plexus) that supply organs in the abdominal cavity supply visceral peritoneum. 
The parietal peritoneum derives its nerve-supply from the sympathetic through 
gray rami communicantes. 
Functions. The functions are : (1) secretory ; (2) absorptive ; (3) ligatory ; (4) 
plicate ; (5) mesenteric ; (6) omental. The distinctions are somewhat arbitrary, 
but the student should bear in mind that the structure is peritoneum, regardless 
of name and location. 
Secretory and Absorptive Functions. Peritoneum secretes serum for lubrication 
of its opposed surfaces. It may absorb not only the excess of its own secretion, 
but also absorbable foreign material introduced by accident or design. 
Ligatory Function. Where peritoneum is reflected from a wall to an organ and 
becomes this latter's visceral peritoneum, and does not contain the nutritive nerves 
and vessels of the organ, it forms a ligament. Examples : Superior, posterior, 
and lateral ligaments of the bladder ; coronary, falciform, and lateral ligaments of 
the liver. 
Plicate Function. When peritoneum is thrown into a small fold by crossing a 
slight elevation, as an artery, the fold is called a plica. Examples : Plica urachi, 
plica hypogastrica, plica epigastrica, superior duodenal plica, inferior duodenal THE PERITONEUM. 
217 
plica, iliocolic plica, parieto-colic plica, and plica infundibulo-pelvicum. A plica 
differs from a peritoneal ligament essentially in size. (Fig. 112.) 
Mesenteric Function. Where peritoneum binds organs to walls, and also conducts 
nutritive nerves and vessels to organs, it is a mesentery. Examples: Mesentery 
proper, transverse mesocolon, mesosigmoid, and mesorectum. (Figs. 118, 119.) 
Omental Function. In some situations peritoneum binds one organ to another, 
and may or may not contain the nutritive nerves and vessels. Examples : Gastro- 
hepatic, gastrocolic, gastrosplenic omenta. (Fig. 115.) 
Coverings and Fossae. Peritoneum may form a physiological covering of the 
testicle, as the tunica vaginalis testis or the sac of a hernia. It also forms the fol- 
lowing fossae, some of which may become the seat of hernia : (1) Lesser sac of 
peritoneum, whose contracted opening is the foramen of Winslow ; (2) superior 
and inferior duodenal fossae; (3) subcaecal, iliocolic, iliocaecal ; (4) duodeno- 
jejunal and intersigmoid ; (5) retrovesical ; retrovaginal and uterovesical. 
Fig. 115. 
Diagram of a sagittal section of the abdomen of an adult, showing the growth of the small cavity, and the appli- 
cation of its rear wall to the transverse colon and mesocolon. Compare with preceding figure. (Gerrish after 
Testut.) 
THE OMENTA. 
The Gastrohepatic, or Lesser Omentum (Fig. 115), is a double fold of peritoneum 
attached above to the transverse fissure of the liver, below to the first part of the 
duodenum and lesser curvature of the stomach. Between its two folds are the 
root-structures of the liver: (1) Hepatic artery, with plexus of sympathetic and 
vagus nerves; (2) vena porta; (3) bile-ducts. The lesser omentum is a remnant 
of the anterior mesogaster and has the following limitations: The fissure of the 
ductus venosus on the left; the right margin contains the root-structures of the 
liver, is called the ligamentum hepatico-duodenale, and forms the anterior boundary 
of the foramen of Winslow. 
T,h.e Gastrocolic, or Great Omentum (Fig. 115), extends from the greater curva- 
ture of the stomach and first part of duodenum above to the transverse colon 
below. It forms a fatty apron, which keeps the small intestine warm, and inter- 
venes between this and the anterior abdominal walls. The lower part of the great 
omentum occupies the pelvis. It is a part of the posterior mesogaster, which 
bags to the left and forward. The interior of the bag is the cavity of the great 218 
A MANUAL OF DISSECTION. 
omentum, also called the lesser sac of the peritoneum. As the pouch increases 
in length, hanging down from the greater curvature of the stomach, it becomes 
adherent to the transverse colon and its mesocolon. 
The Gastrosplenic Omentum is a very delicate double fold of peritoneum con- 
necting fundus of stomach to margins of hilum of spleen. It contains the vasa 
brevia of the splenic vessels, passing to the fundus of the stomach. It is a rem- 
nant of the posterior mesogaster. That part of the posterior mesogaster between 
the spleen and posterior abdominal wall in the embryo, obtains in the adult as the 
phrenosplenic ligament, and contains the splenic vessels and sympathetic splenic 
plexus of nerves. 
FORAMEN OF WINSLOW AND SACS OF PERITONEUM. 
The Foramen of Winslow is the communication between the greater and lesser 
sacs of the peritoneum. (Fig. 116.) It will admit one or two fingers for diag- 
nostic purposes in palpating the bile-ducts. The foramen is bounded in front by 
the free edge of the lesser omentum ; behind, by the ascending vena cava ; above, 
by the caudate and Spigelian lobes of the liver ; below, by the duodenum and 
Ffg. 116. 
Dissection to show relations of the foramen of Winslow, to which the dart points. The front of the right portion 
of the gastrohepatic omentum has been cut and turned off to the left, and the liver lifted up and back, displaying 
the objects in the front wall of the foramen. The horizontal broken line marks the position of the section from 
which the next picture was made. (Gerrish after Testut.) 
hepatic artery. The foramen is brought into view by elevating the liver. The 
free edge of the lesser omentum (anterior boundary of the foramen of Winslow) 
contains the bile-ducts, portal vein, hepatic artery, sympathetic and pneumogastric 
nerve filaments, bound together by connective tissue called the capsule of Glisson. 
The Lesser Sac of the Peritoneum has superior, inferior, anterior, posterior, right 
and left lateral limitations, each of which are here given. Superiorly, it is lim- 
ited by that part of the under surface of the liver behind the transverse fissure; 
inferiorly, by adhesions between the anterior and posterior layers of the great omen- 
tum; anteriorly, by the lesser omentum, posterior surface of stomach, and the two 
anterior layers of the great omentum; posteriorly, by the two posterior layers of 
the great omentum, transverse colon, and ascending layer of the transverse meso- 
colon; laterally, on the right, by the foramen of Winslow; laterally, on the left, 
by the lieno-renal ligament. 
MESENTERY PROPER. 
The Mesentery Proper is a double fold of peritoneum which surrounds and sup- 
ports the jejunum and ileum. (Fig. 115.) It has (1) a free or intestinal margin 
about twenty feet in length; (2) an attached margin or root, about six inches in THE PERITONEUM. 
219 
length. The depth of the mesentery (from root to intestine) is about eight or ten 
inches. The mesenteric attachment extends obliquely from the left side of the 
second lumbar vertebra to the right iliac fossa (a distance of about six inches), 
crossing aorta and ascending vena cava. The contents of the mesentery are (1) 
jejunum and ileum; (2) superior mesenteric artery, its accompanying veins and 
sympathetic nerves; (3) mesenteric glands; (4) more or less lymphatic glands, fat, 
and connective tissue. CHAPTER XVI. 
THE ABDOMINAL AND PELVIC ORGANS. 
ALIMENTARY CANAL. 
The Small Intestine is from sixteen to twenty-four feet long, and includes: the 
duodenum, about ten inches in length ; the jejunum, about eight feet in length; 
the ileum, about twelve feet in length. The large intestine is four to five feet in 
length and includes : the appendix, from three to six inches in length; the ceecum, 
about 2.5 inches in length ; the ascending colon, variable in length ; the trans- 
verse colon, about two feet in length; the descending colon, about twelve inches 
long; the sigmoid, variable in length; the rectum, about six inches in length. 
The liver is a compound tubular gland. The pancreas is a compound racemose 
gland; the spleen is an accessory blood-gland. 
Embryology. The abdominal part of the alimentary canal begins at the oesopha- 
geal opening in the diaphragm, and ends at the external sphincter ani muscle in 
the ischiorectal part of the pelvic outlet. The terminal opening is called the 
anus. The abdominal part of the alimentary canal in the embryo consists of a 
straight gut-tube, in the mid-line of the posterior abdominal wall, located behind a 
layer of general dorsal peritoneum. This primitive canal is nourished by three 
arteries: gastric, superior, and inferior mesenteric. In the embryo, the primitive 
straight tube, growing up behind (and pushing forward) the peritoneum, is so far 
removed in appearance and location from the adult type, as to make its recogni- 
tion a matter of most interesting embryological and morphological study. 
Unequal Growths. In the study of the alimentary canal, bear in mind two 
unequal growths : (1) the rapid growth of the underlying gut-tube ; (2) the slow 
growth of the overlying peritoneum. As a natural sequence of unequal growth, 
the straight tube becomes convoluted in some places, and when the limits of its 
growth have been reached certain parts will have been robbed of their primitive 
peritoneal covering. 
THE STOMACH. 
Dissection. Introduce a glass tube into beginning of jejunum and inflate duodenum and 
stomach. (Fig. 117.) To accomplish this, find jejunum beneath transverse colon and its 
mesocolon. When stomach is fully distended, tie off gut where the inflation was made. 
Study great omentum attached to greater curvature of stomach and transverse colon. Cut 
through great omentum along greater curvature of stomach and insert hand into lesser cavity 
of peritoneum (cavity of great omentum). 
Study attachments of lesser omentum (gastrohepatic) to lesser curvature of stomach and 
transverse fissure of liver. Cut through lesser omentum and insert hand into lesser cavity of 
peritoneum. Find root structures of liver between layers of lesser omentum (hepatic artery, 
portal vein, bile-ducts and nerves). Now, by blunt dissection remove lesser omentum from 
these root-structures. (Fig. 116.) 
Find gastrosplenic omentum connecting fundus of stomach to spleen and demonstrate 
splenic vessels entering latter organ. (Fig. 117.) Demonstrate spot where oesophagus passes 
through diaphragm, and locate gastric artery along lesser curvature of stomach. While 
stomach is inflated study all its relations. Locate thickened band of muscular fibres (the 
pylorus) and tie strong ligature about same. Cut to left of ligature, leaving duodenum still 
inflated. Stomach may now be removed and its interior structure and coats studied with a 
dissecting microscope. 
Location and Size. The stomach is located in the epigastric and left hypochon- 
driac regions. When empty it is below the liver and in front of the pancreas; 
when distended, it presses forward and to the left, and may embarrass the action THE ABDOMINAL AND PELVIC ORGANS. 
221 
of^the diaphragm and heart. The stomach is five inches wide, twelve inches 
long, and has an average capacity of five pints. 
Analysis. (1) The stomach has two surfaces-anterior and posterior; (2) two 
borders-upper (three to five inches long), and lower, twelve to twenty inches 
long; (3) a great cul-de-sac at the cardiac end and a small cul-de-sac at the 
pyloric end; (4) a pyloric orifice at the extreme right end and a cardiac orifice, 
three inches from left end. (Fig. 117.) The cardiac orifice is funnel-like and 
directed upward; the pyloric orifice is one-half inch in diameter, and composed of 
mucosa and circular muscular fibres. The surfaces of the stomach, anterior and 
posterior in the adult (were left and right, respectively, in the embryo, before rota- 
tion of the alimentary canal occurred), and are completely invested by peritoneum. 
Fig. 117. 
Stomach and duodenum, the liver and most of the intestines having been removed. (Gerrish after Testut.) 
Omenta. The stomach is attached to three adjacent organs by modified forms 
of primitive mesogaster: 1. The lesser omentum is a double fold of peritoneum 
extending from the lesser curvature of the stomach to the transverse fissure of the 
liver. It contains the hepatic artery, portal vein, bile-ducts, sympathetic and 
pneumogastric nerves, bound together by the capsule of Glisson. 2. The great 
omentum (derived from posterior mesogaster) binds the greater curvature of the 
stomach to the transverse colon. 3. The gastrosplenic omentum binds the car- 
diac find of the stomach to the spleen. The nerve-supply of the stomach is from 
the solar plexus and vagus nerve. 
Arteries. (1) Gastric, from coeliac axis of aorta; (2) pyloric, a branch of the 
hepatic; (3) gastro-epiploica dextra, a branch of the gastroduodenal; (4) gastro- 
epiploica sinistra, a branch of the splenic; (5) gastroduodenal, a branch of the 
hepatic; (6) vasa brevia, branches of the splenic. 222 
A MANUAL OF DISSECTION. 
The student should remember the primitive relation of the liver, stomach, 
spleen, and pancreas : The liver is in the anterior mesogaster in front of the 
stomach; the spleen and pancreas in the posterior mesogaster. Coeliac axis gives 
off three large arteries for these four organs : (1) The gastric, which passes 
forward to the anterior border of the stomach; (2) the hepatic, which passes 
beyond the stomach between the layers (right and left) of the gastrohepatic omen- 
tum, to the liver; (3) the splenic, which passes backward between the two layers 
of the posterior mesogaster, to the spleen and pancreas. 
General Relations. Above, liver, lesser omentum, and diaphragm ; below, the 
transverse colon and great omentum; in front, the abdominal walls and peri- 
toneum; pylorus, gall-bladder and under part of liver; cardia, spleen and gastro- 
splenic omentum. The cardiac end is continuous with the oesophagus; the pyloric 
with the duodenum. Behind the stomach are the pancreas, crura of diaphragm, 
transverse mesocolon, solar plexus, spleen, left kidney, left adrenal, aorta, and 
ascending vena cava. 
Embryology. Up to the third month of foetal life, the stomach is a dilatation 
with its long axis parallel with the vertebral column. During the third month 
it rotates from left to right, thus making the left surface anterior, and the 
right, posterior; it also rotates transversely, bringing the pylorus to the right side 
and the cardia to the left. This double rotation accounts for the presence (in 
the adult) of the left vagus nerve on the anterior, and the right on the posterior 
surface of the stomach. 
Reflex Phenomena in cancer of the stomach and gastric ulcer may occur as 
somatic pain in the abdominal walls (" epigastric tenderness" in gastric ulcer, or 
lower shoulder region) because the stomach is supplied by the solar plexus, and 
the somatic correspondence of this plexus is from the sixth to the tenth spinal 
nerves. 
THE DUODENUM. 
Dissection. While duodenum is inflated study the four parts of the organ (superior, 
descending, transverse, and ascending). Find the descending part extending to right kidney 
and making abrupt turn across body as transverse duodenum. Find transverse duodenum 
passing beneath superior mesenteric vessels and ending in the ascending portion continuous 
with the initial part of jejunum near point of inflation. For further study and dissection be 
guided by illustrations and text. (Fig. 117.) 
The first eight or ten inches of the small intestine is called duodenum. Ex- 
tent-. From pylorus to left side of second lumbar vertebra. Size: Diameter, two 
inches; length, eight to ten inches. Comparative fixity: Most fixed part of small 
intestine. Comparative diameter: Widest part of small intestine. Morphological 
antecedent: Embryonal fore-gut. Its general relation to the transverse colon is 
behind; its retrocolic position is due to rotation from left to right. General relation 
to pancreas: Curves around the same. Parts: superior, descending, transverse, 
ascending. Arteries: Pancreatic, duodenal, superior, and inferior. 
Superior Portion. Extent: From pylorus to neck of gall-bladder; two inches 
long. Direction: Upward and backward to right. General character: Very 
freely movable. Anterior and lateral peritoneal investment entire. Posterior 
peritoneal investment, near pylorus, incomplete. It is above the foramen of 
Winslow and in front of the hepatic root-structures. 
Descending Portion. Extent: From neck of gall-bladder to third lumbar ver- 
tebra. Direction: Downward, and curving to left. General character: More 
fixed than ascending portion. Peritoneal investment: Covered in front only, above 
and below colon. Derivation of peritoneum : Superior transverse mesocolon. It 
is behind the transverse colon, to the right of the head of the pancreas, and in 
front of the vena cava, right kidney, and renal vessels. The back part is pierced 
by the common bile-duct and the pancreatic duct. THE ABDOMINAL AND PELVIC ORGANS. 
223 
Transverse Portion. Extent: From right of body of third lumbar vertebra 
across spine. Direction: Obliquely upward and to left. General character: 
Longest and most fixed part. Peritoneal investment: Covered in front only. It 
is behind the transverse mesocolon and superior mesenteric vessels, below the 
inferior pancreatico-duodenal artery, pancreas and superior mesenteric artery, and 
in front of the vena cava, aorta, and crura of diaphragm. 
Ascending Portion. Extent: From side of third lumbar vertebra upward about 
one inch. Peritoneal investment: Covered in front and (partially) on the sides. It 
is attached to the left crus of diaphragm, this attachment being called musculus 
suspensorius duodeni. 
Embryology. At an early period the duodenum had a dorsal mesentery. Sub- 
sequently, with rotation of the stomach, it lost its mesentery, by fusion with the 
posterior abdominal wall, and became fixed. The transverse mesocolon fuses with 
the peritoneum of the ventral surface of a part of the duodenum. 
Reflex Phenomena in duodenal ulcer, may occur as somatic pain in right hypo- 
chondrium and lower shoulder region, because its nerve-supply is from solar 
plexus, and this plexus has its somatic correspondence in the spinal nerves from 
the sixth to tenth thoracic. 
JEJUNUM AND ILEUM. 
Dissection. (Fig. 118.) Begin at end of duodenum with jejunum and trace small intestine 
to its point of confluence with the larger intestine-the ileocsecal junction. Lift this mass 
of small intestine and study attachment of its mesentery to posterior abdominal wall. With 
blunt instrument divide one layer of its mesentery and find vessels, nerves, and mesenteric 
glands which supply the small intestine. Find small intestine in free margin of mesentery. 
For further study consult text and illustration. 
The upper two-fifths of the small intestine, counting from end of duodenum, 
is called jejunum. It is about eight feet long, and always more or less empty; 
hence the name, intestinum jejunum. The diameter of the jejunum exceeds that 
of the ileum by one-half inch; its walls are thicker, its mucous membrane more 
complex, and its blood-supply more abundant. Surgical repair on jejunum pro- 
ceeds more rapidly than on ileum; strangulated hernia of ileum, on the other 
hand, is less dangerous than that of the jejunum. 
The Mesentery extends from duodenum to ileocsecal region. The upper mesen- 
tery is, for reasons comprehensible only when rotation is understood, continuous 
with the under layer of transverse mesocolon and with peritoneum of ascendiug 
colon; the lower layer is continuous with peritoneum of descending colon and 
sigmoid. 
Coats: Serous, muscular, submucous, and mucous. The serous or peritoneal 
coat is on the outside, and may be easily studied. The mucous coat is thrown 
into folds called valvulfe conniventes, and can only be seen when the gut is 
opened and cleansed. (See Gray's Anatomy.} 
The Blood-supply of the Small Intestine is from the superior mesenteric artery. 
The arteries are accompanied by veins which ultimately reach the portal vein. 
The arteries are supplied with sympathetic nerves from the superior mesenteric 
plexus. The intestine, with all its accessories, is between two layers of the 
peritoneum called the mesentery. 
Meckel's Diverticulum is occasionally found attached to the ileum from one to 
three feet from the ileoctecal junction. It is most frequently met as a blind tube 
from one to several inches in length. It may be the cause of congenital fecal 
fistula, ''to appreciate which the student should recall the following bit of embry- 
ology : The early gut-tube was connected to umbilical vesicle by vitelline duct. 
During sixth week, vitelline vesicle begins to lose its usefulness. The duct is 
attached to the ileum near ileocsecal region. The duct may do one of three 
things: (1) Become obliterated; (2) remain a cul-de-sac; (3) remain patent, 
connecting interior of ileum, via umbilical aperture, with external world. A MANUAL OF DISSECTION. 
224 
Fig. 118. 
Superior mebeuteric artery. (Gerrish after Testut.) 
LARGE INTESTINE. 
Dissection. Introduce glass tube into lower end of ileum (about six inches from caecum), 
inflate same and tie off. Study the three distinctive characters of large intestine (longitu- 
dinal bands (three), sacculations, and fatty masses). Study attachment of transverse meso- 
colon to abdominal wall, and its relation to transverse duodenum. Study location and limita- 
tions of ascending, transverse, and descending colon. Locate appendix and sigmoid. Be 
guided by text and illustrations. 
The Large Intestine, whose arbitrary subdivisions will presently be described, 
dates its inception from the sixth week of intra-uterine life, at which time a pre- 
viously straight gut, uniform in texture, differentiates at a point known as the 
ileocsecal region, into large and small intestine. 
In the adult the large intestine extends from the ileocsecal region to the anus. 
The ileocaecal region is in the iliac fossa on the iliopsoas muscle. The large intes- 
tine almost completely surrounds the small intestine, except the duodenum. For 
practical purposes in anatomy and surgery we distinguish large from small intes- 
tine by the presence in large intestine of the three following structures: (1) Three 
longitudinal bands of muscular fibre; (2) sacculations produced by the longitudi- 
nal bands; (3) fatty masses, called appendices epiploicse. The function of the 
appendages of fatty masses is not known. The sacculations are variable in size 
in different specimens. The gut must be inflated to appreciate appearance of the 
sacculations. The three longitudinal bands radiate from the appendix and are 
lost on the rectum, these two extremes being the only parts of the large intestine THE ABDOMINAL AND PELVIC ORGANS 
225 
in which longitudinal bands are not present. The bands are equidistant from one 
another, and named and located as follows: (a) Posterior, on attached border of 
intestine; (6) inner, on lower part of transverse colon and inner part of remainder; 
(c) anterior, on front part of intestine. The surgical importance of longitudinal 
bands (and also their importance in dissection) is as a guide in locating the 
appendix. Since these bands radiate from the appendix any band followed 
toward the right iliac fossa leads to the appendix. 
The Caecum (caput coli) is the initial end of the large intestine and a part of 
the ascending colon. It is situated below entrance of ileum into large intestine. 
It is about two and a half inches long and three inches in diameter. In 
the majority of cases the apex of the caecum rests on the psoas muscle. The 
caecum may be wholly within the true pelvis, or, in cases of faulty rotation 
(which are rare), it may be on the left of the mid-line of the posterior abdominal 
walls. The caecum presents the following four types in the adult: (1) Infantile, 
conical; (2) appendix at apex; (3) quadrilateral, appendix between two bulging 
sacculi; (4) right caput undeveloped, apex to left and behind; (5) left caput 
atrophied, no trace of apex. The caecum may be insignificant (microcaecum) or 
overgrown (macrocaecum). The ileum may pass behind the colon and open into 
the colon on the right side; it may enter the front of the caecum or the caecum may 
be found just under the liver or near the umbilicus. The primitive condition 
of a common mesentery may obtain. (See Gerrish's Anatomy.} 
The Vermiform Appendix. This is attached to caecum near ileocaecal valve, on 
inner and posterior part. It varies from one to nine inches in length, and is a 
blind, hollow tube. It is usually behind the ileum. It may hang across the 
pelvic brim, or lie vertically behind the caecum. It has a mesentery derived 
from left mesentery of ileum. Its mesentery is triangular, and has in its free mar- 
gin the appendicular artery, a branch of the ileocaelic. Like the major part of 
the alimentary canal, the tube grows faster than the peritoneal covering-the 
mesentery-hence, the twisted condition of the organ. At the time of its first 
appearance in the embryo, the appendix equals the caecum in size. 
The Ileocaecal Valve (valvula Bauhini) is formed by a double fold of mucous 
membrane and circular muscular fibre at junction of small and large intestine. 
The valve is not perfect, as has been noted in clinical practice by ejections from 
the mouth, of substances injected per rectum. The student should demonstrate 
in the dissecting-room the fact that water introduced into the ascending colon 
near the liver will find its way quite readily into the small intestine. There is 
usually to be found at the beginning of the appendix a small valve formed by a 
fold of mucous membrane. 
Subdivisions. The ascending colon extends from the right iliac fossa to the 
lower margin of the liver. It begins in a blind pouch, the caecum, to which is 
attached the vermiform appendix. The ascending colon is variable in length, 
usually from four to six inches. A very large liver, or imperfect rotation may 
account for its shortness. It is held in position by peritoneum, which covers the 
anterior surface and sides only, and with the exception of a few cases, has no 
mesocolon. The ascending colon may be absent, in which case the caecum belongs 
to the transverse colon. The ascending colon is in relation with right kidney, 
descending duodenum, quadratus lumborum and transversalis muscles. 
The Transverse Colon extends from the hepatic to the splenic flexure of the colon, 
across the junction of the epigastric and umbilical regions, and makes a sharp 
bend downward at the lower border of the spleen, called the splenic flexure. It is 
held in position by the transverse mesocolon. It is in relation above with the 
liver, gall-bladder, and spleen; behind, with third part of duodenum; below, 
with small intestine; anteriorly, with abdominal walls. Its artery is the middle 
colic, a branch of the superior mesenteric. 
The Descending Colon extends from the splenic flexure to the sigmoid. It lies 
in the left hypochondriac and left lumbar regions. It is more movable than the 
ascending colon. Behind, it is related to outer border of left kidney, diaphragm, 226 
A MANUAL OF DISSECTION 
transversalis and quadratus lumborum muscles, while in front of it lies the small 
intestine. The descending colon has, as a rule, no peritoneum posteriorly. In 
one hundred dissections, a distinct mesocolon was found in thirty-six bodies. The 
descending colon receives its blood-supply from the inferior mesenteric artery- 
colica sinistra. 
The Sigmoid Flexure begins at the crest of the ilium aud ends opposite the left 
sacro-iliac synchondrosis. From its resemblance to a Greek letter, the sigmoid is 
called the omega loop. The normal position of omega loop is in the left iliac 
fossa, but it may hang down in the true pelvis. As a rule, the sigmoid is in 
contact with the bladder and hidden from view by the small intestine. The sigmoid 
has a mesosigmoid from one to four inches in length. The mesosigmoid may be 
Fig. 119. 
Inferior mesenteric artery. (Gerrisk after Testut.) 
absent over the psoas magnus muscle. At bifurcation of common iliac artery is the 
intersigmoid fossa, an occasional seat of sigmoid hernia. The fossa is less than 
two inches deep and formed by the sigmoid artery and folds of the mesosigmoid. 
The sigmoid is supplied with blood by the sigmoid artery, a branch of the inferior 
mesenteric. 
The Rectum extends from the sacro-iliac synchondrosis to the anus, and has first, 
second, and third portions. The first portion, four inches long, extends from the 
left sacro-iliac joint to the level of the third sacral vertebra in mid-line; the 
second, three inches long, extends from the third sacral vertebra to apex of pros- 
tate gland, one inch in front of the tip of the coccyx; the third, one inch long, 
extends from apex of prostate to anus. THE ABDOMINAL AND PELVIC ORGANS. 
227 
The lower segment of the rectum is not covered by the peritoneum; the levator 
and muscle are attached to it. It is surrounded by the internal sphincter muscle 
below the prostate. The external sphincter is at its end. Arteries: Superior 
hemorrhoidal, from inferior mesenteric; middle hemorrhoidal, from internal iliac; 
inferior hemorrhoidal, from internal pudic. There are two systems of veins in the 
rectum-portal and iliac; the portal system joins the mesenteric veins, the iliac, 
the internal iliac veins. The veins are longitudinal in the lower part of the 
rectum, where they communicate freely, forming the hemorrhoidal plexus of veins. 
The hemorrhoidal plexus of veins, situated between the mucosa and musculosa, 
surrounds the lower part of the rectum. The plexus discharges (1) into the in- 
ternal pudic vein through the inferior hemorrhoidal vein; (2) into the internal 
iliac vein through the middle hemorrhoidal; (3) into the inferior mesenteric 
through the superior hemorrhoidal vein. 
The Anus is the terminal opening by which the rectum performs its extrusive 
function. The corrugator cutis ani, external sphincter ani, and levator ani are 
important accessory muscles. The internal sphincter ani is produced by a thicken- 
ing of the circular muscular fibre of the rectum for about one-half inch. It is 
located about an inch above the anus, where it forms a complete muscular ring. 
THE LIVER. 
Dissection. Study relations, surfaces, borders, and ligaments of liver. Find round liga- 
ment in free border of falciform ligament. Review root-structures and locate right and left 
lateral ligaments. Pass finger through foramen of Winslow into lesser cavity of peritoneum. 
Dissect (with blunt instrument) branches of hepatic artery, and trace portal vein to its origin. 
Dissect gall-bladder away from its fissure, inflate and study cystic, hepatic, and common ducts. 
Consult illustration and identify the following lobes: right and left lateral, Spigelian quad- 
rate and caudate. Also identify the following fissures: longitudinal, transverse, portal, 
fissure for vena cava, fissure for gall-bladder. 
Location: Epigastric, right and left hypochondriac regions. Weight: about 
five pounds in the male, less in the female. Displacement capacity : ninety-five 
cubic inches. Specific character: firm, solid, friable, chocolate color. It has 
two borders-anterior and posterior; two extremities, right and left; three sur- 
faces, superior, inferior, and posterior; five lobes, right, left, caudate, quadrate, 
Spigelian; five fissures, cystic, caval, transverse, umbilical, and fissure of ductus 
venosus; five ligaments, broad, round, coronary, and right and left lateral. 
The Root-structures of the liver are those nerves and conduits that enter the organ 
through the transverse fissure, between the anterior and posterior layers of the 
lesser omentum, supported by connective tissue known as the capsule of Glisson. 
Names of root-structures of liver: 1. Left vagus nerve filaments, and sympa- 
thetic nerves from solar plexus (accompanying vessels under the name of the hepatic 
plexus) and conferring on the liver sensation, resiliency, and trophic qualities. 
2. Hepatic artery, a branch of the coeliac axis of the aorta, dividing into right 
and left lobe branches ; this artery lies to left of common bile-duct and anterior 
to portal vein; it furnishes the liver and gall-bladder with nutrition. 3. The 
portal vein (about three inches long) is made up behind the head of pancreas by 
confluence of splenic and superior mesenteric veins. In transverse fissure of 
liver the vein dilates to form the portal sinus; it then divides into a right and 
left branch and enters the liver. The portal vein, in its passage to the liver, lies 
posterior to and between the hepatic artery and common bile-duct. The tributaries 
of the portal vein are gastric, cystic, splenic, and superior mesenteric. The inferior 
mesenteric is tributary to the splenic vein. The portal vein begins in capil- 
laries in the spleen and abdominal digestive organs, and ends in capillaries in 
the liver. In the liver the portal vein receives the capillaries corresponding to 
the distribution of the hepatic artery, and leaves on the posterior surface, dis- 
charging into the ascending vena cava under the name of venae cavae hepaticae. 228 
A MANUAL OF DISSECTION. 
The Anterior Border of the liver is a sharp, thin edge. (Fig. 125 ) At 
beginning of the longitudinal fissure is the interlobar notch, which divides the 
right lobe from the left. This border is freely movable. 
The Posterior Border is thick, rounded, fixed, and notched for the ascending 
vena cava and vertebral column. 
The Superior Surface is divided into the right and left lobes by the suspensory 
ligament, a remnant of the anterior mesogaster. On left lobe is a depression for 
the heart. This whole surface is moulded to the concave surface of the diaphragm. 
The Inferior Surface of the liver includes the transverse fissure and the part in 
front of the fissure. The parts of this surface not covered by peritoneum are (1) 
fissure for the gall-bladder, the space between the two layers of the lesser omentum. 
(On this surface are the longitudinal fissure, which contains the umbilical vein in the 
embryo, and is, for this reason, called the umbilical fissure. In adults the umbil- 
ical fissure contains the round ligament of the liver-the obliterated umbilical vein.) 
(2) The fissure for the gall-bladder. (3) The transverse fissure, transmitting 
portal vein, hepatic duct, and hepatic artery. (4) The quadrate lobe, between 
Fig. 120. 
Posterior and under surfaces of the liver. (Gray after Ellis.) 
gall-bladder and umbilical fissure. (5) Certain more or less marked surfaces, 
where adjacent organs impinge on the liver, known as impressio gastrica, impressio 
renalis, impressio coelica, and impressio duodenalis. 
The Grail-bladder is just to the right of the quadrate lobe in the fissure for the 
gall-bladder. It may be inflated on the cadaver, and will then touch the front 
wall of the abdomen at the ninth costal cartilage, where in the living it is acces- 
sible for operation. It is from two and a half to four inches long, pyriform in 
shape, and one and a half inches wide at the fundus; it holds about one ounce. 
The neck is at the transverse fissure of the liver. It has a right curve above and 
a left one below. The part of the gall-bladder between the fundus and neck is 
the body. 
The Gall-ducts are (1) the cystic, about one and a half inches long, unites with 
the hepatic and forms the common bile duct. It lies in front of the portal vein 
and to the right of the hepatic artery. If this duct is obstructed, bile can neither 
escape from nor enter the gall-bladder. (2) The hepatic, made up in the transverse 
fissure of the liver by the junction of right and left hepatic ducts from the right 
and left lobes, respectively. It is about one and a half inches long and unites THE ABDOMINAL AND PELVIC ORGANS. 
229 
with the cystic duct to form the common bile-duct. If this duct is obstructed 
bile cannot escape from the liver. This duct crosses the hepatic artery and portal 
vein to join the cystic. (3) The common bile-duct (ductus communis choledochus) 
is formed by the union of the cystic and hepatic ducts. It is three and a half 
inches long and a quarter of an inch in diameter. It lies between the two layers 
of the lesser omentum.* Its course is (a) behind the first stage of the duodenum; 
(6) in front of portal vein; (c) to right of hepatic artery; (d) to left of descending 
duodenum; (e) behind head of pancreas and descending duodenum. It perforates 
the second part of the duodenum and unites with the pancreatic duct, forming a 
dilatation-the ampulla of Vater. 
The Posterior Surface of the liver is behind the transverse fissure. On it are 
(1) Spigelian lobe, between ascending vena cava and fissure for ductus venosus; 
(2) ascending vena cava; (3) fissure for ductus venosus; (4) tuber omentale. 
Embryology. The liver is a compound tubular gland. Glands in general are 
formed by an ingrowth of the walls of the cavity to which they pertain. At an 
early period the ventral wall of gut, below stomach, forms two diverticula, one the 
future pancreatic, the other the common bile-duct. The common bile-duct 
evaginates two diverticula; one becomes the gall-bladder, the other grows into the 
liver ridge located in future diaphragm, ancl evolves the liver. The liver owes 
its bile-duct epithelia and proper hepatic cells to the ectodermic evagination; its 
connective-tissue parts, to the liver ridge. The liver, therefore, consists of two 
elemental parts, a duodenal and a diaphragmatic. In embryo the liver occupies 
a position between the two layers of the anterior mesogaster, in front of the 
stomach. (See Gerrish's Anatomy.) 
Reflex Phenomena, in biliary colic, cancer of liver, suppurative hepatitis, and 
many other diseases of the liver, may occur as somatic pain in right shoulder or 
abdominal walls, since the liver derives its nerve-supply from the solar plexus, 
and the somatic correspondence of this plexus is in the spinal nerves from the 
sixth to the tenth thoracic. 
THE PANCREAS. 
Dissection. Locate behind the stomach, extending from duodenum across crura of dia- 
phragm, superior mesenteric vessels, aorta and vena cava, splenic vessels, left kidney, 
adrenal, and portal vein to spleen. (Figs. 116, 121.) Dissect with blunt instrument, the 
pancreas from these structures. Find duct of pancreas opening into descending or transverse 
duodenum. Consult illustrations and text. 
Location. Epigastric and left hypochondriac regions. Physiological class : 
A compound, racemose gland. Size: Length, seven inches; breadth, one and a 
half inches, and from one-half to one inch thick. Specific physical character: 
Soft, pinkish, cream-colored. Divisions: Head, neck, body, tail, and excretory 
pancreatic duct. The head is embraced by descending and transverse duodenum, 
and is disk-shaped and flattened. The neck is a slight constriction joining the 
head and body. Surfaces of body: Anterior, inferior, and posterior. Peritoneum 
of anterior surface: Derived from transverse mesocolon. Anterior visceral rela- 
tion: Posterior surface of stomach. Anterior surface: Concave, produced by 
pressure of stomach. The posterior surface is in contact with the crura of the 
diaphragm, superior mesenteric vessels, aorta, vena cava, splenic artery and 
vein, left kidney, left adrenal, and commencement of portal vein. The tail 
touches the inner surface of the spleen. The pancreatic duct: Synonym, duct 
of Wirsung; origin of the duct is in the tail, by smaller ducts; its end is in 
the descending duodenum, where it may join the common bile-duct. There may 
be an accessory duct. (Fig. 121.) Arteries: Splenic, hepatic, and superior 
mesenteric. The veins open into the splenic and superior mesenteric. 
Embryology. The pancreas is produced by evagination of the dorsal wall of the 
duodenum. In early embryo it lies behind the stomach between the two layers 
of the posterior mesogaster, completely invested by peritoneum. With rotation 230 
A MANUAL OF DISSECTION. 
of the alimentary canal, pancreas loses its mesentery and becomes a retroperi- 
toneal organ. The evagination of the duodenal wall, previously referred to, 
meets embryonic connective tissue in posterior mesogaster, and the result of the 
meeting is the formation of the pancreas. The pancreas has then, embryologi- 
cally, two elements-duodenal and embryonal connective tissue. 
Fig. 121. 
Ducts of the pancreas. Part of the front wall of the duodenum is cut away. (Gerrish after Testut.) 
THE SPLEEN. 
Dissection. (Fig. 110.) Locate attached to fundus of stomach by gastrosplenic omentum. 
Dissect through omentum and find splenic vessels entering hilum. Locate and study rela- 
tions of the four borders and two surfaces. Locate costo-colic ligament which supports the 
organ. Cut through fibro-elastic capsule and examine spleen pulp. 
Physiological Class. A great ductless blood gland. Situation .• Deep in the left 
hypochondriac region. Location: Between the fundus of the stomach and the 
diaphragm. It is between the eighth and eleventh ribs; its organic character 
is bluish red in color, soft, and easily torn. Shape: Elliptical, with long axis 
parallel to line of tenth rib. Size: Length, five inches, breadth, three and a 
half inches, and thickness, one and a half inches. It has a displacement capacity 
of fifteen cubic inches. Surfaces: Outer, convex; inner, concave. Inner surface 
is divided by hilum (a vertical slit), which transmits splenic vessels. Borders: 
Anterior, posterior, upper, and lower. Coats: (1) Fibro-elastic, capsule; (2) peri- 
toneal covering. 
The Splenic Artery, a branch of coeliac axis, is large and tortuous and enters 
the spleen by several branches. The arteries in the substance of the spleen are 
supported by trabecular connective tissue derived from the fibrocapsule. The splenic 
artery lies above the splenic vein and passes along the upper border of the pan- 
creas, being partially concealed from view by this gland. The branches of the 
splenic artery are (1) terminal, five to eight, distributed to spleen pulp; (2) vasa 
brevia, to greater cul-de-sac of stomach; (3) left gastro-epiploica sinistra, which 
anastomoses with the gastro-epiploica dextra; (4) the large pancreatic, accom- 
panies the pancreatic duct; (5) small pancreatic to pancreas. THE ABDOMINAL AND PELVIC ORGANS. 
231 
The Splenic Veins begin as capillaries in the splenic pulp; they unite to form 
four or five small veins, which unite before they reach the hilum, to form the 
splenic vein. The vein accompanies the splenic artery, lying below same, and be- 
comes confluent with the superior mesenteric vein behind the head of the pancreas 
to form the portal vein. In its course it receives the following veins : the inferior 
mesenteric, left gastro-epiploica, pancreatic, and vasa brevia. The nerve-supply 
of the spleen is from the solar plexus. Nerves are called splenic sympathetic, 
and accompany splenic artery. The spleen elaborates the albuminous materials 
of the food and stores them up for future use. 
Embryology. In embryo the spleen lies between the two layers of the posterior 
mesogaster near the pancreas. It is differentiated from the mesodermic tissue. 
The characteristic part of the spleen is called pulp, which is formed of nucleated 
cells along the branches of the arteries in the spleen. In addition to the ordinary 
one there may be several smaller spleens-from one to twenty-developed in 
the gastrosplenic or even in the gastrocolic omentum. 
Visceral Relations. The external surface of the spleen is in relation with the dia- 
phragm, and corresponds to the ninth, tenth, and eleventh ribs. The internal 
surface is in relation with the cardiac end of the stomach, tail of pancreas, left 
adrenal, and left crus of diaphragm. The superior border is connected to dia- 
phragm by the suspensory ligament of the spleen. The inferior border is in rela- 
tion with the splenic flexure of the colon The posterior border is attached to the 
left kidney by connective tissue. The hilum is connected to the cardiac end of 
the stomach by the gastrosplenic omentum. 
Reflex Phenomena incident to disease of the spleen may occur either in the 
vicinity of the left shoulder or in the left abdominal walls, as somatic pain, since 
this organ receives its nerve-supply from the solar plexus, and this plexus has its 
somatic correspondence in the spinal nerves from the sixth to the tenth thoracic. 
THE KIDNEYS. 
Dissection. Study the anterior and posterior relations. Trace renal vessels and ureter from 
kidney. Note fatty capsule and fibrous capsule. Search for supernumerary arteries. Identify 
hilum, borders, and surfaces. Study course of ureter to bladder; note its relation to spermatic 
vessels (posterior). Study interior of organ in Gray's Anatomy. 
The kidneys (Fig. 122) are two in number, one on either side of the vertebral 
column. The adrenal body or suprarenal capsule lies on the upper end of each 
kidney in a quantity of connective tissue and fat. Location: The kidney lies 
opposite the twelfth thoracic and first, second, and third lumbar vertebrae, princi- 
pally in the hypochondriac and epigastric regions. Owing to the great size of 
the right lobe of the liver the right kidney is somewhat lower than the left. 
The upper end of each kidney is in relation with the twelfth rib; the lower a 
little above the highest part of the iliac crest. Size: The kidney weighs about 
four and a half ounces ; it is about four inches long, two and a half inches broad, 
and one inch thick. Its shape is characteristic and well understood, but to be 
perfectly appreciated the dissecting material should be preserved in formalin with 
the organ in situ. Analysis : The kidney has two surfaces, anterior and posterior; 
two borders, an internal concave, and an external, convex and smooth ; two 
extremities, upper and lower, and a place where the nerves and conduits enter 
and depart, called the hilum. (See Gray's Anatomy.) 
The Hilum, or anatomical root of the kidney, is a longitudinal fissure in the 
centre of the inner concave border. It accommodates the following root-structures 
enumerated from before backward : (1) renal vein ; (2) renal artery ; (3) sympa- 
thetic nerves ; (4) ureter. The hilum is limited by thick anterior and posterior 
lips, and leads into the renal sinus. 232 
A MANUAL OF DISSECTION. 
The Anterior Surface of the right kidney has three impressions produced by the 
three organs in relation with its anterior surface: (1) Hepatic impression, pro- 
duced by liver, occupying about the upper two-thirds ; (2) colic impression, 
produced by hepatic flexure of colon, occupying about the lower third ; (3) duo- 
denal impression, produced by descending and transverse parts of duodenum, 
occupying a space variable in size in the region of the hilum. The anterior 
surface of left kidney is in relation with (1) stomach in upper third ; (2) colon, in 
lower third ; (3) spleen externally and tail of pancreas internally in middle 
Fjg. 1'22. 
The kidneys, the ureters, and the bladder, in their normal position. (Gerrish after Testut.) 
third. The posterior surface of each kidney is in relation with the psoas magnus, 
crus of diaphragm, diaphragm, quadratus lumborum muscle, twelfth thoracic 
nerve and accompanying artery, iliohypogastric, and ilio-inguinal nerves. 
Peritoneal Areas. The posterior surfaces of both kidneys are non-peritoneal. 
The left kidney areas, in relation with the colon, spleen, and pancreas, are non-per- 
itoneal ; those occupied by the stomach and coeliac vessels are covered by periton- 
eum. The right kidney areas, in relation with the colon and duodenum, are non- 
poritoneal; those in relation with the liver and right coeliac vessels are covered by 
peritoneum. (See Gray's or Gerrish's Anatomy.) THE ABDOMINAL AND PELVIC ORGANS. 
233 
The Capsule of the kidney is a strong, closely-fitting fibrous investment, and 
may be easily stripped off. The capsule enters the hilum and sinus of the 
kidney, and becomes continuous with the outer coat of the ureter and sheaths of 
the vessels and nerves. 
The Ureter (Figs. 122, 123) is the excretory duct of the kidney. Its length is 
about sixteen inches; its diameter is about one-fifth of an inch. The ureter begins 
in the renal sinus by eight or nine tubes called calices. Each calyx embraces a 
Malpighian pyramid. The expanded funnel-like part of the ureter, embraced by 
the lips of the hilum, is behind the renal vessels, and is called the pelvis of the 
ureter. It is nearly an inch wide. The ureter proper begins at the end of the 
pelvis. Portions of the ureter are abdominal, pelvic, and vesical. The abdominal 
portion rests on the psoas muscle, genito-crural nerve, and common iliac artery; the 
pelvic portion crosses the sacro-iliac joint, obturator interims muscle, and its fascia ; 
the vesical portion extends through the walls of the bladder. Arteries : Renal, 
spermatic, internal iliac, and vesical. Nerves: Sympathetic, through renal, 
spermatic, and hypogastric plexuses. 
Arteries: Lumbar, phrenic, and renal. The small vessels are chiefly for 
nutrition of the capsule; they enter in various places and anastomose freely with 
vessels from the renal artery. The renal vessels enter the hilum, in front of the 
ureter; the artery is behind the vein. Nerve-supply: Solar and renal plexuses 
and splanchnic, with filaments from vagus and phrenic. 
Reflex Pain in stone of pelvis of kidney is excruciating in end of the penis and 
in the scrotum-far from the irritation. To account for which recall the nerve- 
supply of the urinary tract: (1) Nerve-supply of the kidney and ureter is from 
hypogastric and renal plexuses; (2) for bladder and urethra, from hypogastric 
plexus, third and fourth sacral nerves; (3) for skin of penis and scrotum, 
from third and fourth sacral. The hypogastric plexus, third and fourth sacral 
nerves correspond in sacral region. The hypogastric pain is reflected to the 
internal pudic (third and fourth sacral), and these sensory nerves report pain 
peripherally. The principal distribution of the internal pudic nerve is to scrotum 
and penis. 
Suprarenal Capsule. For dissection purposes, see this organ under head of 
Identification of Structures, page 212. For detailed histology and relation of this, 
as well as other organs, see Gray's Anatomy. 
THE BLADDER. 
Dissection. Inject with paraffin through urethra. Study ligaments, size, shape, mobility, 
and relation to rectum and pubic bone. Dissect between bladder and pubic bone (space of 
Ritzius) and find puboprostatic ligaments, and veins from dorsum of penis. Remove peri- 
toneum and identify vessels (superior, middle, and inferior vesical arteries). Cut through 
the remaining coats by crucial incision, remove paraffin and study interior. Be guided by 
text and illustrations. 
The Bladder (Figs. 122, 123) is located in the pelvis behind the pubic bone. 
Through the ureter it receives the urine from the kidneys; by the urethra it dis- 
charges its contents. 
The Ligaments of the bladder are true and false. The true are derived from 
the rectovescial fascia and arranged about the base of the organ as follows: Two 
anterior, or puboprostatic; two lateral; one superior, the urachus. The false 
are peritoneal: superior, plica urachi-two lateral and two posterior. 
The Superior or Intestinal Surface of the bladder is in relation with the ileum and 
great omentum ; the anterior surface is separated from the pubic bone by the 
space of Ritzius; the posterior surface rests on the rectum in relation with the 
vesiculae seminales. (Fig. 123.) Arteries: Superior, middle, inferior vesical, and 
internal iliac. Nerves: Third, fourth sacral, and hypogastric plexus. 234 
A MANUAL OF DISSECTION. 
Fra. 123 
Base of the bladder, showing the vasa deferentia and seminal vesicles. The peritoneum is raised by hooks. 
(Gerrish after Testut.) 
THE PROSTATE GLAND. 
Location. The gland surrounds the prostatic urethra. (Figs. 123, 128, 129.) 
The apex is on the upper surface of the triangular ligament; the base is on the 
under surface of the bladder, and continuous with its muscular fibres; the 
lateral surface is covered by the levator ani muscle and vesicoprostatic plexus; the 
anterior surface is separated from the symphysis pubis by the prostatic plexus; 
the posterior surface is on the anterior wall of the rectum, and may be felt through 
the same above the external sphincter ani. The posterior surface of the pros- 
tate has the prostatic fissure which extends inward and forward to the middle of 
the prostatic part of the urethra. This fissure limits inferiorly the middle lobe of 
the prostate gland. The prostatic fissure transmits the ejaculatory duct. The 
prostate has two lateral lobes which surround the urethra and meet posteriorly in 
the prostatic fissure. The gland is surrounded by a dense capsule derived from 
the vesical subdivision of the visceral layer of the pelvic fascia. Arteries: Pros- 
tatic branches from the internal pudic, vesical, and hemorrhoidal arteries. Nerves: 
Pelvic plexus. The prostatico-vesical plexus of veins surrounds the prostate and 
neck of the bladder. Its tributaries are the right and left divisions of the dorsal 
vein of the penis; the prostatic and vesical veins. The plexus communicates 
with the hemorrhoidal plexus, opens by two veins into the internal iliac, and is 
covered by the rectovesical fascia. 
THE FEMALE PELVIS. 
Dissection. Locate the uterus low in the true pelvis between bladder and rectum. Pass a 
thread through upper part of uterus for purpose of moving the organ from place to place. 
Now demonstrate those structures attached to the upper and outer part of the uterus (Fig. 
124): (a) the round ligament of the uterus; (6) the Fallopian tube; (c) the utero-ovarian 
ligament. Grasp the distal end of the oviduct and study its fimbriae. Pass a bristle or 
broom-straw through tube into cavity of uterus, and cut through tube and study interior of 
same. Trace round ligament to outer side of deep epigastric artery, thence through inguinal 
canal to labia majora. (Fig. 124.) Examine broad ligament and demonstrate structures 
between its two layers. Cut through uterus and study interior of same. Find anastomosis 
of ovarian and uterine vessels. Trace ureter from brim of pelvis to bladder and note its 
relation to the cervix of the uterus. 
The Uterus is the organ of menstruation, of normal gestation for the fertilized 
ovum, and of expulsion of the viable or non-viable product of conception. In the THE ABDOMINAL AND PELVIC ORGANS. 
235 
fetus, the uterus is an abdominal organ, retroperitoneal, a differentiated part 
of Muller's duct. In the adult it is in the true pelvis in the unimpregnated 
state, between the two layers of the broad ligament, in front of the rectum and 
behind the bladder. Its departure from the pelvic cavity occurs under two 
conditions: (1) In prolapsus uteri; (2) in pregnancy, when its increased size 
renders its further stay in the limited space between the rectum and bladder a 
physiological impossibility. The uterus varies in size, according to age, pregnancy, 
and virginity. In young children the body of the uterus, compared with the neck, is 
small. In the virgin, the body and neck are equal in length. After the uterus has 
discharged its first function of gestation, the neck is one-half the length of the body. 
During the childbearing period the uterus reaches its greatest size and strength, and 
in old age, atrophies. In a woman who has not borne children the uterus weighs 
about an ounce, is one and a half inches in breadth, two and one-half inches in 
length. In one who has borne children the weight is greater. 
Analysis. The uterus has an upper part called the body; a lower cylindrical 
part, the cervix; an intermediary part between the body and cervix, the 
isthmus. The body has two surfaces-anterior and posterior-covered by perito- 
neum; three borders-a superior and two lateral. The superior border is covered 
by peritoneum, and is the transition-region from anterior to posterior surface. The 
lateral borders of the uterus mark the uterine extremity of the broad ligament, 
the junction of round and ovarian ligaments, and oviduct to the body of the 
uterus, and the entrance and departure of uterine nerves and vessels. The cervix 
consists of a part to which the vagina is attached; a part within vagina; a part 
immediately above the vaginal attachment. 
Ligaments. (Fig. 124.) (1) Utero-vesical, a peritoneal fold which passes from 
the cervix to the bladder ; (2) recto-uterine, a peritoneal fold, limiting laterally 
the pouch of Douglas, and extending from the cervix uteri and vagina to the 
rectum and sacrum ; (3) muscular ligaments, round or uterovaginal and utero- 
ovarian, extending from the superior angle of the uterus behind oviduct to 
ovary ; uteropelvic, extending from the obturator fascia to the lateral margins of 
the body of the uterus; (4) two sacro-uterine, in the recto-uterine folds, extend- 
ing from the uterus to the sacrum along the side of the rectum. 
The Broad Ligaments are double folds of peritoneum extending from the 
lateral margins of the uterus and upper part of the vagina to the lateral part of 
the pelvis, in such a way as to divide the pelvis into an anterior or vesical, 
and a posterior or rectal part. Contents of the broad ligament: (1) Ovary and 
and utero-ovarian ligament; (2) round or utero-inguinal ligament; (3) Fallopian 
tube or oviduct; (4) uterine and ovarian vessels and sympathetic nerves; (5) 
certain fcetal relics. (For description of ovary, see Gerrish's or Gray's Anatomy.) 
The Round Ligament is about five inches long and extends from the superior 
angle of the body of the uterus to the labia majora, in which it is lost. In its 
course the ligament passes successively between the layers of the broad ligament, 
in front of the Fallopian tube; through the internal abdominal ring in the trans- 
versalis fascia to the outer side of the deep epigastric artery; under the roof and 
along the floor of the inguinal canal; through the external abdominal ring in the 
aponeurosis of the external oblique muscle. The round ligament and guber- 
naculum testis represent the inguinal ligament of the primitive kidney, and in the 
embryo are preceded by an evagination of peritoneum (analogous to the processus 
vaginalis in the male) called the canal of Niick. This canal usually becomes 
obliterated, but may obtain in adult life. The round ligament is composed of 
unstriped muscle fibre. 
The Fallopian Tube (Fig. 124) (two in number) extends from the superior angle 
of the uterus, behind the round ligament, to about one inch beyond the ovary, to 
which latter it is attached by the ovarian fimbria. The tube is from three to four 
inches long, and its free end opens into the peritoneal cavity by a constricted 
orifice-the ostium abdominale. The orifice is surrounded by processes called 
fimbriae, one of which is attached to the ovary. The tube has three stages or 236 
A MANUAL OF DISSECTION. 
typical positions: The first lies on the floor of the pelvis; the second, along the 
anterior border of the ovary, and the third, along the posterior border and inner 
surface of the ovary. 
Nerves. Third and fourth sacral, hypogastric, and renal plexuses; the two latter 
also supply the ovary and Fallopian tubes. Contraction of the uterus normally 
occurs at the menstrual period and at the end of gestation. Premature contrac- 
tion of the uterus in the course of gestation may produce miscarriage. The uterus 
contracts reflexly on stimulation of the hypogastric plexus, nervi erigentes, nipple, 
trigeminus, sacral plexus, great sciatic nerve, lumbar plexus, brachial plexus, and 
intercostal nerves. 
The Hypogastric Plexus supplies the rectum, bladder, prostate, vagina, and 
uterus. In the female it lies on each side of the rectum, bladder, and vagina. 
Fig. 124. 
Female pelvic viscera, from above. The ovary and tube of the left side have been lifted out of place. 
(Gerrish after Testut.) 
Branches of this plexus accompany the arteries to the pelvic organs and take the 
same name as the arteries. This plexus is continued down from the superior hypo- 
gastric plexus, situated in the lumbar and upper sacral regions. It is joined by 
branches from the third and fourth sacral nerves and from the sacral part of the 
sympathetic cord. The nervi erigentes, called by Gaskell the pelvic splanchnics, 
arise from the sacral plexus. (They contain vasodilator fibres, and their stimu- 
lation produces erection of the clitoris.) Contraction of the uterus may be in- 
duced by stimulation of the nervi erigentes. These nerves also supply the rectum. 
Arteries of Uterus and Appendages. The uterine branch of the internal iliac 
enters the base of the broad ligament and runs toward the cervix in front of the 
ureter. It gives branches to the bladder and vagina, and runs along the side of 
the body of the uterus, giving off in its course anastomotic transverse branches to THE ABDOMINAL AND PELVIC ORGANS. 
237 
the walls of this organ. At the angle of the uterus the artery anastomoses with 
the ovarian and funicular. The uterine artery is accompanied by sympathetic 
nerves from the hypogastric plexus. 
The Ovary is connected (a) to the posterior layer of the broad ligament; (6) to 
the uterus by the utero-ovarian ligament; (c) to the Fallopian tube, by the ovarian 
fimbria. There are two ovaries, and each has a superior and an inferior surface; 
an anterior and a posterior border; a superior and an inferior extremity. The 
ovarian artery supplies the ovary with blood. 
The Ovarian Artery is a branch of the aorta, homologous to the spermatic in the 
male, and, like the spermatic, has a horizontal course in the embryo. The outer 
margin of the broad ligament, external to the fimbriated end of the Fallopian 
tube, presents a sharp fold in which is located the ovarian artery. This 
fold or plica is called the ligamentum infundibulo-pelvicum. (See plicate function 
of peritoneum, p. 216.) The ovarian artery divides into (a) a tubal branch that 
lies beneath and supplies the oviduct; (6) an ovarian branch which supplies the 
ovary and passes to the angle of the uterus to anastomose with the uterine and 
funicular. The ovarian artery is accompanied by sympathetic nerves from the 
renal plexus. 
The Funicular Artery is a branch of the vesical, joins the round ligament at 
the internal abdominal ring (in the transversalis fascia) and divides into an internal 
branch which runs in the substance of the round ligament to the angle of the 
uterus, where it anastomoses with the ovarian arteries and an external branch, which 
passes through the inguinal canal to the labia majora, where it anastomoses with 
the external pudic, a branch of the femoral artery. 
The Uterine Veins are large. They form a plexus in the broad ligament and 
finally unite to form a vein corresponding to the artery, which opens into the 
internal iliac. The ovarian veins form the pampiniform plexus around the ovarian 
artery. The right vein follows the course of the artery and opens into the ascend- 
ing vena cava; the left opens into the left renal vein. 
The Rectum of the male has been described in the dissection of the alimentary 
canal. (See p. 226.) In the female, the cul-de-sac of Douglas separates the sec- 
ond part of the rectum for a short distance from the cervix uteri and upper part 
of the vagina; below this the rectum in the female rests on the posterior wall of 
the vagina. 
The Bladder in the female is rounder than in the male. The base is in relation 
with the cervix uteri and vagina. The neck of the bladder in the female has no 
prostate ; vas deferens and vesiculse seminales are absent. Its relation to the peri- 
toneum, hypogastric remnants, and pelvic walls are similar to those in the male. 
The Female Urethra is about one and a half inches long and extends in a curved 
manner from the neck of the bladder to the vestibule, where the meatus urinarius 
externus is located. The urethra is almost entirely embedded in the anterior wall 
of the vagina. 
The Female Ureters have the same nerve-supply, blood-supply, and abdominal 
course, and relations as in the male. In the pelvis they are longer. After 
crossing the internal iliac artery the ureter extends forward to the cervix uteri. 
At the base of the bladder it lies in relation with the vagina for a short distance, 
and then pierces the bladder obliquely. 
The Pelvic Fascia of the Female. The parietal layer differs in one respect from 
the male; it is retlected onto the urethra and vagina (instead of onto the prostate) 
to join the vesical layer. The visceral fascia divides into (1) a vesical layer that 
forms'1 the true lateral ligaments of the bladder; (2) a rectovesical layer which 
extends between the bladder and rectum; (3) a rectal layer which embraces the 
lateral and posterior aspects of the bladder; (4) a rectovaginal layer, between 
rectum and vagina. CHAPTER XVII. 
THE ABDOMINAL VESSELS. 
There are two varieties of abdominal vessels-arteries and veins. The arteries, 
derived from the abdominal aorta, are distributed (a) to the walls (sacra media 
and lumbar); (6) to the viscera (gastric, hepatic). The veins, tributary to the 
inferior vena, convey blood from both viscera and walls. We may therefore speak 
of visceral and parietal vessels. Veins returning blood from the spleen and 
abdominal organs of digestion form the vena porta, blood in which reaches the 
vena cava via the liver. Blood in the remaining veins reaches the vena cava 
without interruption in the liver. All abdominal vessels are beneath the peri- 
toneum (in sheaths of connective tissue), and accompanied by sympathetic nerves. 
With the exception of the hepatic, each abdominal artery has a corresponding- 
accompanying vein. 
Dissection. Turn small intestines to right side and expose aorta from diaphragm to its 
bifurcation below, by cutting through and removing the overlying peritoneum. Compare 
dissection with illustration and identify each branch as given in the text. Next follow out 
each branch by stripping off the peritoneum. Observe small nerves accompanying each artery. 
In same manner remove peritoneum covering the inferior vena cava. Identify each tributary as 
given in the text and shown in the illustration. Notice that (below the diaphragm) arteries 
are anterior to their veins, except the renal. Divide the mesentery and find the superior 
mesenteric artery and vein. Demonstrate formation of portal vein as given in the text. 
(Fig. 125.) 
The Abdominal Aorta. (Fig. 112.) The abdominal aorta enters the abdominal 
cavity opposite the twelfth thoracic vertebra, through the aortic opening in the 
diaphragm. In the lumbar region the aorta lies to the left of the mid-line and 
ends opposite the body of the fourth lumbar vertebra, where it divides into the right 
and left common iliacs. Relations: On right side, inferior vena cava, Spigelian 
lobe of liver, right crus of diaphragm, right semilunar ganglion, and great 
splanchnic nerve; on left side, pancreas, left crus of diaphragm, small intestine, 
left semilunar ganglion, and left great splanchnic nerve; posteriorly, left crus of 
diaphragm, bodies of vertebrae, anterior common vertebral ligament, and left 
lumbar veins ; anteriorly, stomach, liver, lesser omentum, pancreas, transverse 
duodenum, left renal vein, splenic vein, spermatic and inferior mesenteric arteries, 
solar and aortic plexuses, ascending layer of transverse mesocolon, small intestine, 
and mesentery proper. Nerves : Sympathetic, from aortic plexus. 
Branches. Phrenic, coeliac axis, gastric, hepatic, splenic, superior mesenteric, 
suprarenal, renal, spermatic (ovarian), inferior mesenteric, lumbar, and sacra 
media. Of these, the phrenic, lumbar, and sacra media are parietal branches, the 
others, visceral. (Fig. 112.) 
The Inferior Vena Cava. (Fig. 112.) The inferior vena cava corresponds to 
the abdominal aorta. Its usual location is to the right of the aorta, but in rare 
cases of transposition of the thoracic and abdominal organs it is on the left side 
of the aorta. The vena cava is formed by the common iliac veins on the right 
side of the fifth lumbar vertebra, and ends in the lower and back part of the right 
auricle of the heart, where its opening is guarded by the Eustachian valve. It 
perforates the central tendon of the diaphragm and base of the pericardium, and 
lies in a groove on the posterior border of the liver. (Fig. 120.) Relations: On 
the right, the psoas muscle and right kidney ; on the left, the aorta and aortic 
plexus; posteriorly, the vertebral column, right crus of diaphragm, right renal 
artery, right lumbar arteries, right semilunar ganglion, and right sympathetic THE ABDOMINAL VESSELS. 
239 
gangliated cord; anteriorly, the liver, portal vein, pancreas, transverse duodenum, 
right spermatic (or ovarian) artery, and mesentery. Nerves of the vena cava are 
sympathetic, from the aorta plexus. 
The tributaries of the vena cava are (1) right and left common iliacs; (2) lumbar 
veins, four in number on each side, returning blood from the muscles and skin of 
the loins and abdominal walls; (3) spermatic, two in number, returning blood 
from the testicles; (4) renal, two in number, from the kidneys, placed in front of 
the renal arteries; (5) suprarenal, two in number, returning blood from the supra- 
renal bodies; (6) phrenic, two in number, returning blood from the diaphragm; 
(7) hepatic, two in number, commencing in the capillary terminations of the 
portal vein and hepatic artery. (See hepatic veins.) 
The Right Phrenic Artery (Fig. 112) crosses the right crus of the diaphragm, 
behind the vena cava, gives branches to the diaphragm, vena cava, right adrenal 
body, liver, and pericardium, anastomoses with the left phrenic, superior phrenic, 
and intercostals. 
The Left Phrenic Artery crosses the left crus of the diaphragm behind the oesoph- 
agus, gives branches to the diaphragm, oesophagus, left adrenal, spleen, pericar- 
dium, and anastomoses with the right phrenic, superior phrenic, left musculo- 
phrenic, and intercostals. The phrenic veins correspond to the distribution of the 
arteries and open into the inferior vena cava. 
The Coeliac Axis (Fig. 112) is about one-half inch long. It arises from the 
front of the aorta near the diaphragm, divides into the gastric, splenic, and hepatic 
arteries, and rests on the pancreas. (Fig. 121.) To its left are the stomach and 
left semilunar ganglion; to its right, the right semilunar ganglion and Spigelian 
lobe of the liver. The axis lies beneath the lesser omentum. 
The Gastric Artery (Figs. 112, 116) runs along the lesser curvature of the 
stomach, between the two layers of the lesser omentum. It gives branches to the 
stomach, oesophagus, and left lobe of the liver, and anastomoses with the pyloric 
branch of the hepatic. The gastric vein returns blood from the territory sup- 
plied by the gastric artery, and its branches correspond thereto. It is tributary 
to the portal vein. The gastric artery and its corresponding vein are attended by 
sympathetic nerves called the gastric or coronary plexus, from the solar plexus. 
The Hepatic Artery (Fig. 125) (larger than the gastric and smaller than the 
splenic) arises from the coeliac axis, passes to the pyloric end of the stomach, 
forms in part the lower boundary of the foramen of Winslow, and then passes in 
the lesser omentum, with the portal vein and bile-ducts, to the transverse fissure 
of the liver, and divides into right and left hepatic terminals. The artery and 
its branches, together with the portal vein and bile-ducts, are accompanied by the 
hepatic plexus from the solar plexus. "The hepatic artery has directly nothing 
to do with the elaboration of the special products of the organ, its particular 
province being to supply blood for the nutrition of Glisson's capsule and of the 
interlobular structures, including the bloodvessels and the bile-ducts. Minute 
arterial twigs are distributed to the walls of these tubes, where they end in deli- 
cate capillary networks, which in turn, at the periphery of the lobule, pour their 
contents into the intralobular network of the portal vein." (Green.) 
Branches of the Hepatic Artery: Pyloric, gastroduodenal, cystic. The 
pyloric branch passes along the lesser curvature of the stomach and anastomoses 
with the gastric artery. The gastroduodenal branch passes behind the duodenum, 
and at the lower border of the first part of the duodenum divides into (1) the 
gastro-epiploica dextra, which passes along the greater curvature of the stomach 
between the layers of the great omentum and anastomoses with the gastro- 
epiploica sinistra, a branch of the splenic artery; (2) the pancreaticoduodenalis 
superior, which lies between the duodenum and the pancreas, anastomosing with 
the pancreaticoduodenalis inferior, a branch of the superior mesenteric artery. 
The cystic branch of the hepatic artery supplies the gall-bladder. 
The Hepatic Veins have no course outside of the liver. They open into the 
ascending vena cava, on the posterior border of the liver, near the diaphragm. 240 
A MANUAL OF DISSECTION. 
They return blood taken to the liver by the hepatic artery and portal vein. 
The hepatic veins differ from the portal, and in transverse section of the liver 
may be distinguished as follows : They are not attended by other vessels; their 
mouths are usually open; their walls are exceedingly thin, and, apparently, in 
direct apposition with the liver substance. The portal veins are always accom- 
panied by a branch of the hepatic duct and a branch of the hepatic artery; their 
mouths are usually collapsed; their walls are thicker and are separated from the 
liver substance by Glisson's capsule. 
Fig. 125. 
Portal vein and its branches. (Gray.) 
The Portal Vein (Fig. 125) is formed between the head of the pancreas and the 
vena cava by the confluence of the splenic aud superior mesenteric veins. It passes 
between the two layers of the lesser omentum (posterior to the hepatic artery), into 
the transverse fissure of the liver. Tributaries : Gastric, splenic, cystic, superior 
and inferior mesenteries, aud venous blood from the hepatic arterial system, 
received by numerous small branches of the portal vein while these are still 
within the interlobular connective tissue. (See Gerrish's Anatomy.} THE ABDOMINAL VESSELS. 
241 
Physiology. The hepatic artery supplies the capsule of Glisson, portal vein, 
bile-ducts, and other structures in the interlobular spaces. Venous blood from the 
distribution of the hepatic artery reaches the branches of the portal vein in the 
interlobular spaces; hence, a mixture of hepatic and portal blood occurs. 
Branches of the portal vein in the interlobular spaces encircle the hepatic lobules 
at various places, from which the capillary network comes into relation with the 
liver cells. ''The blood from the portal vein contains soluble products absorbed 
from the alimentary canal, such as sugar and proteid, and these absorbed products 
are submitted to the metabolic activity of the liver cells before reaching the 
general circulation. The hepatic artery brings to the liver cells the arterialized 
blood. In addition, each lobule gives origin to bile-capillaries which arise 
between the separate cells and which carry off the bile formed within the cells. 
In accordance with these facts, the physiology of the liver cell falls naturally 
into two parts-one treating of the formation, composition, and physiological 
significance of bile, and the other dealing with the metabolic changes produced in 
the mixed blood of the portal vein and the hepatic artery, as it flows through the 
lobules. In this latter division, the main phenomena to be studied are the 
formation of urea and the formation and significance of glycogen." (American 
Text-book of Physiology.') 
The Splenic Artery, large and tortuous, is a branch of the coeliac axis. It passes 
withand above the splenic vein (Fig. 125), behind the peritoneum, along the upper 
border of the pancreas to the hilum of the spleen, where it divides into the 
splenic terminals. Branches: Pancreaticeeparvae, pancreaticamagna, vasa brevia, 
and gastro-epiploica sinistra. The pancreaticae parvae are small branches to the 
body and tail of the pancreas. The pancreatica magna is the largest of the small 
branches and accompanies the duct of the pancreas. The vasa brevia are short 
arteries between the layers of the great omentum given off to the greater curva- 
ture of the stomach. The gastro-epiploica sinistra passes between the layers of 
the great omentum to the greater curvature of the stomach and anastomoses with 
the gastro-epiploica dextra. 
The Splenic Vein (Fig. 125) returns blood from the spleen and corresponds with the 
distribution of the splenic artery. It lies below the artery and behind the pancreas. 
It crosses the aorta and superior mesenteric artery and joins the superior mesen- 
teric vein, to form the vena porta. Its tributaries are (1) inferior mesenteric; 
(2) pancreatic; (3) vasa brevia; (4) left gastro-epiploic vein. The splenic 
artery and vein are accompanied by the splenic plexus of nerves from the solar 
plexus. 
The Superior Mesenteric Artery (Figs. 112 and 117) arises from the aorta, one- 
quarter inch below the coeliac axis, and supplies all the small intestines except the 
first part of duodenum, the ascending and transverse colon. It is located in the 
mesentery proper and attended by a corresponding vein. Both artery and vein are 
accompanied by the superior mesenteric plexus of sympathetic nerves, derived 
from the solar plexus. Branches : Pancreaticoduodenalis inferior, colica media, 
colica dextra, ileocolic, appendicular, and vasa intestiui tenuis. (1) The pancrea- 
ticoduodenalis inferior lies behind the superior mesenteric vein. It passes 
between the head of the pancreas and the duodenum and anastomoses with the 
pancreaticoduodenalis superior, a branch of the gastroduodenal. (2) The middle 
colic (colica media) supplies the transverse colon. It arises below the head of 
the pancreas, passes in the transverse mesocolon, where it divides into right and 
left * branches, which anastomose respectively with the ascending branches of 
the right and left colic arteries. (3) The right colic (colica dextra) supplies 
the ascending colon and anastomoses with the ileocolic and middle colic. (4) The 
ileocolic divides into two branches: one supplies the caecum, the other the 
terminal part of the ileum. (5) The appendicular arises from one or both 
of the terminal branches (iliac or colic) of the ileocolic. It lies near the free 
border of the meso-appendix, and sends numerous small vessels to the appendix. 
(6) Intestinal branches (vasa intestini tenuis) are twelve to sixteen in number. 242 
A MANUAL OF DISSECTION. 
Each artery divides into two branches, which deviate in their course, but soon 
inosculate, forming a primary loop. Each loop divides into two branches, which 
deviate for a short distance and soon inosculate. In this manner, loops are 
formed, named primary, secondary, and tertiary. Branches are given off from the 
terminal loops which bifurcate, surround the intestine, and inosculate one with 
another. 
The Superior Mesenteric Vein (Fig. 125) is composed of tributaries from (1) 
parts of the alimentary canal supplied by the superior mesenteric artery; (2) the 
right gastro-epiploic vein. The vein lies in front of and to the right of the 
mesenteric artery, leaves the mesentery, passes in front of the duodenum and 
behind the pancreas, where it unites with the splenic vein to form the vena 
porta. 
The Inferior Mesenteric Artery (Fig. 119) arises from the left side of the aorta 
about two inches above its bifurcation, and supplies the descending colon, sigmoid 
flexure, and the greater part of the rectum. It is accompanied by the inferior 
mesenteric vein. (Fig. 125.) Both artery and vein are innervated by the inferior 
mesenteric plexus, from the solar plexus. Branches : (1) Left colic (colica sinistra). 
This vessel divides into ascending and descending branches, which supply the 
descending colon and anastomose with the middle and sigmoid colic branches 
respectively. (2) Sigmoid (colica sigmoidea), which supplies the sigmoid flexure 
and divides into an upper branch which anastomoses with the left colic, and a lower 
one which anastomoses with the superior hemorrhoidal artery. (3) Superior hemor- 
rhoidal. This is a continuation of the inferior mesenteric artery and supplies the 
rectum. It enters the pelvis behind the rectum and divides into two branches (one 
on either side of the rectum), within four or five inches of the anus, where each 
again divides. The rectal branches pierce the muscular coat and descend between 
this and the mucosa, anastomosing with the middle hemorrhoidal and with each 
other, thus forming a series of small vessels which run parallel to each other and 
longitudinally to the rectum, as far as the internal sphincter; here the vessels 
anastomose and form loops around the lower part of the rectum. (See Gerrish's 
Anatomy.') 
The Inferior Mesenteric Vein (Fig. 125) is composed of tributaries correspond- 
ing to the branches of the inferior mesenteric artery. The vein lies to the outer 
side of the artery on the left psoas magnus muscle. It passes behind the pancreas 
and becomes tributary to the splenic vein. 
The Suprarenal Arteries (Fig. 112) are small in the adult, but as large as the 
renals in the foetus. They arise from the aorta, cross the crura of the diaphragm, 
and enter the under surface of the suprarenal capsule. 
The Renal Arteries (Fig. 112) arise from the aorta below the superior mesenteric, 
and cross the crura of the diaphragm. They are attended by the renal veins; 
both veins and arteries are accompanied by sympathetic nerves called the renal 
plexus, derived from the solar plexus. Branches: (1) Terminal; three or four 
branches enter each kidney. Behind the arteries (as they enter the hilum of the 
kidney) is the beginning of the ureter; in front of the artery, lie the renal veins. 
The right renal artery is longer and on a lower plane than the left, and passes 
behind the vena cava. Each renal artery lies posterior to its accompanying vein. 
(2) Capsular, supplies the proper capsule of the kidney, perirenal fat, and anasto- 
moses with renal branches from contiguous lumbar arteries. (3) Adrenal (supra- 
renal). The inferior suprarenal branch is given off to the suprarenal capsule. (4) 
Ureteral, supplies the ureter and anastomoses with similar branches from the 
spermatic, ovarian, superior vesical, and common iliac arteries. (5) Suprarenal 
(middle). This branch is the proper artery of the suprarenal body. It crosses 
the crus of the diaphragm. In the foetus this is as large as the renal. It anasto- 
moses with the superior suprarenal branch of the phrenic and the inferior supra- 
renal branch of the renal artery. 
The Renal Veins (Fig. 112) return blood from the kidney and adrenals and are 
tributary to the ascending vena cava. The left vein, longer than the right, crosses THE ABDOMINAL VESSELS. 
243 
in front of the aorta and receives the spermatic or ovarian veins of the same side. 
The renal veins lie anterior to their arteries. 
The Spermatic Arteries (Fig. 112) arise from the aorta below the renal. Each 
artery lies on the psoas magnus muscle. The right lies in front of the vena cava, 
crosses the ureter and external iliac artery, to the internal abdominal ring; the left 
lies beneath the sigmoid, but bears the same relation as the right to the left 
ureter and left internal abdominal ring. The spermatic arteries are accompanied 
by the spermatic veins, and both arteries and veins are supplied by the spermatic 
plexus, derived from the solar plexus. Branches : Testicular (Fig. 127), perforate 
the tunica albuginea posteriorly, and are the proper arteries of the testicle; they 
anastomose with the arteries of the vas deferens. (2) Epididymal, supplies the 
epididymis and anastomoses with the artery of the vas deferens. (3) Cremasteric, 
supplies the cremaster muscle and anastomoses with the cremasteric branch of 
the deep epigastric artery. (4) Ureteral, supplies the ureter joining the same 
where the spermatic vessels cross this conduit, and anastomoses with ureteral 
branches of the common iliac and superior vesical arteries. 
The Spermatic Veins (Fig. 112) terminate differently on the two sides. They 
return blood from the testicles. The left vein is tributary to the left renal; the 
right, to the ascending vena cava. The ovarian veins are the homologues of the 
spermatic veins and discharge in like manner. 
The Ovarian Arteries are similar in origin from the aorta to the spermatics. The 
upper part of their course is also similar. At the pelvic brim they pass between 
the layers of the broad ligament of the uterus and are accompanied by the ovarian 
veins; both arteries and veins are innervated by the ovarian plexus from the solar 
plexus. The right ovarian vein opens into the ascending vena cava; the left, into 
the left renal. Branches : (1) Terminal, 'supplies the ovary. It crosses the 
common iliac artery, and gains the space between the two layers of the broad liga- 
ment, where it lies below the Fallopian tube and anastomoses with the uterine 
artery. (2) Fallopian, supplies the Fallopian tube. (3) Uterine, accompanies 
the oviduct to the cornu of the uterus, and is distributed to the fundus uteri. It 
anastomoses with uterine branches of the internal iliac. (4) Ligamentous, supplies 
the round ligament of the uterus and anastomoses with the external pudic arteries. 
(5) Ureteral, are distributed to the ureter. Ovarian veins, as mentioned above, 
are homologues to the spermatic veins. 
The Lumbar Arteries, four in number, on each side, are analogous to the 
intercostals. They arise from the back part of the aorta and pass behind the 
psoas magnus muscle and sympathetic nerve. The arteries on the right side are 
covered by the ascending vena cava. The two upper arteries on each side are 
covered by the crura of the diaphragm. Each artery divides into a dorsal and an 
abdominal branch, between the transverse processes of the lumbar vertebrae. 
Branches: (1) Vertebral, to the vertebrae and their ligaments. (2) Renal, to the 
capsule of the kidney. (3) Muscular, to the psoas, quadratus lumborum, trans- 
versalis, internal oblique and external oblique muscles. (4) Dorsal, pass between 
the transverse processes with the posterior primary divisions of the spinal nerves, 
supplying the deep muscles of the back (and skin corresponding thereto), spinal 
cord, cauda equina and walls of the neural canal. The lumbar veins correspond 
with the arteries both in number and distribution and are tributary to the 
ascending vena cava. The left lumbar veins pass behind the aorta. 
The Sacra Media Artery arises from the back part of the aorta near its bifurca- 
tion.'" It extends along the mid-line of the sacrum and coccyx and ends in the coc- 
cygeal or Luschka's gland. It gives branches to the posterior part of the rectum 
and anastomotic branches to the lateral sacral arteries. (For common, external, 
and internal iliac arteries and their branches, see chapter on Iliac Region.) 244 
A MANUAL OF DISSECTION. 
NERVE-SUPPLY OF ABDOMINAL ORGANS. 
The organs in the abdominal cavity receive their nerve-supply from the solar 
plexus, distributed (under the name of specific plexuses) with branches of the 
abdominal aorta. Hence, phrenic, suprarenal, renal, spermatic, coeliac, gastric, 
hepatic, splenic, aortic, superior and inferior mesenteric plexuses are self-explana- 
tory; a definition of one plexus will apply to all: The hepatic plexus consists of 
sympathetic nerves (from the solar or epigastric plexus) which accompany the 
hepatic artery. (See sympathetic nerve.) 
The Solar Plexus consists of nerves and ganglia. Nerves: The great and small 
splanchnic on both sides, and filaments from the right vagus nerve. The plexus 
is located between the suprarenal capsules and extends from the coeliac axis to the 
pancreas. Ganglia: The principal ganglia are the semilunar. 
The Aortic Plexus extends on the front and sides of the aorta, from the superior 
to the inferior mesenteric artery. It is composed of branches from the solar plexus 
and semilunar ganglia on each side. From this plexus arise the spermatic plexus 
(in part), the inferior mesenteric, and hypogastric plexuses. 
The Hypogastric Plexus is between the common iliac arteries on the promontory 
of the sacrum. It consists of filaments from the aortic plexus and lumbar sympa- 
thetic ganglia, and ends below in the pelvic plexuses. 
The Pelvic Plexuses, derived from the hypogastric plexus, are joined by branches 
of the second, third, and fourth sacral nerves; they give off inferior hemor- 
rhoidal, vesical, prostatic, vaginal, and uterine branches, which accompany 
arteries of like name to parts they are destined to supply. CHAPTER XVIII. 
THE PELVIC OUTLET. 
Boundaries. (Fig. 134.) Symphysis pubis, subpubic ligament, rami of the pubes 
and ischia, ischial tuberosities, greater sacrosciatic ligament, and tip of the 
coccyx. The anterior triangular part of this diamond-shaped space contains the 
penis, urethra, testicle and its coverings, and the perineal body; the posterior 
contains the lower segment of the rectum, with its accessory muscles, and the 
ischiorectal fossa. To study systematically this region follow the subjoined 
directions. 1. Place the cadaver in the lithotomy position (Fig. 126), that is, flex 
the thighs on the abdomen, the legs on the thighs, and place the buttocks slightly 
over the end of the table, and tie the hands to the feet as represented in Fig. 126. 
2. Study the testicles, spermatic cord, penis, and male urethra according to 
the directions in the text. 3. Remove the skin according to the incisions in 
Fig. 126 and study Colles' fascia, the anal and genito-urinary muscles, the 
triangular ligament or deep perineal fascia, and ischiorectal region according to 
the general and specific directions for "Dissection." 
Fig. 126. 
Dissection of perineum and ischiorectal region. (Gray.) 
TESTICLES. 
Dissection. Draw the testicles and their covering well down (and the penis upward), incise 
the skin and demonstrate the coverings represented in Fig. 127. Trace the coverings to their 
abdominal origin as far as possible. Cut through the tunica vaginalis and demonstrate the 
serous cavity. Cut through the testicle and demonstrate its proper coverings: (a) tunica 
vaginalis (peritoneum); (6) tunica albuginea (bluish-white fibrous coat); (c) tunica vasculosa, 
composed of vessels and connective tissue and immediately beneath the preceding coat. 
Demonstrate the size of the testicle: breadth and thickness, one inch each; length two 
inches, and weight about one ounce. 
Coverings of the Testicle. (Fig. 127.) 1. Integument, derived from and 
continuous with that of the abdomen and thigh, and, taken with the dartos, 
forms the scrotum. 2. Dartos, derived from and continuous with the superficial 
fascia of the abdomen and thigh. It consists of unstriped muscle fibre and 
elastic tissue, by which the transverse scrotal ridges of the skin are formed. 
3. Intercolumnar fascia, derived from and continuous with the aponeurosis of 246 
A MANUAL OF DISSECTION. 
the external oblique muscle, at the external abdominal ring. (Fig. 109.) 4. 
Cremasteric fascia (cremaster muscle), derived from and continuous with the 
lower border of the internal oblique muscle. 5. Infundibuliform fascia, derived 
from and continuous with the transversalis fascia. 6. The tunica vaginalis, 
derived from and continuous with the peritoneum. The first and second cover- 
ings constitute the scrotum; the third, fourth, and fifth the external, middle, 
and internal spermatic fasciae, respectively. The peritoneum, tunica albuginea, 
and tunica vasculosa are the proper coverings of the testicle. 
Vessels of the Testicle. 1. The spermatic artery, a branch of the abdominal aorta, 
is the proper artery of the testicle. 2. The deferential, a branch of the superior 
vesical artery, is the proper artery of the excretory duct of the testicle-the vas 
deferens. 3. The superficial and deep external pudic from the femoral artery 
supply the scrotum. 4. The cremasteric, a branch of the deep epigastric artery, 
supplies the cremaster muscle. 
Fig. 127. 
Transverse section through the left side of the scrotum and the left testicle. The sac of the tunica vaginalis 
represented in a distended condition. (Delepine.) 
Serves of the Testicle. The testicle itself is supplied by sympathetic nerves from 
the pelvic plexus. They reach the organ with the spermatic and deferential 
arteries forming plexuses about these vessels. The coverings of the testicle are 
supplied by (a) the superficial perineal (from the pudic); (6) the inferior pudendal 
(from small sciatic); (c) the ilio-inguinal (from the lumbar plexus); the genital 
branch of the genito-crural (from the lumbar plexus) to the cremaster muscle. 
SPERMATIC CORD. 
Dissection. (Fig. 109.) Divide the skin in line with the cord as far upward as the external 
abdominal ring. Make traction on the testicle. The ilio-inguinal nerve is anterior and the 
genito-crural posterior to the cord. Locate the vas deferens by its cord-like feel, behind the 
other structures of the cord. Compare the dissection with the text and illustration. With 
blunt dissection trace the spermatic artery and vas deferens to the testicle. 
Composition and Extent. The spermatic cord extends from the internal abdom- 
inal ring, in the transversalis fascia, to the summit of the testicle. (Fig. 109.) 
It is composed of (1) the vas deferens, the excretory duct of the testicle; (2) the THE PEL VTC 0 UTLET. 
247 
deferential artery, behind the vas; (3) the spermatic artery, in front of the vas; 
(4) the spermatic veins, forming the pampiniform plexus; (5) lymphatic vessels, 
accompanying the veins; (6) sympathetic nerves, accompanying the spermatic 
and deferential arteries; (7) the internal cremaster muscle of Henle, a remnant 
of the gubernaculum; (8) the processus vaginalis, a peritoneal relic of a tube 
connecting the tunica vaginalis with the peritoneum-the processes vaginalis; 
(9) fat and connective tissue, derived from the subperitoneal connective tissue; 
(TO) the ilio-inguinal nerve; (11) the genital branch of the genito-crural nerve. 
The Spermatic Artery (Fig. 112) is a branch of the aorta, and given off below the 
renal. In the foetus the spermatic arteries pass horizontally outward, and sub- 
sequently gain the position they occupy in the adult, by the descent of the testicle. 
After the testicle has descended, the artery crosses the psoas muscle, ureter, and 
external iliac artery. The right artery is between the end of the ileum and the 
vena cava; the left, beneath the sigmoid flexure. At the internal abdominal 
ring, and to the outer side of the deep epigastric, the spermatic artery meets the vas 
deferens and the other constituent parts of the spermatic cord. In its course, the 
spermatic artery gives branches to the ureter, cremaster muscle, epididymis, and 
testicle. The right spermatic vein opens into the inferior vena cava; the left, 
into the left renal. The deferential arteries are branches of the deep epigastric 
and spermatic. 
The Vas Deferens (Fig. 128) extends from the lower part of the globus minor 
of the epididymis to the prostatic urethra, and has four stages : (1) Testicular, 
behind the testicle, one and a quarter inches long; (2) funicular, extending from 
the top of the testicle to the external abdominal ring, three inches long; (3) ingui- 
nal, in the inguinal canal, one and three-quarter inches long; (4) pelvic, extending 
from the outer side of the deep epigastric artery to the lower end of the vesicula 
seminalis, ten inches long. The total length is sixteen inches. 
The Vesiculae Seminales are diverticular reservoirs foi' the semen, situated between 
the bladder and the rectum. Each vesicula when dissected consists of a central 
tube, about three inches long, with lateral blind pouches. Its lower end joins 
the vas deferens to form the ejaculatory duct, which opens on the verumontanum 
of the prostatic urethra (Fig. 130) by the side of the orifice of the sinus pocularis, 
or uterus masculinus. The seminal vesicles add to the semen a fluid of their own. 
THE PENIS. 
Dissection. Introduce a sound into the bladder and remove the integument of the penis. 
Find the suspensory ligament extending from the pubic bone to the dorsum. (Fig. 129.) 
With blunt dissection demonstrate the dorsal vessels and nerves on the back of the penis. 
These structures pierce the suspensory ligament. Demonstrate the meatus urinarius, corona 
glandis, cervix, prepuce, and fraenum. Put the organ on the stretch, make a transverse 
incision one inch from the glans (Fig. 129) and demonstrate: (a) urethra surrounded by the 
corpus spongiosum; (&) corpora cavernosa; (c) dorsal vessels and nerves. Trace the corpus 
spongiosum downward to where it ends in the bulb; and the corpora cavernosa to the crura, 
attached to the ischiopubic rami. Demonstrate the bulb covered by the accelerator urime 
and the crus invested by the erector penis. Compare the work with the illustrations, and 
verify your dissection. 
The glans penis is the heart-shaped distal extremity. The base of the glans is 
the corona glandis; the constriction behind the corona is the cervix, and separates 
the glahs from the body. The end of the urethra-meatus urinarius externus- 
is in the glans. The root of the penis is attached to the front of the symphysis 
by a suspensory ligament; to the ischiopubic ramus by the crura of the corpora 
cavernosa. (Fig. 129.) The body of the penis (the greater part of the organ) is 
between the glans and the root. It is cylindrical when flaccid, triangular when 
erect, the broad side, facing upward, being called the dorsum. 
Coverings. 1. Skin, pigmented, free from fat, highly elastic, and laxly attached* 
except over the glans. 2. Bartos, continuous with that of the scrotum, is free 248 
A MANUAL OF DISSECTION. 
from fat, and forms a sphincter about the orifice of the prepuce. 3. Connective- 
tissue sheath, very elastic, contains the superficial vessels and nerves, and confers 
mobility on the skin of the penis. 4. Fascial sheath, very elastic, fuses with 
the skin at the base of the glans (forming the corona glandis), and by virtue of its 
elasticity aids the dartos, erector penis, and accelerator in compressing the deep 
veins. This sheath is continuous with the superficial perineal fascia and suspen- 
sory ligament. These four tunics surround the penis as a whole. It is now 
necessary to see the penis divested of its four coverings and study its three cylin- 
drical masses of erectile tissue. 
Erectile Masses. Aside from the four coverings previously studied, the penis 
consists of three masses of erectile tissue, each firmly enclosed in a strong sheath 
(tunica albuginea), and possesses nerves and vessels. These masses are the corpus 
spongiosum and two corpora cavernosa. (Fig. 129.) While the specific erectile 
tissue in each mass is histologically the same, important modifications in its 
distribution obtain, and new words will be introduced by which to designate it. 
Fig. 128. 
Fig. 129. 
Base of the bladder, with the vasa deferentia 
and vesiculee seminales. 
The penis, proximal portion, seen from below. 
(Gerrish after Testut.) 
A transverse section of the three cylindrical masses has been compared, and 
not inaptly, in arrangement, to a double-barrelled shotgun, the corpus spongiosum 
bearing in the simile the same relation to the two corpora cavernosa that the ramrod 
bears to the barrels of a shotgun. 
The Corpus Spongiosum forms distally the glans, proximally the bulb, while 
the intervening part is the body of the corpus spongiosum. (Figs. 129, 130.) 
The bulb rests on and receives an investment from the anterior layer of the 
triangular ligament (or middle perineal fascia), and is in the superficial perineal 
space. (Fig. 129.) The corpus spongiosum is perforated from end to end by 
the spongy portion of the urethra. The posterior part of the bulb is one-half 
inch in front of the anus; it is three-quarters of an inch wide and one and a 
half inches long. The glans is heart-shaped, contains the meatus urinarius 
externus, and receives the apical part of the corpus cavernosum. The body of 
the corpus spongiosum lies in a groove between the corpora cavernosa. 
The Corpora Cavernosa are two in number. (Fig. 129.) Each is about six inches 
long and one-half inch in diameter. They are united by the septum pectiniforme 
along their distal three-fourths; proximally, they diverge (under the name of 
crura) to their insertions into the middle third of the ischiopubic rami. The THE PELVIC OUTLET. 
249 
crura penis occupy the superficial perineal space, and are inserted as tendinous, 
flattened masses. Each crus presents an enlargement prior to its insertion (bulb 
of the crus), and should not be mistaken for the bulb of the corpus spongiosum. 
Blood-supply. The four coverings of the penis (skin, dartos, connective tissue, 
and fascial sheaths) are supplied by the external pudic (a branch of the femoral), 
superficial perineal, and dorsal arteries, branches of the internal pudic. These 
arteries are attended by corresponding veins, which lie between the dartos and 
the fascial sheath, and open into the long saphenous and femoral veins. The 
corpus spongiosum is supplied by the artery of the bulb and the dorsal artery, 
branches of the internal pudic. The corpus cavernosum is supplied by the caver- 
nous branch of the internal pudic. The arteries (called deep) to the three 
cylindrical masses anastomose with each other and with the arteries of the 
coverings of the penis. The deep veins, corresponding to the deep arteries, 
anastomose freely with each other and also with the superficial veins, and terminate 
through the deep dorsal vein in the internal pudic and plexus of Santorini, behind 
the pubic bone. From this plexus blood reaches the internal iliac vein. 
Nerves. The coverings of the penis are supplied (1) by the genital branch of 
the genito-crural, from the lumbar plexus; (2) by the superfn ial perineal branches 
of the internal pudic, a branch of the sacral plexus; (3) the erectile cylindrical 
masses are innervated by the dorsal nerves of the penis, the superficial perineal 
branches of the internal pudic, and hypogastric plexus. 
Fig.130. 
The male urethra, in sagittal section. (Gerrish after Testut.) 
The Male Urethra. 
The male urethra extends from the bladder to the end of the penis. It consists of 
a prostatic portion, one and a quarter inches long; a membranous, one-quarter inch 
long; a spongy, four and a half inches long; total length, six and a half inches. 
The proximal orifice is called the meatus urinarius internus; the distal, the meatus 
urinarius externus. The urethra perforates (1) the prostate from base to apex; 250 
A MANUAL OF DISSECTION. 
(2) the deep and superficial parts of the triangular ligament; (3) the compressor 
urethrae; (4) the corpus spongiosum. The meatus externus is the most constricted 
part, the prostatic the most distensible part 
of the urethra. The membranous part is not 
easily dilated, on account of the unyielding 
nature of the triangular ligament. The 
curves of the urethra are (1) the prostatico- 
membranous part, two inches long, passing 
almost vertically downward and slightly 
forward (Fig. 130): (2) about two inches of 
spongy urethra, passing horizontally forward, 
then making a sharp bend vertically down- 
ward in the region of the suspensory ligament. 
During erection the second curve is obliter- 
ated. The spongy urethra has two dilatations 
-the pars bulbosa, in the bulb, and the fossa 
navicularis, in the glans. (Fig. 131.) On 
the posterior wall of the prostatic urethra 
is an elevation-verumontanum-having the 
opening of the uterus masculinus, on the 
margins of which opening the ejaculatory ducts 
are located. 
COLLES' FASCIA. 
Dissection. Remove the skin as indicated in 
Fig. 132, the rectum having been filled with cotton 
and the margins sewed together. Introduce the 
sound and permit an assistant to hold the same so 
as to make the bulb of the urethra prominent. 
Now make a transverse incision through the super- 
ficial fascia (extending from ramus to ramus), and 
down to the muscle covering the bulb. Force two 
fingers through this incision, break up the con- 
nective tissue, and observe that the superficial 
fascia cut through is attached both below and on 
the sides. This is Colles' fascia. 
Colles' Fascia is a rather strong lamina of 
superficial fascia attached to the tuberosity 
of the ischium, the ischiopubic ramus, and the posterior or lower border of 
the conjoined anterior and posterior layers of the triangular ligament. Above, 
this fascia has no bony attachments, but is continuous with the fascial invest- 
ments of the scrotum and penis. The attachments of this fascia form three sides 
of a bag or pouch, called the superficial perineal space. The floor of the pouch is 
at the junction of the triangular ligament and Colles' fascia; the sides of the pouch 
are at the junction of Colles' fascia with the tuberosity of the ischium and the 
ischiopubic ramus; the mouth of the pouch is where Colles' fascia becomes con- 
tinuous with the superficial facial investments of the penis and scrotum; the inner 
and outer walls of the pouch are formed, respectively, by the anterior layer of 
the triangular ligament and Colles' fascia. 
Extravasation. In rupture of the bulbous urethra, urine may extravasate into 
the surrounding tissues. When the pouch above described is full, urine finds 
its way through the mouth of the pouch into the superficial fascia of the scrotum, 
penis, and abdomen. The structures in the superficial perineal space (Fig. 133) are 
(1) crura of the corpora cavernosa, invested by the erector penis muscles (musculi 
ischiocavernosi); (2) bulb of corpus cavernosum, invested by the accelerator urinee 
• muscle (musculus bulbo-cavernosus); (3) superficial transversus perinan muscles. 
Fig. 131. 
The male urethra, laid open on its anterior (upper) 
surface. (Testut.) THE PELVIC OUTLET. 
251 
ANAL AND GENITO-URINARY MUSCLES. 
Dissection. Remove Colles' fascia and bring into view the corrugator cutis ani, the 
external sphincter ani, the erector penis, the accelerator urinae, the superficial trans- 
versus perinsei, and levator ani. Compare the dissection with Fig. 133, and identify the 
structures. Study the attachment of Colles' fascia to the pubic ancl ischial rami and deep 
perineal fascia. 
The Corrugator Cutis Ani surrounds the anus and throws the skin into ridges. 
Internally, the fibres are inserted into the submucous tissue; externally, into the 
skin. Study this muscle with a dissecting microscope. 
The External Sphincter Ani (Fig. 133) is a voluntary muscle surrounding the 
anus, attached to the central perineal point and the tip of the coccyx. The 
fibres of this muscle are pierced by the longitudinal fibres of the rectum. 
Superficially, the external sphincter is in relation with the skin; deeply, with the 
Fig. 132. 
A transverse section of the pelvis, showing the pelvic fascia from behind. (Gray.) 
levator ani; externally, with the ischiorectal fat; internally, with the mucous 
membrane of the rectum. This muscle receives its blood-supply from the inferior 
hemorrhoidal, a branch of the internal pudic artery. Its veins terminate in the 
internal pudic vein. Its nerves are from the internal pudic and fourth sacral. 
The special function of the muscle is to close the anus in vomiting, parturition, 
urination, and expiration. 
The Erector Penis (Fig. 133) (musculus ischiocavernosus) partially covers the 
crus penis. Origin: (1) Pubic ramus and adjacent part of the crus; (2) inner 
surface of the ischial ramus and tuberosity. Insertion: Tunica albuginea of the 
corpora cavernosa, near the suspensory ligament of the penis. 
The Accelerator Urinae (Fig. 133), (musculus bulbo-cavernosus), covers the bulb 
of the corpus spongiosum, and lies between the two erector muscles of the penis. 
The muscle arises from the median raphe along the whole length of the bulb, and 252 
A MANUAL OF DISSECTION. 
is inserted by three sets of fibres: (1) Posterior, into the bulb and triangular 
ligament ;• (2) anterior, into the tunica albuginea of the corpora cavernosa; (3) 
median, into the dorsum of the penis. This muscle practically surrounds the 
bulb, and is to it what the hand is to the bulb of a syringe-a compressor. 
The Superficial Transversus Perinsei (Fig. 133) is variable in size and location, and 
accessory inaction to the accelerator urinae, since it fixes the raphe from which the 
fibres of this latter take origin. This muscle arises from the inner surface of the 
ramus and the tuberosity of the ischium. 
The Levator Ani Muscle (Figs. 132, 133), with its fellow of the opposite side, 
separates the pelvic cavity from the ischiorectal fossa, and forms the greater part 
of the muscular floor of the pelvis. It arises from (1) the inner surface of the 
spine of the ischium; (2) the posterior part of the body of the pubic bone, external 
to the symphysis pubis; (3) the white line. The muscle is invested above by the 
rectovesical fascia; below, by the anal fascia, and is inserted as follows: (1) The 
Fig. 133. 
The superficial muscles and vessels ot the perineum, (Gray.) 
posterior fibres, into the tip of the coccyx; (2) with the opposite muscle, into the 
median raphe; (3) into the side of the rectum, so as to interlace with its longi- 
tudinal muscular fibres. The fibres of the levator aui pass downward, backward, 
and inward to their insertion, giving the pelvic floor a sagging reality. Nerve : 
Fourth sacral supplies this and the coccygeus muscle. Action: (1) To elevate 
the pelvic floor; (2) to constrict the vagina; (3) to compress the rectum; (4) to 
aid in prostatic excretion. 
The Central Point of the perineum is tendinous, located one inch in front of the 
anus, and is a common meeting-place of the external sphincter ani, accelerator 
urinse, superficial transversus perinsei muscles, and triangular ligament. (Fig. 
132.) It corresponds to the lower margin of the triangular ligament, and is 
the objective point in perineal lithotomy. 
In Median Perineal Lithotomy the knife is thrust backward and slightly upward, 
and enters the membranous urethra between the bulb and prostatic urethra. (Fig. 
130 ) In operation the incision is one and a half inches long and divides skin, THE PEL VIC 0 UTLET. 
253 
Colles' fascia, external sphincter ani, ledge of triangular ligament, membranous 
urethra (and its compressor muscle), and a few twigs of the transverse perineal 
vessels and nerves. 
In Lateral Perineal Lithotomy the incision is about three inches long. It begins 
one and a half inches in front of the anus, and is carried into the ischiorectal fossa, 
midway between anus and tuberosity of ischium. The structures divided are 
skin, Colles' fascia, transverse perineal vessels and nerves, inferior hemor- 
rhoidal vessels and nerves, superficial and deep transversi perinsei muscles, trian- 
gular ligament, membranous urethra, prostatic urethra, lobe of the prostate (with 
its capsule), and the levator prostatse muscle. 
TRIANGULAR LIGAMENT. 
Dissection. Remove the sound from the bladder, make gentle upward and backward 
traction on the penis and cut through the corpus spongiosum just beyond the bulb of urethra 
where it rests on the middle perineal fascia. (Fig. 129.) Now turn aside the bulb and the 
outer layer of the triangular ligament appears. Detach with a sharp knife the two crura 
from their attachment to the pubes and ischium. Also remove with scissors the outer layer 
of the triangular ligament and expose the pudic vessels and nerves. (Fig. 133.) The 
deep perineal space is between the two layers of the triangular ligament. Identify its 
contents by comparison with the text. 
Triangular Ligament of the Urethra and deep periueal fascia are synonymous 
terms. This structure is a strong, double, fibrous membrane, which occupies the 
space under the pubic arch, being, therefore, a pelvic floor-structure. It consists 
of two layers-an anterior and a posterior. These are united at their lower 
borders; hence, on antero-posterior section the triangular ligament is V-shaped. 
The anterior (or outer) layer is, beyond doubt, periosteal in derivation and 
analogous to the obturator membrane; the posterior is morphologically a part of 
the obturator fascia, although its continuity is interrupted by the pubic bone. 
The triangular ligament is about one and a half inches in depth. The uses of this 
ligament are quite numerous, and its attachments and relations are of such a 
complicated nature that we must consider it analytically as follows : The anterior, 
or outer layer; the posterior, or inner layer; the deep perineal interspace; Colles' 
fascia and the superficial perineal space. 
The Anterior Layer of the Triangular Ligament is very firmly attached to the 
posterior lips of the ischiopubic rami, behind the crura penis. Above, it is laxly 
attached to the subpubic ligament; below, it is connected to the tendinous central 
point of the perineum, and is continuous externally with the fascia of Colles and 
internally with the posterior layer of the triangular ligament. The deep surface 
is intimately related to the compressor urethrae muscle; the superficial surface 
supports the bulb of the urethra, and forms the inner wall of the superficial 
perineal interspace. The anterior layer of the triangular ligament is perforated, 
as follows (1) one inch below the symphysis, for the membranous urethra; (2) for 
the dorsal nerves and arteries of the penis; (3) for the arteries of the bulb and 
corpus cavernosum; (4) for the ducts of Cowper's glands. The dorsal vein of 
the penis passes between the subpubic ligament and the apex of the triangular 
ligament. (See Gray's Anatomy, Fig. 595.) 
The Posterior Layer of the Triangular Ligament is a prolongation of the obturator 
fascia, being continuous below the symphysis with the corresponding layer of the 
opposite side. It is in relation with the deep transversus perintei muscle externally; 
internally, it forms, on each side, the floor of an anterior prolongation of the 
ischiorectal fossa. It is pierced by the internal pudic artery and vein and dorsal 
nerve of the penis. Posteriorly, it unites with the anterior layer, to form the 
perineal ledge. 
The Deep Perineal Space is between the anterior and posterior layers of the 
triangular ligament. In sagittal section this space is V-shaped, owing to the 
union, posteriorly, of the two layers of the triangular ligament. This space 254 
A MANUAL OF DISSECTION. 
contains (1) the membranous urethra, surrounded by a sphincter of smooth 
muscular fibre, the compressor urethrae; (2) Cowper's glands, with their ducts 
piercing the anterior layer of the triangular ligament; (3) the internal pudic 
arteries, giving branches to the bulb, Cowper's gland, and compressor urethrae, 
and breaking up into the artery to the corpus cavernosum and the dorsal artery 
of the penis; (4) the internal pudic veins and accompanying lymphatics; (5) the 
dorsal nerves of the penis, giving branches to the compressor urethrae, then 
piercing the anterior layer of the triangular ligament and passing to the dorsum 
of the penis; (6) the compressor urethrae (muscle of Guthrie, or deep transversus 
perinaei). 
The Compressor Urethrae arises from the ischiopubic ramus. The fibres run 
transversely across the subpubic angle, some behind, others in front of the mem- 
branous urethra. Action: (1) To assist expulsion of urine and semen; (2) to 
aid erection of the penis by compressing the dorsal veins; (3) to compress Cowper's 
glands and facilitate the discharge of their contents during seminal emission. 
ISCHIORECTAL REGION. 
Dissection. Dissect with blunt instruments the fatty space between the rectum and tuber- 
osity of the ischium. Do not injure the vessels and nerves traversing this space. Make trac- 
tion on one of the hemorrhoidal nerves and trace the same through the obturator fascia into 
Alcock's canal. Remove the fat from the under surface of the levator ani muscle and study 
the anal fascia investing the same. Examine the lower end of the rectum in the embrace of 
the levatores ani muscles. (Figs. 132, 133.) 
The Ischiorectal Region is triangular, and situated posterior to a line extending 
from tuberosity to tuberosity of the ischium. It contains a small part of the 
rectum, the external sphincter ani, and the ischiorectal fossse, of which latter there 
are two, separated from each other by the rectum. (Fig. 132.) Distinguish 
between the ischiorectal region and the ischio-rectal fossa; the former contains the 
latter. 
The Ischiorectal Fossse (Figs. 132, 133), as previously stated, are two in 
number, separated from each other by the rectum. In analysis we speak of one 
fossa only. The ischiorectal fossa has, (1) an apex, formed by the white line 
extending from the spine of the ischium to the pubic bone; (2) a base, formed by 
the skin, fasciae, and a small part of the gluteus maxim us muscle; (3) an outer 
wall, formed by a part of the ischium and the obturator interims muscle and 
fascia, below the white line; (4) an inner wall, formed by the levator ani and 
coccygeus muscles, covered by the anal fascia; (5) an anterior recess, extending 
forward as far as the symphysis, between the triangular ligament and levator ani, 
limited internally by the prostate and puboprostatic ligament, and externally, 
by the ischiopubic ramus; (6) a posterior recess, extending toward the sacrum, 
above the greater sacrosciatic ligament. The ischiorectal fossa contains fat and 
connective tissue, is traversed from outer to inner wall by the inferior hemorrhoidal 
vessels and nerves, for the supply of the external sphincter ani muscle and its 
investing and adjacent skin and fascise. 
Alcock's Canal (Fig. 132) is situated on the outer wall of the ischiorectal fossa. 
It is about two inches in length, extending from the lesser sacrosciatic foramen 
(along the inner surface of the tuberosity and ramus of the ischium) to the lower 
border of the triangular ligament. It is formed by a delamination of the obturator 
fascia. In the distal part of its course, the walls of the canal are strengthened 
by the falciform process of the greater sacrosciatic ligament. (See page 261.) 
Alcock's canal contains the internal pudic nerve and vessels, in transit to the 
perineum, rectum, and external organs of generation. 
The Internal Pudic Nerve (Fig. 134), (from the second, third, and fourth sacral), 
has a complex course, and is attended by the internal pudic vessels. It leaves 
the pelvis through the greater sacrosciatic foramen, below the pyriformis muscle, THE PELVIC OUTLET. 
255 
with the sciatic nerves and vessels. It crosses the lesser sacrosciatic ligament 
.(near the spine of the ischium) and re-enters the pelvis through the lesser sacro- 
sciatic foramen, internal to the pudic vessels. It enters Alcock's canal, gives off 
the inferior hemorrhoidal nerve, and divides into the perineal nerve and the 
dorsal nerve of the penis. The perineal nerve pierces the two layers of the 
triangular ligament, and supplies the erector penis, accelerator urinse, compressor 
urethrae, bulb of the urethra, superficial transverse perinsei muscles, scrotum, 
perineum, and skin on the under surface of the penis and around the anus. The 
dorsal nerve of the penis pierces the posterior layer of the triangular ligament, 
traverses the deep perineal space, then pierces the anterior layer of the triangular 
ligament, and (having supplied the corpora cavernosa) passes between the pubic 
bone and the crus penis; thence, it passes beneath or through the suspensory 
ligament of the penis, to skin of the dorsum of this organ. 
Fig. 134. 
External iliac vein of right side. (Gerrish after Testut.) 
The Rectum extends from the third piece of the sacrum to the anus. Its 
termination is in the ischiorectal part of the pelvic outlet, where its opening-the 
anus-is guarded (1) by the external sphincter ani, a voluntary muscle; (2) by 
the corrugator cutis ani. This latter muscle consists of longitudinal fibres of 
the rectum, which have piered the external sphincter and contracted cutaneous 
insertion fit the margin of the anus. 
The rectum has two segments : (1) An upper, three and a half inches long, 
extending from the third piece of sacrum to tip of coccyx; (2) a lower, one and 
a half inches long, extraperitoneal, and extending from tip of coccyx to anus. 
Relations: Behind, sympathetic nerve, sacrum, and coccyx; in front, bladder, 
prostate, trigone, and vesiculae seminales. In the female, the rectum is in relation 
in front with the upper part of the vagina and cervix uteri. Arteries: (a) 
Superior hemorrhoidal, from the inferior mesenteric; (6) middle hemorrhoidal, 256 
A MANUAL OF DISSECTION. 
from the internal iliac; (c) inferior hemorrhoidal, from the internal pudic. In 
the lower part of the rectum arteries are arranged longitudinally, but they com- 
municate freely near the anus. 
Hemorrhoidal Plexus of Veins. Venous blood is collected by veins which form 
a plexus between the mucosa and musculosa oE the rectum. In this plexus take 
origin three large veins, which correspond in name and location to the hemor- 
rhoidal arteries. From the manner in which these veins discharge two systems 
of venous circulation are recognized in the hemorrhoidal veins: (1) The portal, to 
which the superior hemorrhoidal belongs, because this vessel discharges into the 
inferior mesenteric vein, and its blood ultimately reaches the liver; (2) the iliac, to 
which the middle and inferior hemorrhoidal veins belong, because they discharge 
into the internal iliac vein; hence their contents reach the general venous circu- 
lation via the ascending vena cava, without interruption in the liver. The 
hemorrhoidal veins have no valves. In cirrhosis of the liver the inferior hemor- 
rhoidal veins become enlarged, and are known as piles, or hemorrhoids. 
FEMALE PELVIC OUTLET. 
Before dissection of the female pelvic outlet is begun remember (1) that the bony 
and ligamentous parts are practically the same as in the male; (2) that the outlet 
has an anterior triangular or perineal part, which contains the perineal body and 
external genito-urinary organs; and a posterior ischiorectal part, containing the 
rectum and ischiorectal fossae as in the male; (3) that the corpora cavernosa 
differ from their homologous structures in the male in size only; (4) that the 
corpus spongiosum is cleft or replaced by the vulvar orifice, and obtains, on 
each side of the vulvar cleft, as the erectile bulbi vestibuli; (5) that the 
accelerator urinae of the male obtains in the female homologically as the sphincter 
vaginae muscle; (6) that the clitoris is, in the main, a diminutive penis, and 
capable of erection. 
Homologies of the Sexual System. 
Male. . Female. 
Penis . Clitoris. 
Glans penis ..... . . Glans clitoridis. 
Preputium penis Preputium clitoridis. 
Fraenum . Labia minora. 
Scrotum ........ Labia majora. 
Testicle . . . * Ovary. 
Uterus masculinus Uterus and vagina. 
Vas deferens Duct of Gartner. 
Accelerator urinae Sphincter vaginae. 
Erectores penis . Erectores clitoridis. 
Tube of epididymis ...... Long tube of parovarium. 
Corpora cavernosa Corpora cavernosa. 
Corpus spongiosum Bulbi vestibuli and vulvar cleft. , 
Gubernaculum testis ...... Round ligament. 
Membrano-prostatic urethra .... Urethra, vestibule. 
Stalked hydatid of Morgagni .... Stalked hydatid of Morgagni. 
Sessile hydatid Fimbria of oviduct. 
Duct of Rathke Oviduct. 
Rete testis and coni vasculosi .... Short tubules of parovarium. 
Paradidymis Paroophoron. 
Cowper's glands ...... Bartholin's glands. 
The Mons Veneris (Fig. 135) is located above the symphysis, and after or about 
the time of puberty is covered with hair. It is continuous above with the skin 
and panniculus adiposus of the abdominal walls, below with the labia majora, and 
laterally, is limited by the genito-crural crease. The mons is composed of 
pigmented skin, fat, and connective tissue. THE PEL VIC 0 UTLET. 
257 
The Labia Majora (Fig. 135) are the most prominent parts of the vulva in the 
adult. They extend from themons to the posterior commissure of the vulva, which 
they form by their union posteriorly in the mid-vulvar line. They form an 
ellipse, enclosing the labia minora, bulbi vestibuli, meatus urinarius externus, 
vaginal fissure, clitoris, hymen, or its remains, the carunculae myrtiformes. 
Each major lip consists of skin, dartos, and a quantity of encapsulated fat, which 
latter blends above with the round ligament of the uterus. The labia are 
homologous to the scrotum; the round ligament to the gubernaculum testis. 
Each labium has (1) an outer pigmented surface, covered with crisp hair; (2) 
an inner surface, beset with rudimentary hair and sebaceous follicles. The dartos, 
or second covering of the labia majora, is not so fully developed as in its 
homologue, the scrotum. 
Fig. 135. 
Vulva of a virgin. The labia have been widely separated. (Gerrish after Testut.) 
The Labia Minora (Fig. 135) are homologous to the prepuce and fraenum, and 
are free from hair and fat. They unite above, embracing the clitoris, and 
forming both prepuce and fraenum; below, they end opposite the vaginal fissure. 
The minor lips are small before puberty and concealed by the major lips, except 
in the foetus. They reach their greatest size during pregnancy. 
The Vestibule (Fig. 135) is triangular, with its apex at the clitoris; the base is 
at the vaginal fissure; the sides are formed by the minor lips. It contains the 
meatus urinarius externus and the openings for the ducts of the glands of Bartholin 
-two racemose structures which represent Cowper's glands in the male. 
The Bulbi Vestibuli and Pars Intermedialis. On either side of the vestibule, 
beneath the mucous membrane, is a quantity of erectile tissue, the bulbi vestibuli, 
homologous to the bulb of the corpus spongiosum in the male. This is invested 
by the tunica albuginea, attached to the orifices of the urethra and vagina, and 
covered by fibres of the bulbo-cavernosus or sphincter muscle of the vagina. 258 
A MANUAL OF DISSECTION. 
The Clitoris (Fig. 135) is about one inch long, forms the apex of the vestibule, 
and is homologous to the penis. It is composed of two corpora cavernosa, which 
form distally the glans clitoridis by their union. The crura of the corpora 
cavernosa of the clitoris are attached to the ischiopubic rami, and bound to the 
symphysis pubis by the suspensory ligament of the clitoris. The clitoris has glans, 
corona and cervix, but no corpus spongiosum and urethra. The corpus spongiosum 
of the male is replaced by the vulvar orifice in the female. 
Interlabial Cleft. (Fig. 135, 136.) This is the common opening for the genital 
and urinary organs. It is limited above by the clitoris; below, by the posterior 
commissure or fourchette; laterally, by the minor and major labia. The floor of 
the space is formed by the vestibule, meatus urinarius, hymen, fossa navicularis, 
and vaginal orifice. 
Fig. 336. 
Muscles of the female perineum. (Gray.) 
The Female Urethra (Fig. 135) is about one and a half inches in length, and extends 
along the anterior wall of the vagina from the bladder to the vestibule of the vulva. 
It is a very dilatable canal, and, like the male urethra, is smallest distally. Laterally, 
and in front, it is surrounded by veins (plexus of Santorini), while posteriorly in 
the greater part of its course it lies about one-sixth of an inch from the vagina. 
The vesical end of the female urethra has muscular fibres, homologous to those of 
the prostate and deep transversus perinsei muscles. 
The Vagina is a musculomembranous conduit, extending from the cervix uteri, 
which it embraces, to the vulvar opening. It gives passage to the menstrual flow, 
to the mature or abortive product of conception, and is the female organ of copulation. 
The anterior wall is three, the posterior, four inches in length. (See Gray.) 
The Anterior Wall of the Vagina is in relation with the urethra and bladder; 
the posterior, with the perineal body, rectum, and peritoneal cul-de-sac of Douglas. 
Laterally, the vagina is crossed in its upper third by the ureters-a fact which 
should be borne in mind by the operator in vaginal hysterectomy; in its lateral 
lower two-thirds, the vagina is in relation with the levatores ani muscles. 
Laterally are located the vaginal arteries and a venous plexus. THE PEL VIC 0 UTLET. 
259 
The Vaginal Walls are one-sixth of an inch thick, and have three coats : (1) 
A fibrous, derived from the rectovesical fascia; (2) a non-striated muscular coat, 
consisting of a longitudinal layer (continuous with the uterus), and a circular 
layer, very strong, near the vulvar orifice; (3) a mucous, having no true glands, 
very elastic, and continuous with the mucous membrane of the os uteri and vulva. 
The striated sphincter vagi me muscle is homologous to the accelerator urime in 
the male. 
The Nerves of the Vagina are from the internal pudic, fourth sacral and hypo- 
gastric plexus. The arteries are from the external pudic, internal pudic, uterine, 
internal iliac, and middle hemorrhoidal. The vessels are arranged along the 
lateral aspect of the vagina. The veins form the vaginal plexus in the muscular 
and mucous coats, and finally reach the internal iliacs. 
The Perineal Body is situated between the genital canal and the rectum. It is 
bounded in front by the vagina and vulva; behind, by the anterior wall of the 
rectum; below, by the skin, between anal and vulvar apertures. The sphincter 
ani, levatores ani, sphincter vaginae, and central tendinous point of the perineum 
enter into its formation. 
Dissection. Observe the following steps after having learned the foregoing, including the 
table of homologues: 1. Place the cadaver in the same position, and care for the rectum as 
directed in the dissection of the male pelvic outlet. 2. Remove the hair from mons and labia 
majora with a sharp scalpel and scissors; then thoroughly cleanse the parts with soap and 
water. 3. Fill the vagina with cotton saturated with carbolized glycerin. 4. Grasp the 
glans clitoridis with forceps, withdraw it from its surrounding prepuce and secure it by a 
thread. 5. Remove the labia majora and observe their fatty composition blending with the end 
of the round ligament superiorly. 6. Remove the integument covering the clitoris and demon- 
strate this latter's glans, body, prepuce, and crura. 7. Pass a sound into the bladder and pal- 
pate anterior vaginal wall to appreciate the relation of the urethra to the vagina. 8. Remove 
the integument and demonstrate (a) the sphincter vagina, (6) the meatus urinarius, (c) the 
erectores clitoridis muscles investing the crura clitoridis, (d) the transversus perinsei muscles, 
(e) the external sphincter ani muscle and ischiorectal fossse. 9. After having read the text on 
the perineal body cut through the same from the vagina to the rectum and demonstrate its 
composition and relations. The vessels and nerves are homologous to the male structures and 
may be studied in the description of the male pelvic outlet, page 254. 
THE BONY PELVIS. 
Formation. The pelvis is formed by the sacrum, coccyx, ossa innominata, and 
certain ligaments. The sacrum is formed by the fusion of five, the coccyx of four 
vertebrae. The innominate bone is formed by the fusion of the pubis, ilium, 
and ischium, in such relation as to form the acetabulum at their place of meeting; 
the pubic part contributes one-fifth, the other parts two-fifths each, to the 
acetabular circumference. The individual bones forming the sacrum and coccyx 
have departed so far from a typical vertebra that they are called false vertebrae. 
The sacrum and coccyx are united by ligaments (analogous to those in the superior 
regions of the spine) in an amphiarthrodial joint, called the sacrococcygeal. 
This joint has its nerve-supply from the fourth and fifth sacral and coccygeal, 
and may be the seat of reflex pain incident to disease of any of the pelvic organs 
except the ovary. 
The Apex of the Sacrum articulates with the coccyx. The base of the sacrum 
(in the centre) is analogous to and articulates with the body of the fifth lumbar 
vertebra) laterally, the base of the sacrum expands to form the alse, which 
morphologically are the result of fusion of the transverse and costal processes of 
vertebrae. The promontory is an eminence formed by the union of the sacrum 
and the body of the fifth lumbar vertebra. 
The Anterior Surface of the Sacrum is concave both vertically and horizontally. 
On this surface are (1) parts corresponding to the bodies of vertebrae; (2) four anterior 
sacral foramina; (3) four transverse ridges. The foramina are large and give 
passage to the anterior primary divisions of the sacral nerves; they are continuous 260 
A MANUAL OF DISSECTION. 
outward, interrupting the plane surface of the bone, so that this latter presents an 
alternating succession of grooves and ridges. From the grooves and ridges, corre- 
sponding to the second, third, and fourth sacral vertebrae the pyriformis muscle 
originates. The value of the coccyx is not intrinsic, but consists in the impor- 
tance of soft structures attached to it. 
The Pubic Part of the Os Innominatum consists of a body and ramus. The ramus 
descends, fuses with the ramus of the ischium, and separates the subpubic arch 
from the obturator foramen. The body of the pubis contributes internally to the 
symphysis and externally to the acetabulum. The symphysis pubis is the junction 
between the right and left pubic bones. The pubic crest extends from the spine 
to the angle, is about one inch long, and gives attachment to the conjoined tendon, 
the pyramidalis, and rectus muscles. The spine of the pubis gives insertion to 
the crural arch or Poupart's ligament, and is crossed by the spermatic cord or its 
homologue, the round ligament of the uterus. 
Fig. 137. 
Articulations of the pelvis, rear view. (Gerrish after Testut.) 
The Ischium has a ramus, body, and tuberosity. The ischial ramus joins the pubic 
ramus to form the ischiopubic ramus. The body of the ischium enters into the 
formation of the acetabulum. The tuberosity of the ischium intervenes between 
the ramus and body, supports the body weight in the sitting posture, and 
gives origin to the hamstring muscles, adductor magnus, quadratus femoris, 
gemellus inferior, and obturator interims muscles. 
The Spine of the Ischium is on the inner border of the body, and separates the 
greater from the lesser sacrosciatic notch. From its outer surface arises the 
gemellus superior muscle. To its inner surface are attached the coccygcus and 
levator ani muscles, lesser sacrosciatic ligament, and the pelvic white line, from 
which latter the levator ani muscle gains its principal origin. 
Tip of the Coccyx. Notice the ease with which this bone may be moved forward 
and backward. It articulates with the sacrum, forming the sacrococcygeal joint. 
The external sphincter ani is attached to the tip of the coccyx, which may be 
demonstrated by pulling the coccyx forcibly backward, when the soft structures 
around the anus will be perceptibly put on the stretch. 
The Tuberosities of the Ischium are very prominent, about three inches to the 
right and left of the anus. When the cadaver is in the lithotomy position the THE PEL VIC 0 UTLET. 
261 
tuberosities are not covered by the gluteus maximus muscle, which, however, is 
the case when the long axis of the lower limb is in line with the long axis of the 
trunk. In the lithotomy position there is flexion of the thigh on the abdomen, flexion 
of the leg on the thigh, flexion of the foot on the leg, and abduction of the knees. 
The Bony Extension leading upward from the tuberosity of the ischium to the 
subpubic arch is the ischiopubic ramus. To the middle part of this is attached 
that part of the corpus cavernosum called the crus of the penis. 
The Symphysis Pubis is the junction between the bodies of the pubic bones. 
Surmounting the body of the pubic bone is the part called the pubic crest. This 
crest is limited internally by the angle and externally by the spine. It requires 
a little practice to locate the pubic spine; the spermatic cord either crosses or 
passes external to it. Make traction on one testicle and demonstrate the relation 
of the spermatic cord to the pubic spine. 
The Lesser Sacrosciatic Notch (Fig. 137) is between the spine and tuberosity of 
the ischium, and is converted into a foramen of the same name (in the recent state) 
by the greater sacrosciatic ligament. Through the foramen pass the tendon of the 
obturator internus muscle and the internal pudic nerve and vessels. 
The Greater Sacrosciatic Notch (Fig. 137) is between the spine of the ischium 
and the posterior inferior spine of the ilium. This notch is converted into a 
foramen by the lesser sacrosciatic ligament in the recent state. Through the fora- 
men pass the pyriformis muscle, which divides the same into an upper and a 
lower compartment; through the upper compartment pass the superior gluteal 
nerve and vessels; through the lower, the sciatic and internal pudic nerves and 
vessels. 
The Lesser Sacrosciatic Ligament (Fig. 137) is triangular. Its strength and 
importance as a pelvic floor structure are often underestimated. It is coexten- 
sive with an inconsiderable muscle, called the coccygeus, which occupies and 
is intimately blended with its inner surface. The ligament is firmly attached 
to the front and sides of the coccyx and sacrum, as high as the fourth anterior 
sacral foramen. The fibres of the ligament, converging to their insertion into 
the inner surface and borders of the spine of the ischium, decussate. This liga- 
ment converts the greater sacrosciatic notch into a foramen in the recent state. 
The Greater Sacrosciatic Ligament (Fig. 137) arises from the upper two pieces of 
the coccyx, the lower three pieces of the sacrum, the posterior iliac spines, and the 
posterior part of the iliac crest. It is inserted into the inner border of the 
tuberosity of the ischium, and is prolonged forward on the ramus of the ischium 
as the falciform process. The greater sacrosciatic ligament converts the lesser 
sacrosciatic notch into a foramen in the recent state. 
The Obturator Foramen (Fig. 137) is enclosed above and in front by the pubic 
part, behind and below by the ischial part of the innominate bone. It is covered 
by a membrane (save a small passage above)-the obturator groove. The obtu- 
rator membrane is periosteal in derivation, and bears the same relation to the 
pubis and ischium that interosseous membranes in general bear to the bones 
between which they are found. The outer surface of the obturator membrane 
is occupied by the external obturator muscle: the inner, by the internal obturator. 
The obturator groove transmits the obturator nerve and vessels. 
THE PELVIC FLOOR. 
Dissection. (1) Review carefully on the skeleton the osteological points given on a preced- 
ing page. (2) Cut sagittally through the pelvis with a saw, according to Fig. 134. (3) Thor- 
oughly cleanse the dissection field with warm water. (4) Study the interior of the bladder 
and rectum, which have been traversed by the cutting instrument. (5) Note the location of 
the ureters entering the bladder. (6) Note from four to six folds of the mucous membrane- 
the plica recti or Huston's valves-in the rectum. (7) Cut the rectum on a level with the 
pelvic floor, and turn the same onto the promontory of the sacrum. (8) Turn the bladder 
forward onto the pubic bone. (9) Remove the peritoneum from the sides of the pelvis, and 
with blunt dissection develop vessels and nerves as shown in Fig. 134. (10) Expose the 262 
.4 MANUAL OF DISSECTION. 
levator ani muscle and study its origin from the white line and its insertion into the mid-line 
of the pelvic floor where it embraces the rectum. (11) Now cut through the levator ani, 
turn the same aside, and expose the obturator internus muscle. 
The floor of the pelvis consists of the pyriformis, coccygeus, levator ani muscles, 
and triangular ligament. To these must be added the obturator internus and 
obturator fascia covering the same, not that this muscle figures directly as an 
integral part of the floor of the pelvis, but its fascia-the obturator-is of such 
far-reaching importance that any demonstration of the pelvic floor would be 
imperfect in the absence of a thorough knowledge of it. 
The Pyriformis Muscle arises from (1) the side of the front of the sacrum, between 
the first, second, third, and fourth anterior sacral foramina; (2) the great sacrosciatic 
ligament; (3) the bone at the upper part of the great sacrosciatic foramen. The 
muscle leaves the pelvis through the great sacrosciatic foramen, and is inserted 
into the upper border of the greater trochanter. In front of this muscle are the 
rectum, branches of the internal iliac artery, and the sacral plexus. Above the 
muscle, the superior gluteal nerve and vessels leave the pelvis; below, the sciatic 
and internal pudic nerves and vessels escape. 
The Coccygeus Muscle is supported by and blended with the lesser sacrosciatic 
ligament. It arises from the inner surface of the spine of the ischium, and is 
inserted into the side of the coccyx and the last two pieces of the sacrum. The 
muscle is triangular, with apex at the ischial spine. This muscle aids the levator 
ani in drawing the coccyx forward. Nerve: Fourth sacral. 
The Obturator Internus Muscle arises from (1) the body of the pubis; (2) the rami 
of the pubes and ischium; (3) the surface of bone behind the obturator foramen, 
corresponding to the acetabulum; (4) the inner surface of the obturator membrane; 
(5) the obturator and pelvic fasciae. The muscle leaves the pelvis through the lesser 
sacrosciatic foramen, is joined outside the pelvis by the two gemelli muscles, and is 
inserted into the crest of the greater trochanter. This muscle forms a thick pad 
on the lateral wall of the pelvis. 
The Obturator Fascia (Fig 132) derives its name from the obturator muscle, and 
forms the greater part of the general pelvic fascia. The lesser part covers the sacral 
plexus and pyriformis muscle, and is called the pyriformis fascia. The attachments 
of the obturator fascia to the bone are very extensive, but should be studied with bone 
in hand to be understood and remembered. It is attached in front to the back of 
the symphysis pubis ; below, to the inner margin of the tuberosity of the ischium 
and the lower border of the ischiopubic ramus; above, to the posterior lip of the 
pubic crest and the iliopubic line, as far as the sacroiliac articulation; behind, to 
the bony border of the greater sacrosciatic foramen. At the lesser sacrosciatic 
foramen the fascia passes out of the pelvis with the obturator internus muscle; 
hence this same channel is open for the passage of pus in case of extensive ischio- 
rectal abscess. The outer surface of the obturator fascia is in relation with the 
obturator internus muscle; the inner is divided by the " white line " into an upper 
or pelvic and a lower, or ischiorectal part. The upper part is above the " white 
line;" the lower, below. The lower part forms (1) the outer wall of the ischio- 
rectal fossa: (2) Alcock's canal, for the lodgement of the internal pudic nerve and 
vessels. The "white line" gives off two thin processes-the rectovesical fascia, 
which covers the upper surface of the levator ani muscle, and the anal fascia 
(ischiorectal), investing the under surface of the same muscle. 
The " White Line " is formed by a thickening of the obturator fascia along a line 
extending from the inner surface of the spine of the ischium to the posterior part 
of the pubic bone. This line is not straight, but conforms to the curve of the 
pelvic wall, to which it pertains. See page 252 for levator ani muscle. CHAPTER XIX. 
CUTANEOUS VESSELS AND NERVES OF THE LOWER EXTREMITY. 
Dissection. Having removed the skin locate the long saphenous vein (by consulting the 
illustration Fig. 138), and follow it and its tributaries by careful dissection with forceps and 
scissors as far as possible. As a rule, cutaneous veins and nerves are in the deep layer of the 
superficial fascia. Next locate the long saphenous nerve accompanying the long saphenous 
vein below the knee. Consult Fig. 139 as an aid in locating the short saphenous structures. 
To dissect the cutaneous nerves, consult Figs. 140 and 141, page 267, and study table on 
pages 265-268. 
CUTANEOUS VESSELS. 
The Cutaneous Vessels. Arteries convey blood from the heart to the skin ; 
veins, in an opposite direction, toward the heart. Cutaneous arteries are derived 
from the underlying deep arteries; they pierce the deep fascia and supply not only 
the skin, but the superficial and deep fasciae as well. Owing to their small size, but 
comparatively few cutaneous arteries and veins receive special names. Arteries 
having special names are : superficial epigastric, superficial circumflex iliac, and 
superficial external pudic. Veins having special names are : the long saphenous 
and the short saphenous. The long saphenous has the following tributaries : 
External femoral cutaneous, internal femoral cutaneous, superficial external pudic, 
superficial epigastric, superficial circumflex iliac, and deep communicating veins. 
Action and Source of Gray Rami Communicantes. Vessels derive their power 
of dilating and contracting, under certain conditions, from sympathetic nerves, 
called gray rami communicantes. These nerves originate in cells in the vertebral 
ganglia of the sympathetic, and pass with spinal nerves for the supply of bone, 
cartilage, fasciae and unstriped muscle fibre of hair, glands, and vessels. (See 
sympathetic nerve.) 
The Cutaneous Veins. (1) Digital, returning blood from the skin of the toes; 
(2) the dorsal arch of the foot, formed largely by the digital veins; (3) the long 
saphenous vein, tributary to the common femoral; (4) the external and internal 
femoral cutaneous; (5) the superficial external pudic; (6) the superficial epigastric ; 
(7) the superficial circumflex iliac; (8) veins communicating with deep veins; 
(9) the short saphenous, tributary to the popliteal. 
1. The Digital Veins (Fig. 138) are in the superficial fascia of the toes. They 
form, by their confluence, a venous arch on the back of the foot from which 
the long and short saphenous veins originate. 
2. The Dorsal Arch (Fig. 138) of the foot is homologous to the dorsal arch of 
the hand. It is situated on the back of the foot, about midway between the ends 
of the toes and the instep. The arch is formed by veins from the skin of the 
toes, has outer and inner ends, terminating respectively in the short and long 
saphenous veins and rests on the cutaneous nerves of the back of the foot. 
The arch communicates with the vena? comites of the dorsalis pedis artery by a 
deep communicating vein. 
3. The Long Saphenous (Fig. 138) is the largest and longest superficial vein in 
the body. It begins at the inner end of the dorsal arch of the foot, passes in 
front of'•the internal malleolus of the tibia, along the inner side of the leg to the 
knee, where it winds behind and internal to the inner tuberosity of the tibia and 
inner condyle of the femur. It now pursues an upward course on the front and 
inner aspect of the thigh, and having perforated the cribriform fascia covering 
the saphenous opening, becomes tributary to the common femoral vein. Below 
the knee, the vein is accompanied by the long saphenous nerve, a branch of the 
anterior crural. 264 
A MANUAL OF DISSECTION. 
Source of .Tributaries of Long Saphenous Vein. (Fig. 138.) (1) The 
external femoral cutaneous vein returns blood from the skin of the outer part of the 
thigh; (2) the internal femoral 
cutaneous, returns blood from the 
skin of the posterior and inner 
parts of the thigh; (3) the super- 
ficial external pudic, returns 
blood from the skin of the penis, 
scrotum, and inguinal region; 
'4) the superficial epigastric, 
returns blood from the skin of the 
abdominal walls, in the region of 
the umbilicus; (5) the superficial 
circumflex iliac, returns blood 
from the skin of the abdominal 
walls and upper part of the 
thigh; (6) frequent communica- 
tions with the deep veins in its 
entire course. 
4. The Short Saphenous Vein 
begins at the outer end of the 
dorsal arch of the foot, passes 
behind the external malleolus of 
the fibula, and gaining the pos- 
terior mid-line of the leg, passes 
between the two heads of the 
gastrocnemius muscle and opens 
into the popliteal. This vein is 
attended by the short saphenous 
nerve, formed by the union of 
the communicans tibialis and 
communicans fibularis. 
Source of Tributaries of 
Short Saphenous Vein. (1) 
Many small veins from the skin 
of the heel; (2) veins from the 
outer side of the foot and leg; 
(3) veins from the back of the 
leg; (4) communicating branches 
to the vense comites of the 
peroneal artery; (5) a branch from the posterior part 
of the thigh. The blood from the skin of the lower 
extremity, therefore, is collected by the two saphenous 
veins, and through these reaches the deep veins. 
CUTANEOUS NERVES. 
Dissection. The skin having been removed, according to 
incisions in Fig. 143, locate in the deep fascia the emergence 
points of the nerves (Figs. 140, 141, 142) and trace same by 
blunt dissection and scissors to their distribution. Having 
located any particular nerve, study its source, course, and 
distribution in the subjoined table. 
Cutaneous Nerves supply the skin with sensa- 
tion. They are dendritic processes of cells in the posterior root ganglia of the 
spinal nerves. They are derived from the thoracic, lumbar, and sacral regions 
Fig. 138. 
Fig. 139. 
External or short saphenous 
vein. (Gray,) 
The internal or long saphenous 
vein and its branches. (Gray.) CUTANEOUS VESSELS AND NERVES OF THE LOWER EXTREMITY. 
265 
as given in the following table, and are distributed as indicated in the illustra- 
tions on pages 267 and 268. Hilton demonstrated that nerve trunks supplying 
muscles that move joints also supply the joints with articular branches, and the 
skin covering the insertions of the muscles, with sensory branches. 
Cutaneous Nerves of Anterior and Lateral Regions. (Fig. 140.) 
Nerve. 
Source. 
Course. 
Distribution. 
Genito-crural 
First and second 
Passes in the femoral sheath 
To the integument of the 
(cutaneous branch) 
lumbar, branch 
anterior to the femoral 
central upper part of the 
(n. lumbo-inguinalis). 
of the genito- 
crural. 
artery and pierces the 
fascia lata. 
anterior surface of the 
thigh (motor branch to 
cremaster muscle). 
External cutaneous 
Second and third 
Enters the thigh beneath 
To the outer and posterior 
(n. cutaneus femoris 
lumbar, a di- 
Poupart's ligament near 
aspect of the thigh as far 
lateralis). 
vorced branch 
of the anterior 
crural nerve. 
the anterior superior 
iliac spine, and divides 
into anterior and poste- 
rior divisions ; descends 
beneath the fascia lata 
and perforates the deep 
fascia four inches below 
Poupart's ligament. 
as the knee. 
Internal cutaneous 
Second and third 
Divides in front of the 
Supplies the skin on the 
(ramus cutaneus 
lumbar, a branch 
femoral artery into an 
inner and anterior parts 
femoris). 
of the anterior 
crural nerve. 
anterior and a posterior 
branch; the anterior 
branch lies on the sarto- 
rius, and perforates the 
deep fascia in the lower 
third of the thigh; the 
posterior follows the 
inner border of the Sar- 
torius, and perforates the 
deep fascia near the 
knee. 
of the thigh as far as 
the knee. 
Middle cutaneous 
Second and third 
Pierces the deep fascia 
To the integument of the 
(ramus cutaneus 
lumbar, a branch 
about four inches below 
anterior part of the thigh 
anterior). 
of the anterior 
crural nerve. 
Poupart's ligament, and 
divides into two branches. 
as low as the knee. 
Ilio-inguinal 
First lumbar, a 
Lies in front of the sper- 
To the integument of the 
(n. ilio-inguinalis). 
branch of the 
ilioinguinal. 
mitic cord or its homo- 
logue in the inguinal 
canal; it escapes through 
the external abdominal 
ring. 
In Scarpa's triangle, ex- 
inner and upper part of 
the thigh ; to the 
scrotum or its homo- 
logue, the labia majora. 
Long saphenous 
Third and fourth 
To the skin of the front 
(n. saphenus). 
lumbar, ante- 
rior crural 
nerve. 
ternal to the femoral 
artery ; in Hunter1 s 
canal, crosses the femoral 
artery; pierces the deep 
fascia between the gra- 
cilis and sartorius, and 
accompanies the long 
saphenous vein belo v 
the knee. 
and inner side of the leg; 
to the patellar plexus; to 
the plexus on the inner 
side of the thigh formed 
by the obturator and 
internal cutaneous; to the 
ankle joint; to the inner 
side of ankle and foot. 
Musculocutaneous 
Fourth and fifth 
Given off with the anterior 
To dorsum of foot, great, 
(n. peroneus 
lumbar, a branch 
tibial, on the neck of the 
second, third, and one- 
superficialis). 
of the external 
popliteal. 
fibula; passes between 
the peronei muscles and 
extensor longus digito 
rum, and pierces the 
deep fascia on the front 
and outer side of the leg 
in its lower third; di- 
vides into internal and 
external branches. 
half of little toe (motor 
part supplies peroneus 
longus and peroneus 
brevis muscles). 266 
A MANUAL OF DISSECTION. 
Nerve. 
Source. 
Course. 
Distribution. 
Anterior tibial 
Fourth and fifth 
Given off with musculo- 
To adjacent surfaces of the 
(n. peroneus 
lumbar and first 
cutaneous, on neck of 
great and second toes; 
to ankle-joint (muscular 
profundus). 
sacral, a branch 
fibula, between peroneus 
longus and fibula; passes 
of the external 
branches to tibialis an- 
popliteal. 
beneath the extensor 
longus digitorum to the 
interosseous membrane, 
and reaches the outer 
side of the anterior tibial 
artery; in upper third of 
leg, external to artery; in 
middle third, on artery; 
in lower third, external 
to artery. 
ticus, extensor proprius 
hallucis, extensor longus 
digitorum and peroneus 
tertius). External branch 
to extensor brevis digi- 
torum, to tarsal and 
metatarsophalangeal 
joints of second, third, 
and fourth toes, and 
second dorsal interosseous 
muscle. The internal 
branch supplies the first 
dorsal interosseous 
muscle, metatarsopha- 
langeal joint of great 
toe, and adjacent surfaces 
of great and second toes). 
Lateral cutaneous 
External popliteal 
Pierces the deep fascia 
To the skin of the outer 
(ramus cutaneous 
or peroneal. 
near the neck of the 
side and upper two-thirds 
surge lateralis). 
fibula. 
of the leg. 
Cutaneous Nerves of Posterior Region and Sole of Foot. (Figs. 141, 142.) 
Nerve. 
Source. 
Course. 
Distribution. 
Small sciatic (n. cu- 
First, second, and 
Leaves the pelvis through 
To the back part of the 
taneus femoris 
third sacral, a 
divorced branch 
of the great 
sciatic, and 
may be adher- 
ent to the sheath 
of the inferior 
gluteal. 
the greater sacrosciatic 
thigh as far down as the 
posterior). 
foramen below the pyri- 
formis muscle, and behind 
the great sciatic nerve. 
lower part of the poplit- 
eal space ; to scrotum or 
its homologue, as the in- 
ferior pudendal ; to outer 
part of thigh, femoral 
cutaneous branches; to 
skin covering lower half 
of gluteus maximus 
muscle. 
Cutaneous branch of 
Fourth sacral, a 
Pierces the levator ani; 
To the integument between 
pudic (n. clunii). 
branch of nerve 
to levator ani. 
appears in the ischio- 
rectal fossa anterior to 
the coccyx. 
the anus and coccyx. 
Perforating cutaneous 
nerve (n. perforans). 
Fourth sacral. 
Pierces the great sacro- 
sciatic ligament. 
To the skin of the buttock, 
near the median line and 
below the distribution of 
the dorsal divisions of 
the sacral nerves. 
Dorsal cutaneous 
Sacral nerves, 
Pierce the gluteus maxi- 
To the skin in the region 
(nn. clunium 
three in num- 
mus in a line extending 
of the sacral origin of 
medii).- 
ber, from poste- 
rior primary 
divisions. 
from the posterior supe- 
rior iliac spine to the tip 
of the coccyx. 
the gluteus maximus. 
Dorsal cutaneous 
Lumbar nerves, 
Cross crest of the ilium 
To the skin of the upper 
(nn. clunium 
superiores). 
three in num- 
ber, posterior 
primary divi- 
sions. 
external to the iliac 
origin of the erector 
spinse muscle, and 
descend vertically. 
gluteal region. 
Lateral cutaneous 
Iliohypogastric, 
Crosses the crest of the 
To the integument of the 
(n. cutaneus 
lateralis). 
first lumbar. 
ilium and descends 
vertically. 
upper gluteal region, 
anterior to the distribu- 
tion of dorsal branches 
of the lumbar nerves. 
Lateral cutaneous 
Twelfth dorsal, 
Crosses the crest of the 
To the skin of the gluteal 
(n. intercostalis 
anterior 
ilium and descends 
region, anterior to the 
distribution of ilio- 
hypogastric. 
xii). 
primary divi- 
sion. 
vertically. CUTANEOUS VESSELS AND NERVES OF THE LOWER EXTREMITY. 
267 
Nerve. 
Source. 
Course. 
Distribution. 
Short saphenous 
First and second 
Pierces the deep fascia in 
To back of leg; to outer 
(n. suralis). 
dorsal, commu- 
the middle third of the 
part of ankle, heel, and 
nicans poplitei 
posterior surface of the 
foot as far forward as the 
and communi- 
leg ; accompanies the 
little toe; to the astrag- 
cans peronei, 
short saphenous vein 
alo-calcaneal articula- 
branches of the 
internal and ex- 
ternal popliteal 
nerves, respec- 
tively. 
down the back of the 
leg to the outer side of 
the ankle and foot. 
tion. 
Fig. 140. 
Fig. 141. 
Areas of distribution of cutaneous nerves of the front of the 
lower limb. (Gerrish after W. Keiller after Testut.) 
Areas of distribution of the cutaneous nerves 
of the back of the lower limb. (Gerrish after 
Testut.) 268 
A MANUAL OF DISSECTION. 
Nerve. 
Source. 
Course. 
Distribution. 
External plantar, cu- 
External plantar 
Pierce the plantar fascia 
To the skin of the anterior 
taneous branches 
branch of pos- 
with the corresponding 
two-thirds of the sole of 
(n. plantaris 
lateralis). 
terior tibial. 
vessels, between the 
abductor minimi digiti 
and flexor brevis digi- 
torum. 
the foot, corresponding to 
the little and one-half 
of the adjacent toe ; also 
to the skin of the same 
toe on the dorsal surface 
around the nail. 
Internal plantar, cu- 
Internal plantar, 
Pierce the plantar fascia 
To the skin of the anterior 
taneous branches 
a branch of the 
with corresponding 
two-thirds of the sole of 
(n. plantaris 
posterior tibial 
vessels between the 
the foot corresponding to 
medialis). 
nerve. 
abductor hallucis and 
flexor brevis digitorum. 
the inner 3.5 toes; also 
to the skin of the same 
toes around the nail. 
Internal calcanean 
Calcaneo-plantar, 
Pierce the internal annular 
To the skin of the heel and 
branches (rami 
calcanei mediates). 
a branch of the 
posterior tibial. 
ligament. 
sole as far forward as 
the distribution of tlie 
plantar nerves. 
Fig. 142. 
Areas of distribution of the cutaneous nerves of the sole of foot. (Gerrish after W. Keiller ) CHAPTER XX. 
THE ILIAC REGION. 
Dissection and Identification. Remove the peritoneum by careful manipulation and 
read iliac and pelvic fasciae, p. 272. To dissect the lumbar plexus (Fig. 145), study relation of 
its nerves to the psoas, then dissect longitudinally through the psoas magnus until the 
plexus is fully developed and can be demonstrated. To dissect the sacral plexus (Fig. 147), 
remove the parietal branches of the internal iliac artery and dissect through the pelvic fascia 
covering the plexus and pyriformis muscle. 
Bifurcation of Aorta. (Fig. 147.) Identify (1) by the location on and a little to the left 
of the body of the fourth lumbar vertebra ; (2) by the two large arteries-common iliacs- 
derived therefrom. 
Ascending Vena Cava. Identify (1) by its location on the vertebral column, to the right 
of the aorta ; (2) by its formation, the confluence of the common iliac veins; (3) by its blue 
color, flabby walls, and flattened appearance. 
Right Common Iliac Artery. (Fig. 132.) Identify (1) by its crossing the confluence of the 
common iliac veins; (2) by the formation, the confluence of the internal and external 
iliac arteries, opposite the sacro-iliac joint; (3) by its attending vein of same name and course. 
External Iliac Artery. (Fig. 132.) Identify (1) by its location along the pelvic brim, 
extending from the sacro-iliac joint to Poupart's ligament; (2) by the derivation of the 
deep epigastric and deep circumflex iliac arteries therefrom ; (3) by its attending vein of 
same name and course. 
Internal Iliac Artery. (Fig. 132) Identify (1) by its location on the outer wall of 
the pelvis between the bifurcation of the common iliac and great sacrosciatic foramen; (2) by 
its distribution to the pelvic organs and region of the hip; (3) by its attending vein of same 
name. Identify its branches by illustrations and description in text. 
Fascia Transversalis. Identify (1) by its location immediately beneath the parietal 
peritoneum ; (2) by its special features in areas described in text, page 272. 
Psoas Magnus Muscle. (Fig. 143.) Identify (1) by its extensive attachment to the twelfth 
thoracic and all the lumbar vertebrae; (2) by its insertion with the iliacus into the lesser 
trochanter; (3) by its relation to the genito-crural, obturator, iliohypogastric, ilio-inguinal, 
external cutaneous, and anterior crural nerves. (Fig. 145.) 
Lumbar Plexus and Branches. Identify (1) by the location of the plexus in the substance 
of psoas magnus muscle; (2) by the distribution of the branches according to the table 
dealing therewith on pages 274-276. 
Sacral Plexus. Identify (1) by its location on the sacrum and pyriformis muscle (Fig. 
147); (2) by its triangular shape and extending as low as the greater sacrosciatic foramen; 
(3) by its formation-the lumbosacral cord and subsequent sacral nerves. Identify its 
branches by description of same given in the table on pages 278-280. 
ILIAC VESSELS AND BRANCHES. 
The iliac vessels are : (1) Common iliac arteries and veins; (2) external iliac 
arteries and veins; (3) internal iliac arteries and veins. These are bilaterally 
located and designated right and left. The common iliac arteries begin at the 
bifurcation of the abdominal aorta, on the fourth lumbar vertebra, and end at the 
sacro-iliac joint in the external and internal iliac arteries. Each common iliae 
artery is about two inches long. 
The Right Common Iliac Artery crosses the confluence of the common iliac veins. 
In front of the artery are the ureter, small intestine, and branches of the sympathetic; 
to the outside, the vena cava, psoas magnus muscle, and right common iliac vein. 
The- Left Common Iliac Artery is crossed by the ureter, superior hemorrhoidal 
artery, and sympathetic nerves, and covered by the small intestine. The left 
common iliac vein is behind and internal to the artery. The psoas magnus 
muscle is external to it. The common iliac arteries give small branches to the 
psoas, ureters, and peritoneum. 
The Common Iliac Veins correspond to the common iliac arteries, and occupy a 
plane posterior to them. The left is beneath both left and right common iliac 270 
A MANUAL OF DISSECTION. 
arteries; the right, behind and external to its corresponding artery. The common 
iliac veins are formed by the external and internal iliacs, and form by their conflu- 
ence, on the fourth or fifth lumbar vertebra, the beginning of the ascending vena 
cava. 
The External Iliac Artery (Fig. 134) begins at the bifurcation of the common iliac, 
opposite the sacro-iliac joint, and ends under Poupart's ligament, in the common 
femoral artery. On the right side, the artery is in relation with the ileum; on 
the left, with the sigmoid flexure. The genito-crural nerve is on the outer side, 
the external iliac vein on the inner. Branches: Deep epigastric, deep circumflex 
iliac. (Fig. 133.) 
The External Iliac Vein (Fig. 134) begins under Poupart's ligament and ends in 
the common iliac, opposite the sacro-iliac joint. This union takes place beneath 
the internal iliac artery. Branches: Deep epigastric and deep circumflex veins. 
The Internal Iliac Artery (Fig. 134) begins at the bifurcation of the pommon 
iliac, and ends opposite the great sacrosciatic foramen, in anterior and posterior 
branches. It is about one inch long. It is covered by the peritoneum and crossed 
by the ureter. (Fig. 124.) In the adult, this artery is smaller than the external 
iliac; in the embryo, much larger, and gives origin to the hypogastric, which 
conveys blood to the placenta. Behind the internal iliac artery lie the internal 
iliac veins, the pyriformis muscle, and the lumbosacral cord. 
The Internal Iliac Vein (Fig. 134) joins the external to form the common iliac. 
It is short and extends from the greater sacrosciatic foramen to the sacro-iliac joint. 
It is behind and internal to its artery. With the exception of the umbilical vein, 
which in the adult is vestigial, the tributaries of the internal iliac vein correspond 
to those of the internal iliac artery. Branches: Iliolumbar, lateral sacral, gluteal, 
hypogastric, superior vesical, middle vesical, inferior vesical, middle hemorrhoidal, 
uterine, vaginal, obturator, sciatic, internal pudie. 
Branches of the Internal Iliac Artery. 
The Iliolumbar branch (Fig. 134) passes between the obturator nerve and the 
lumbosacral cord, crosses behind the common iliac artery, and thence between the 
psoas muscle and vertebral column. At the pelvic brim it divides into an iliac 
and a lumbar branch. The iliac branch supplies the ilium and iliacus muscle, 
and anastomoses with the obturator, lumbar, gluteal, external, and deep circumflex 
iliac arteries. The lumbar branch supplies the psoas and quadratus lumborum 
muscles, anastomoses with the lumbar arteries, sends off spinal arteries, and is 
analogous to the lumbar arteries. 
The Lateral Sacral branches (Fig. 134) are two in number-upper and lower. 
The upper branch enters the first anteriqr sacral foramen, supplies the spinal 
membranes, and leaves the sacral canal through the posterior sacral foramina to 
supply the skin over the sacrum. The lower branch descends internal to the 
anterior sacral foramina to the coccyx, and anastomoses with the middle sacral 
artery. It gives off branches to the rectum, sacral plexus, spinal cord, and 
muscles of the pelvic floor. 
The Gluteal Artery (Fig. 134) is the largest branch of the internal iliac. 
It passes between the first sacral nerve and the lumbosacral cord, and leaves the 
pelvis through the greater sacrosciatic foramen, above the pyriformis muscle, with 
the superior gluteal nerve. It divides (external to the pelvis) into a superficial 
branch, which lies between the gluteus maximus and medius, and a deep branch, 
which lies between the gluteus medius and minimus. (Fig. 157.) The superficial 
branch supplies the gluteus maximus. In the pelvis, branches are distributed to 
the pelvic bones, levator ani, coccygeus, obturator internus, and pyriformis. The 
gluteal artery anastomoses with the lateral sacral, circumflex, and sciatic arteries. 
The Hypogastric Artery is the most important artery in the fcetus, but in the 
adult it is vestigial. In the foetus it conveys blood to the placenta. It passes THE ILIAC REGION. 
271 
along the side of the pelvis, enters the false ligament of the bladder, and passes 
with the urachus to the umbilicus. The umbilical vein returns the blood from the 
placenta, and obtains in the adult as the round ligament (ligamentum teres) of 
the liver. (Fig. 120.) 
The Superior Vesical Artery (Fig. 134) is the unobliterated part of the hypo- 
gastric, and supplies the bladder, vas deferens, uterus, ureter, and occasionally 
gives off the middle vesical. 
The Middle Vesical Artery (Fig. 134), as previously stated, may be a branch of 
the superior vesical; it usually rises separately from the internal iliac, however, 
and is distributed to the bladder. 
The Inferior Vesical (Fig. 134) branch supplies the bladder, and arises from the 
internal iliac with the middle hemorrhoidal artery. It gives branches to the 
prostate, vesiculae seminales, vagina, and sometimes an artery to the vas deferens. 
The Middle Hemorrhoidal branch supplies the rectum, and arises with the inferior 
vesical. It anastomoses above with the superior, and below with the inferior 
hemorrhoidal. 
The Uterine branch arises near or with the middle hemorrhoidal. It runs in 
the infundibulo-pelvic ligament, crosses the ureter one-half inch external to the 
cervix, turns upward, becomes tortuous, and anastomoses with the uterine branch 
of the ovarian artery. 
The Vaginal branches are three or four in number. They arise separately from 
the internal iliac, or may even come from the uterine, inferior vesical, or middle 
hemorrhoidal. They pass to the side of the vagina and anastomose with the 
artery of the cervix and with the arteries of the opposite side. The lower vaginal 
arteries anastomose with the internal pudic in the bulb of the vagina-bulbi 
vestibuli. 
The Obturator (Fig. 134) is below the brim of the pelvis, with the obturator 
nerve. It lies between the peritoneum and the pelvic fascia, and is crossed 
by the vas deferens. It leaves the pelvis through the obturator canal. Branches: 
Iliac to the ilium, vesical to the bladder, pubic to the pubes, muscular to the 
obturator muscles, articular to the ligamentum teres and synovial membrane of 
the hip-joint. The artery anastomoses with the deep epigastric, internal circum- 
flex, and sciatic. 
The Sciatic branch (Fig. 134) crosses the sacral plexus and pyriformis muscle 
escapes from the pelvis behind the internal pudic artery, through the greater sacro- 
sciatic foramen, and anastomoses with the internal circumflex and profunda. 
Branches within the pelvis are : to the rectum, bladder, prostate, vesiculte semi- 
nales, and muscles of the floor of the pelvis. Branches outside of the pelvis are : 
coccygeal, inferior gluteal to the gluteus maximus, muscular to the external 
rotators, articular to the hip, cutaneous to the skin over the gluteus maximus, 
comes nervi ischiadici, which anastomoses with the internal circumflex and the 
four perforating branches of the profunda. In ligation of the femoral artery, 
the parts below may receive blood through this anastomotic channel. 
The Internal Pudic (Fig. 134) branch leaves the pelvis through the greater 
sacrosciatic foramen, below the pyriformis muscle, and crosses the outer surface of 
the spine of the ischium. It re-enters the pelvis through the lesser sacrosciatic 
foramen, and enters Alcock's canal in the outer wall of the ischiorectal fossa; it 
traverses this latter to the posterior layer of the triangular ligament, which it 
perforates. Between the two layers of the triangular ligament it gives off the 
artery of the bulb, the artery of the corpus cavernosum, and the dorsal artery 
of the penis. These three arteries pierce the anterior layer of the triangular 
ligament. The pudic artery in Alcock's canal gives off the inferior hemorrhoidal 
artery, crosses the spine of the ischium and gives branches to the obturator 
internus and gluteus maximus. 272 
A MANUAL OF DISSECTION. 
GENERAL FASCIA TR ANS VERS ALIS. 
The general fascia transversalis lines the pelvic and abdominal cavities. It is 
dense and thick over the iliacus and obturator interims muscles; thin on the 
under surface of the levator ani and diaphragm; and fairly strong where it forms 
test-tube-like prolongations about vessels and organs leaving the pelvis-the 
femoral sheath and infundibuliform fascia. Subdivisions : (1) That part covering 
the anterior and lateral abdominal walls is called the transversalis fascia; (2) that 
Fig. 143. 
Psoas, iliacus, and obturator externus muscles. (Gerrish after Testut.) 
lining the back part of the abdominal cavity and covering the psoas and iliacus 
muscles-the iliac fascia; (3) that lining the true pelvis both above and below 
the white line-the pelvic fascia. (See dissection of abdominal walls for trans- 
versalis fascia, page 203.) 
The Iliac Fascia consists of two portions : (1) that covering the psoas muscles; 
(2) that covering the iliacus muscle. Since this fascia determines the course of 
purulent discharges in lumbar abscesses, its attachments and also its prolongations 
out of the pelvic cavity must be thoroughly learned. 
Attachments of the Iliac Fascia. The iliac fascia covering the psoas njuscle 
is attached (1) to the ligamentum arcuatum internum of the diaphragm (Fig. 97); THE ILIAC REC ION. 
273 
(2) to the bodies and transverse processes of the vertebras; (3) to the upper part 
of the sacrum; (4) to the lumbar fascia, covering the quadratus lumborum muscle. 
The two portions-psoas and iliac-are continuous below the iliac crest. The 
portion of the iliac fascia covering the iliacus muscle is attached (1) to the inner 
lip of the crest of the ilium; (2) to Poupart's ligament, external to the femoral 
vessels; (3) to the iliac and pubic parts of the iliopectineal line; (4) to the pubic 
portion of the fascia lata, posterior to the femoral vessels. The iliac fascia behind 
the femoral vessels is prolonged out of the pelvis, and forms the posterior part of 
the femoral sheath; the anterior part of this sheath is derived from a prolongation 
of the transversalis fascia. The iliac fascia is prolonged into the thigh with the 
iliacus and psoas muscles. 
In psoas abscess pus is directed by the attachments of the iliac fascia into the 
deep part of the thigh, along the common tendon of the psoas and iliacus muscles. 
From here it is directed by the internal intermuscular septum of the fascia lata 
into the lower third of the thigh, whence it may burrow into the popliteal space 
and ultimately reach the ankle by passing between the superficial and deep layers 
of muscles of the back of the leg. (See fascia lata, page 286.) 
The Pelvic Fascia is that part of the general fascia transversalis which lines the true 
pelvis both above and below the pelvic floor. It is attached to the anterior surface 
of the sacrum, the brim of the pelvis, the lower part of the symphysis, and the sur- 
face of bone around the obturator internus muscle. A prolongation of this fascia 
accompanies the obturator internus muscle through the lesser sacrosciatic foramen. 
Obturator and Rectovesical Portions. (Fig. 132.) The pelvic fascia divides 
along a line extending from the spine of the ischium to the lower part of the 
symphysis pubis, into an obturator and a rectovesical portion. The place of divi- 
sion is called the white line, and gives origin to the levator ani muscle. (Fig. 
147.) The obturator fascia below the white line covers the obturator internus 
muscle, on the outer wall of the ischiorectal fossa, and also invests the under surface 
of the levator ani muscle, forming the anal fascia. The rectovesical portion of the 
pelvic fascia descends on the upper surface of the levator ani muscle to the rectum, 
bladder, and prostate. (See dissection of pelvic organs and pelvic outlet.) 
Canal for the Pubic Nerve and Vessels. (Fig. 132.) The obturator fascia on the 
outer wall of the ischiorectal fossa splits to form a canal for the pudic nerve and 
vessels. This canal is about an inch above the inner border of the tuberosity of the 
ischium, and extends from the lesser sacrosciatic foramen to the triangular 
ligament. All branches of the internal iliac artery, on emerging from the pelvis, 
are surrounded by tubular prolongations of pelvic fascia, just as the femoral 
vessels derive their sheaths from the transversalis and iliac fasciae. 
MUSCLES OF THE ILIAC REGION. 
Psoas Magnus. (Fig. 143.) Origin: (1) Intervertebral cartilages, between the 
twelfth thoracic and first lumbar vertebra; (2) sides of the bodies of the twelfth 
thoracic and all the lumbar vertebrae. Insertion: Lower and back part of the lesser 
trochanter of the femur. Action : Flexion of the thigh on abdomen. Synergists: 
Iliacus, pectineus, sartorius. Nerves: Second and third lumbar. The lumbar 
plexus is in the fleshy part of this muscle. The psoas is covered by the peritoneum 
and (a thin layer of) the iliac fascia. The lumbar part of the sympathetic 
gangliated cord lies along the inner margin of the psoas, obscured on the right 
by the ascending vena cava; on the left, by the abdominal aorta. (Fig. 145.) 
Behind the psoas muscle are the lumbar arteries and veins, four in number, on 
either side, analogous to the intercostal vessels. 
The Psoas Parvus. (Fig. 143.) This muscle is often absent. Origin: Side 
of the intervertebral disk, between the twelfth thoracic and the first lumbar and 
the adjacent borders of the same vertebrae. Insertion: Iliopectineal line. 
Action : To flex the pelvis on the thorax. Nerve : First lumbar. 274 
A MANUAL OF DISSECTION. 
The Iliacus. (Fig. 143.) Origin: (1) Wing of the sacrum; (2) iliolumbar, 
lumbosacral, and anterior sacro-iliac ligaments; (3) upper and outer half of the 
ventral surface of the ilium. Insertion : Back of lesser trochanter and back of 
femur, below lesser trochanter. Action: A flexor of the thigh. Synergists: 
Iliacus, pectineus, and sartorius. Antagonists: The gluteal muscles. Nerve: 
Anterior crural. Artery: Iliolumbar branch of the internal iliac. 
THE LUMBAR PLEXUS (PLEXUS LUMBALIS). 
This plexus of nerves is in front of the transverse processes of the lumbar 
vertebne in the substance of the psoas magnus muscle. (Fig. 145.) It is formed by 
the union of the anterior primary divisions of the first, second, third, and fourth 
lumbar nerves and a branch of the twelfth thoracic. (Fig. 144.) The plexus 
communicates with the twelfth thoracic nerve, through the dorsilumbai- nerve; 
with the sacral plexus, through the lumbosacral cord; with the lumbar part of 
the sympathetic, through both the gray and white rami communicantes. 
Fig. 144. 
The names, source, course, and distribution of the several branches of the 
lumbar plexus may be studied from the following table : 
Plan of lumbar plexus. (Gerrish after W. Keiller.) 
Table of Branches of Lumbar Plexus. 
Branch. 
Source. 
Course. 
Distribution. 
Iliohypogastric 
(n. iliohypogastricus). 
First lumbar. 
Crosses the quadratus 
lumborum. 
Sensory to gluteal and hypogastric 
regions. 
Ilio-inguinal 
(n. ilio-inguinalis). 
First lumbar. 
Crosses the quadratus 
lumborum. 
Sensory to the upper and inner 
parts of the thigh,contiguous to 
the scrotum, and to the integu- 
ment of the scrotum or its 
homologue. 
Genito-crural 
First and second 
Descends on the psoas 
Motor, to the cremasteric muscle ; 
(n. genitofemoralis), 
dividing into a 
genital and a crural 
branch-n. sperm- 
aticus and n. lumbo- 
inguinalis, respec- 
tively. 
lumbar. 
and divides into two 
branches on same. 
Genital branch 
passes through the 
inguinal canal 
behind the cord or 
its homologue; the 
crural branch accom- 
panies the external 
iliac artery. 
sensory to the skin of the upper 
part of the thigh in the region 
of the femoral vessels, near the 
distribution of the external 
cutaneous nerve; vasomotor to 
the femoral artery. THE ILIAC REGION. 
275 
Branch. 
Source. Course. 
Distribution. 
External cutaneous 
Second and Or >sses the iliacus, 
third lumbar. leaves the pelvis 
Sensory to the postero-extern al 
(n. cutaneous 
part of the thigh. It may be 
femoris lateralis). 
beneath Poupart's 
ligament below the 
anterior superior 
iliac spine. 
considered a dismembered part 
of the anterior crural nerve. 
Fig. 145. 
Deep and superficial dissection of the lumbar plexus. (Gerrish after Testut.) 
Obturator 
Second, third, 
Runs along lateral 
Sensory, to knee and hip ; motor, 
(n. obturatorius). 
and fourth 
lumbar. 
wall of pelvis above 
obturator vessels, 
and escapes into the 
thigh through the 
obturator canal. 
to adductor muscles of thigh 
and occasionally to pectineus 
muscle; vasomotor, to_ femoral 
artery. 
Accessory obturator 
Third and 
Inner border of psoas ; 
Sensory, to hip-joint; motor, to 
(n. obturatorius 
accessorius). 
fourth lumbar. 
crosses the horizontal 
ramus of the pubic 
bone; passes under 
the pectineus and 
divides into 
numerous branches. 
pectineus muscle. The nerve 
is often absent. 276 
A MANUAL OF DISSECTION. 
Branch. 
Source. 
Course. 
Distribution. 
Anterior crural 
Second, third, 
Passes between the 
Sensory, to hip-, knee-, and ankle- 
(n. fem oralis). 
and fourth 
lumbar. 
psoas and iliacus; 
enters the thigh 
beneath Poupart's 
ligament external 
to the femoral 
vessels. 
joints through articular 
branches; sensory, to inner 
part of leg and foot through 
long saphenous; sensory, to 
front surface of thigh through 
internal and middle cutaneous 
nerves; motor, to pectineus, 
sartorius, and quadriceps 
extensor cruris, through 
muscular branches. 
Muscular branches to 
certain polymeric 
muscles (rami 
musculares). 
Whole plexus. 
Direct into substance 
of muscles to which 
they are distributed. 
Motor, to psoas, iliacus, and 
quadratus lumborum muscles. 
Dissection and Identification. First remove the peritoneum and the thin layer of fascia, 
if this has not been previously done, and study the following branches with relation to the 
psoas magnus muscle (Fig. 145): 
1. The genito-crural nerve emerges from the inner border of the psoas muscle, descends 
on the same, and divides into two branches-genital and crural. 
2. The obturator and accessory obturator nerves emerge from the inner border of the 
muscle; the latter may be absent. The obturator nerve crosses the lateral pelvic wall 
below the brim and escapes through the obturator canal into the adductor region of the thigh. 
3. The iliohypogastric, ilio-inguinal, external cutaneous, and anterior crural nerves emerge 
from the outer border of the psoas; the two former cross the quadratus lumborum; the 
two latter cross the iliacus. The anterior crural, the largest branch beneath Poupart's liga- 
ment, is in a groove between the psoas and iliacus muscles. (Fig. 143.) 
Specific Distribution of Branches of Lumbar Plexus. 
The Iliohypogastric Nerve arises from the first lumbar nerve and emerges from the 
outer border of the psoas magnus. It crosses the quadratus lumborum, perforates 
the transversalis muscle, and divides into its two terminal branches between this 
muscle and the internal oblique. Branches: (1) The iliac-a lateral cutaneous- 
crosses the crest of the ilium and supplies the skin over the upper gluteal region 
(Fig. 141); (2) the hypogastric (Fig. 109) pierces the internal and external oblique 
musclesand supplies the skin of the hypogastric region; (3) muscular branches to 
the internal oblique and transversalis; (4) gray rami communicantes. 
The Ilio-inguinal Nerve arises from the first lumbar, in common with the ilio- 
hypogastric. It emerges from the outer border of the psoas and crosses the 
quadratus lumborum. It perforates the transversalis muscle and lies between 
this and the internal oblique. Near the internal abdominal ring, this nerve 
pierces the internal oblique muscle and passes along the inguinal canal in front 
of the spermatic cord. It leaves the inguinal canal through the external 
abdominal ring and divides into the following branches (Fig. 109): (1) Iliac 
and inguinal, to skin of the scrotum and adjacent upper part of skin of the thigh; 
(2) muscular, to the internal oblique and transversalis muscles; (3) communi- 
cating, to the iliohypogastric; (4) gray rami communicantes. 
The Genito-crural Nerve arises from the first and second lumbar, lies on the 
psoas muscle to the outer side of the external iliac artery. It divides into the 
following branches: (1) A genital, which passes through the inguinal canal, 
behind the spermatic cord, to the cremaster muscle; (2) a crural, which passes 
in front of the femoral artery in the femoral sheath, to the skin of the upper, 
front, and central parts of the thigh; (3) gray rami communicantes. 
The External Cutaneous Nerve arises from the second and third lumbar nerves, 
crosses the iliacus muscle, leaves the pelvis below the anterior superior iliac spine 
(Fig. 151), and gives off: (1) Cutaneous, anterior and posterior, to skin of the outer 
part of the thigh; (2) nerves to the patellar plexus; (3) gray rami communicantes. 
This nerve may be regarded as a divorced cutaneous branch of the anterior crural. THE ILIAC REGION. 
277 
The Anterior Crural Nerve (Fig. 145) arises from the second, third, and fourth 
lumbar nerves. It passes downward in the psoas muscle to Poupart's ligament, 
where it lies in a groove between the psoas and the iliacus muscle. It leaves the 
pelvis beneath Poupart's ligament, one-half inch to the outer side of the femoral 
sheath, and enters Scarpa's triangle. (Fig. 151.) 
The branches of the anterior crural nerve are divided into an anterior and a 
posterior set by the external circumflex artery. (Fig. 152.) In the anterior set 
are said to be the middle cutaneous, internal cutaneous, and muscular branches to 
the pectineus and sartorius muscles; in the posterior set the long saphenous, artic- 
ular branches to the hip, knee, and ankle, and muscular branches to the rectus, 
vasti, and crureus. Branches to the iliacus muscle and the femoral artery are given 
off within the pelvis. 
Summary of Articular Branches of the anterior crural nerve : (1) To the hip-joint, 
from the muscular branch to the rectus femoris; (2) to the knee-joint, from 
muscular branches to the vastus internus; (3) to the ankle-joint, from the long 
saphenous nerve. 
The Obturator Nerve arises from the third and fourth lumbar nerves. It passes 
between the psoas muscle and the fifth lumbar vertebra, and crosses the outer wall 
of the pelvis to the obturator foramen. The nerve divides, external to the 
pelvis, into an anterior and a posterior division. (Fig. 151.) The anterior divi- 
sion crosses the obturator externus, passes between the pectineus and adductor 
brevis, and gives off (1) an articular branch, to the hip; (2) a branch, to the 
femoral artery; (3) a cutaneous twig, to the subsartorial plexus; (4) muscular 
branches, to the adductor longus, brevis, gracilis, and pectineus muscles. The 
posterior division gives branches to (1) the hip; (2) the knee; (3) muscular 
branches, to the obturator externus and adductor magnus muscles. 
The Accessory Obturator Nerve, when present, arises from the third and fourth 
lumbar nerves, passes along the inner border of the psoas, and gives off (1) 
articular branches, to the hip; (2) branches to the pectineus muscle; (3) gray rami 
communicantes. 
Muscular Branches are given off in the substance of the psoas magnus to the 
iliacus, quadratus lumborum, psoas magnus and psoas parvus muscles. 
Blood-supply. The lumbar plexus derives its nourishment from the lumbar 
branches of the iliolumbar arteries. 
Polymeric Nerve-supply of Muscles. Some muscles-as the pectorals, latissimus 
dorsi, external and internal oblique, transversalis, rectus abdominis, psoas, 
quadratus lumborum, and iliacus-are derived from more than one myotome, and 
"muscles derived from more than one myotome are innervated by nerves derived 
from the ventral roots belonging to more than one neurotome." (Barker: The 
Nervous System.) 
Rami Communicantes. The upper lumbar nerves are connected to the vertebral 
ganglia of the sympathetic by both gray and white rami communicantes; the lower 
by gray only. "The gray rami communicantes are distributed to the spinal 
nerves, and in them reach the vessels, fasciae, and bones for which they are 
destined." (Gerrish.) For the purpose of impressing this principle on the student, 
gray rami are considered in this book as accompanying each spinal nerve. 
(See sympathetic nerve.) 
THE SACRAL PLEXUS (PLEXUS SACRALIS). 
The sacral plexus (Figs. 146, 147) is formed by the union of the lumbo- 
sacral cord and the anterior primary divisions of the first, second, third (and 
a part of the fourth) sacral nerves. The lumbosacral cord (Fig. 146) is formed 
by the anterior primary division of the fifth lumbar nerve and a part of the fourth; 
the fourth lumbar nerve, therefore, contributes to both lumbar and sacral plexuses. 
The sacral plexus is triangular in shape, its base corresponding to the exit 278 
A MANUAL OF DISSECTION. 
foramina of the lumbar and sacral nerves entering into its formation, and its apex 
to the greater sacrosciatic foramen. The plexus rests on the wing (ala) of the 
sacrum and the anterior surface of the pyriformis muscle, and is covered by the 
pelvic fascia. (Fig- 147.) The nerves of the sacral plexus receive their nourish- 
ment through small arteries, called vasa nervorum, from the lateral sacral 
branches of the internal iliac artery. 
Communications of the sacral plexus (Fig. 145) are with the lumbar plexus 
above, through the lumbosacral cord; with the fifth sacral nerve below; with 
the sacral part of the sympathetic, through gray rami communicantes. 
Fig. 146. 
Plan of sacral plexus. (G'errish.) 
The names, source, course, and distribution of the branches of the sacral plexus 
may be studied in the following table : 
Table of Branches of Sacral Plexus. 
Branch. 
Source. 
Course. 
Distribution. 
Muscular (ramus 
muscularis). 
First and second 
sacral. 
Direct. 
Motor, to pyriformis. (Fig. 146.) 
Muscular (ramus 
Firstand second 
Leaves the pelvis through 
Motor, to obturator internus 
muscularis). 
sacral and 
lumbosacral 
cord. 
the great sacrosciatic 
foramen; re-enters 
through the lesser 
sacrosciatic foramen. 
muscle; distributed to the 
inner surface. (Fig. 146.) 
Muscular (ramus 
First and second 
Through the greater sacro- 
Motor, to the gemellus superior. 
muscularis). 
sacral and 
lumbosacral 
cord 
sciatic foramen as a part 
of the nerve to the 
obturator internus. 
(Fig. 146.) 
Muscular (ramus 
First sacral and 
Through the greater sacro- 
Motor, to the gemellus inferior 
muscularis). 
lumbosacral 
cord. 
sciatic foramen; beneath 
tendons of gemelli and 
obturator internus. 
and quadratus femoris ; 
distributed to their deep 
surfaces ; sensory, to the hip- 
joint. 
Superior gluteal 
First sacral and 
Through the greater sacro- 
Motor, to gluteus medius, gluteus 
(n. glutseus 
lumbosacral 
sciatic foramen above the 
minimus, and tensor vaginae 
superior). 
cord. 
pyriformis. 
femoris. (Fig. 146.) THE ILIAC REGION. 
279 
Branch 
Source. 
Course. 
Distribution. 
Inferior gluteal 
First and second 
Greater sacrosciatic fora- 
Motor, to gluteus maximus; 
(n. gluteus 
sacral and 
men beneath the 
distributed to the under surface 
inferior). 
lumbosacral 
cord. 
pyriformis. 
of the muscle. (Fig. 146.) 
Perforating 
Second and 
Perforates the great sacro- 
Sensory, to the skin of the but- 
cutaneous 
(n. cutanei per- 
forantes). 
third sacral. 
sciatic ligament. 
tocks. 
Pudic 
Third and 
Through the greater sacro- 
1. Perineal branch is sensory to 
(n. pudendus). 
fourth sacral; 
sciatic foramen beneath 
skin of scrotum or its homo- 
occasionally, 
also, first and 
second sacral. 
(Fig. 146 ) 
the pyriformis muscle; 
crosses the spine of the 
ischium and re-enters 
the pelvis through the 
lesser sacrosciatic fora- 
men ; passes along Al- 
cock's canal in the outer 
wall of the ischiorectal 
fossa (Fig. 132), and di- 
vides into: 1. Perineal. 
2. Dorsal nerve of penis. 
3. Inferior hemor- 
rhoidal. 
logue; sensory to urethra; 
vasomotor to corpus spongiosum; 
motor to accelerator urinse, 
superficial transversus perinei, 
erector penis, external sphincter 
ani, levator ani, and deep in- 
ternal transversus perinei, or 
compressor urethrae. 
2. Dorsal nerve of penis is sensory 
to glans, prepuce, dorsum, and 
sides of penis ; vasomotor to 
corpora cavernosa. 
3. The inferior hemorrhoidal 
crosses the ischiorectal fossa, 
and is sensory to skin around 
anus. 
Small sciatic 
Second and 
Through the great sacro- 
1. Perineal cutaneous branches to 
(n. cutaneus 
femoris 
posterior). 
(Fig. 160.) 
third sacral. 
sciatic foramen beneath 
the pyriformis muscle. 
perineum and upper, inner 
posterior part of thigh. 2. The 
inferior pudendal supplies the 
scrotum or its homologue with 
sensation. 
2. Femoral cutaneous branches 
supply the inner and outer as- 
pects of the thigh posteriorly as 
far as its middle third ; middle 
part of posterior aspect of thigh, 
popliteal region, and upper 
third of posterior part of leg. 
2. The ascending cutaneous 
branches supply the skin of 
the gluteus maximus with sen- 
sation. 
Great sciatic 
First, second, 
Through the great sacro- 
1. Main trunk gives articular 
(n. ischiadicus). 
and third 
sciatic foramen with the 
branches to the hip-joint; 
This nerve divides 
sacral and 
inferior gluteal nerve, 
motor branches to the biceps, 
in the upper part 
lumbosacral 
the small sciatic nerve, 
semitendinosus, semimembrano- 
of the popliteal 
cord. (Fig. 
the sciatic vessels and the 
sus, and adductor magnus 
space into internal 
and external 
popliteal nerves. 
(Fig. 160.) 
146.) 
pudic nerve and vessels ; 
beneath the pyriformis, 
it rests between the 
tuber ischii and greater 
trochanter of the femur. 
muscles. 
Internal popliteal 
Begins in the 
Passes through the centre 
1. Articular, three in number, to 
knee-joint. 2. Communicans 
(n. tibialis). 
upper part of 
of the popliteal space 
(Fig. 160.) 
the popliteal 
space at the 
bifurcation of 
the great 
sciatic nerve. 
vertically downward, and 
ends in the upper part of 
the leg in the posterior 
tibial nerve. 
tibialis, which joins communi- 
cans fibularis to form short 
saphenous (n. suralis). 3. Mus- 
cular (rami musculares) to 
gastrocnemius, plantaris, soleus 
and popliteus. 
Posterior tibial 
Begins at the 
Passes between the super- 
1. Motor, to tibialis posticus, 
(n. tibialis). 
lower part of 
ficial and deep groups of 
flexor longus digitorum, flexor 
(Fig. 160.) 
the popliteal 
space as a 
continuation 
of the internal 
popliteal. 
muscles of the back of 
the leg downward and 
slightly inward, to the 
inner part of the ankle, 
where it divides into the 
internal and external 
plantar. 
longus hallucis, and all muscles 
of sole (through its plantar 
branches). 2. Articular (rami 
articulares) to ankle-joint. 3. 
Calcaneo-plantar (internal cal- 
canean) to integument of heel 
and inner side of sole. 4. In- 
ternal plantar (n. plantaris 
medialis). 5. External plantar 
(n. plantaris lateralis). 280 
A MANUAL OF DISSECTION. 
Branch. 
Source. 
Course. 
Distribution. 
Internal plantar 
Begins beneath 
Passes between the first 
1. Cutaneous (nn. plan tares) to 
(n. plantaris 
the internal 
and second layers of the 
skin of sole. 2. Muscular 
medialis). 
annular liga- 
muscles of the sole to 
(nn. musculares to abductor 
(Fig. 142.) 
ment as a 
terminal 
branch of the 
posterior 
tibial. 
the toes. 
hallucis and flexor brevis digi- 
torum. 3. Articular (nn. 
articulares) to tarsal and meta- 
tarsal joints. 4. Digital 'nn. 
digitales plantares proprii 
(four), (a) To inner border of 
great toe and flexor brevis 
hallucis. (6) To adjacent sides 
of first and second toes and first 
lumbrical muscle, (c) To ad- 
jacent sides of second and third 
toes, (d) To adjacent sides of 
third and fourth toes and 
receives filament from external 
plantar. (e) Articular (from 
digital cutaneous branches) to 
joints of the toes. 
External plantar 
Begins beneath 
Passes between the first 
1. Muscular (rami musculares) to 
(n. plantaris 
the internal 
and second layers of the 
flexor accessorius, abductor 
lateralis). 
annular liga- 
muscles of the sole to 
minimi digiti, interossei (except 
(Fig. 142.) . 
Notice: "This 
distribution of 
digital branches 
to the toes from 
the plantar nerves 
is precisely similar 
to that of the 
median and ulnar 
nerves in the 
hand." (Gray.) 
ment as a 
terminal 
branch of the 
posterior 
tibial. 
the toes.' 
those of the fourth space), three 
outer lumbricales, adductor 
obliquus hallucis, and adductor 
transversus hallucis. 
2. Cutaneous to little toe and outer 
half of adjacent one. Each 
digital cutaneous branch fur- 
nishes articular branches to the 
joints. 
3. Articular (from digital cuta- 
neous nerves) to joints of toes. 
External popliteal 
Begins in the 
Passes downward and out- 
1. Articular (three in number) 
(n. perongeus 
upper part of 
ward along the tendon of 
to the knee. 
communis). 
the popliteal 
the biceps, leaves the 
2. Cutaneous, to back and outer 
parts of leg in upper and 
middle thirds. 
3. Communicans fibularis (n. 
cutaneus surge lateralis), which 
joins communicans tibialis (n. 
cutaneussurgemedialis), to form 
short saphenous. 
4. Anterior tibial (n. perongeus 
profundus. 
5. Musculocutaneous (n. perongeus 
superficialis). 
(Fig. 160.) 
space at the 
bifurcation of 
the great 
sciatic. 
popliteal space between 
the biceps tendon and 
outer head of the gas- 
trocnemius muscle, runs 
behind the head of the 
fibula, turns inward on 
the neck of the fibula, 
and divides into several 
branches. 
Short saphenous 
Begins by union 
The nerve (or its constitu- 
1. Cutaneous, to back of leg, outer 
(n. suralis). 
of communi- 
ent parts) pierces the 
part of ankle, heel, and foot as 
(Figs. 139 and 
cans tibialis (n. 
deep fascia at a variable 
far forward as the little toe. 2. 
162.) 
cutaneus surge 
medialis) and 
communicans 
fibularis (n. 
cutaneus surge 
lateralis) from 
internal and 
external pop- 
liteal nerves, 
respectively. 
distance below the knee. 
Articular to astragalo-calcanean 
articulation. 
Anterior tibial 
Begins as a 
Passes deeply down front 
1. Motor (rami musculares) to all 
(n. peronaeus 
branch of the 
of the leg with anterior 
muscles of anterior part of the 
profundus). 
external pop- 
tibial artery, and gives 
leg and to the first dorsal inter- 
(Fig. 166.) 
liteal on the 
neck of the 
fibula with the 
musculo- 
cutaneous. 
otf its branches. 
osseous and extensor brevis 
digitorum muscles. 
2. Cutaneous to skin between 
great and second toes (nn. 
digitales dorsales hallucis 
laterales et digiti secundi 
medialis). (Fig. 140.) 
3. Articular (rami articulares) to 
ankle, tarsal, and metatarso- 
phalangeal joints. THE ILIAC REGION. 
281 
Branch. 
Source. 
Course. 
Distribution. 
Musculocutaneous 
Begins as a 
Passes through the sub- 
1. Motor (rami musculares) to 
(n. peronaeus 
branch of the 
stance of the peroneus 
peroneus longus and brevis 
superficialis). 
external pop- 
longus muscle, and 
muscles. 
(Fig. 166.) 
liteal on the 
neck of the 
fibula with the 
anterior tibial. 
divides into its terminal 
branches. 
2. Sensory, to outer side of leg 
and dorsum of foot. 
Fig. 147. 
Sacral plexus of the right side. (Gerrish after Testut.) 
Specific Distribution of Branches of Sacral Plexus. 
Pyriformis. (Fig- 146.) The nerve- to this muscle arises from the first and 
second sacral nerves. It leaves the pelvis through the great sacrosciatic fora- 
men, crosses the spine of the ischium, enters the pelvis through the lesser sacro- 
sciatic foramen, and is distributed to the internal surface of the muscle. 
Obturator Internus. (Fig. 146.) The nerve to this muscle arises from the first 
and second sacral nerves and lumbosacral cord. It leaves the pelvis through the 
great sacrosciatic foramen, re-enters the pelvis through the lesser sacrosciatic 
foramen, and is distributed to the inner surface of the muscle. 
Gemellus Superior. (Fig. 146.) The nerve to this muscle arises from the first 
and second sacral nerves and the lumbosacral cord. It leaves the pelvis through 
the great sacrosciatic foramen as a part of the nerve to the obturator internus, 
and reaches the gemellus superior, external to the pelvis. 
Gemellus Inferior and Quadratus Femoris. (Fig. 146 ) These two muscles are 
supplied by the same nerve, which arises from the first sacral nerve and the 282 
A MANUAL OF DISSECTION. 
lumbosacral cord. It leaves the pelvis through the great sacrosciatic foramen 
and passes beneath the tendons of the gemellus and obturator interims, to the 
quadratus femoris. Twigs from this nerve are given off to the gemellus inferior 
as the nerve passes beneath the tendons of the gemelli and obturator internus 
muscles. This nerve gives a branch to the hip-joint. 
The Superior Gluteal Nerve (Fig. 146) arises from the lumbosacral cord and 
first sacral nerve. It leaves the pelvis with the superior gluteal vessels through 
the greater sacrosciatic foramen, above the pyriformis muscle, and gives off (1) 
muscular branches to the gluteus medius, gluteus minimus, and tensor vagime 
femoris; (2) sympathetic branches-gray rami communicantes-to bone, ligament, 
fasciae and vessels in the course of the superior gluteal. (Fig. 162.) 
The Inferior Gluteal Nerve arises from the first, second, and third sacral and 
fifth lumbar nerves. It leaves the greater sacrosciatic foramen below the pyri- 
formis muscle with the sciatic and pudic vessels and nerves, and gives muscular 
branches to the gluteus maximus and gray rami communicantes to bone, ligament, 
fasciae, and vessels in its course. (Fig. 162.) 
The Perforating Cutaneous Nerve (Fig. 141) arises from the second and third 
sacral nerves. It perforates the greater sacrosciatic ligament, and supplies 
the integument covering the lower and inner parts of the gluteus maximus 
muscle. 
The Pudic Nerve (Figs. 144, 147, and 154) arises from the third and fourth 
sacral nerves. It leaves the pelvis through the greater sacrosciatic foramen, 
crosses the spine of the ischium, and re-enters the pelvis through the lesser sacro- 
sciatic foramen, where it enters Alcock's canal (Fig. 132), in the outer wall of 
the ischiorectal fossa, and breaks up into three terminal branches-the hemor- 
rhoidal, perineal, and dorsal nerve of the penis. Each of these three nerves has 
a definite course and distribution, as follows : 
The Inferior Hemorrhoidal pierces the inner wall of Alcock's canal, crosses the 
ischiorectal fossa with vessels of like name, and is distributed to the skin 
around the anus. 
The Perineal Branch divides into cutaneous and muscular parts. The cutaneous 
part-the superficial perineal nerve-leaves Alcock's canal in the anterior portion 
of the ischiorectal fossa, pierces the base of the triangular ligament, and is dis- 
tributed to the skin of the scrotum or its homologue, the labia majora. 
The Dorsal Nerve of the penis pierces the posterior layer of the triangular liga- 
ment and traverses the deep perineal space along the inner margin of the ramus 
of the pubic bone; it then pierces the anterior layer of the triangular ligament, 
gives a vasomotor branch to the corpus cavernosum, lies between the crus penis 
and pubic bone, and passes to the dorsum of the penis. It supplies the integument, 
glans, and prepuce of the penis or its homologue, the clitoris. 
The Small Sciatic Nerve (Fig. 160) arises from the first, second, and third sacral 
nerves, and leaves the pelvis through the great sacrosciatic foramen, below the 
pyriformis muscle, in company with the great sciatic nerve and sciatic vessels, infe- 
rior gluteal nerve, internal pudic nerve and vessels. Branches: (1) Perineal 
cutaneous, to the skin of the upper, inner, and posterior aspects of the thigh and 
perineum (the inferior pudendal, the longest of these branches, crosses the tuber- 
osity of the ischium to supply the scrotum); (2) the femoral cutaneous branches 
supply the inner, central, and outer sides of the posterior part of the thigh and 
also the skin of the popliteal space and upper third of the posterior part of the 
leg; (3) the ascending cutaneous branches of the small sciatic supply the skin 
over the gluteus maximus. 
The Great Sciatic has the most extensive distribution of any nerve in the body. 
It supplies (1) the leg; (2) the flexor and extensor muscles of the knee; (3) the 
adductor magnus, in part; (4) the hip, knee, ankle, and joints of the foot. The. 
main trunk gives off certain articular and muscular branches, and then divides 
into the internal and external popliteal divisions, which, as the following table 
shows, have a number of branches each: THE ILIAC REGION. 
283 
1. Branches of main trunk 
Articular, to hip. 
Muscular, to flexors of knee and adductor 
magnus. 
Articular, to knee-joint. 
Muscular, to popliteus and superficial group of 
muscles of posterior part of leg. 
Communicans poplitei, to short saphenous. 
The posterior tibial and its branches. 
2. Branches of internal popliteal 
Articular, to knee-joint. 
Cutaneous branches, to leg. 
The communicans popliteal, to short saphenous. 
The anterior tibial and its branches. 
The musculocutaneous and branches. 
3. Branches of external popliteal 
Branches of the Main Trunk. (Fig. 162.) Articular branches to the hip are 
given off immediately after its exit from the pelvis. They perforate the posterior 
part of the capsule of the joint with the articular branches of the sciatic artery. 
Muscular Branches (Fig. 162) are given off in the upper third of the thigh, to 
the adductor magnus, semitendinosus, semimembranosus, and long head of the 
biceps; in the middle third, to the short head of the biceps. 
The Internal Popliteal (Fig. 163), the larger of the two terminal divisions of the 
great sciatic, passes through the centre of the popliteal space, and ends beneath the 
fibrous arch of the soleus muscle, in the posterior tibial nerve. In the upper part 
of the popliteal space the nerve is external to the popliteal vessels; opposite the 
knee it crosses to the inner side of the same. Its branches are : 
(a) Articular, to the knee-joint, three in number-superior internal, superior 
external, and azygos. 
(6) Muscular, to the gastrocnemius, soleus, plantaris, and popliteus, given off 
between the two heads of the gastrocnemius muscle. 
(c) The communicans poplitei unites with the coramunicans peronei, a branch 
of the external popliteal, to form the short saphenous, for the supply of the'integu- 
ment of the posterior part of the leg and the outer surface of the foot. (Fig. 141.) 
(d) The posterior tibial nerve (Fig. 163) is a continuation of the internal popliteal. 
It begins at the lower part of the popliteal space beneath the fibrous arch of the 
soleus muscle, and ends in the plantar nerves, beneath the internal annular ligament 
at the ankle. In the upper third of its course the nerve crosses from the inner to 
the outer side of the posterior tibial vessels. In the lower third of the leg, the 
posterior tibial nerve and vessels are very superficial and lie parallel to the inner 
margin of the tendo-Achillis. Branches: Muscular, to the flexor longus digitorum, 
flexor longus hallucis, tibialis posticus; the internal calcanean (a cutaneous branch) 
accompanies an artery of the same name, and supplies the skin and fasciae of the 
heel and a part of the sole; articular, to the ankle; internal and external plantar 
nerves for the supply of the bottom of the foot. These latter nerves are 
accompanied by arteries of the same name, and are found in a neurovasal area 
between the first and second layers of muscles of the sole of the foot. 
The External Popliteal Nerve (Figs. 163, 166) begins at the bifurcation of 
the great sciatic with the internal popliteal nerve, in the superior angle of the 
popliteal space, and lies in contact with the biceps tendon, on the outer wall of the 
space. At the knee the nerve lies between the biceps tendon and the outer head 
of the gastrocnemius muscle, and ends on the neck of the fibula. Branches: 
(1) The superior and inferior external articular; (2) the recurrent articular, to 
head of the tibia, the knee, and superior tibiofibular articulation; (3) the com- 
municans peronei, unites with the communicans poplitei (a branch of the internal 
popliteal) to form the short saphenous nerve; (4) the musculocutaneous, which 
begins on the neck of the fibula, passes downward in the substance of the peroneus 
longus, and gives off muscular branches to the peroneus longus and brevis, a 
cutaneous branch to the skin of the dorsum of the foot, and gray rami comrau- 
nicantes to bone, fasciae, and vessels; (5) the anterior tibial, which begins on the 284 
A MANUAL OF DISSECTION. 
neck of the fibula, passes through the peroneus longus, intermuscular septum, and 
extensor longus digitorum, descends on the interosseous membrane, between the 
extensor longus digitorum and tibialis anticus. Branches of anterior tibial: (a) 
Muscular, to the tibialis anticus, extensor proprius hallucis, extensor longus digi- 
torum, and one or more dorsal interossei; (6) articular, to the tarsal, metatarso- 
phalangeal, and interphalangeal joints; (c) cutaneous, to the skin of the adjacent 
sides of the great and second toes (Fig. 140); gray rami communicantes, to bone, 
fasciae, and vessels. 
Relations of the Great Sciatic. (Fig 160.) Superficial: long head of the 
biceps, gluteus maximus, small sciatic nerve, fasciae, and integument; deep: 
ischium, tendon of the obturator internus, gemelli, quadratus femoris, and 
adductor magnus. The comes nervi ischiadici (the proper artery of the great 
sciatic nerve), a branch of the sciatic artery, anastomoses with the first, second, 
third, and fourth perforating branches of the profunda and internal circumflex. 
The Visceral Branches of the sacral plexus (Fig. 146) arise from the third and 
fourth sacral nerves, and represent the white rami communicantes in the thoracic 
region. There are no white rami communicantes in the sacral region, except 
those from the thoracic and lumbar regions (See Gerrish.) Distribution: To 
the longitudinal muscle fibre of the bladder; longitudinal muscle fibre of the 
rectum; circular inhibitory fibres of the rectum; motor fibres of the uterus; 
secretory fibres of the prostate gland; vasodilator fibres for the erectile tissue of 
the penis. 
The Nerve to the Quadratus Femoris (Fig. 146) and gemellus inferior arises from 
the fourth and fifth lumbar and first sacral nerves. It leaves the pelvis through 
the greater sacrosciatic foramen (below the pyriformis muscle), passes under the 
obturator internus tendon and the gemelli, and gives muscular branches to the 
gemellus inferior and quadratus femoris, and gray rami to bone, fasciae, and vessels. 
The Anterior Primary Divisions of the Fifth Sacral and coccygeal nerves unite 
with the fourth sacral, and form a small plexus behind the second part of the 
rectum. Branches : (a) To the hypogastric plexus; (6) to the posterior part of the 
coccyx. (Fig. 146.) CHAPTER XXI. 
THE ANTERIOR FEMORAL REGION. 
Dissection. The superficial vessels and nerves having been dissected (pages 263-268), 
proceed now to remove all fat and superficial fascia, in order to make exposure of the deep 
fascia. Consult the illustration and identify structures 
in the order in which they are given in the text. 
Always employ blunt dissection in tracing branches of 
vessels and nerves. 
Superficial Fascia. Identify (1) by its location im- 
mediately beneath the skin and containing a variable 
amount of fat; (2) by the presence of a large vein on 
the inner and anterior part-long saphenous. (Fig. 138.) 
Cutaneous Nerves and Vessels Identify (1) by 
study of the chapter dealing therewith (page 263); (2) 
by their location in the superficial fascia. 
Fascia Lata. (Fig. 149.) Identify (1) by its location 
beneath the superficial fascia; (2) by its great density 
and firm attachments to bone and Poupart's ligament. 
Inguinal Lymphatic Glands. Identify (1) by their 
location in the inguinal region ; (2) by their adjacency 
to the femoral vessels and Poupart's ligament. 
Tensor Vaginae Femoris. (Figs. 150, 151.) Iden- 
tify (1) by its location on the outer part of the ilium 
and origin from the outer lip of its crest; (2) by its in- 
sertion into the fascia lata on the outer part of the thigh. 
Sartorius Muscle. (Figs. 150, 151.) Identify (1) 
by its origin from the anterior superior iliac spine 
and its insertion into the upper third of the tibia ; (2) 
by its diagonal course across the anterior and inner 
parts of the thigh. 
Rectus Femoris. (Figs. 150, 151.) Identify (1) by 
its central location on the front of the thigh; (2) by its 
origin from the ilium and insertion into the patella. 
Vastus Externus. (Figs. 150, 151.) Identify (1) by 
its location external to and contact with rectus femoris ; 
(2) it overlaps the outer part of the vastus internus and 
is inserted into the patella. 
Vastus Internus. (Figs. 150, 151.) Identify (1) at 
the great muscular mass occupying the inner, ante- 
rior, and outer surfaces of the shaft of the femur ; (2) by 
its insertion into the patella. 
Crureus. (See Gray and Gerrish.) Identify by its 
location beneath the rectus femoris and forming a part 
of the vastus internus. 
Ligamentum Patellae. (Fig. 150.) Identify (1) by 
its location just below the patella; (2) by its attach- 
ment to the tubercle of the tibia and patella; (3) by 
its muscles inserted thereby into the tibia (rectus 
crureus, and vasti). 
Anterior Crural Nerve. (Fig. 151.) Identify (1) by the distribution of large branches 
to the integument (Fig. 140) and muscles on the anterior region of the thigh; (2) by its loca- 
tion external to the femoral artery, in the groove between the iliacus and psoas magnus muscles. 
SUPERFICIAL FASCIA OF THE THIGH. 
The superficial fascia is beneath the integument and forms an investment for 
the entire thigh. It is continuous with that of the leg and abdomen, and consists 
of an upper and a lower layer, between which are the superficial vessels and 
nerves.1 The superficial fascia is attached (1) to the margin of the saphenous 
Fig. 148. 
Dissection of lower extremity. Front view. 
(Gray.) 
1 Technically these structures are in the lower layer, but the line of distinction cannot be closely drawn between 
the upper and lower layers. 286 
A MANUAL OF DISSECTION. 
opening (Fig. 149); (2) to the femoral sheath, through the saphenous opening; 
(3) very intimately to the fascia lata, a little below Poupart's ligament. That 
part of the superficial fascia which covers the saphenous opening is called the 
cribriform fascia, and forms one of the coverings of a femoral hernia. The 
cribriform fascia is perforated by a number of vessels, among which is the 
long saphenous vein. The very intimate attachment of the superficial to the 
deep fascia below Poupart's ligament, accounts for the fact that in extravasation 
of urine, this fluid cannot pass down into the superficial fascia of the thigh. 
(See extravasation of urine, page 250.) 
DEEP FASCIA OF THE THIGH-FASCIA LATA. 
The Deep Fascia (fascia lata) (Fig 149) is beneath the skin and superficial fascia 
and forms a strong covering for the thigh. It is thin over the inner and back parts 
of the thigh, but thick in front and externally. The fascia lata receives fibrous 
Fig. 149. 
Femoral hernia, showing fascia lata and saphenons opening. (Gray.) 
expansions from the glutens maximus, tensor vaginae femoris, biceps, sartorins, 
quadriceps muscles, which add to both its strength and symmetry. 
Attachments of the Fascia Lata. To Poupart's ligament and the body of the 
pubic bone, in front; to the tuberosity of the ischium, the pubic and ischial rami, 
internally; to the back of the sacrum and coccyx, behind ; to the head of the 
fibula, tuberosities of the tibia and condyles of the femur, in the region of the knee. 
Intermuscular Septa. The fascia lata gives off from its deep surface two strong 
intermuscular septa-an external and an internal-which afford origin to muscles, THE ANTERIOR EEMORAL REGION. 
287 
delimit their physiological groups, and determine the direction of pus in deep- 
seated abscesses. The external intermuscular septum is attached to the linea 
aspera, extends from the insertion of the gluteus maximus to the outer femoral 
condyle, separates the vastus externus from the short head of the biceps, and gives 
partial origin to both these muscles. The internal intermuscular septum is 
attached to the linea aspera, extends from the lesser trochanter of the femur to 
the adductor tubercle, and separates the vastus interims from the pectineus and 
adductors. This septum, thinner than the external, is pierced by the perforating 
branches of the profunda artery on their way to the hamstring muscles, and 
by the superficial femoral artery, passing to the popliteal space, through an 
opening in the adductor magnus. (Fig. 153.) Purulent discharges, originating 
in the lumbar region, in psoas abscess, are directed by the iliac fascia into the 
deep part of Scarpa's triangle, whence they pass down the inner side of the 
thigh, between the vastus internus on the outer side and the pectineus and 
adductors, internally. (See page 272.) The fascia lata gives off smaller septa 
that ensheath each muscle in each group. 
Special Parts of Fascia Lata. (Fig. 149.) (1) Iliotibial band ; (2) gluteal apon- 
eurosis; (3) iliac portion; (4) pubic portion. The iliotibial band corresponds in 
origin to the tensor vaginae femoris (tensor fasciae latse, Fig. 150), ensheaths this 
muscle between its outer and inner layers, in the upper fourth of the thigh, and 
is inserted into the outer tuberosity of the tibia. 'The gluteal aponeurosis takes 
origin from the outer lip of the iliac crest, posterior to the iliotibial band, 
covers the gluteus medius muscle, and at the anterior border of the gluteus 
maximus divides and encloses this muscle. 
The Iliac Portion of the Fascia Lata (Fig. 149) is in front of the pubic portion 
and behind the femoral vessels. The saphenous opening is a passage between the 
iliac and pubic portions of the fascia lata, leading from the space of the superficial 
fascia to the femoral vessels. Attachments : The iliac portion of the fascia lata is 
attached to the crest of the ilium and to the whole length of Poupart's ligament; 
to the iliopectineal line with Gimbernat's ligament, where it is continuous with 
the iliac fascia. The pubic portion is attached above, to the iliopectineal line. 
It crosses the gracilis, adductor longus, and pectineus, passes beneath and is 
attached to the sheath of the femoral vessels. The iliac and pubic portions 
meet at the lower part of the saphenous opening, the margin of which is called 
the falciform process. 
The Inguinal Lymphatic Glands are (1) superficial, situated along Poupart's 
ligament and around the saphenous opening; (2) deep, situated near the upper 
end of the femoral vessels. (See Gerrish and Gray.) 
MUSCLES. 
The Tensor Vaginae Femoris (tensor fasciae latae). (Figs. 150, 151.) Origin: 
Outer lip of the crest of the ilium for about two inches. Insertion: Upper 
fourth of the fascia lata on outer surface of the thigh. Nerve: Superior gluteal. 
Artery: Superior gluteal. Action: Abductor and internal rotator of the thigh. 
The Sartorius (Figs. 150, 151) extends across the thigh from the anterior 
superior iliac spine to the inner surface of the upper third of the tibia; it is the 
longest muscle in the body. Origin: (1) Anterior superior spine of ilium; (2) 
superior iliac notch. Insertion: (1) Internal surface of the tibia; (2) deep fascia 
and periosteum of upper part of the leg. The aponeurotic insertion covers the 
tendons of the gracilis and semitendinosus muscles. Action : (1) To flex and 
abduct the thigh and rotate the same outward; (2) to flex the knee and rotate 
the same inward; (3) to make tense the inner part of the fascia lata; (4) to flex 
the pelvis on the thigh. Nerve: Anterior crural. Artery : Femoral. 
Rectus Femoris. (Figs. 150, 151.) Origin by two heads: (1) Straight head, 
anterior inferior iliac spine; (2) reflected head, acetabular brim, and external 288 
A MANUAL OF DISSECTION. 
part of the capsule of the hip. Insertion: Front border of patella. Action; To 
extend the leg. Synergists: Vasti. Antagonists: Biceps, semitendinosus, and 
semimembranosus. Nerve : Anterior crural. Artery : Femoral. 
Vastus Externus. (Figs. 150, 151.) Origin: (1) Anterior intertrochanteric 
line and surface of femur in front of the greater trochanter; (2) lower border of 
Fig. 150. 
Fig. 151. 
Superficial muscles in front part of the 
right thigh. (Gerrish after Testut.) 
Deep nerves of the front of the thigh. 
(Gerrish after Testut.) 
the greater trochanter; (3) outer lip of the gluteal ridge; (4) outer lip of the 
linea aspera, upper half; (5) external intermuscular septum. Insertion: (1) 
Upper and outer border of patella; (2) external tuberosity of tibia and deep 
fascia of leg. Action: To extend the leg. Nerve: Anterior crural. Artery: 
External circumflex. (Fig. 152.) THE ANTERIOR FEMORAL REGION. 
289 
Vastus Internus. (Figs. 150, 151.) Origin: (1) Outer lip of the linea 
aspera, lower half; (2) external condylar ridge; (3) lower part of the anterior 
intertrochanteric and spiral lines; (4) inner lip of the linea aspera; (5) internal 
condylar ridge; (6) greater part of the inner, outer, and anterior surfaces of the 
femur. Insertion: (1) Upper half and upper border of patella; (2) inner tuber- 
osity of tibia and deep fascia of leg. Nerve: Anterior crural. Artery: Super- 
ficial femoral. (Fig. 152.) 
The Crureus is that part of the vastus internus beneath the rectus femoris. 
The subcrureus consists of fibres of the crureus inserted into the upper part of the 
synovial membrane of the knee. Quadriceps femoris is a term by which the rectus, 
the two vasti, and the crureus are designated collectively. Action: To extend the leg. 
The Ligamentum Patellae (Figs. 150, 151) is the common tendon by which the 
muscles of the quadriceps extensor femoris are inserted into the tubercle of 
the tibia. It is attached above to the apex and lower part of the posterior 
surface of the patella. Size : One-quarter of an inch thick, one inch broad, 
and from two to three inches long. 
ANTERIOR CRURAL NERVE. 
The anterior crural is the large nerve external to the femoral artery, in a groove 
between the psoas and iliacus muscles. (Fig. 151.) It has an immense distribution 
to muscles, integument, articulations, and unstriped muscular fibre. The follow- 
ing table gives its intrapelvic and extrapelvic branches: 
Muscular, to the iliacus muscle. 
Gray rami, to the femoral artery. 
Intrapelvic portion 
Middle cutaneous. 
Internal cutaneous. 
Muscular, to the sartorius and pectineus. 
Anterior division 
Posterior division 
[ Long saphenous. 
Muscular, to the extensor muscles. 
[ Articular, to the hip and knee-joints. 
The Anterior Crural Nerve is a branch of the lumbar plexus, from the second, 
third, and fourth nerves. The constituent parts of the nerve unite in the groove 
between the psoas magnus and iliacus muscles, under the iliac fascia. The nerve 
passes beneath Poupart's ligament (external to the sheath of the femoral vessels) 
into Scarpa's triangle, and divides into (1) a superficial; (2) a deep group of 
branches separated by the external circumflex artery. (Fig. 152.) 
The Superficial Branches of the anterior crural nerve supply (1) the pectineus 
muscle, by a branch which passes behind the femoral sheath; (2) the sartorius 
muscle; (3) the skin of the inner side of the thigh, through the internal cutaneous; 
(4) the front of the thigh, through the middle cutaneous. The anterior crural 
sends a twig to the femoral artery, and also to the iliacus muscle before it 
emerges from the pelvis. (Figs. 140, 151.) 
The Deep Branches of the anterior crural nerve are (1) to the vastus internes 
muscle in Scarpa's triangle, on the outer side of the long saphenous nerve; (2) to 
the subcrureus muscle and knee; (3) to the crureus, entering the upper part of the 
muscle ; (4) to the vastus externus and knee ; (5) to the rectus femoris and hip; 
(6) the long saphenous nerve in Scarpa's triangle is between the nerve to the 
vastus interims and the femoral artery; in Hunter's canal it lies successively external 
to, in front of, and internal to the femoral artery. It becomes cutaneous at the 
inner side of the knee, passing between the sartorius and gracilis. (Fig. 154.) 
It supplies the skin of the inner and anterior part of the leg, passes in front of 
the inner malleolus to a point two inches below the ankle. 
Gray Rami Communicantes in General are described with the spinal nerves. 
They originate in the ganglion cells of the vertebral ganglia, and pass with the 290 
A MANUAL OF DISSECTION. 
spinal nerves to bone, fasciae, and unstriped muscle fibre, and are ultimately dis- 
tributed to the above structures with the vessels. In the case under consideration 
the gray rami, destined to accompany the ramifications of the femoral artery, 
come down with the anterior crural nerve and figure as "a branch to the femoral 
artery." (See Gray.) 
The anterior and posterior divisions of the anterior crural nerve (as seen in the 
table of branches) are separated from each other by the external circumflex artery. 
This artery lies on the iliacus and pectineus muscles, and much care is necessary, 
with blunt dissection, to properly develop this region. 
FEMORAL ARTERY AND VEIN. 
The Femoral Artery (Fig. 152), a continuation of the external iliac, is in Scarpa's 
triangle and Hunter's canal. It begins midway between the anterior superior 
iliac spine and the symphysis pubis, and ends at the opening in the adductor 
magnus, where it becomes the popliteal artery. (Figs. 153,164.) The femoral 
artery has the following branches: 
Superior epigastric. 
Superficial circumflex iliac, 
Superficial external pudic. 
Deep external pudic. 
Common femoral 
Profunda femoris 
External circumflex. 
Internal circumflex. 
Three perforating. 
Muscular branches. 
Anastomotica magna, 
Superficial femoral 
The Femoral Vein (Fig. 152) has the same course and stages as the artery, audits 
tributaries, in the main, correspond to the branches of the artery. The relations 
of the vein to the arteries may be thus generalized ; 1. In the upper third of the 
thigh, the vein and artery are on the same plane. 2. In the middle third, the vein 
is behind the artery. 3. In the lower third, the vein is somewhat external to and 
behind the artery. The femoral vein has four or five valves. (Consult the 
following table for tributaries of the femoral vein) : 
Tributaries oe the Femoral Vein 
Superficial epigastric. 
Superficial circumflex iliac 
Superficial external pudic. 
Deep external pudic. 
Long saphenous. 
Common femoral vein 
External circumflex. 
Internal circumflex. 
Three perforating. 
Profunda femoris vein 
Superficial femoral vein 
Muscular branches. 
Anastomotica magna. 
The object of the above table is to impress on the student the fact that each 
branch of the femoral artery is attended by a vein of similar course and name. 
As will be seen on dissection, the long saphenous vein has no corresponding 
artery. (Fig. 138.) 
The Femoral Sheath invests the femoral artery and vein, and contains an unoc- 
cupied space (internal to the vein) called the femoral canal. The sheath is formed 
by two fasciae-the iliac and transversalis-which come down from the abdomen 
under Poupart's ligament, into the thigh. (See femoral sheath and general fascia 
transversalis, pages 203, 272.) THE ANTERIOR FEMORAL REGION. 
291 
In Scarpa's triangle the anterior crural nerve lies to the outer side of the femoral 
artery in a groove between the psoas and iliacus muscles; to the inner side of 
the artery, is the femoral vein ; in Scarpa's triangle, the artery is crossed by a 
branch of the internal cutaneous nerve. In Hunter's canal, the long saphenous 
nerve crosses the artery from without inward. (Fig. 151.) On leaving the pelvis, 
the femoral vessels are invested by the femoral sheath. 
Fig. 152. 
Femoral artery. (Gerrish after Testut.) 
BRANCHES OF THE FEMORAL ARTERY. 
1. The Superficial Epigastric Artery (Fig. 152) is given off one-half inch below 
Poupart's ligament. It passes through the saphenous opening and crosses in the 
superficial fascia of the abdomen, toward the umbilicus. A vein of like name 
attends the artery. The artery supplies the skin and superficial lymphatic glands 
in this region. 292 
A MANUAL OF DISSECTION. 
2. The Superficial Circumflex Iliac (Fig. 152), attended by a vein of like name, 
runs below and parallel with Poupart's ligament, giving branches to the skin, 
fasciae, inguinal lymphatics, iliacus, and sartorius muscles. 
3. The Superficial External Pudic (Fig. 152) passes inward in front of the 
spermatic cord, and supplies the penis and the skin of the pubes. 
4. The Deep External Pudic (Fig. 152) crosses the pectineus and adductor longus 
muscles, and supplies the skin of the scrotum or its homologue, the labia majora. 
5. The Profunda Femoris (Fig. 152) arises from the outer and back part of 
the femoral, and passes downward and inward behind the parent artery. In the 
middle third of the thigh, it passes behind the adductor longus, pierces the 
adductor magnus, and ends in the flexor muscles of the back of the thigh. 
(Figs. 157, 159.) The artery lies on the iliacus, pectineus, adductor brevis, and 
adductor magnus muscles, and is the principal source of nourishment to the thigh. 
Its internal circumflex branch supplies the adductors; its external circumflex, the 
extensors of the knee; its perforating branches, the hamstring muscles and the 
femur. The profunda has the following branches: (a) External circumflex. 
(Fig. 152.) This branch runs outward under the rectus and sartorius muscles 
and divides into three branches-ascending, transverse, and descending. The 
ascending branch, anastomoses with the superior gluteal and deep circumflex iliac 
between the gluteus medius and minimus. The transverse branch, pierces the 
vastus externus and anastomoses with the sciatic and internal circumflex. (Fig. 
159.) The descending branch accompanies the nerve to the vastus externus 
muscle and anastomoses with the superior articular branches of the popliteal 
artery. (Fig. 159.) The branches of the external circumflex supply principally 
the extensor muscles of the knee. (6) Internal circumflex. (Fig. 152.) The 
internal circumflex branch arises from the back and inner part of the artery and 
supplies the adductors and obturator externus muscles. The course of the 
vessel is between the psoas and pectineus; between the adductor brevis and 
obturator externus; between the quadratus femoris and adductor magnus, 
where it anastomoses with the sciatic, external circumflex, and superior 
perforating arteries, to form the crucial anastomosis, (c) Perforating branches. 
(Fig. 159.) These are four in number-superior, middle, inferior, and fourth. 
They pass through the adductor group of muscles, principally to supply the 
biceps, semitendinosus, and semimembranosus; they anastomose with one another, 
with the gluteal, sciatic and internal circumflex above, and with the muscular and 
articular branches of the popliteal below. (Figs. 153, 159.) The first, second, 
and third are given off near or behind the adductor longus, and are seen by 
cutting this muscle near its insertion and turning the same aside. 
6. Muscular Branches are given off from the superficial femoral in its whole 
course; they supply the sartorius and vastus intern us muscles. 
7. The Anastomotica Magna (Fig. 152) arises from the lower end of the super- 
ficial femoral artery and divides into a superficial and a deep branch. The super- 
ficial branch passes with the long saphenous nerve between the sartorius and gracilis 
muscles, supplies the skin of the leg and anastomoses with the inferior internal 
articular branch of the popliteal artery. The deep branch runs in front of the 
tendon of the adductor magnus to the inner condyle, and anastomoses with the 
internal superior articular, the external superior articular (articular branches of 
the popliteal), and the anterior tibial recurrent arteries. CHAPTER XXII. 
THE INTERNAL FEMORAL REGION. 
Dissection and Identification. Abduct the limb and remove the integument. (Fig. 148.) 
Notice the long prominence on the inner part of the thigh produced by the gracilis muscle. 
The long saphenous vein (Fig. 138) skirts the outer 
boundary of this region to reach the femoral 
vein. The cutaneous nerves (Fig. 140) are the 
ilio-inguinal, internal cutaneous, and a cutaneous 
branch of the obturator. The deep fascia is thin. 
(Fig. 149.) The anterior division of the obturator 
nerve is between the adductor longus and adductor 
brevis; the posterior, between the adductor brevis and 
magnus. (Fig. 151.) 
Gracilis Muscle. (Fig. 154.) Identify (1) by the 
location on the innermost region of the thigh and its 
slender form; (2) by the origin from the pubic body 
and ramus and the insertion into the upper third of 
the tibia. 
Pectineus Muscle. (Figs. 153,154.) Identify (1) by 
the location on the pubic bone beneath the femoral 
canal and femoral vein; (2) by the location beneath 
the pubic part of the fascia lata and its insertion into 
the femur, behind the lesser trochanter. 
AdductorLongusMuscle. (Figs. 153,154.) Identify 
(1) by the origin from the anterior surface of the 
pubic bone and the insertion into the middle third of 
the femur; (2) by its adjacency to the pectineus and 
gracilis muscles. 
Adductor Brevis Muscle. (Fig. 153.) Identify (1) 
by the origin from the pubic bone lower than the 
origin of the adductor longus; (2) by the location 
beneath the adductor longus and in front of the 
adductor magnus. 
Adductor Magnus. (Fig. 153.) Identify (1) by the 
great size, and its location ; (2) by the origin from 
the ischiopubic ramus and tuber of the ischium; (3) 
by the insertion into the adductor tubercle and linea 
aspera. Make full exposure of this muscle by cutting 
through the adductor brevis in the region of the 
director (Fig. 153) and turning it aside. 
Obturator Nerve. (Fig. 154.) Identify (1) by its 
anterior division located between the longus and ad- 
ductor brevis; (2) by its posterior division, between 
the adductor brevis and adductor magnus; (3) by its 
distribution to the adductor muscles. 
Obturator Artery. (Fig. 134.) Identify (1) by the 
location in the adductor region and its course with 
the obturator nerve; (2) it leaves the pelvis through 
the obturator canal with the obturator nerve. 
Scarpa's Triangle. (Figs. 150, 151.) Identify (1) 
by the location in the upper and anterior part of the 
thigh; (2) by the boundary structures-Poupart's 
ligament, adductor longus and sartorius muscles; (3) 
by the contents-femoral vessels and anterior crural 
nerve. 
Hunter's Canal. (Figs. 151, 152.) Identify (1) by 
the location in a hollow, bounded on the outside by 
the vastus internus, on the inside by the adductor 
longus and magnus muscles; (2) by extending from tne apex oi scarpas mangle to tne 
popliteal space; (3) by the contents-femoral vessels and long saphenous nerve. 
Fig. 153. 
Adductores magnus and brevis of right side. 
The pectineus (above) and the adductor 
longus (below) are turned aside and held by 
hooks. The openings transmit the femoral 
artery to the popliteal space and the perforat- 
ing branches of the profunda artery to the 
back of the thigh. (Gerrish after Testut.) 294 
A MANUAL OF DISSECTION. 
THE ADDUCTOR MUSCLES. (Figs. 151, 153.) 
The Gracilis Muscle. (Figs. 151, 154.) Origin: Inner edge of the anterior 
surface of the body and descending ramus of the pubic bone. Insertion: Below 
the inner tuberosity of the tibia, under cover of the sartorius, and on a plane 
above, and anterior to insertion of the semitendi nosus. Action ; Adduction of the 
thigh and flexion of the knee. Nerve: Anterior division of obturator. 
Artery : Profunda. Note the long, ribbon-shape of this muscle. 
The Pectineus Muscle. (Figs. 153, 154.) Origin: (1) Iliopectineal line and 
the bone in front of this line; (2) deep surface of the pubic portion of the 
fascia lata. Insertion: Back of the femur, and into a vertical line behind the 
lesser trochanter. Action: Flexion, adduction and external rotation of the thigh. 
Arteries: Internal circumflex and obturator. Nerves: Obturator, accessory 
obturator, and anterior crural. (Fig. 151.) 
Adductor Longus Muscle. (Fig. 153, 154.) Origin: Front of the body of the 
os pubis below the crest and angle. Insertion: Middle lip of the linea aspera and 
middle third of femur. Action: Adduction, flexion and outward rotation of femur. 
Nerve: Anterior division of the obturator. Arteries: Obturator (a branch of the 
internal iliac), internal circumflex, and superior perforating branch of deep femoral. 
Adductor Brevis Muscle. (Fig. 153.) Origin: Body and descending ramus of 
the os pubis. Insertion : Inner lip of the linea aspera, extending from below 
the lesser trochanter to the middle of the back of the femur. Action : Flexion, 
adduction, and outward rotation of the thigh. Nerve: Anterior division of the 
obturator. Arteries: Obturator (from internal iliac), internal circumflex, and 
superior perforating branch of the deep femoral. 
Adductor Magnus Muscle. (Fig. 153.) Origin: (1) Outer part of the lower border 
of the tuber ischii; (2) outer surface of the ascending ramus of the ischium; (3) 
outer surface of the descending ramus of the pubes. Insertion : (1) Back of the 
femur, into a line beginning at the lower end of the linea quadrati, and extending 
along the inner border of the gluteal ridge and the middle lip of the linea aspera, 
down to the latter's bifurcation; (2) the adductor tubercle on the inner femoral 
condyle; (3) the lower part of the internal intermuscular septum. Action: Adduc- 
tion and internal rotation of the thigh. Nerves: Obturator (posterior division) 
and great sciatic. Arteries : Internal circumflex, obturator, perforating branches 
of profunda and superior sural branches of the popliteal. This muscle is 
pierced by the first, second, third, and fourth perforating branches of the 
profunda artery and by the femoral vessels, gaining the popliteal space to 
become the popliteal vessels. (Fig. 153.) 
THE OBTURATOR NERVE. 
The Obturator Nerve (Figs. 144, 154) arises from the third and fourth lumbar 
and receives a branch from the second. Course : (a) Between the psoas muscle and 
fifth lumbar vertebra; (6) to the outer side of the internal iliac vessels and ureter; 
(c) below the external iliac vessels; (d) on the outer wall of the pelvis, above 
the obturator artery. The nerve passes through an opening in the obturator 
membrane and divides into an anterior and a posterior division. (Fig. 154.) 
The anterior division passes between the pectineus and adductor brevis muscles 
and gains the space between the adductor longus and adductor brevis. The 
posterior division pierces the obturator externus and gains the space between the 
adductor brevis and adductor magnus. 
Branches of Anterior Division : An articular branch, to the hip-joint; a muscular 
branch,to the adductor longus; a muscular branch,to the adductor brevis; a muscular 
branch, to the gracilis ; a muscular branch, to the pectineus ; a cutaneous branch, to 
the subsartorial plexus; a branch to the femoral artery (a gray ramus communicans). THE INTERNAL FEMORAL REGION. 
295 
Branches of Posterior Division: 
Articular branches, to the hip- 
joint ; a geniculate branch, to the 
knee-joint; a branch to the obtura- 
tor externus muscle; several 
branches to the adductor magnus. 
The twig to the hip-joint passes 
through the cotyloid notch. The 
branch for the knee-joint-the 
geniculate-pierces the adductor 
magnus muscle, near the opening 
for the femoral artery, and 
descends on the popliteal artery. 
Gray Rami Communicantes. The 
anterior crural and obturator 
nerves contribute twigs to the 
femoral artery. It is through 
these twigs that the non-medul- 
lated axis-cylinder processes of the 
sympathetic ganglion cells reach 
the vessels, fasciae, bones, cartil- 
ages, and periosteum of the lower 
extremity. (Gerrish.) Wherever a 
somatic nerve gives a twig to a 
vessel, this same interpretation 
applies. (See Chapter on the 
Sympathetic Nerve.) 
THE OBTURATOR ARTERY. 
The Obturator Artery (Fig. 134) 
is a branch of the internal iliac. 
On the outer wall of the pelvis it 
lies below the obturator nerve. 
It pierces the obturator fascia, and 
leaves the pelvis through the 
obturator canal, with the obturator 
nerve. The artery may arise from 
the deep epigastric, one case in 
thirty-five; from the external iliac, 
one case in seventy-two; from 
both deep epigastric and external 
iliac, one case in seventy-two. 
The usual branches of the obtu- 
rator artery are : a vesical, which 
reaches the bladder via false liga- 
ment ; a pubic, to the pubic bone ; 
an internal, to the obturator exter- 
nus, pectineus, and adductors: 
an external, to the hip-joint and 
obturator muscles; an iliac branch, 
to the ilium and iliacus muscle. 
The Obturator Vein opens intc 
the internal iliac. Its tributaries 
correspond to the branches of th( 
obturator artery both in numbej 
Fig. 154. 
Nerves of the lower extremity. Front view. (Gray.) 296 
A MANUAL OF DISSECTION 
and location. On the outer wall of the pelvis the vein lies below the obturator 
artery. (Divided structures in this region may now be replaced as well as 
possible, so as to gain an idea of Scarpa's triangle.) 
SCARPA'S TRIANGLE. 
Scarpa's Triangle (Figs. 150, 154) occupies the upper and anterior part of 
the thigh. It is triangular, the base being above and the apex down. It 
derives its surgical importance, in part, from the following pathological con- 
ditions: Diseased inguinal lymphatic glands; inguinal and femoral hernise; 
fractures of neck of femur; dislocation of head of femur; varicose scrotal and 
spermatic veins; ligation of femoral vessels; primary and secondary abscesses; 
obliteration of long saphenous vein ; bloodless amputation at hip; injection of 
tubercular hip-joint. Analysis: Scarpa's triangle is bounded superiorly, by 
Poupart's ligament; externally, by the sartorius muscle; internally, by the adductor 
longus muscle. The roof consists of integument, superficial fascia, and fascia 
lata. The saphenous opening (Fig. 149) is in the fascia lata; the superficial 
fascia covering this opening is the cribriform fascia. The floor is formed, from 
without in, by the iliacus, psoas magnus, pectineus, and adductor longus muscles. 
In females and thin males, an interval persists between the pectineus and 
adductor longus muscles, hence in these cases the adductor brevis may be seen on 
the floor of the triangle. The apex of the triangle is at the junction of the 
adductor longus and sartorius muscles. 
Contents. (Figs. 151, 154). The common femoral artery and vein; the profunda 
artery and vein; the superficial femoral artery and vein; the anterior crural nerve 
and its branches; the femoral sheath and femoral canal; the saphenous opening 
and cribriform fascia; the termination of the long saphenous vein; the spermatic 
cord or round ligament; the superficial and deep inguinal lymphatic glands; the 
ilio-inguinal and genito-crural nerves. 
HUNTER'S CANAL. (Fig. 151.) 
Location. Hunter's canal is a groove extending from the apex of Scarpa's 
triangle to the aperature in the adductor magnus muscle, at the junction of the 
middle and lower thirds of the thigh. The canal is bounded externally by the 
vastus internus muscle, internally by the adductor longus and adductor magnus. 
The roof is formed by a dense aponeurosis, the sartorius muscle, the skin, 
superficial and deep fasciae. Contents: The superficial femoral vessels and the 
long saphenous nerve (external to the vessels), but not in their sheath. This nerve 
accompanies the femoral vessels as far as the opening in the adductor magnus; 
here it passes through the roof of the canal and becomes cutaneous, on the inner 
side of the knee, between the sartorius and gracilis muscles. CHAPTER XXIII. 
THE GLUTEAL REGION. 
Dissection and Identification. Place a block under cadaver in such a manner as to elevate 
hips and put the gluteal region on the stretch. Remove skin (leaving the superficial fascia in 
place) in accordance with skin incisions in Fig. 155. To aid in learning the cutaneous 
nerves, consult Fig. 141 and refer to table of cutaneous nerves, pages 166-168. 
The Superficial Fascia in the gluteal region contains much fat. It is tough and elastic, over 
the tuberosity of the ischium; thick, along the lower border of the gluteus maximus. The 
cutaneous nerves, as shown in the table, are (a) the posterior branch of the external cutaneous; 
Fig. 155. 
Fig. 156. 
Dissection of lower extremity. Posterior view. 
(Gray.) 
Gluteus maximus of right side. 
(Gerrish after Testut.) 
(5) the lateral cutaneous branch of the twelfth thoracic ; (c) the iliac branch of the iliohypo- 
gastric ; (tZ) the ascending and long pudendal branches of the small sciatic; (e) the three 
posterior divisions of the sacral nerves; (/) the three posterior divisions of the lumbar nerves, 
and other branches of minor importance. (See table of cutaneous nerves of lower extremity, 
pages 166-168.) 
The Deep Fascia of the gluteal region is a part of the fascia lata. (Fig. 149.) It descends 
from the crest of the ilium, ensheaths the tensor vaginae femoris, covers the gluteus medius, 
and at the anterior border of the gluteus maximus splits and encloses this muscle. Over the 
posterior part of the gluteus maximus muscle the fascia is thin. In Fig. 156 the deep fascia 
is represented as held aside by a hook, thereby making exposure of the fibres of the gluteus 
maximus muscle. 298 
A MANUAL OF DISSECTION. 
Remove with a sharp scalpel the deep fascia from the gluteus maximus muscle. (Fig. 156.) 
Divide the deep fascia along the lower border of the muscle and elevate same so as to expose 
the great and small sciatic nerves, semitendinosus, semimembranosus muscles, and the long 
head of the biceps, all of which muscles originate from the tuber of the ischium. Cut vertically 
through the gluteus maximus in a line with the great sciatic nerve, carefully turn aside the 
two parts of the muscle and expose and identify following structures (Fig. 157, 159): 
The Great Sciatic Nerve (Fig. 160) emerges from the pelvis below pyriformis muscle through 
the great sacrosciatic foramen, and rests successively on the gemellus superior, obturator 
internus, gemellus inferior, obturator externus, quadratus femoris, and adductor magnus muscle. 
The obturator externus is concealed by the quadratus femoris. 
Fig. 157. 
Arteries of the back of the hip and thigh. (Gerrish after Testut.) 
The Small Sciatic Nerve (Fig. 160) leaves the pelvis below the pyriformis muscle and 
lies behind the great sciatic. The sciatic vessels emerge below the pyriformis and lie internal 
to the great sciatic. 
The Internal Pudic Nerve and Vessels (Figs. 157,160) emerge from the greater sacrosciatic 
foramen, below the pyriformis, cross the spine of the ischium, and re-enter the pelvis through 
the lesser sacrosciatic foramen. 
The Superior Gluteal Nerve and Vessels (Fig. 157) emerge from the pelvis above the 
pyriformis, through the great sacrosciatic foramen. The vessels divide into (1) superficial 
branches which pass between the gluteus maximus and gluteus medius; (2) deep branches 
which pass between the gluteus medius and gluteus minimus. The nerve passes between the 
gluteus medius and minimus, supplying these muscles and the tensor vaginae femoris. THE GLUTEAL REGION. 
299 
The Gluteus Medius (Fig. 158) lies above the pyriformis. Cut its insertion into the oblique 
line of the greater trochanter, and on turning the muscle aside, the deep branches of the 
superior gluteal vessels, resting on gluteus minimus, appear. (Fig. 157.) 
The Synovial Bursae, under the gluteus maximus : Identify (1) one between the aponeurosis 
of this muscle and the greater trochanter; (2) one between the tendon of the muscle and the 
gluteal ridge; (3) one between the muscle and the tuber of the ischium. 
THE GLUTEAL MUSCLES. 
The Gluteus Maximus. (Figs. 156, 160.) Origin : (1) Outer lip of the iliac crest; 
(2) iliac surface between the superior gluteal line and outer lip of the crest; (3) 
lumbar aponeurosis, between the posterior superior iliac spine and sacrum; (4) 
lateral surface of the fourth and fifth sacral vertebrae; (5) side of the coccyx; (6) back 
of the great sacrosciatic ligament; (7) fascia lata investing the gluteus medius. 
Insertion: Gluteal ridge of femur, leading from greater trochanter, to the linea 
aspera and fascia lata. Action: Extension of hip. Antagonists: Psoas, iliacus, 
pectineus, and sartorius. Nerves : Inferior gluteal and sacral plexus. Arteries : 
Sciatic and superior gluteal, from internal iliac. (Figs. 134, 157.) 
Gluteus Medius. (Figs. 158, 159.) Origin: (1) Outer lip of the iliac crest, 
anterior four-fifths; (2) iliac surface between the middle and superior gluteal lines; 
(3) investing deep fascia, which also separates this from the gluteus maximus ; (4) 
intermuscular septa between the gluteus medius and gluteus maximus. Insertion : 
Oblique line on the outer surface of the greater trochanter. (Fig. 159.) Action : 
Abduction and inward rotation of the hip. Synergists: Tensor vaginae femoris and 
gluteus maximus. Antagonists: Adductor longus, adductor brevis, adductor mag- 
nus, adductor gracilis, and obturator externus muscles. Nerves : Superior gluteal, 
and sacral plexus. Arteries: Superior gluteal internal and external circumflex. 
The Gluteus Minimus. (Figs. 159,160.) Origin : (1) Outer surface of the ilium, 
between the middle and inferior gluteal lines; (2) intermuscular septum between 
the gluteus medius and gluteus minimus; (3) capsule of the hip. Insertion : 
Anterior border of the greater trochanter. Action: Abduction and inward 
rotation of the thigh. Synergists: Gluteus medius and tensor vaginae femoris. 
Antagonists: Adductors and external rotators. Nerve: Superior gluteal. 
Arteries: Superior gluteal, internal and external circumflex. 
EXTERNAL ROTATOR MUSCLES. 
The six external rotator muscles of the thigh are: the pyriformis, gemellus 
superior, obturator internus, gemellus inferior, obturator externus, and quadratus 
femoris. They are all inserted about the greater trochanter and are in relation 
with the posterior part of the capsule of the hip-joint. When the long axis of the 
limb is parallel to that of the trunk, they are external rotators. When, however, 
the thigh is at right angles to the trunk, as in the sitting posture, all the external 
rotators, except the obturator externus and quadratus femoris, become abductors 
of the thigh. 
The Pyriformis. (Figs. 158, 160.) Origin: (1) Front of the sacrum between 
first, second, and third anterior sacral foramina; (2) deep surface of the great 
sacrosciatic ligament; (3) posterior border of the os innominatum. Insertion : 
Muscle leaves the pelvis through the greater sacrosciatic foramen and is inserted 
into the inner surface of the superior border of the greater trochanter. Action : 
Outward rotation of the thigh. Synergists : The remaining five external rotators. 
Antagonists: Gluteus medius, gluteus minimus, and tensor vaginae femoris. 
Nerve : Second sacral. Arteries : Sciatic and internal circumflex. 
Obturator Internus. (Fig. 158.) Origin: (1) Posterior surface of the body of 
the pubic bone; (2) ischiopubic ramus; (3) inner surface of the obturator membrane; 
(4) surface of the bone corresponding to the acetabulum, externally; (5) pelvic and 300 
A MANUAL OF DISSECTION. 
obturator fasciae. Insertion: Greater trochanter. Action: External rotation. 
Synergists: The remaining external rotators, five in number. Antagonists: The 
tensor vaginae femoris, gluteus medius, and gluteus minimus. Nerves: First and 
second sacral. Arteries: Sciatic and internal circumflex. 
Gemellus Superior. (Fig. 158.) 
Origin: (1) Outer surface of the ischial 
spine ; (2) upper half of the outer edge 
of the lesser sacrosciatic notch. Inser- 
tion : Tendon of the obturator interims. 
Action: External rotation of the hip. 
Synergists: The five remaining external 
rotators. Antagonists : Tensor vaginae 
femoris,gluteus medius and gluteus min- 
imus. Nerves : First and second sacral. 
Arteries: Sciatic and internal circumflex. 
The Gemellus Inferior. (Fig. 158.) 
Origin: (1) Inner border of the tuber 
ischii ; (2) lower half of the outer edge 
of the lesser sacrosciatic foramen. 
Insertion: Tendon of the obturator 
internus. Action: External rotation. 
Synergists: Five remaining external 
rotators. Antagonists: Tensor vaginae 
femoris, gluteus medius, and gluteus 
minimus. Nerve: Sacral plexus. Artery: 
Internal posterior circumflex. (Fig. 
159.) 
The Quadratus Femoris. (Fig. 158.) 
Origin: Outer border of the tuber of the 
ischium. Insertion : Linea quadrati of 
the femur. Action: External rotation. 
Synergists: The five remaining external 
rotators. Antagonists: Tensor vaginae 
femoris, gluteus medius, and gluteus 
minimus. Nerve: Sacral plexus. Arteries: Internal circumflex and sciatic. 
(Figs. 157, 159.) 
Obturator Externus. (Fig. 153.) Origin: Inner half of the outer surface of the 
obturator membrane ; (2) ischiopubic ramus. Insertion: Digital fossa of the femur, 
on the inner surface of the greater trochanter. Action: Adduction and outward 
rotation of the thigh. Nerve: Posterior division of the obturator. Artery: 
Obturator. To expose this muscle posteriorly, cut through the insertion of the 
quadratus femoris and turn the same aside. 
VESSELS AND NERVES. 
The Gluteal Artery (Figs. 157, 159) is a branch of the internal iliac. It leaves 
the pelvis through the great sacrosciatic foramen above the pyriformis, with the 
superior gluteal nerve and veins. On emerging, it divides into a superficial and 
a deep branch. (The superior gluteal nerve undergoes a like division and has a 
similar distribution.) The superficial branch supplies the gluteus maximus and 
anastomoses with the lateral sacral, sciatic, and circumflex iliac arteries. The 
deep branch sends one part between the gluteus medius and the bone ; another 
between the gluteus medius and the gluteus minimus. The gluteal veins accom- 
pany the artery, and open into the internal iliac veins. 
The Superior Gluteal Nerve (Fig. 160) arises from the lumbosacral cord and first 
sacral nerve. (Fig. 146.) It leaves the pelvis through the great sacrosciatic 
foramen above the pyriformis muscle with the gluteal artery, and divides into an 
Fig. 158. 
Muscles of the right hip viewed from behind, the gluteus 
maximus having been cutaway. (Gerrish after Testut.) THE GLUTEAL REGION. 
301 
upper and a lower branch ; the upper branch terminates in the gluteus medius ; 
the lower branch supplies both the gluteus medius and the gluteus minimus, and 
terminates in the tensor vaginae femoris. The nerve to the obturator internus and 
gemellus superior arises from the first and second sacral. (Fig. 146.) It leaves 
the pelvis through the greater sacrosciatic foramen, and as it crosses the spine of 
the ischium, gives a branch to the gemellus superior. The nerve now re-enters the 
pelvis through the lesser sacrosciatic foramen and supplies the obturator internus. 
The Inferior Gluteal Nerve (Fig. 146) is from the first and second sacral and 
lumbosacral cord. It leaves the pelvis through the greater sacrosciatic foramen, 
below the pyriformis muscle with the sciatic and internal pudic vessels and 
nerves. It is often adhered to the sheath of the small sciatic. The nerve is 
distributed to the gluteus maximus. 
The Sciatic Artery (Figs. 157, 159) is a branch of the internal iliac. It emerges 
from the pelvis through the great sacrosciatic foramen, below the pyriformis muscle. 
It is to the inner side of the great sciatic nerve and midway between the tuber of the 
ischium and the greater trochanter. It crosses in its course from above downward, 
the gemelli, the obturators, the quadratus femoris, and the upper part of the 
adductor magnus. It is accompanied by veins of the same name, which unite to 
form one trunk, before the internal iliac vein is reached. Branches: In the pelvis, 
to the levator ani, the coccygeus, and the pyriformis muscles; to the rectum, the 
bladder, the prostate, and the vesiculse seminales; external to the pelvis, to the 
obturator internus, the gemelli, and the pyriformis; to the posterior part of the 
capsule of the hip; the inferior gluteal, to the gluteus maximus muscle; and the 
comes nervi ischiadici, which accompanies the great sciatic nerve and anastomoses 
with the first, second, third, and fourth perforating, and internal circumflex arteries. 
The Internal Pudic Nerve arises from the second, third, and fourth sacral, and, 
accompanied by its own vessel, emerges from the pelvis through the greater sacro- 
sciatic foramen below the pyriformis muscle with the sciatic vessels and nerves. 
The nerve crosses the lesser sacrosciatic ligament near the ischial spine, and re-enters 
the pelvis through the lesser sacrosciatic foramen internal to its vessels. It now 
enters and traverses Alcock's canal in the outer wall of the ischiorectal fossa. 
In Alcock's canal it gives off inferior hemorrhoidal branches, which, piercing the 
wall of the canal, gain and traverse the ischiorectal fossa to the anus. At the 
triangular ligament the internal pudic nerve divides into the perineal nerve and 
the dorsal nerve of the penis. 
The perineal branch of the internal pudic nerve pierces the two layers of the 
triangular ligament and supplies the erector penis, the superficial transversus 
perinsei, the accelerator urinse, the compressor urethra, the corpus spongiosum, the 
scrotum, and the skin on the under surface of the penis, and around the anus. 
The dorsal nerve of the penis perforates the posterior layer of the triangular 
ligament and passes through the deep perineal interspace ; it then pierces the 
anterior layer of the triangular ligament, and having given branches to the corpora 
cavernosa, passes between the crus penis and the pubic ramus, and is distributed 
to the skin of the dorsum, sides, and prepuce of this organ. (See dissection of 
the pelvic outlet.) 
The Pudic Artery is a branch of the internal iliac. It accompanies the pudic 
nerve. In the pelvis the artery crosses the pyriformis muscle and sacral plexus. 
On the spine of the ischium the pudic nerve is internal, and the nerve to the obtura- 
tor internus, external to the artery and under cover of the greater sacrosciatic 
ligament. In Alcock's canal the pudic artery gives off the internal hemorrhoidal 
which crosses the ischiorectal fossa with the inferior hemorrhoidal nerve to the 
anus; the superficial perineal to the scrotum and perineum; in the deep perineal 
interspace, branches to the bulb of the corpus spongiosum and to Cowper's gland. 
The terminal branch of the internal pudic is the dorsal artery of the penis. 
The Pudic Vein begins in the corpus cavernosum, but its minute radicals com- 
municate with the dorsal vein of the penis. With the exception just mentioned, the 
internal pudic vein accompanies this artery and receives corresponding tributaries. 302 
A MANUAL OF DISSECTION. 
Fig. 159. 
Fig. 160. 
The arteries of the gluteal and posterior femoral 
regions. (Gray.) 
Nerves of the lower extremity.1 Posterior 
view. (Gray.) 
1 In this diagram the external saphenous and communieans peronei are not in their normal position. They 
have been displaced by the removal of the superficial muscles. CHAPTER XXIV. 
THE POSTERIOR FEMORAL REGION. 
Dissection and Identification. Remove skin according to the incisions in Fig. 155. 
Do not remove the superficial fascia with the integument. Find the following structures and 
identify by comparison with the illustrations. 
The Superficial Fascia contains fat in large meshworks of connective tissue. There are no 
arteries in this region with special names ; they are small and simply called cutaneous, because 
they supply the skin. The cutaneous nerves, as shown by the table (p. 266) are the descending 
branches of the small sciatic; the anterior branch of the external cutaneous; small branches, 
on the inner aspect, from the obturator and internal cutaneous nerves. 
The Small Sciatic Nerve. (Fig. 160.) Find this nerve in the mid-line of the posterior part 
of the thigh, and trace same to the middle third of the leg. 
The Short Saphenous Vein. (Fig. 139.) This is in the mid-line of the posterior part of 
the leg, usually in company with the short saphenous nerve. The vein perforates the deep fascia 
and opens into the popliteal. Find opening in the deep fascia through which the vein passes. 
The Popliteal Fascia. The deep fascia covering the popliteal space is the popliteal fascia. 
It extends across the space and binds its boundary structures together. 
The Communicans Poplitei and Communicans Peronei Nerves pass through this fascia, 
and unite to form the short saphenous nerve; these two nerves are traceable to the internal and 
external popliteal nerves, respectively, and have been previously identified. (Fig. 162.) 
The Internal Popliteal Nerve and its Branches. (Fig. 160.) Cut through the popliteal fascia, 
midway between the femoral condyles, and find the internal popliteal nerve, a branch of the 
great sciatic. Elevate the nerve on the index finger, trace its muscular branches to the pop- 
liteus, gastrocnemius, plantaris, and soleus muscles, and the communicans poplitei to the short 
saphenous nerve. 
The Popliteal Vessels are an artery and a vein. (Fig. 164.) The artery is deeply placed; the 
vein is superficial to it, and both are in the centre of the popliteal space, behind the internal 
popliteal nerve. The vessels are in fat and connective tissue, and give off lateral branches 
above, below, and opposite the knee. 
The External Popliteal Nerve (Figs. 160, 162), like the internal, a branch of the great 
sciatic, lies in contact with the biceps muscle on the outer wall of the popliteal space, and 
leaves this space between the tendon of the biceps and the outer head of the gastrocnemius. 
The Boundary Muscles of the Popliteal Space. (Fig. 161.) Carefully separate the 
biceps from the semitendinosus, and this latter from the semimembranosus. Separate the 
two heads of the gastrocnemius. 
The Great Sciatic Nerve passes from without inward, beneath the long head of the biceps 
muscle to the popliteal space. (Fig. 160.) Turn the biceps outward and find muscular branches 
from this nerve to the adductor magnus and hamstring muscles. The great sciatic divides at 
a variable level above the knee, into the internal and external popliteal nerves, and is attended 
by a small artery, the comes nervi ischiadici, a branch of the sciatic. 
FLEXOR MUSCLES ON BACK OF THIGH. 
The Biceps Femoris Muscle. (Figs. 161,162.) Origin : Long head: lower and inner 
facet at the back of the tuber ischii, in common with the semitendinosus. Short 
head: (1) Outer lip of the linea aspera in the middle third of the femur; (2) 
external condylar ridge, upper two-thirds; (3) external intermuscular septum. 
Insertion: (1) Fossa below and in front of the styloid process of the head of the 
fibula; (2) fascia covering the peronei muscles; (3) outer tuberosity of the tibia. 
Action: Extension of the hip and flexion of the knee. Synergists: Semitendinosus, 
semimembranosus, and sartorius. Antagonists : Quadriceps femoris and iliopsoas. 
Nerve: Great sciatic. Arteries: Perforating branches of the profunda and superior 
muscular branches of the popliteal artery. (Fig. 159.) 
Long Head of Biceps and Great Sciatic Nerve. (Fig. 162.) The great sciatic 
nerve passes behind the long head of the biceps in the upper third of the thigh. 
A fibrous arch unites the two heads of the biceps in the middle third of the thigh. 
The nerve to the short head of the biceps is given off from the great sciatic in 
the middle third of the thigh; the nerve to the long head of the biceps (in 304 
A MANUAL OF DISSECTION. 
company with the nerves to the semitendinosus, semimembranosus, and adductor 
magnus) is given off from the great sciatic in the upper third of the thigh. 
The Semitendinosus Muscle. (Fig. 161.) Origin : Common tendon with the long 
head of the biceps, from the inner and lower facet of the back of the tuber ischii. 
Fig. 161. 
Fig. 162. 
Muscles in the dorsum of the right thigh. 
(Gerrish after Testut.) 
Deep nerves of buttock and back of thigh. 
(Gerrish after Testut.) 
Insertion : (1) Inner surface of the upper part of the tibia, below and behind the 
insertion of the gracilis; (2) deep fascia of the leg. Action : Extension of hip 
and flexion of knee. Synergists: Biceps, semimembranosus, sartorius. Antagon- 
ist : Quadriceps extensor. Nerve : Great sciatic. Arteries: Perforating branches 
of the profunda and superior muscular branches of the popliteal. THE POSTERIOR FEMORAL REGION. 
305 
Semimembranosus Muscle. (Fig. 161.) Origin : Upper and outer facet of the back 
of the tuberosity of the ischium. Insertion: (1) Groove on the back of the inner 
tuberosity of the tibia; (2) posterior ligament of the knee; (3) internal lateral liga- 
ment of the knee; (4) oblique line of the tibia (forming the popliteal aponeurosis). 
Action : Extension of the hip and flexion of the knee. Synergists: Biceps, semi- 
tendinosus, and sartorius. Antagonist: Quadriceps femoris. Nerve : Great sciatic. 
Arteries: Peforating branches of the profunda and superior muscular branches of the 
popliteal. The preceding muscles (biceps, semitendinosus, semimembranosus) 
are called collectively the hamstring muscles. 
GREAT SCIATIC NERVE. 
The Great Sciatic Nerve (Fig. 160), the largest nerve in the body, includes the 
greater part of the sacral plexus, and begins at the lower border of the great 
sacrosciatic foramen. It ends in name in the upper part of the popliteal space, 
in the internal and external popliteal nerves. The nerve leaves the pelvis 
through the greater sacrosciatic foramen, below the pyriformis muscle, and 
crosses successively the gemellus superior, ischium, obturator interims tendon, 
gemellus inferior, quadratus femoris, and adductor magnus. The long head of 
the biceps crosses the nerve. Internal to the great sciatic, are the pudic nerve, 
sciatic artery, and small sciatic nerve. In the region of the hip the nerve is 
about midway between the tuber of the ischium and the greater trochanter of the 
femur. (Fig. 162.) 
Branches: (1) Articular, to the hip, perforates the posterior part of the capsule; 
(2) muscular, to the biceps, semitendinosus, semimembranosus, and adductor 
magnus, given off beneath the biceps; (3) the external popliteal; (4) the internal 
popliteal. 
EXTERNAL POPLITEAL NERVE. (Figs. 162, 163.) 
The external popliteal nerve passes from the superior angle of the popliteal 
space, along the inner border of the biceps, to the interval between the biceps and 
the outer head of the gastrocnemius muscle, where it leaves the popliteal space, 
crosses the popliteus muscle, passes behind the head, and winds forward around the 
neck of the fibula, and divides into the following branches : Recurrent articular, 
superior external articular, inferior external articular, external cutaneous, com- 
municans peronei, anterior tibial, and musculocutaneous. 
The Recurrent Articular accompanies the anterior tibial recurrent artery through 
the upper part of the tibialis anticus, to the front of the knee. The nerve is 
given off on the neck of the fibula in the substance of the peroneus longus muscle. 
The Superior and Inferior External Articular branches accompany the vessels of 
like name to the knee, and their successful dissection depends on a faithful 
dissection of the articular arteries. (See table of nerves and vessels of the knee, 
page 310.) The external cutaneous nerve supplies the skin of the upper and outer 
part of the leg. The communicans peronei unites with the communicans poplitei, 
a branch of the internal popliteal, to form the short saphenous nerve. (See cuta- 
neous nerves of the lower extremity, page 264 et seq.) 
The Anterior Tibial Nerve (Fig. 166) is given off from the external popliteal on 
the neck of the fibula, beneath the peroneus longus muscle, with the recurrent 
articular, and musculocutaneous. It passes beneath the extensor longus digitorum 
to the outer side of the anterior tibial artery on the interosseous membrane. 
In the upper and lower thirds of its course the nerve is to the outer side of the 
anterior tibial artery; in the middle third it lies on the artery. Branches: 
Muscular, to tibialis anticus, extensor longus digitorum, peroneus tertius, and first 
and second dorsal interosseous muscles; articular, to the ankle, tarsal, and 306 
A MANUAL OF DISSECTION. 
metatarsophalangeal to the first, second, third, and fourth toes; cutaneous, to the 
skin between the first and second toes. 
The Musculocutaneous Nerve (Figs. 165, 166) begins (as a branch of the 
external popliteal) with the anterior tibial and the recurrent articular, on 
the neck of the fibula. It passes down the leg between the extensor longus 
digitorum and theperonei muscles to the lower third of the leg, where its cutaneous 
branch pierces the deep fascia and divides into the internal and external cutaneous. 
Branches : (1) Muscular, to the peroneus longus and peroneus brevis; (2) sensory, 
to the lower anterior part of the leg ; (3) sensory, to the dorsum of the third and 
fifth toes, except the distal phalanges; (4) sensory, to the inner side of the great 
toe; (5) sensory, to the inner side of the foot and ankle; (6) sensory, to the outer 
side of the foot and ankle; (7) sensory, to the whole dorsum of the foot. 
INTERNAL POPLITEAL NERVE. 
The Internal Popliteal Nerve (Figs. 160, 163) begins at the bifurcation of the 
great sciatic in the upper part of the popliteal space, and ends at the lower part of 
the popliteal space in the posterior tibial nerve, under the fibrous arch of the soleus 
muscle. In the upper part of the popliteal space the nerve is external to the 
popliteal vessels; opposite the knee, it crosses to their inner side. This nerve 
is the direct continuation of the great sciatic. Branches: (1) Articular, to the 
knee; (2) com municans poplitei, to the short saphenous; (3) muscular, to the 
gastrocnemius, plantaris, soleus, and popliteus ; thence the nerve is continued 
downward between the superficial and deep layers of the muscles of the back of 
the leg as the posterior tibial. 
The Articular Branches of the internal popliteal nerve are three in number : (1) 
Superior internal articular; (2) inferior internal articular; (3) azygos articular. 
These nerves accompany arteries of the same name. (See table of nerves and 
vessels of the knee-joint, page 310.) The communicans poplitei unites with the 
communicans peronei to form the short saphenous. The posterior tibial and its 
branches will be considered in the dissection of the leg. Muscular branches are 
given off between the two heads of the gastrocnemius muscle as stated in the 
foregoing paragraph. 
The Nerve to the Popliteus Muscle gives off the following branches : An articular 
branch, to the superior tibiofibular joint; a branch to the nutrient artery of the 
tibia; a branch to the interosseous membrane; a branch to the anterior and poste- 
rior tibial arteries. 
The dissected parts should now be replaced in their natural position as far as 
possible, and the following important surgical area-the popliteal space-studied 
according to the subjoined analysis. 
THE POPLITEAL SPACE. 
The Popliteal Space (Figs. 161, 164) occupies approximately the lower 
posterior third of the thigh and the upper posterior sixth of the leg. It is some- 
what diamond-shaped and has boundary structures both above and below the 
knee-joint. The space communicates superiorly with Hunter's canal and inferiorly 
with the leg, between the superficial and deep groups of muscles. To gain a 
comprehensive idea of the space, study and locate its roof, floor, superior and 
inferior boundaries, and contents on the dissection. 
The Roof is formed by skin, superficial and deep fasciae. In the superficial 
fascia the short saphenous vein pierces the deep fascia and enters the popliteal 
vein. It is through the roof that incisions may be made by the surgeon for 
operative purposes. The floor of the popliteal space is formed by (1) the popliteal 
surface of the femur; (2) the posterior ligament of the knee ; (3) the popliteus THE POSTERIOR FEMORAL REGION. 
307 
muscle and its fascia. On the floor of the space, in a bed of fatty connective 
tissue, are the popliteal vessels and lymphatic glands. 
Boundaries and Contents. The superior boundary of the popliteal space is formed, 
on the outside, by the biceps muscle; on the inside, by the semitendinosus, semi- 
membranosus, gracilis, and sartorius muscles. The inferior boundaries on both 
inner and outer sides are formed by the convergence of the two heads of the 
gastrocnemius muscle. The space contains (1) the termination of the short 
Fig. 163. 
Deep nerves of the back of the leg. (Gerrish after Testut.) 
saphenous vein; (2) the descending branch of the small sciatic nerve; (3) the 
communicans poplitei and communicans peronei nerves; (4) the internal popliteal 
nerve; (5) the external popliteal nerve; (6) the popliteal artery and its muscular, 
glandular, and articular branches; (7) the popliteal vein and its tributaries; (8) 
several lymphatic glands; (9) a large amount of fat and connective tissue; 
(10) the plantaris muscle. 
The Internal Popliteal Nerve (Figs. 160, 162) extends through the centre of the 
popliteal space, bisecting the same vertically. It begins in the superior angle 308 
A MANUAL OF DISSECTION. 
at the bifurcation of the great sciatic nerve, and ends in the inferior angle 
at the lower border of the popliteus muscle, whence it is continued to the inner 
ankle as the posterior tibial nerve. In the upper third of the space the nerve 
is external to the popliteal vessels; in the middle third it crosses them; in the 
lower third it is internal to and behind the vessels. Branches: (1) Three 
articular, to the knee; (2) the comm unicans poplitei; (3) muscular, to the popliteus, 
gastrocnemius, plantaris, and soleus. The muscular branch to the popliteus 
gives a twig to the superior tibiofibular articulation. 
Fig. 164. 
Popliteal artery. (Gerrish after Testut.) 
THE POPLITEAL ARTERY. 
The Popliteal Artery, a continuation of the femoral, extends from the opening 
in the adductor magnus to the lower border of the popliteus muscle. (Fig. 164.) 
Here the artery bifurcates, forming the anterior and posterior tibials. The 
popliteal artery is attended by the popliteal vein and the articular branch of the 
obturator nerve, to the knee. The artery lies on the femur, posterior ligament 
of the knee, and popliteal fascia, and has the following branches : 
Cutaneous ....... 
. To skin of back of leg. 
Superior muscular ...... 
. To adductors and hamstrings. 
Inferior muscular (sural) .... 
. To muscles of calf of leg. 
Articular (superior internal) .... 
To knee-joint. 
Articular (superior external) . 
To knee-joint. 
Articular (inferior internal) .... 
. To knee-joint. 
Articular (inferior external) . 
. To knee-joint. 
Articular (azygos) ..... 
To knee-joint. 
Table of Branches of the Popliteal Artery. THE POSTERIOR FEMORAL REGION. 
309 
Function of Articular Branches : (1) To supply the contiguous bones and soft 
structures of the knee-joint; (2) to supply the skin and fasciae about the knee; 
(3) to establish a collateral circulation in ligation of the popliteal or femoral artery. 
The superficial anastomosis is between the skin and fasciae ; the deep is on the 
bones around and external to the attachment of the capsule. 
Collateral Circulation about the Knee in Ligation of the Popliteal and Femoral 
Arteries. The four articular branches of the popliteal concerned are given off above 
and below the joint on each side. These four arteries communicate with one 
another in such a manner as to form a frame, about the patella, as a centre-piece. 
The anterior tibial recurrent artery opens into the lower part of this arterial frame. 
The anastomotica magna (a branch of the superficial femoral), the external circum- 
flex, and the fourth perforating branches of the profunda, open into the upper part 
of the arterial frame. In ligation of the popliteal artery, blood from the femoral 
artery reaches the arterial frame, through the anastomotica magna, the external 
circumflex, and the fourth perforating branch of the profunda. From this circle, 
blood reaches the anterior tibial artery through the anterior tibial recurrent. 
In ligation of the superficial femoral artery (either in Scarpa's triangle or 
Hunter's canal), blood reaches the circle, through the descending branch of the 
external circumflex and the fourth perforating. 
The Popliteal Vein (Fig. 164) is the strongest vein in the body; it accompanies 
and lies superficial to its artery. Its tributary branches correspond to the 
branches of the popliteal artery, both in number and location, with the addition 
of the short saphenous vein. Lymphatic glands, five or six in number, are in 
the fat and connective tissue in the neighborhood of the popliteal vessels. 
THE KNEE-JOINT. 
Dissection. Learn and locate the twelve synovial bursae described in the text. Divide the 
ligamentous muscles of the knee, near their attachments. Having removed the muscles, study 
the anterior, posterior, and lateral ligaments. Cut through the capsule below the patella and 
study the articular surfaces and crucial ligaments. Study the table of nerves and vessels of 
the knee on page 310. 
Bursae. Where muscles or their tendons play over bony eminences, a synovial 
bursa is interposed to prevent friction. This is especially true about the knee- 
joint. Synovial bursae about the knee are : (a) One between the skin and patella 
(patellar bursa); (6) one between the ligamentum patellae and the tubercle of the 
tibia; (c) one between the skin and tubercle of the tibia; (d) one between the inner 
femoral condyle and the inner head of the gastrocnemius; (e) one between 
the internal lateral ligament and the gracilis, semitendinosus, and sartorius 
muscles; (/) one between the internal lateral ligament and the semimembranosus; 
(g) one between the semitendinosus and semimembranosus; (h) one between the 
semimembranosus and the inner tuberosity; (i) one between the outer head 
of the gastrocnemius and the external femoral condyle; (J) one between the 
biceps tendon and the external lateral ligament; (&) one between the popliteus and 
external lateral ligament; (£) one between the popliteal tendon and the outer 
condyle of the femur. 
Nerves supplying groups of muscles that move a joint, supply the joint moved; 
hence the knee derives its nerve-supply from the obturator, anterior crural, 
internal and external popliteal. The nerves pierce the capsule with the arteries. 
Ligaments of Joints in General: (1) Ligamentous muscles, or those muscles that 
cross and aid in moving the joints; they are also called the elastic ligaments; (2) 
fibrous or periosteal, the basis and simplest form of which is a capsule. They 
derive their nerve-supply from the gray rami communicantes. (See Sympathetic.) 
The capsule is lined by synovial membrane. There are in the knee, as well as in 
other major joints, certain bony structures, muscles, and ligamentous attachments 
to be memorized. 310 
A MANUAL OF DISSECTION. 
The Long External Lateral Ligament of the knee is morphologically the 
obsolete upper end of the peroneus longus muscle; likewise the internal lateral 
ligament is the fibrous remnant of the adductor magnus muscle. 
Table of Nerves and Vessels of the Knee 
Nerve. 
Source. 
Course. 
Distribution. 
Attending. 
Artery. 
Superior 
Internal 
Above inner head of gastroc- 
Femur, patella, 
capsule, and 
Superior internal 
internal 
popliteal 
nemius, beneath semimem- 
branosus,. through tendon of 
adductor magnus. 
articular from 
articular. 
nerve. 
joint. 
popliteal artery. 
Inferior 
Internal 
Below internal tuberosity of the 
Lower and inner 
Inferior internal 
internal 
popliteal 
tibia; beneath the internal 
part of knee- 
articular from 
articular. 
nerve. 
lateral ligament and around 
the head of the fibula. 
joint. 
popliteal artery. 
Superior 
External 
Above the outer head of the 
Femur, patella, 
Superior external 
external 
popliteal 
gastrocnemius, beneath the 
and outer part 
articular from 
articular. 
nerve. 
biceps tendon and across the 
femur. 
of knee-joint. 
popliteal artery. 
Inferior 
External 
Above the head of the fibula and 
Outer and lower 
Inferior external 
external 
articular. 
popliteal. 
outer head of the gastrocnemius; 
under the tendon of the biceps 
and between the long and 
short external lateral liga- 
ments. 
part of knee- 
joint. 
articular from 
the popliteal 
artery. 
Azygos 
articular. 
Internal 
popliteal. 
Through Winslow's ligament. 
Crucial ligaments; 
ligamentaalaria 
and ligamenta 
mucosa. 
Azygos articular 
artery, a branch 
of the deep part 
of the popliteal. 
Recurrent 
External 
Through upper part of the tibialis 
Anterior part of 
Anterior tibial re- 
articular. 
popliteal. 
anticus. 
the knee. 
current artery. 
Articular 
branches. 
Obturator; 
from 
branch 
to adductor 
magnus. 
Through the ligament of Wins- 
low. 
Knee-joint. 
Superior internal 
articular from 
the popliteal. 
Articular 
branches, 
Anterior 
crural; 
from nerve 
to vastus 
extern us. 
Through the anterior part of the 
capsule. 
Knee-joint. 
Superior external 
articular artery. 
Articular 
branches. 
Anterior 
crural; 
from nerve 
to vastus 
internus. 
Through the internal part of the 
capsule. 
Knee-joint. 
Deep branch of the 
anastomotica 
magna. CHAPTER XXV. 
THE ANTERIOR TIBIOFIBULAR REGION. 
Dissection and Identification, Place a block under the knee, extend the foot, and render 
the skin of the leg and foot tense. Make incisions in the skin in accordance with Fig. 148, 
page 285. Exercise care to leave superficial fascia in place. Compare dissection with illus- 
trations and follow order given in text. Review pages 263-268 on cutaneous structures. 
The Superficial Fascia varies in thickness according to the amount of fat, and is very 
dense and tough in the sole. The superficial fascia contains in its deep layer, near the 
deep fascia, the cutaneous vessels and 
nerves. 
The Digital Veins and Dorsal Arch. 
(Fig. 138) The digital veins are made 
up in the skin of the toes, and by their 
confluence form an arch on the dorsum 
of the foot-arcus dorsalis pedis. 
The Long Saphenous Vein (Fig. 138) 
begins at the inner end of the dorsal 
arch and passes in front of the inner 
malleolus; posterior to the inner tuber- 
osity of the tibia and internal condyle of 
the femur; along the inner part of the 
thigh to the saphenous opening in the 
fascia lata, through which it passes 
and becomes tributary to the femoral 
vein. This vein is attended by the 
long saphenous nerve below the knee, 
and great care must be exercised in 
its dissection. 
The Cutaneous Branch of the 
Musculocutaneous Nerve pierces the 
deep fascia in the lower third of the 
leg, and divides into internal and 
external branches, which pass beneath 
the dorsal arch to the toes. (Fig. 165.) 
The Deep Fascia is very thick and 
strong over the tibiofibular muscles, 
and between the internal and external 
malleoli it forms the anterior annular 
ligament. (Fig. 165.) The deep fascia 
should be cut longitudinally to expose 
the deep structures. 
The Anterior Annular Ligament 
(Figs. 165-167) has vertical and hori- 
zontal parts; these bind the tendons in 
place and form compartments, lined by 
synovial membrane, for their easy 
transmission to the tarsus and toes. 
The vertical part of the anterior an- 
nular ligament extends from the tibia to 
the fibula, immediately above the mal- 
leoli, and is but little stronger than the 
general deep fascia, with which it is 
continuous above, and of which it is only a special part. Beneath it are the tendons of the 
anterior tibiofibular muscles, with the anterior tibial nerve and vessels. The tibialis anticus 
has a synovial sheath ; the other tendons beneath the vertical part have none. (Fig. 165.) 
The horizontal part of the anterior annular ligament arises on the outer side of the os calcis, 
and passes below the external .malleolus, inward; it splits and forms a compartment for the 
peroneus tertius and extensor longus digitorum-one part in front of the other behind these 
muscles. At the inner border of the extensor longus digitorum the ligament divides into an 
upper and a lower part; the latter crosses the remaining structures in this region. The upper 
part is inserted into the internal malleolus, the lower, into the scaphoid and internal cunei- 
form bonesand plantar fascia. There are three synovial compartments beneath the horizontal 
portion of the anterior annular ligament-one for the tibialis anticus, one for the extensor 
proprius hallucis, and one in common for the extensor longus digitorum and peroneus 
tertius. The anterior tibial nerve and vessels are beneath the anterior annular ligament. 
Fig. 165. 
Nerves of the dorsum of the foot. (Gerrish after Testut.) 312 
A MANUAL OF DISSECTION. 
MUSCLES. 
Tibialis Anticus. (Fig. 166.) Origin: (1) Outer tuberosity of the tibia; (2) 
outer surface of the tibia, upper two-thirds ; (3) interosseous membrane; (4) deep 
fascia of the leg; (5) intermuscular septum, between it and the extensor longus 
Fig. 166. 
Deep nerves of the front of the leg. (Gerrish after Testut.) 
digitorum. Insertion: (1) Internal cuneiform bone; (2) base of the first meta- 
tarsal. Action: To flex the foot. Synergist: The peroneus tertius. Antag- 
onists: Tibialis posticus, peroneus longus and peroneus brevis. Nerve: Anterior 
tibial. Artery: Anterior tibial, a branch of the popliteal. THE ANTERIOR TIBIOFIB ULAR REGION. 
313 
Extensor Proprius Hallucis. (Fig. 166.) Origin: (1) Middle half of the anterior 
surface of the fibula; (2) interosseous membrane. Insertion: Dorsal base of the 
second phalanx of the great toe. Synergist: The extensor brevis tendon to 
great toe. Antagonists: The flexor longus and the flexor brevis pollicis. 
Nerve: Anterior tibial. Artery: Anterior tibial. 
Extensor Longus Digitorum. (Fig. 166.) Origin: (1) External tuberosity of 
the tibia; (2) anterior surface of the fibula, upper three-fourths; (3) interosseous 
membrane; (4) deep fascia of the leg; (5) intermuscular septa. Insertion: (1) 
Dorsal bases of the second and third phalanges of the four outer toes; (2) lateral 
ligaments of the metatarsophalangeal joints. Action: To extend the four outer 
toes. Synergist: Extensor brevis digitorum. Antagonists: Flexor longusand flexor 
brevis digitorum. Nerve: Anterior tibial. Artery: Anterior tibial. (Fig. 166.) 
Peroneus Tertius. (Fig. 166.) Origin: (1) Anterior surface of the fibula, 
lower fourth; (2) interosseous membrane; (3) deep fascia and intermuscular 
septum. Insertion: Dorsal base of the fifth metatarsal. Action: To flex the foot. 
Synergist: Tibialis antieus. Antagonists : The peroneus longus, peroneus brevis, 
tibialis posticus. Nerve: Anterior tibial. Artery: Anterior tibial. 
Extensor Brevis Digitorum. Origin : (1) Upper surface of the os calcis; (2) 
anterior annular ligament. Insertion: Four inner toes; one tendon indepen- 
dently into the base (dorsal) of the first phalanx ; the remaining three conjointly 
with the tendons of the extensor longus digitorum into the second and third 
phalanges. Action ; Extends the four inner toes. Synergist: Extensor longus digi- 
torum. Antagonist: The flexor longus digitorum. Nerve: Anterior tibial. Artery : 
Anterior tibial. 
ANTERIOR TIBIAL NERVE. 
The Anterior Tibial Nerve Proper begins on the neck of the fibula as a terminal 
branch of the external popliteal. (Fig. 166.) Course: (1) Pierces the intermus- 
cular septum, between the peronei muscles and the muscles on the front of the 
leg; (2) it passes through the upper part of the extensor longus digitorum to the 
anterior surface of the interosseous membrane and joins the anterior tibial artery; 
(3) it lies, at first, between the extensor longus digitorum and the tibialis antieus, 
a little later between the extensor proprius hallucis and the tibialis antieus ; (4) 
it ends in front of the ankle, in the internal and the external branches. In the 
upper and lower thirds the nerve is external to the artery ; in the middle third it 
lies on the artery. 
Branches: (1) Articular, to the ankle-joint; (2) muscular, to the tibialis antieus, 
extensor proprius hallucis, extensor longus digitorum and peroneus tertius; (3) the 
external branch to the extensor brevis digitorum and tarsal articulations. This nerve 
develops a ganglion beneath the extensor brevis digitorum, from which branches 
supply the tarsometatarsal articulation and the first and second interossei muscles; 
(4) the internal branch supplies the contiguous margins of the great and second toes. 
Serial Course. This nerve consists of fibres from the fourth and fifth lumbar and 
the first sacral nerves. They leave the pelvis through the greater sacrosciatic fora- 
men below the pyriformis muscle, as a part of the great sciatic nerve. In the 
popliteal space these fibres leave the great sciatic, forming a part of the external 
popliteal nerve, which follows the inner border of the tendon of the biceps; they 
lie between the biceps and the outer head of the gastrocnemius; they cross the 
popliteus behind the head of the fibula and wind forward on the neck of the fibula, 
between the bone and the peroneus longus muscle. Here the fibres leave the 
external popliteal and form the anterior tibial nerve proper. 
ANTERIOR TIBIAL ARTERY. 
The Anterior Tibial Artery. (Figs. 166, 167.) A line drawn from the head of 
the fibula to a point midway between the malleoli, indicates the course of the 314 
A MANUAL OF DISSECTION. 
artery. The artery is a terminal branch of the popliteal. It is given off at the 
lower border of the popliteus muscle and passes forward between the two heads 
of the tibialis anticus muscle, between the tibia and fibula, above the interosseous 
membrane. From this point to the ankle, the artery lies in a canal having definite 
boundaries: The floor of the canal, in the upper two-thirds of its course, is the 
interosseous membrane; in the lower third, the tibia and ankle; the inner wall is 
Fig. 167. 
Arteries of the dorsum of the foot. (Gerrish after Testut.) 
the tibialis anticus ; the outer wall, the extensor longus digitorum and extensor 
proprius hallucis; the roof is formed by skin, superficial and deep fascise. 
Branches : (1) Muscular, ten or twelve in number, to the muscles of the front 
of the leg; (2) the superior fibular, to the soleus and peroneus longus muscles; 
(3) the posterior tibial recurrent, to the tibiofibular joint; (4) the anterior tibial 
recurrent, which figures in the collateral circulation at the knee, and passes through THE ANTERIOR TIBIOFIR ULAR REGION. 
315 
the upper part of the tibialis anticus muscle and over the outer tuberosity of the 
tibia; (5) the internal and external malleolar. (Fig. 167.) 
The Dorsalis Pedis Artery (Fig. 167) is a continuation of the anterior tibial and 
lies between the extensor proprius hallucis and the extensor longus digitorum. It 
gives off (1) a communicating branch to the external plantar, by which the 
plantar arch is completed ; (2) a tarsal branch, to the extensor brevis digitorum 
and tarsus; (3) the dorsalis hallucis, to the great toe; (4) interosseous arteries, to 
the interosseous spaces. CHAPTER XXVI. 
THE POSTERIOR TIBIOFIBULAR REGION. 
The Short Saphenous Vein (Fig. 168) is in the mid-line, with a nerve of like name. The 
vein is blue, as large as a lead-pencil, pierces the deep fascia, disappears behind the knee, and 
is traceable between the os calcis and external malleolus, to the outer side of the foot. 
The Short Saphenous Nerve (Fig. 168), somewhat larger than a knitting needle, is in the 
mid-line on the posterior part of the leg, with the short saphenous vein. Trace the nerve upward 
to a variable distance below the knee, where it is formed by the union of two branches-one 
Fig 168 
Superficial nerves of the back of the leg. (Gerrish after Testut.) 
from the internal, the other from the external popliteal nerve. Also trace both nerve and 
vein between the external malleolus and os calcis to the outer side of the foot, Other cuta- 
neous nerves in this region are (a) descending branches of the small sciatic; (6) a cutaneous 
branch of the posterior tibial; (c) the posterior branch of the internal cutaneous; (d) long 
saphenous, which are to be studied in the table of cutaneous nerves of the lower extremity, 
pages 163-168, and in Fig. 141. THE POSTERIOR TIBIOFIB ULAR REGION. 
317 
The Tendo Achillis is in the mid-line, very prominent, quite strong, and inserted into the 
os calcis. Parallel with its inner border are the posterior tibial nerve and vessels. Twro 
muscles of the superficial group of the posterior tibiofibular region are inserted into the heel 
bone through this tendon. 
The Popliteal Vessels and internal popliteal nerve pass between the two heads of the 
gastrocnemius muscle beneath the fibrous arch. Force the index finger under the arch 
between the gastrocnemius and soleus, cut lengthwise six inches downward through the 
middle of the gastrocnemius, and separate the two halves of the muscle; the tendon of the 
plantaris, lying on the soleus, will come into view. This (plantaris) is often mistaken for a 
nerve. There is a synovial bursa between the inner head of the gastrocnemius and the ten- 
don of the semimembranosus muscle. 
The Popliteal Fascia is the only part of the deep fascia on the posterior part of the lower 
extremity that receives a special name. It covers the popliteal space and occupies the lower 
posterior third of the thigh and upper posterior sixth of the leg. It contains transverse 
muscular fibres, and is sometimes called muscular fascia. It is pierced by the short saphenous 
vein and the communicating branches from the internal and external popliteal nerve that unite 
to form the short saphenous nerve. The descending branch of the small sciatic nerve rests on 
the popliteal fascia. This fascia is attached laterally to the boundary muscles of the popliteal 
space, and in Fig. 168 is represented as being held aside by hooks. 
Gastrocnemius. (Fig. 169.) Identify (1) by the location on the back of the leg as the most 
superficial muscle; (2) by the insertion through the tendo Achillis in the os calcis ; (3) two 
heads of origin from the femoral condyles, 
Plantaris. Identify (1) by the location between the gastrocnemius and the soleus and 
the insertion with the tendo Achillis into the os calcis; (2) by the very long, slender tendon. 
Soleus. Identify (1) by the location beneath the gastrocnemius and plantaris; (2) by the 
origin from the tibia and fibula (Fig. 171); (3) by the insertion with the gastrocnemius and 
plantaris into the os calcis. 
Deep Transverse Fascia of the Leg. Identify (1) by the location immediately beneath 
the superficial group of muscles identified; (2) by its attachments to the tibia and fibula; 
(3) by its high degree of transparency, permitting the subjacent structures to be seen. 
Popliteus. (Fig. 169.) Identify (1) by the location below the knee and insertion into the 
oblique line of the tibia; (2) by the strong investing aponeurosis. 
Flexor Longus Digitorum. (Fig. 171.) Identify (1) by the location on the posterior sur- 
face of the tibia; (2) by the location of the tendon beneath the internal annular ligament, 
next to the tendon of the tibialis posticus. 
Flexor Longus Hallucis. (Fig. 171.) Identify (1) by the location on the posterior surface 
of the fibula; (2) by the insertion into the distal phalanx of the great toe; (3) by the four 
grooves which it traverses. 
Tibialis Posticus. (Fig. 171.) Identify (1) by its origin from the tibia, fibula, and interos- 
seous membrane; (2) by the location between the two preceding flexor muscles; (3) by the 
insertion into the scaphoid bone and location of its tendon on the internal malleolus. 
Internal Annular Ligament. (Fig. 170.) Identify (1) by the location at the inner side of 
the ankle and attachment to the tibia and os calcis; (2) by the posterior tibial nerve and 
vessels and three flexor tendons beneath the ligament. 
Posterior Tibial Nerve. Identify (1) by the location beneath the deep transverse fascia of 
the leg, with the posterior tibial nerve and vessels; (2) by its derivation from the internal 
popliteal nerve. 
Posterior Tibial Artery. Identify (1) by the location beneath the deep transverse fascia 
of the leg with the posterior tibial nerve; (2) by its derivation from the popliteal artery. 
SUPERFICIAL GROUP OF MUSCLES. 
The Gastrocnemius (Fig. 169) has two heads connected by a fibrous arch. 
Origin of the Outer Head: (1) An impression upon the upper and posterior part 
of the outer surface of the external condyle; (2) posterior surface of the femur 
above the outer condyle. Origin of the Inner Head: (1) Impression on the 
posterior surface of the femur, above the internal condyle; (2) adductor tubercle. 
Insertion: By the tendo Achillis, into the posterior surface of the os calcis, 
with the plantaris and the soleus. Action: Extension of the foot. Synergists: 
Soleus, plantaris, tibialis posticus, peroneus longus, peroneus brevis. Antagon- 
ists: Tibialis anticus and peroneus tertius. Nerve: Internal popliteal. Arteries: 
Inferior sural branches of the popliteal. 
The Plantaris (Fig. 171) is occasionally attached to the plantar fascia, hence 
its name. Origin: (1) Lower two-thirds of the external condylar ridge of the 
femur; (2) adjacent surface of the femur and the posterior ligament of the knee. 318 
A MANUAL OF DISSECTION. 
Insertion: Posterior surface of the os calcis. Action: Extension of the foot. 
Synergists: Gastrocnemius, soleus, tibialis posticus, peroneus longus, peroneus 
Fig. 169. 
Fig. 170. 
Gastrocnemius of the right side. (Gerrish 
after Testut.) 
Muscles of the back of the leg. Superficial layer. 
(Gray.) THE POSTERIOR TIBIOFIB ULAR REGION. 
319 
brevis. Antagonists: Tibialis anticus, peroneus tertius. Nerve: Internal pop- 
liteal. Arteries: Inferior, muscular, or sural branches of the popliteal. 
The Soleus. (Fig. 170.) Origin: (1) Middle lip of the oblique line of the 
tibia ; (2) inner border of the posterior surface of the tibia, extending from the 
lower end of the oblique line to a point below the middle of the tibia ; (3) the 
back of the head of the fibula ; (4) the upper third of the outer border of the 
posterior surface of the fibula ; (5) the external intermuscular septum. Inser- 
tion : Tendo Achillis. Action: Extension of the foot. Synergists: Gastroc- 
nemius, plantaris, tibialis posticus, peroneus longus, peroneus brevis. Antagon- 
ists : Tibialis anticus and peroneus tertius. Nerve: Internal popliteal, a branch 
of the great sciatic. Arteries: Inferior sural branches of the popliteal. The 
tibial and fibular origins of the soleus are connected by a fibrous arch. Under 
the soleus muscle the deep transverse fascia of the leg extends from the tibia 
to the fibula. Beneath this fascia are the posterior tibial vessels and nerve and 
the tibialis posticus, flexor longus digitorum, and flexor longus hallucis muscles. 
The tendo Achillis, a common tendon of insertion of the gastrocnemius, 
plantaris, and soleus, is about three-fourths of an inch broad, and inserted into the 
lower part of the posterior surface of the os calcis. A bursa intervenes between 
it and the upper part of the os calcis. The narrowest part of the tendon is on a 
level with the internal malleolus and is where tenotomy is performed. (Fig. 170.) 
Nerve-supply. The muscles of the superficial group derive their nerves from the 
internal popliteal. To dissect these nerves properly, elevate the internal popliteal 
on the left index finger and trace its several branches (which are now brought into 
view) to the muscles. Locate the popliteal artery on the floor of the popliteal 
space and trace certain of its branches to the superficial group of muscles. 
DEEP GROUP OF MUSCLES. 
Dissection. Detach the soleus from the tibia and fibula (Fig. 173), cut the tendo Achillis 
two inches above its insertion into the os calcis and turn the superficial group to one side. 
(Fig. 172.) Identify the deep transverse fascia as a thin fascial covering through which the 
posterior tibial nerve and vessels may be seen. Demonstrate the two heads of the tibialis 
posticus arising from tibia and fibula. Identify the origin of the flexor longus digitorum from 
the tibia, that of the flexor longus pollicis from the fibula. Trace muscular branches of 
nerves and vessels to their ending. Demonstrate relation of posterior tibial nerve and 
artery to each other. (Fig. 172.) 
Deep Transverse Fascia of the Leg. (Fig. 172.) If the preceding dissection has 
been properly performed the deep fascia covering the deep group of muscles with 
their vessels and nerves is now exposed. This fascia is thick above, where it 
covers the popliteus muscle and receives one of the aponeurotic insertions of the 
semimembranosus muscle ; below, where it covers the tendons, passing behind the 
malleoli of the tibia and fibula. In the middle third of the leg, the fascia is 
thin, and permits the posterior tibial nerve and vessels to be seen through it. 
The fascia is attached latterly to the tibia and fibula ; above to the tibia, fibula, 
and ligament of Winslow; below, it blends with the internal lateral ligament. 
The Popliteus Muscle. (Fig. 172.) Origin: (1) Lower part of the external 
surface of the outer femoral condyle ; (2) posterior ligament of the knee-joint. 
Insertion : (1) Posterior surface of the tibia, above the oblique line ; (2) popliteal 
aponeurosis. The tendon of origin of this muscle passes beneath the external 
lateral ligament of the knee, and is surrounded by a synovial membrane. Action : 
A feeble flexor and internal rotator of the leg when the knee is flexed. Synergists : 
Biceps, semitendinosus, semimembranosus, sartorius. Antagonists: Quadriceps 
extensor femoris. Nerve: Internal popliteal. Artery: Popliteal. This muscle 
is covered by an expansion of the aponeurosis of the semimembranosus. The 
plantaris, popliteal vessels, and internal popliteal nerve cross the muscle. 
Flexor Longus Digitorum. (Fig. 172.) Origin: (1) Inner part of the posterior 
surface of the tibia, below the oblique line, extending to within three inches of 320 
A MANUAL OF DISSECTION. 
the ankle; (2) deep fascia of the leg ; (3) intermuscular septum, between this muscle 
and the tibialis posticus. Insertion: Under surface of the distal phalanx of each of 
the four outer toes. The tendon of the muscle passes in a compartment of the 
internal annular ligament, behind the tibialis posticus; in the sole of the foot, the 
muscle receives the muscular fibres of the accessorius and a tendinous slip from the 
flexor longus hallucis. The muscle divides into four tendons, about the middle of 
the foot, and each tendon passes through a slit in the corresponding tendon of the 
flexor brevis digitorum. The lumbrical muscles arise from the tendon of this 
muscle. Action: Flexion of the third phalanges of the four outer toes. Syner- 
gists : Tendons of the flexor brevis digitorum. Antagonists: Extensor longus and 
extensor brevis digitorum. Nerve: Posterior tibial. Artery: Posterior tibial. 
Flexor Longus Hallucis. (Fig. 172.) Origin: (1) Lower two-thirds of the 
postero-internal surface of the fibula; (2) intermuscular septa between this and the 
peronei muscles; (3) deep fascia and interosseous membrane. Insertions: (1) 
Under surface of the base of the distal phalanx of the great toe; (2) Flexor longus 
digitorum. Course: The tendon of this muscle passes through the following 
grooves: (1) A groove on the posterior surface of the tibia; (2) a groove on the 
posterior surface of the astragalus; (3) a groove in the under surface of the susten- 
taculum tali; (4) a groove between the two sesamoid at the metatarsophalangeal 
Fig. 171. 
The internal annular ligament of the ankle and the artificially distended synovial membranes of the tendons 
which it confines. (Gerrish after Testut.) 
articulation of the great toe. Under the internal annular ligament the tendon lies 
deeply buried in a special compartment lined by synovial membrane. (Fig. 171.) 
Action: Flexion of the second phalanx of the great toe. Synergist: Flexor 
brevis hallucis. Antagonists : The extensor proprius and extensor brevis hallucis. 
Nerve: The posterior tibial. Arteries : Posterior tibialand peroneal. 
Tibialis Posticus. (Figs. 172, 173.) Origin: (1) Interosseous membrane and 
adjacent surface of the tibia; (2) internal surface of the fibula; (3) deep fascia 
and intermuscular septa. Insertion: (1) Tuberosity of the scaphoid bone; (2) 
sustentaculum tali and the under surfaces of all the tarsal bones except the astra- 
galus ; (3) the bases of the second, third, and fourth metatarsals. Course : In the 
lower third of the leg the muscle passes beneath the tendon of the flexor longus 
digitorum, enters a groove in the inner malleolus and passes in a synovial sheath 
to its insertion. Action: Extension of the foot. Synergists: Peroneus longus, 
peroneus brevis, gastrocnemius, plantaris, soleus. Antagonists : Tibialis anticus, 
peroneus tertius. Nerve: Posterior tibial. Arteries : Posterior tibial and peroneal. 
[Observe that the muscle that flexes the great toe (the flexor longus hallucis) 
arises from the posterior surface of the bone on the opposite side of the leg, the THE POSTERIOR TIBIOFIBULAR REGION. 
321 
fibula; and the muscle that flexes the four outer toes (the flexor longus digitorum) 
arises from the posterior surface of the boue of the opposite side of the leg, the 
tibia. Hence, the tendons of these two muscles cross, a verification to be made 
in dissection of the sole of the foot.] 
INTERNAL ANNULAR LIGAMENT. 
The Internal Annular Ligament (Fig. 171) is a very strong band of fibrous tissue 
extending from the internal malleolus to the os calcis. It converts three grooves 
into three canals for three tendons, and forms a neurovasal space for the posterior 
tibial nerve and vessels. The grooves are (1) on the posterior border of the inter- 
nal malleolus, for the tendons of the tibialis posticus and flexor longus digitorum; 
(2) on the posterior part of the lower end of the tibia ; (3) on the posterior surface 
of the astragalus. The grooves on the tibia and astragalus are continuous, and 
transmit the tendon of the flexor longus hallucis. Each of the three grooves is 
lined by a separate synovial membrane. (Fig. 171.) The space for the nerve and 
vessels is midway between the os calcis and internal malleolus and superficial 
to the groove containing the flexor longus hallucis; hence, to liberate this tendon 
it is necessary to turn the nerve and vessels aside. 
POSTERIOR TIBIAL NERVE. 
The Posterior Tibial Nerve (Fig. 172), a continuation of the internal popliteal, be- 
gins at the lower border of the popliteus muscle and ends midway between the in- 
ternal malleolus and os calcis in the internal and external plantar nerves. The nerve 
crosses the posterior tibial artery from within out, an inch and a half below the 
origin of the artery, and remains on the outer side of the same for the rest of its 
course. The nerve is covered by deep fascia and rests successively on (1) the 
tibialis posticus; (2) the flexor longus digitorum; (3) the tibia, in the lower part 
of its course, and lies parallel with the inner border of the tendo Achillis.' 
Branches: (1) Muscular, to the tibialis posticus, flexor longus digitorum, flexor 
longus hallucis, and soleus; (2) articular (one or two), to the ankle-joint; (3) cuta- 
neous (internal calcanean), to the skin and fascia of the heel and adjacent part of 
the sole; (4) the internal and external plantar, to the structures of the sole of the 
foot. 
POSTERIOR TIBIAL ARTERY. 
The Posterior Tibial Artery (Fig. 172) begins at the bifurcation of the popliteal, 
at the lower border of the popliteus muscle, and ends under the internal annular 
ligament, midway between the internal malleolus and the os calcis, in the internal 
and external plantar arteries. It is accompanied by the posterior tibial nerve and 
two vens comites, which anastomose freely across the artery. The artery lies on 
the tibialis posticus, flexor longus digitorum, and lower part of the tibia. About 
an inch and a half below its origin, the artery is crossed from within out by the 
internal popliteal nerve. 
Branches : (1) Muscular, to tibialis posticus, flexor longus digitorum, and soleus; 
(2) cutaneous, to the skin of the inner part of the leg; (3) communicating (given 
off two inches above the internal malleolus), passes beneath the flexor longus 
hallucis and tendo Achillis, and anastomoses with the communicating branch of 
the peroneal; (4) malleolar, to the skin over the internal malleolus; (5) calcanean, 
to the soft parts on the inner side of the os calcis ; (6) internal and external 
plantar; (7) a nutrient, to the tibia, enters the nutrient foramen, at the lower end of 
the oblique line of the tibia, on a ridge separating the origin of the tibialis 
posticus from the flexor longus digitorum; (8) peroneal, the largest branch of the 
posterior tibial (given off one inch below the popliteus muscle); it passes close to 322 
A MANUAL OF DISSECTION. 
Fig. 172. 
Fig. 173. 
The popliteal, posterior tibial, and peroneal 
arteries. (Gray.) 
Bones of the right leg. Posterior surface. 
(Gray.) THE POSTERIOR TIBIOFIBULAR REGION. 
323 
the fibula, to the lower part of the interosseous membrane, and is attended by 
two venae comites. 
Branches of the Peroneal Artery: (1) Nutrient to the fibula; (2) cutaneous, to 
the outer side of the leg; (3) external calcanean, to the outer surface of the os 
calcis; (4) posterior peroneal, to the external malleolus and the heel; (5) anterior 
peroneal (passes through the lower part of the interosseous membrane), to the 
peroneus tertius and the inferior tibiofibular joint, anastomosing with the external 
plantar and anterior tibial arteries. CHAPTER XXVII. 
THE FIBULAE REGION. 
Dissection and Identification. Adduct and extend the foot to render the skin and peronei 
tendons tense. Remove the integument. (Fig. 148.) Cut longitudinally, through the fasciae 
covering the peronei muscles in the upper two-thirds of the outer surface of the fibula. Find 
the peroneal, or external popliteal nerve on the neck of the fibula, dividing into (1) a recur- 
rent branch, to the knee; (2) the anterior tibial, to the muscles on the front of the leg; 
(3) the musculocutaneous, to the peronei muscles and skin of the dorsum of the foot. Trace 
tendons of the peronei muscles beneath the external annular ligament, posterior to the 
external malleolus. (Fig. 175.) The superficial fascia contains cutaneous branches of the 
external popliteal nerve. The deep fascia is quite strong. 
External Malleolus. Identify (1) by the location, very prominent on the outer side of the 
ankle; (2) by continuity with the fibular shaft; (3) by the presence of the tendons of the 
peroneus longus and brevis, in the groove on the posterior border. (Fig. 174.) 
External Annular Ligament. Identify (1) by the location on the outer side of the ankle, 
extending from the posterior border of the external malleolus to the outer surface of the 
os calcis. (Fig. 174.) 
Peroneus Longus and Brevis Muscles. (Fig. 175.) Identify (1) by the location on the 
outer surface of the fibula and origin chiefly therefrom ; (2) by the location of their tendons 
beneath the external annular ligament, posterior to the external malleolus. (Fig. 174.) 
Musculocutaneous Nerve. (Fig. 166.) Identify (1) by the location between the outer 
head of the gastrocnemius and the tendon of the biceps ; (2) by the location on the neck of 
the fibula, in the substance of the peroneus longus muscle; (3) by the distribution to the 
peronei muscles (longus and brevis), and the dorsum of the foot. 
Peroneal Artery. (Fig. 172.) Identify (1) by the location near the fibula and distribution 
to the peronei muscles; (2) by the derivation from the posterior tibial artery (largest branch). 
Head of Fibula. Identify (1) by the location below the knee and on the outer side of the leg; 
(2) by the continuity with the shaft of the fibula; (3) by insertion of the tendon of the biceps. 
The Head of the Fibula is joined to the shaft of the bone, by the neck. The posterior 
part of the head (pointed) is called the styloid process; into the styloid is inserted the 
short external lateral ligament, morphologically, 
the divorced tendon of the peroneus longus. 
The posterior surface gives attachment to the 
soleus; the outer, to the peroneus longus; the an- 
terior, to the extensor longus digitorum ; the in- 
ternal articulates, with the outer tuberosity of the 
tibia, and gives attachment to the capsule of the 
superior tibiofibular joint. Behind the head of 
the fibula is the external popliteal nerve, which 
a little lower crosses the neck of the bone and 
divides into the recurrent articular, anterior 
tibial, and musculocutaneous. 
The External Malleolus is the lower end of 
the fibula. (Fig. 174.) The upper part of the 
malleolus is the base ; the lowest part, the apex. 
To the apex is attached the middle band of the 
external lateral ligament of the ankle. The outer 
surface of the malleolus is subcutaneous. The 
inner surface above and in front articulates with 
the astragalus. Below and behind, this surface 
forms the digital fossa, into which is inserted 
the posterior band of the external lateral liga- 
ment and the transverse inferior tibiofibular liga- 
ment ; the anterior border of the malleolus gives 
attachment to the anterior band of the external 
lateral ligament of the ankle. The posterior bor- 
der is grooved for passage of the tendons of the 
peroneus longus and brevis muscles. 
Fig. 174. 
The external annular ligament of the ankle and the 
artificially distended synovial membrane of the ten- 
dons which it confines. (Gerrish after Testct.) THE FIB ULAR REGION. 
325 
EXTERNAL ANNULAR LIGAMENT. 
The External Annular Ligament (Figs. 174, 175) extends from the posterior 
border of the outer malleolus to the outer surface of the os calcis and peroneal 
tubercle. Beneath this ligament pass the tendons of the peroneus longus and 
brevis muscles in a synovial sheath. The external saphenous nerve and vein, 
embedded in the superficial fascia, lie on the ligament. (Fig. 139.) 
PERONEI MUSCLES-LONGUS AND BREVIS. 
The Peroneus Longus Muscle. (Fig. 175.) Location: Outer side of the leg 
and sole of the foot. Origin: (1) Outer surface of the upper two-thirds of the 
fibula; (2) head of the fibula; (3) outer tuberosity of the tibia; (4) deep fascia of 
the leg. Insertion; (1) Plantar base of the first metatarsal bone ; (2) internal 
cuneiform bone. Course: (1) Behind the outer malleolus and beneath the ex- 
ternal annular ligament in a synovial sheath with the peroneus brevis; (2) outer 
surface of the os calcis, below the peroneus brevis, in a special synovial sheath; 
(3) in an osseo-aponeurotic canal on the under surface of the cuboid bone; (4) 
across the bottom of the foot to its insertion into the plantar base of the first 
metatarsal. Action: Extends the foot. Synergists: Peroneus brevis, tibialis 
posticus, gastrocnemius, plantaris, soleus, and tendo Achillis. Antagonists : 
Peroneus tertius and tibialis anticus. Nerve: Musculocutaneous, a branch of 
the external popliteal. Artery: Peroneal branch of the posterior tibial. The 
plantar stage of this muscle will be studied in the dissection of the sole of the 
foot. (Figs. 178, 179.) 
The Peroneus Brevis. (Fig. 175.) Location: Outer side of the leg. Origin: 
(1) Outer surface of the fibula, lower two-thirds; (2) deep fascia. Insertion : 
Dorsal base of the fifth metatarsal. Course : (1) Behind the outer malleolus with 
the peroneus longus; (2) above the peroneus longus, in a special synovial sheath, 
on the outer surface of the os calcis. Action : Extends the foot. Synergists: 
Peroneus longus, tibialis posticus, gastrocnemius, soleus, plantaris, and tendo 
Achillis. Antagonists : Peroneus tertius and tibialis anticus. Nerve : Musculo- 
cutaneous. Artery: Peroneal branch of the posterior tibial. 
MUSCULOCUTANEOUS NERVE. (Figs. 160, 166.) 
The Musculocutaneous Nerve (serial course). This nerve consists of fibres 
from the fourth and fifth lumbar and the first sacral, which leave the pelvis as a 
part of the great sciatic nerve. In the popliteal space these fibres depart from the 
great sciatic nerve with the external popliteal, passing along the inner margin of 
the biceps tendon ; between the biceps aud the outer head of the gastrocnemius; 
also behind the head and across the neck of the fibula; and, lastly, between the 
fibula and peroneus longus, where they leave to form the musculocutaneous nerve 
proper. 
The musculocutaneous nerve proper begins on the neck of the fibula as a 
branch of the external popliteal. It passes through the peroneus longus muscle 
and gains its way between the peroneus longus and the extensor longus digitorum. 
It supplies the peroneus longus and brevis and ends in internal and external 
cutaneous branches, which, piercing the deep fascia in the middle third of the 
leg, become cutaneous and supply the dorsum of the foot, communicating with the 
internal and external saphenous and anterior tibial nerves. (Fig. 140 ) 
The Peroneal Artery (the largest branch of the posterior tibial) is given off 
one inch below the popliteus muscle. (Fig. 172.) Its course is downward close 
to the bone, as far as the lower limit of the interosseous membrane. Here the 
artery gives off the anterior peroneal and passes downward across the tibiofibular 326 
A MANUAL OF DISSECTION. 
joint and ends in a network about the os calcis and outer malleolus. Branches : 
(1) Muscular, to the soleus, peronei, tibialis posticus, and flexor longus hallucis; 
(2) nutrient, to the fibula; (3) communicating to the posterior tibial; (4) cuta- 
neous, to the outer side of the leg; (5) external calcanean, to the outer surface of 
the os calcis; (6) posterior peroneal, to the outer side of the os calcis. 
Fig. 175. 
Muscles on the outer side of the right leg and dorsum of the foot. (Gerrish after Testut.) CHAPTER XXVIII. 
THE SOLE OF THE FOOT. 
Dissection and Identification. Hastily read the whole chapter on this subject, and care- 
fully study the illustrations showing the successive strata as revealed by dissection. Make 
skin incisions as in Fig. 155. Remove the integument with a very sharp scalpel. Study 
distribution of cutaneous nerves in Fig. 142. 
The Integument of the plantar surface of the foot, like that of the palm of the hand, is 
wanting in free mobility, a peculiarity due to the presence of fibrous processes extending 
from the deep fascia to the skin. 
The Superficial Fascia of both the sole and palm contains granular fat, and is thickest 
over the heel. 
The Cutaneous Nerves are derived from the long and short saphenous, internal and external 
plantar, and internal calcanean nerves. The blood-supply is from the plantar arteries. 
The Deep Fascia (Fig. 176) of the sole of the foot (called the plantar) is dense, strong, 
and homologous to the palmar fascia. It is divided into three parts, central, outer, and inner, 
but these are not entirely separate. Each division corresponds to a muscle: the central, to 
the flexor brevis digitorum; the outer, to the abductor minimi digiti; the inner, to the 
abductor hallucis. 
The Central Part (Fig. 176) of the plantar fascia is thick, strong and triangular, and 
extends from the under surface of the os calcis to the heads of the metatarsal bones, where 
it divides into slips for the toes. The slips are united imperfectly by transverse fibres, and 
are continued forward along the plantar surfaces of the toes as fibrous sheaths for the flexor 
tendons. Each sheath is lined by synovial membrane, which is reflected onto the tendon. 
The Outer Part (Fig. 176) of the plantar fascia covers the abductor minimi digiti muscle, 
is continuous with the dorsal fascia of the foot externally, and blends with the central part 
internally. Origin: (1) Lesser tubercle of the os calcis; (2) external annular ligament. 
Insertion: (1) Base of first phalanx of the fifth toe; (2) deep fascia of the instep. 
The Inner Part (Fig. 176) of the plantar fascia is thin, invests the abductor hallucis, and 
is continuous internally with the dorsal fascia of the foot. It blends with the central part. 
Origin: (1) Under surface of the os calcis; (2) internal annular ligament. Insertion: (1) 
Base of the first phalanx of the great toe; (2) deep fascia of the instep. 
Table of Structures in Sole of Foot According to Layers. 
1. Skin and fasciae. (Fig. 176) . . . 
1. Integument. 
2. Superficial fascia. 
3. Plantar fascia. 
Abductor hallucis. 
Flexor brevis digitorum. 
Abductor minimi digiti. 
2. First layer of muscles. (Fig. 176) . 
Internal plantar nerve. 
Internal plantar vessels. 
External plantar nerve. 
External plantar vessels. 
3. Neurovasal layer. (Fig. 177) . . . 
Flexor accessorius muscle. 
Four lumbrical muscles. 
Flexor longus digitorum. 
Flexor longus hallucis. 
4. Second layer of muscles. (Fig. 177) 
•5. Third layer of muscles. (Fig. 179) 
Flexor brevis hallucis. 
Adductor obliquus hallucis. 
Adductor transversus hallucis. 
Flexor brevis minimi digiti. 
6. Fourth layer of muscles. (Figs. 180, 
181) 
Plantar interossei (three). 
Dorsal interossei (four). 
Tendon of peroneus longus. 
Tendon of tibialis posticus. 
Long calcaneo-cuboid ligament. 
Short calcaneo-cuboid ligament. 
7. Layer of tendons and ligaments. 
(Fig. 182) 328 
A MANUAL OF DISSECTION. 
FIRST LAYER OF MUSCLES. 
The Abductor Hallucis. (Fig. 176.) Origin: (1) Under surface of the os calcis 
and its inner tuberosity; (2) inner part of the plantar fascia; (3) internal 
intermuscular septum; (4) internal annular ligament; (5) tuberosity of the 
scaphoid bone and tendon of tibialis posticus. Insertion: Base of the under 
surface of the first phalanx of the great toe. Action: Abduction of the great 
toe. Synergists: None. Antagonists: Adductor hallucis. Nerve: Internal 
plantar. Artery : Internal plantar, a branch of the posterior tibial. 
Fig. 176. 
Muscles of the superficial layer of the right foot. The plantar fascia remains near the heel 
(Gerrish after Testot.) 
The Flexor Brevis Digitorum. Origin: (1) Inner tuberosity of the os calcis; 
(2) central part of the plantar fascia; (3) internal and external intermuscular 
septa of the plantar fascia. Insertion: Sides of the middle phalanges of the four 
outer toes. Action: Flexion of the second phalanges of the toes. Synergists: 
Tendons of the flexor longus digitorum. Antagonists: Extensor brevis and 
extensor longus digitorum. Nerve: Internal plantar. Arteries : Plantar. 
The Abductor Minimi Digiti. Origin: (1) Under surface and lesser tuberosity 
of the os calcis; (2) outer part of the plantar fascia; (3) external intermuscular 
septum of the plantar fascia. Insertion : Under surface of the base of the first 
phalanx of the little toe. Synergists: None. Antagonist: Third plantar inter- 
osseous muscle. Nerve : External plantar. Artery: External plantar. THE SOLE OF THE FOOT. 
329 
LAYER OF NERVES AND VESSELS. 
The Neurovasal Region consists of the plantar vessels and nerves, and is exposed 
on turning aside the three muscles of the first layer. The plantar nerves begin 
at the bifurcation of the posterior tibial, between the os calcis and internal 
malleolus, beneath the internal annular ligament. The plantar arteries begin in 
a similar manner and place, at the bifurcation of the posterior tibial. (Fig. 177). 
The Internal Plantar Nerve (Fig. 177) begins beneath the internal annular liga- 
ment, at the bifurcation of the posterior tibial. It lies between the first and second 
layers of muscles of the sole of the foot. It accompanies the internal plantar 
artery, and has the following branches : (1) Articular, to tarsal, metatarsal, and 
Fig. 177. 
Plantar nerves. (Gerrish after Testut.) 
phalangeal articulations; (2) cutaneous, to the heel; (3) digital, to the inner 
three and a half toes; (4) muscular, to the abductor hallucis, flexor brevis hal- 
lucis, flexor brevis digitorum, and the innermost part of the lumbrical muscles. 
The distribution of the internal plantar nerve resembles that of the median in 
the hand. (See Gray.) 
The External Plantar Nerve (Fig. 177) begins at the bifurcation of the poste- 
rior tibial. It accompanies the external plantar artery, and is similar in distri- 
bution to the ulnar in the hand. It supplies a larger number of muscles than the 
internal plantar. Branches: (1) To the interossei; (2) to the two lumbricals on the 
outer side; (3) to the abductor hallucis; (4) to the transversus pedis; (5) to the 
flexor accessorius; (6) to the abductor minimi digiti. This nerve has a cutaneous 
distribution to one and a half toes on the fibula side of the foot. 330 
A MANUAL OF DISSECTION. 
The Internal Plantar Artery (Fig. 178) begins with the external plantar, at the 
bifurcation of the posterior tibial, beneath the internal annular ligament, between 
the internal malleolus and the os calcis, and is accompanied by the internal 
plantar nerve. 
The External Plantar Artery (Fig. 178) is larger than the internal. It crosses 
the sole of the foot obliquely to the head of the metatarsal bone of the little 
toe, where it turns abruptly inward and forward to a space between the first and 
second metatarsal bones, and anastomoses with the communicating branches of 
the dorsalis pedis, to form the plantar arch. 
SECOND LAYER OF MUSCLES. (Fig. 178.) 
Fig. 178. 
Fig. 179. 
The plantar arteries. Deep view. 
(Gray.) 
Muscles in the third layer of the right sole. 
(Gerrish after Testut.) 
The Plantar Arch is a continuation of the external plantar artery, and is formed 
by the external plantar and dorsalis pedis. It lies on the interossei muscles. It 
sends off digital branches to three and a half outer toes. At the clefts of the 
toes these send off perforating branches, which pass through the interosseous 
spaces, and communicate with the metatarsal artery, on the dorsum of the foot. 
(The external plantar artery is accompanied by the deep branch of the external 
plantar nerve and venas comites. The digital branches to the three and a half 
toes are homologous to branches of the superficial palmar arch of the hand. The 
blood-supply for the great toe and adjacent half of the second toe (dorsal surface) 
comes from the dorsalis pedis, through two arteries which are homologous to the 
arteria princeps pollicis and radialis indicis in the hand.) (See Gerrish's Anatomy.) 
The Flexor Accessorius Muscle. Origin: (1) Inner surface of the os calcis, 
below the groove for the flexor longus hallucis; (2) the os calcis, in front of the THE SOLE OF THE FOOT. 
331 
outer tuberosity; (3) the long plantar ligament. Insertion: Upper surface and 
outer border of the flexor longus digitorum. Action: Flexion of the last pha- 
langes of the four outer toes. Synergist: Flexor longus digitorum. Antagonists: 
Extensor longus and extensor brevis digitorum. Nerve: External plantar. 
Artery: External plantar. 
The Four Lumbrical Muscles. (Fig. 177.) Origin: The first arises from the 
inner border of the inner tendon of the flexor longus digitorum; (2) the other 
three, from the adjoining surfaces of the first, second, third, and fourth tendons 
of the flexor longus digitorum. Insertion : Inner border of the tendons of the 
extensor longus digitorum. Action: (1) Flexion of the metatarsophalangeal 
joints; (2) extension of the first and second phalangeal joints. Synergists: Flexor 
longus and flexor brevis digitorum and interossei muscles. Antagonists: Exten- 
sor longus and extensor brevis digitorum. Nerve : The inner one, by the internal 
plantar; the three external ones, by the external plantar. Arteries: Plantar. 
THIRD LAYER OF MUSCLES. (Fig. 179.) 
Fig. 180. 
Interossei dorsales of the right foot. The line xx is that from which abduction is made. (Gerrish after Testut.) 
The Flexors, Longus Digitorum, and Longus Hallucis have been described in the dis- 
section of the deep muscles of the back of the leg, page 320. The four tendons of 
the flexor longus digitorum perforate the four corresponding tendons of the flexor 
brevis digitorum; the tendon of the flexor longus hallucis gives a slip to the 
flexor longus digitorum, and lies between the two heads of the flexor brevis 
hallucis in a groove, between two sesamoid bones, at the metatarsophalangeal 
articulation; it is inserted into the base of the last phalanx of the great toe. 
The Flexor Brevis Hallucis. (Fig. 179.) Origin: (1) Plantar ligament and 
continuation of the tendon of the tibialis posticus; (2) under surface of the cuboid 
bone. Insertion : Inner and outer border of the base of the first phalanx of 
the great toe. Synergist: Flexor longus hallucis. Antagonists : The extensor 
longus and extensor brevis hallucis. Nerve: Internal plantar. Arteries: In- 
ternal and external plantar. 332 
A MANUAL OF DISSECTION. 
The Adductor Obliquus Hallucis. (Fig. 179.) Origin : (1) Sheath of the peroneus 
longus, formed by the long plantar ligament (Fig. 182); (2) bases of the second, 
third, and fourth metatarsal bones. Insertion: Base of the first phalanx of the 
great toe. Action: Adduction of the great toe. Synergist: Transversus pedis 
(obliquus transversus hallucis). Antagonist: Abductor hallucis. Nerve: Ex- 
ternal plantar. Artery : External plantar. 
The Adductor Transversus Hallucis. Origin : (1) Plantar ligaments of the three 
outer metatarsophalangeal joints; (2) deep transverse metatarsal ligament. In- 
sertion: Base of the first phalanx of the great toe. Action: Adduction of the 
great toe. Synergist: Adductor obliquus hallucis. Antagonist: Abductor hallucis. 
Nerve: External plantar. Arteries: Plantar. 
Fig. 181. 
Interossei plantares of the right foot. The line x x is that to which adduction is made. (Gerrish after Testut.) 
The Flexor Brevis Minimi Digiti. Origin; (1) Base of the fifth metatarsal 
bone; (2) sheath of the tendon of the peroneus longus. Insertion: Base of the 
first phalanx of the little toe and fifth metatarsal. Action: Flexion of the little 
toe. Synergists : Flexor longus digitorum, flexor brevis digitorum and interossei. 
Antagonist: Extensor longus digitorum. Nerve: External plantar. Artery: 
External plantar. 
FOURTH LAYER OF MUSCLES. (Figs. 180, 181.) 
The Interossei Muscles, named from their position between the metatarsal bones, 
are, like those of the hand, seven in number-three plantar and four dorsal. The 
plantar are small, fusiform bundles ; the dorsal are bipenniform. The interossei of 
the foot differ from those of the hand in that they adduct and abduct with respect 
to the longitudinal axis through the line of the second toe; whereas in the hand 
this axis passes through the middle finger. (Figs. 180, 181.) 
Plantar Interossei (interossei plantares). Origin : (1) Inner and lower surfaces 
of the three outer metatarsal bones ; (2) adjacent part of the sheath of the 
peroneus longus tendon. Insertion : Inner side of the bases of the first phalanges THE SOLE OF THE FOOT. 
333 
of the three outer toes and inner border of the expansions of the long extensor 
tendons on the back of the first phalanges of the same toes. 
The Dorsal Interossei (interossei dorsales) arise from the adjacent surfaces of the 
metatarsal bones. The first differs in its internal head, which arises from 
the base only of the first metatarsal bone and the adjacent outer surface of the 
internal cuneiform bone. Insertion: (1) Inner side of the base of the first 
phalanx of the second toe; (2) inner edge of the aponeurosis of the extensor 
longus digitorum tendon, back of the first phalanx. The second, third, and 
fourth are inserted respectively into (a) the outer side of the bases of the first 
phalanges of the second, third, and fourth toes; (6) the outer border of the extensor 
tendon, on the back of the same phalanges. Action: Interossei, acting with the 
lumbricales, produce flexion of (1) the metatarsophalangeal articulation of the 
four outer toes ; (2) extension of the second and third phalanges. Synergists : 
Lumbricales. Special action of the plantar interossei, adduction of the three 
outer toes; special action of the dorsal interossei, abduction of the second, third, 
and fourth toes. Nerve : External plantar. Arteries : Plantar. 
LAYER OF TENDONS AND LIGAMENTS. (Fig. 182.) 
Fig. 182. 
The plantar ligaments. (Gerrish alter Testut.) 
Tendon of Tibialis Posticus. (Fig. 182.) Insertion: (1) Tuberosity of the 
scaphoid bone; (2) fibrous slips to every bone of the tarsus except the astragalus, 
and also the bases of the second, third, and fourth metatarsal bones. A sesamoid 
bone is in this tendon under the head of the astragalus. 
The Tendon of the Peroneus Longus passes through a groove in the under surface 
of the cuboid bone, thence, through an osseo-aponeurotic canal, to the base of the 
metatarsal bone of the great toe and the internal cuneiform bone, into both of 
which it is inserted. The osseo-aponeurotic canal is lined by a synovial mem- 
brane. (Fig. 182) 
The Long Calcaneo-cuboid Ligament (long plantar) is attached posteriorly to the 
under surface of the calcaneum (os. calcis). Most of its fibres pass directly for- 334 
A MANUAL OF DISSECTION. 
ward and are fixed to the outer two-thirds of the oblique ridge, behind the pero- 
neal groove on the cuboid, while some pass further forward and inward, expand- 
ing into a broad layer, and are inserted into the bases of the second, third, fourth, 
and inner half of the fifth metatarsals. This anterior expanded portion com- 
pletes the canal of the peroneus longus tendon. From the under surface of the 
ligament arise the adductor obliquus hallucis and the flexor brevis minimi digiti 
muscles. 
The Short Calcaneo-cuboid Ligament (short plantar) is attached to the rounded 
eminence of the upper surface of the calcaneum, to the bone in front of it, and to 
the inferior surface of the cuboid, behind the oblique ridge. (Fig. 182.) 
Table of Muscles of the Lower Extremity. 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Psoas magnus 
1. Front of bases and 
Lesser trochanter of 
Anterior 
1. Iliolumbar 
(m. psoas 
lower borders of 
femur, after having 
branches of 
branch of in- 
major). 
transverse processes 
of lumbar vertebrae 
by five slips. 2. 
Sides of bodies and 
intervertebral disks 
of twelfth dorsal and 
all the lumbar ver- 
tebrae. 
received nearly all 
the fibres of the 
iliacus muscle. 
second and 
third lumbar 
nerves. 
ternal iliac. 
2. Lumbar 
branches of 
aorta. 
Psoas parvus 
Sides of bodies of the 
Uiopectineal eminence 
Anterior branch 
Lumbar 
(may be ab- 
sent) (m. 
psoas minor.) 
twelfth dorsal and 
first lumbar verte- 
brae and their inter- 
vertebral disk. 
and iliac fascia. 
of first lumbar 
nerve. 
branches of 
abdominal 
aorta. 
Iliacus (m. 
1. Upper two-thirds of 
1. Outer side of tendon 
Anterior 
Iliolumbar 
iliacus). 
iliac fossa. 2. In- 
ner margin of iliac 
crest. 3. Ilio- 
lumbar ligament 
and base of sacrum. 
4. Anterior superior 
and anterior infe- 
rior spines of ilium 
and notch between. 
5. Capsule of hip. 
of psoas magnus. 
2. Shaft of femur, 
below and in front 
of lesser trochanter. 
branches of 
second and 
third lumbar 
nerves 
through the 
anterior 
crural. 
branch of in 
ternal iliac. 
Tensor fasciae 
1. Anterior part of 
Between two layers of 
Superior 
Superior 
femoris (m. 
tensor fasciae 
latae). 
outer lip of iliac 
crest. 2. Outer sur- 
face of anterior supe- 
rior spinous process 
of ilium. 3. Gluteal 
fascia. 
fascia lata, in upper 
one-third of outer 
surface of thigh. 
gluteal. 
gluteal and 
external cir- 
cumflex. 
Sartorius (m. 
sartorius). 
Anterior superior 
spine of ilium and 
upper one-third of 
notch below. 
Upper part of inner 
surface of shaft of 
tibia by aponeurosis 
which covers inser- 
tion of semitendino- 
sus and gracilis. 
Anterior 
crural. 
Femoral. 
Rectus femoris 
(m. rectus 
femoris). 
1. Anterior inferior 
iliac spine. 2. 
Groove above ace- 
tabulum. 
Tubercle of tibia 
through ligamentum 
patella with vasti. 
Anterior 
crural. 
Femoral. 
Vastus externus 
1. Upper one-half of 
Outer border of 
Anterior 
Femoral, 
(m. vastus 
lateralis). 
anterior intertro- 
chanteric line. 2. 
Anterior and infe- 
rior borders of root 
of great trochanter. 
3. Anterior lip of 
gluteal ridge. 4. 
Upper one-half of 
outer lip of linea 
aspera. 
patella. 
crural. 
through ex- 
ternal cir- 
cumflex. THE SOLE OF THE FOOT. 
335 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Vastus interims 
(m. vastus 
medialis). 
1. Lower one-half of 
anterior intertro- 
chanteric line. 2. 
Spiral line. 3. In- 
ner lip of linea 
aspera. 4. Upper 
part of supracondy- 
lar line. 5. Tendon 
of adductor magnus. 
6. Internal inter- 
muscular septum. 
Inner border of patella 
and quadriceps ex- 
tensor tendon. 
Anterior 
crural. 
Femoral. 
Crureus (m. 
vastus inter- 
medius). 
1. Front and outer 
part of upper two- 
thirds of shaft of 
femur. 2. Lower 
part of external in- 
termuscular septum. 
Aponeurosis forming 
deep part of quad- 
riceps femoris. 
Anterior 
crural. 
Femoral. 
Subcrureus (m. 
articularis 
genu). 
Anterior surface of 
lower part of shaft 
of femur. 
Upper part of capsular 
ligament of knee. 
Anterior 
crural. 
Femoral. 
Gracilis (m. 
gracilis). 
1. Lower one-half of 
margin of symphy- 
sis. 2. Anterior 
one-half of pubic 
arch. 
Upper part of inner 
surface of shaft of 
tibia below tuber- 
osity and beneath 
sartorius. 
Obturator. 
Obturator and 
femoral. 
Pectineus (m. 
_1. Uiopectineal line. 
Line leading from 
Anterior crural 
Femoral and 
pectineus). 
2. Pectineal fascia. 
lesser trochanter to 
linea aspera. 
and accessory 
obturator. 
obturator. 
Adductor 
longus (m. 
adductor 
longus). 
Front of os pubis be- 
low pubic crest. 
Linea aspera between 
vastus internus and 
adductor magnus. 
Obturator. 
Obturator ; per- 
forating 
branches of 
profunda 
femoris. 
Adductor 
brevis (m. 
adductor 
brevis). 
1. Outer surface of 
body and descending 
ramus of pubic bone, 
between gracilis and 
obturator externus. 
Line leading from 
lesser trochanter to 
linea aspera. 
Obturator. 
Obturator; per- 
forating 
branches of 
profunda 
femoris. 
Adductor 
1. Descending ramus 
1. Line leading from 
Obturator and 
Femoral ; per- 
magnus (m. 
adductor 
magnus). 
of pubic bone. 2. 
Ramus of ischium. 
greater trochanter to 
linea aspera internal 
to gluteus maximus. 
2. Linea aspera and 
internal condylar 
ridge; adductor tu- 
bercle of femur. 
great sciatic. 
forating 
branches of 
profunda 
femoris. 
Gluteus maxi- 
mus (m. 
glutaeus 
maximus). 
1. Superior curved 
line of ilium. 2. 
Iliac crest behind 
superior curved line. 
3. Posterior surface 
of lower part of 
sacrum. 4. Side of 
coccyx. 5. Aponeu- 
rosis of erector 
spinae. 6. Great 
sacrosciatic liga- 
ment. 7. Fascia 
covering gluteus 
medius. 
1. Fascia lata on outer 
side of thigh. 2. 
Line leading from 
greater trochanter to 
linea aspera. 
Inferior gluteal. 
Superior and in- 
ferior gluteal. 
Gluteus medius 
1. Outer surface of 
Oblique line of greater 
Superior 
Superior 
(m. glutaeus 
medius). 
ilium, between supe- 
rior and middle 
curved lines. 2. 
Outer lip of iliac 
crest, between supe- 
rior and middle 
curved lines. 3. 
Gluteal aponeurosis. 
trochanter. 
gluteal. 
gluteal. 
Gluteus mini- 
1. Outer surface of 
Anterior border of 
Superior 
Superior 
mus (m. 
glutaeus mini- 
mus). 
ilium, between mid- 
dle and inferior 
curved lines. 2. 
Margin of greater 
sacrosciatic notch. 
greater trochanter. 
gluteal. 
gluteal; 
external 
' circumflex. 336 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Pyriformis (m. 
pyriformis). 
1. Front of sacrum by 
three digitations be- 
tween first, second, 
third, and fourth 
anterior sacral fora- 
mina. 2. Margin of 
great sacrosciatic 
foramen. 
Upper border of great 
trochanter. 
First and second 
sacral nerves. 
Sciatic. 
Obturator in- 
ternus (m. 
obturator in- 
ternus). 
1. Inner surface of 
anterior and external 
wall of pelvis. 2. 
Obturator mem- 
brane. 3. Arch of 
obturator canal. 
Forepart of inner sur- 
face of greater tro- 
chanter. 
Fifth lumbar, 
first and sec- 
ond sacral. 
Sciatic. 
Gemellus supe- 
Outer surface of ischial 
With obturator in- 
Fifth lumbar, 
Sciatic and ex 
rior (m. 
gemellus 
superior). 
spine. 
ternus into inner 
surface of greater 
trochanter. 
first and sec- 
ond sacral. 
ternal cir- 
cumflex. 
Gemellus infe- 
Upper part of ischial 
Inner surface of greater 
Last lumbar and 
Sciatic and 
rior (m. 
gemellus 
tuberosity. 
trochanter with ob- 
turator internus. 
first sacral. 
external 
circumflex. 
inferior). 
Quadratus 
External lip of ischial 
Linea quadrata of 
Last lumbar and 
Sciatic and 
femoris (m. 
quadratus 
tuberosity. 
femur. 
first sacral. 
internal 
circumflex. 
femoris). 
Obturator ex- 
ternus (m. 
obturator 
externus). 
1. Margin of obtura- 
tor. 2. Obturator 
membrane. 3. Arch 
of obturator canal. 
Digital fossa of femur. 
Obturator. 
Obturator and 
femoral. 
Biceps (m. bi- 
1. Lower and inner 
1. Outer side of head 
Great sciatic- 
Perforating 
ceps femoris ; 
impression on back 
of fibula. 2. Lateral 
a nerve for 
branches of 
caput 
longum ; 
caput breve). 
of tuberosity of 
ischium and greater 
sacrosciatic liga- 
ment. 2. Outer lip 
of linea aspera. 3. 
External condylar 
ridge. 4. External 
intermuscular sep- 
tum. 
surface of external 
tuberosity of tibia. 
each head. 
profunda 
femoris. 
Semitendinosus 
(m. semi- 
tendinosus). 
1. Lower and inner 
impression of ischial 
tuberosity with long 
head of biceps. 3. 
Deep fascia. 
Upper part of inner 
surface of shaft of 
tibia. 
Great sciatic. 
Perforating 
branches of 
profunda 
femoris. 
Semimem- 
branosus (m. 
semimem- 
branosus). 
Upper and outer im- 
pression on back of 
ischial tuberosity. 
1. Groove on inner 
and back part of 
inner tuberosity of 
tibia beneath inter- 
nal lateral ligament. 
2. Outer condyle of 
femur, forming a 
part of Winslow's 
ligament. 3. Ob- 
lique line of tibia. 
4. Internal lateral 
ligament of knee. 
Great sciatic. 
Perforating 
branches of 
profunda 
femoris. 
Tibialis anticus 
(m. tibialis 
anterior). 
1. Outer tuberosity 
and upper two-thirds 
of external surface 
of shaft of tibia. 2. 
Interosseous mem- 
brane and investing 
deep fascia. 3. Ad- 
jacent intermuscular 
septum. 
Inner and under sur- 
face of internal 
cuneiform bone. 2. 
Base of first meta- 
tarsal bone. 
Anterior tibial. 
Anterior tibial 
artery. 
Extensor pro- 
prius hallucis 
. (m. extensor 
hallucis 
1. Middle two-fourths 
of anterior surface 
of fibula. 2. Inter- 
osseous membrane. 
Base of last (second) 
phalanx of great toe. 
Anterior tibial. 
Anterior tibial 
artery. 
longus). THE SOLE OF THE FOOT. 
337 
Name. 
Origin. 
Insertion. 
Nem. 
Blood-supply. 
Extensor longus 
1. Outer tuberosity of 
Second and third pha- 
Anterior tibial. 
Anterior tibial 
digitorum 
(m. extensor 
digitorum 
longus). 
tibia. 2. Upper 
three-fourths of an- 
terior surface of 
fibula. 3. Interos- 
seous membrane. 4. 
Deep fascia and 
intermuscular septa. 
langes of four lesser 
toes. The tendons 
of the second, third, 
and fourth toes are 
joined by tendons 
of the extensor 
brevis digitorum. 
artery. 
Peroneus 
1. Lower one-fourth of 
Dorsal surface of base 
Anterior tibial. 
Anterior tibial 
tertius (m. 
peronaeus 
tertius). 
anterior surface of 
fibula. 2. Interos- 
seous membrane. 3. 
Deep fascia and in- 
termuscular septa. 
of fifth metatarsal 
bone. 
artery. 
Gastrocnemius 
1. Depression on upper 
Unites with soleus, 
Internal 
Popliteal 
(m. gastroc- 
nemius: caput 
laterale; ca- 
put mediale). 
and back of inner 
condyle. 2. Impres- 
sion on outer side of 
external condyle and 
posterior surface of 
femur above con- 
dyle. 
forming tendo 
Achillis, which is 
inserted into the 
posterior surface of 
os calcis. 
popliteal. 
artery. 
Soleus (m. 
1. Back of head of 
Joins gastrocnemius, 
Internal 
Popliteal 
soleus: arcus 
fibula. 2. Upper 
to form the tendo 
popliteal and 
artery. 
tend ineus 
musculi 
solei). 
one-third of poste- 
rior surface of shaft 
of fibula. 3. Ob- 
lique line of tibia 
and middle one- 
third of internal 
border. 
Achillis. 
posterior 
tibial. 
Plantaris (m. 
Lower part of external 
Posterior surface of os 
Internal 
Popliteal 
plantaris). 
supracondylar ridge. 
2. Ligament of 
Winslow. 
calcis ; internal an- 
nular ligament or 
plantar fascia. 
popliteal. 
artery. 
Popliteus (m. 
1. Depression on outer 
Inner two-thirds of 
Internal 
Popliteal 
popliteus). 
side of external con- 
dyle of femur. 2. 
Posterior ligament 
of knee. 
triangular surface 
above oblique line 
of tibia. 2. Ten- 
dinous expansion of 
semimembranosus 
covering this muscle. 
popliteal. 
artery. 
Flexor longus 
1. Lower two-thirds of 
Base of last phalanx 
Posterior 
Posterior 
hallucis (m. 
flexor hallu- 
cis longus). 
posterior surface of 
fibula. 2. Interos- 
seous membrane. 3. 
Intermuscular septa 
and fascia covering 
tibialis posticus. 
of great toe. 
tibial. 
tibial 
artery. 
Flexor longus 
1. Posterior surface of 
By four tendons into 
Posterior 
Posterior 
digitorum 
shaft of tibia below 
bases of distal pha- 
tibial. 
tibial 
(m flexor 
digitorum 
longus). 
oblique line. 2. 
Fascia of tibialis 
posticus. 
langes of four outer 
toes. 
Posterior 
artery. 
Tibialis posticus 
1. Interosseous mem- 
1. Tuberosity of navic- 
Posterior 
(m. tibialis 
posterior). 
brane. 2. Outer 
ular and internal 
tibial. 
tibial 
part of posterior 
surface of shaft of 
tibia. 3. Upper 
two thirds of inter- 
nal surface of fibula. 
4. Deep transverse 
fascia and intermus- 
cular septa. 
cuneiform. 2. Sus- 
tentaculum tali, 
middle and external 
cuneiform, and 
cuboid. 3. Bases of 
second, third, and 
fourth metatarsal 
bones. 
artery. 
Peroneus longus 
1. Head and upper 
Outer side of base of 
Muscular 
Peroneal 
(m. peronseus 
two-thirds of outer 
metatarsal bone of 
branches of 
artery. 
longus). 
surface of fibula. 2. 
Deep fascia and in- 
termuscular septa. 
great toe. 
musculo- 
cutaneous. 
Peroneus brevis 
1. Lower two-thirds of 
Tuberosity of base of 
Muscular 
Peroneal 
(m. peronaeus 
external surface of 
metatarsal bone of 
branches of 
artery. 
brevis). 
fibula. 2. Inter- 
muscular septa. 
little toe. 
musculo- 
cutaneous. K 338 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Extensor brevis 
1. Forepart of upper 
1. The innermost 
Anterior 
Dorsalis pedis 
digitorum 
(m. extensor 
digitorum 
brevis). 
and outer surface of- 
os calcis. 2. Ex- 
ternal calcaneo- 
astragaloid ligament. 
3. Annular ligament. 
tendon into the 
dorsal surface of base 
of first phalanx of 
great toe. 2. The 
three other tendons 
into the second and 
third phalanges of 
the second, third, 
and fourth toes with 
tendons of extensor 
longus digitorum. 
tibial. 
artery. 
Abductor 
1. Inner tubercle on 
Inner side of base of 
Internal 
Internal 
hallucis (m. 
abductor 
hallucis). 
under surface of os 
calcis. 2. Internal 
annular ligament, 
plantar fascia, and 
intermuscular 
septum. 
first phalanx of great 
toe with flexor brevis 
hallucis. 
plantar. 
plantar 
artery. 
Flexor brevis 
1. Inner tubercle of os 
Sides of second 
Internal 
Plantar 
digitorum 
(m. flexor 
digitorum 
brevis). 
calcis. 2. Central 
part of plantar 
fascia. 3. Inter- 
muscular septum. 
phalanges of four 
outer toes-about 
their middle. 
plantar. 
arteries. 
Abductor 
1. Outer and inner 
Outer side of base of 
Externa 
External 
minimi digiti 
(m. abductor 
minimi 
digiti). 
tubercles of os calcis 
and ridge of bone 
between. 2. Plantar 
fascia and intermus- 
cular septum. 
first phalanx of little 
toe with flexor 
brevis minimi 
digiti. 
plantar. 
plantar 
artery. 
Flexor accesso- 
1. Inner surface of os 
Outer margin, upper 
External 
External 
rius (m.quad- 
ratus plantae). 
calcis below groove 
for tendon of flexor 
longus hallucis. 2. 
Outer surface of os 
calcis in front of 
outer tubercle. 3. 
Long plantar liga- 
ment. 
and under surfaces 
of tendon of flexor 
longus digitorum. 
plantar. 
plantar 
artery. 
Lumbricals,four 
Tendons of flexor 
Tendons of extensor 
The internal 
Plantar 
in number 
(mm. lum- 
bricales). 
longus digitorum, 
each arising by 
two heads, except 
the inner. 
longus digitorum, 
on inner side of 
dorsum of first 
phalanx. 
plantar sup- 
plies the 
innermost 
muscle ; the 
external, the 
other three. 
arteries. 
Flexor brevis 
1. Under surface of 
Inner and outer sides 
Internal 
Internal 
hallucis (m. 
flexor hallu- 
cis brevis). 
cuboid bone 2. Ex- 
ternal cuneiform 
bone. 3. Tendon of 
tibialis posticus. 
of base of first 
phalanx of great toe. 
plantar. 
plantar 
artery. 
Adductor 
1. Tarsal ends of 
Outer side of base of 
External 
Plantar 
obliquus 
hallucis (m. 
adductor hal- 
lucis : caput 
obliquum and 
caput trans- 
versum). 
second, third, and 
fourth metatarsal 
bones. 2. Sheath of 
tendon of peroneus 
longus. 
first phalanx of great 
toe with outer part 
of flexor brevis . 
hallucis. 
plantar. 
arteries. 
Flexor brevis 
1. Base of first meta- 
Base of first phalanx 
External 
External 
minimi digiti 
(m. flexor 
digiti quinti 
brevis). 
tarsal bone of little 
toe. 2. Sheath of 
peroneus longus. 
of little toe on outer 
side. 
plantar. 
plantar 
artery. 
Adductor 
Inferior metatarso- 
Outer side of first 
External 
External 
transversus 
hallucis 
(transversus 
pedis). 
phalangeal liga- 
ments of three outer 
toes. 
phalanx of great 
toe. 
plantar. 
plantar 
artery. 
First dorsal 
Adjacent surfaces of 
1. Inner side of base 
External 
Plantar 
interosseous 
muscle (m. 
interosseus 
dorsalis I.). 
first and second 
metatarsal bones. 
of first phalanx of 
second toe. 2. Com- 
mon extensor 
tendon. 
plantar. 
arteries. THE SOLE OF THE FOOT. 
339 
Name. 
Origin. 
Insertion. 
Nerve. 
Blood-supply. 
Second dorsal 
Adjacent surfaces of 
1. Outer side of base of 
External 
Plantar 
interosseus 
muscle (m. 
interosseus 
dorsalis IL). 
second and third 
metatarsal bones. 
first phalanx of sec- 
ond toe. 2. Apon- 
eurosis of common 
extensor tendon. 
plantar. 
arteries. 
Third dorsal 
Adjacent surfaces of 
1. Outer side of base of 
External 
External 
interosseous 
third and fourth 
first phalanx of third 
plantar 
plantar 
muscle (m. 
interosseus 
dorsalis III.). 
metatarsal bones. 
toe. 2. Common 
extensor tendon. 
nerve. 
artery. 
Fourth dorsal 
Adjacent surfaces of 
1. Outer side of base of 
External 
Plantar 
interosseous 
muscle (m. 
interosseus 
dorsalis IV.). 
fourth and fifth 
metatarsal bones. 
first phalanx of 
fourth toe. 2 Com- 
mon extensor 
tendon. 
plantar. 
arteries. 
First plantar 
Base and inner side of 
1. Inner side and base 
External 
External 
interosseous 
muscle. 
third metatarsal 
bone. 
of first phalanx of 
third toe. 2. Com- 
mon extensor 
tendon. 
plantar. 
plantar 
artery. 
Second plantar 
Inner side and base of 
1. Inner side and base 
External 
External 
interosseous 
muscle. 
fourth metatarsal 
bone. 
of first phalanx of 
fourth toe. 2. Com- 
mon extensor 
tendon. 
plantar. 
plantar 
artery. 
Third plantar 
Inner side and base of 
1. Inner side and base 
External 
External 
interosseous 
muscle. 
fifth metatarsal 
bone. 
of first phalanx of 
fifth toe. 2. Com- 
mon extensor 
tendon. 
plantar. 
plantar 
artery. CHAPTER XXIX. 
THE BACK. 
Dissection and Identification. Remove integument. Study carefully illustrations, so as 
not to overlook the cutaneous vessels and their accompanying nerves. (Fig. 185.) Study 
origin and insertion, nerve-supply and blood-supply of muscles in the tables. Consult Gray 
and Gerrish for function and details. Make skin incisions according to Fig. 183. Dissect 
structures in the order given in the following identification. Consult the illustrations and 
study the text. 
Superficial Fascia. (Fig. 183.) Identify (1) by the location immediately beneath the in- 
tegument and the presence of granular fat; (2) by the free mobility it confers on the skin, 
even in very emaciated persons. 
Six Upper Dorsal Cutaneous Nerves (Fig. 185) (ramicutanei dorsales). Identify (1) by the 
location near the six upper dorsal spines and distribu- 
tion to the integument; (2) by piercing the trapezius 
and rhomboidii muscles. These nerves are from the 
internal branches of the posterior divisions of the dorsal 
nerves, and emerge between the multifidus spinee and 
semispinalis dorsi. 
Six Lower Dorsal Cutaneous Nerves (Fig. 185) (rami 
cutanei dorsales). Identify (1) by the location in line 
with the angles of the ribs; (2) by piercing the latissi- 
mus dorsi, serratus posticus inferior, and ramifying in 
the integument. They are derived from the external 
branches of the posterior divisions. Identify the lum- 
bar cutaneous nerves in the same way. 
Dorsal Cutaneous Vessels (rami cutanei dor- 
sales). Identify (1) by the location and association 
with the cutaneous nerve above identified. (Fig. 185.) 
They are derived from the dorsal branches of the 
intercostal and lumbar nerves. 
Suboccipital Nerve (Fig. 184) (n. suboccipitalis), 
posterior division of the first cervical nerve. Identify 
(1) by the location in the suboccipital triangle, which 
it enters between the vertebral artery and the arch of 
the atlas; (2) by the distribution of the muscular 
branches to the boundary and roof-muscles of the sub- 
occipital triangle. (This nerve is one of the most 
deeply located, as well as the most difficult structure 
in this region to dissect, and its identification is given 
in this place with the cutaneous nerves as a matter of 
routine only.) 
Great Occipital Nerve (Fig. 184) (n. occipitalis 
major), posterior division (internal branch) of the sec- 
ond cervical nerve. Identify (1) by the large size and 
distribution to the scalp ; (2) by piercing the trapezius 
and complexus near the superior curved line, about two 
inches from the external occipital protuberance ; (3) by 
association with the occipital artery in the scalp distri- 
bution. See table, page 352, for third occipital, fourth, 
fifth, sixth, seventh, and eighth cervical nerves, poste- 
rior divisions. 
uccipnai Artery tgs. 154: ana 159) (a. occipitalis). Identify (1) by the location near the 
superior curved line, where it pierces the fascia at the junction of the trapezius and sterno- 
mastoid muscles; (2) by association with the great occipital nerve and general location some- 
what external to this latter. The occipital vein and its tributaries correspond to the occipital 
artery and its branches. 
Deep Fascia (fascia profunda). Identify (1) by the location immediately beneath the 
superficial fascia with its mass of granular fat; (2) by its very frail structure and attachment to 
the occipital bone, spinous processes, scapular spine, and iliac crest. The muscles of the first 
group (trapezius and latissimus dorsi) are readily seen through the deep fascia, and this latter 
is continuous with the deep fascia of the axilla, chest, and abdominal walls. 
Latissimus Dorsi Muscle. (Fig. 185) Identify (1) by the broad origin, including the 
sacral, lumbar, and six lower dorsal spines; (2) by the upward, forward, and outward direction 
across the inferior angle of the scapular to the humerus. 
Fig. 183. 
Dissection of the muscles of the back. 
(Gray.) THE BACK. 
341 
Ligamentum Nuchse. (Fig. 185.) Identify (1) by the location between the muscles of the 
right and left sides of the back of the neck; (2) by the extent from the external occipital 
protuberance to the spine of the seventh cervical vertebra; (3) by the attachment to the cer- 
vical spines and external occipital crest. 
Vertebral Aponeurosis (fascia lumbodorsalis). Identify (1) by the location between 
the muscles acting on the shoulder girdle and those acting on the head and neck; (2) by its 
attachments-internally, to the dorsal spines ; externally, to the angles of the ribs ; below, to 
the serratus posticus inferior; above, to the deep cervical fascia. 
The Lumbar Fascia (or vertebral aponeurosis of the transversalis muscle) divides into an 
anterior thin layer attached to the front of the lumbar transverse processes and twelfth 
rib, forming the ligamentum arcuatum externum; a middle layer, attached to the apices of 
the spinous processes ; the quadratus lumborum lies between the anterior and middle layers ; 
the erector spinse between the middle and posterior layers ; the posterior layer receives the 
attachment of the internal oblique, and, blending with the aponeuroses of the serratus posticus 
inferior and latissimus dorsi, forms the lumbar fascia. 
Fig. 184. 
Dorsal primary divisions of the upper three cervical nerves. (Gerrish after Testut.) 
Trapezius Muscle. (Fig. 185.) Identify (1) by the extensive central attachment to the 
occipital bone, ligamentum nuchae, vertebra prominens, and dorsal spines ; (2) by the inser- 
tion into the scapular spine, acromion, and clavicles. Having thoroughly identified the 
muscle, put the same on the stretch, and with a sharp scalpel remove the deep fascia so as to 
demonstrate the direction of its muscular fibres. 
Spinal Accessory Nerve and Branches of the Third and Fourth Cervical Nerves to 
the Trapezius Muscle. (Fig. 59.) Identify (1) by the location, entering beneath the ante- 
rior margin of the trapezius; (2) the spinal accessory nerve pierces the sternomastoid muscle, 
crosses the posterior triangle of the neck, and enters the trapezius with the branches of the 
third and fourth cervical. 
Subtrapezial Region. (Fig. 186.) Removal of the trapezius exposes, partially or com- 
pletely, the complexus, splenius, levator anguli scapulae, rhomboidei minor and major, supra- 
spinatus, infraspinatus, vertebral aponeurosis, spinal accessory nerve, third and fourth cervical 
nerves, and the superficial cervical artery, a branch of the arteria princeps cervicis of the 
occipital artery. (Fig. 190.) 
Transversalis Colli Artery. Identify (1) by the course through the subclavian triangle 
across the scaleni muscles, phrenic nerve, and brachial plexus to the anterior margin of the 
trapezius; (2) by the division of the artery beneath the anterior margin of the trapezius, 
into the superficial cervical and posterior scapular. The posterior scapular passes beneath the 
levator anguli scapulae, along the posterior border of the scapula, beneath the rhomboid 
muscles, anastomosing with the suprascapular, subscapular, and posterior branches of the 
intercostal arteries. 
Levator Anguli Scapulae. (Fig. 186.) Identify (1) by the insertion into the posterior 
border of the scapula, between its superior angle and the root of the spine; (2) by the origin 
from the transverse processes of the upper five cervical vertebrae ; (3) by the presence of 
the posterior scapular artery, which passes beneath this muscle and the rhomboids. 
Rhomboid Muscles. (Fig. 186.) Identify (1) by the insertion into the posterior border of 
the scapula between the root of the scapular spine and the inferior angle; (2) by the origin 342 
A MANUAL OF DISSECTION. 
from the spinous processes extending from the seventh cervical to the fifth dorsal; (3) by 
the presence of the posterior scapular artery (branch of the transversalis colli of the thyroid 
axis) beneath these, and the levator anguli scapulae ; (4) by the presence of the nerve for these 
muscles in the cellular interval between the levator anguli scapulae and rhomboids. 
Posterior Scapular Artery. Identify (1) by the location beneath the levator anguli 
scapulae and rhomboidei muscles, near the posterior border of the scapula; (2) by the deriva- 
tion from the transversalis colli (with the superficial cervical artery) beneath the anterior 
border of the trapezius muscle. 
Serratus Posticus Superior. (Fig. 186.) Identify (1) by the origin from the ligamentum 
nuchae and spines of the seventh cervical, first, second, third, and fourth upper dorsal verte- 
brae; (2) by the direction of its fibres downward and outward, and their insertion into the 
upper borders of the second, third, fourth, and fifth ribs, external to their angles ; (3) by the 
location beneath the trapezius, rhomboids, and levator anguli scapulae muscles. 
Fig. 185. 
Dorsal primary divisions of the spinal nerves. (Gerrish after Testut.) 
Serratus Posticus Inferior. (Fig. 186.) Identify (1) by the origin from the eleventh and 
twelfth dorsal, first, second, and third lumbar spines; (2) by the insertion into the lower 
borders of the ninth, tenth, eleventh, and twelfth ribs, beyond their angles; (3) by the direc- 
tion of the fibres upward and outward ; (4) by the location beneath the latissimus dorsi. 
Splenius. (Fig. 186.) Identify (1) by the origin from the seventh cervical and sixth 
upper dorsal spines and lower half of the ligamentum nuchae; (2) by the insertion into the 
mastoid process of the temporal bone and the posterior tubercles of the transverse processes 
of the first, second, and third cervical vertebrae; (3) by the location beneath the trapezius, 
rhomboids, and serratus posticus superior. 
Oomplexus. (Fig. 187.) Identify (1) by the origin from the transverse processes of the 
six or seven upper dorsal and seventh cervical vertebrae, and the articular processes of the THE BACK. 
343 
fourth, fifth, and sixth cervical; (2) by the insertion into the occipital bone, between the two 
curved lines. 
Anastomosis, Superficial. Identify (1) by the location between the splenius and com- 
plexus muscles; (2) by its composition: superficial branch of the arteria princeps cervicis 
(occipital branch) and the superficial cervical artery (from the transversalis colli). 
Anastomosis, Deep. (Fig. 190.) Identify (1) by the location between the complexus and 
semispinalis colli; (2) by its composition: deep branch of the arteria princeps cervicis 
and the deep cervical artery (superior intercostal branch). 
The remaining muscles are to be identified by reference to the consecutive illustrations 
and the table of muscles. 
Table of Muscles of the Back. 
Name. 
First Layer. 
Origin. 
Insertion and Nerve-supply. 
Trapezius. It has three 
varieties of fibres founded 
on direction toward their 
insertion (m. trapezius). 
(Fig. 185.) 
1. 
External occipital protuber- 
ance. 2. Inner third superior 
curved line. 3. Ligamentum 
nuchee. 4. Vertebra promi- 
nens. 5. The twelve dorsal 
spines. 6. Supraspinous liga- 
ment. 
The superior fibres are inserted into 
outer third of posterior border of 
clavicle; the middle fibres, into inner 
margin of acromion process and 
superior lip of posterior border of 
scapular spine ; the inferior fibres 
into tubercle at inner end of scapular 
spine. Nerves: anterior divisions 
of third and fourth cervical, spinal 
accessory (the eleventh cranial). 
Latissimus dorsi. The 
upper fibres of this mus- 
cle are horizontal; the 
middle, oblique; the 
lower, vertical (m. latis- 
simus dorsi). (Fig. 185.) 
1. 
From sacral, lumbar, and 
six lower dorsal spines. 2. 
Outer lip of iliac crest. 3. 
The four lower ribs. 4. Pos- 
terior layer of lumbar apo- 
neurosis. 
Second Layer. 
Inserted into bottom of bicipital groove 
of humerus, higher than insertion of 
teres major. The muscle curves 
around teres major, so that the supe- 
rior fibres are posterior and inferior 
in succession, and the vertical fibres 
anterior and superior. Nerve: long 
subscapular from posterior cord of 
brachial plexus. 
Levator anguli scapulae 
(m. levator anguli 
scapulae). (Fig. 186.) 
1. 
Transverse process of atlas 
and second, third, and fourth 
cervical vertebrae; posterior 
tubercles. 
Inserted into posterior border of sca- 
pula, between superior angle and 
root of spine. Nerves: anterior 
divisions of third and fourth cervi- 
cals. 
Rhomboideus minor (m. 
rhomboideus minor). 
(Fig. 186.) 
1. 
Ligamentum nuchae. 2. 
Seventh cervical and first dor- 
sal spines. 3. Supraspinous 
ligament. 
Inserted into margin of triangular, 
smooth surface at root of scapular 
spine. Nerve: anterior division of 
fifth cervical. 
Rhomboideus major (m. 
rhomboideus major). 
(Fig. 186.) 
1. 
Spinous processes of four or 
five upper dorsal vertebrae. 
2. Supraspinous ligament. 
Third Layer. 
Inserted into a narrow tendinous arch, 
extending from root of scapular 
spine to inferior scapular angle. 
Nerve: anterior division of fifth 
cervical. 
Serratus posticus superior 
(m. serratus posterior 
superior). Find beneath 
rhomboid muscles. 
(Fig. 186.) 
1. 
Ligamentum nuchae. 2. 
Spinous processes of seventh 
cervical and first, second, 
third, and fourth upper dor- 
sal vertebrae. 3. Supraspin- 
ous ligament. 
Inserted into upper borders of second, 
third, fourth and fifth ribs, beyond 
their angles. Nerves: posterior 
divisions of spinals. 
Serratus posticus inferior 
(m. serratus posterior 
inferior). 
1. 
Spinous processes of eleventh 
and twelfth dorsal and first, 
second, and third lumbar ver- 
tebrae. 2. Supraspinous liga- 
ment. 
Inserted into lower borders of ninth, 
tenth, eleventh, and twelfth ribs, 
beyond their angles. Nerves : pos- 
terior divisions of spinals. 
Splenius (m. splenius). 
(Figs. 186 and 187.) 
Splenius capitis (m. 
splenius capitis). 
1. 
Lower one-half of ligamen- 
tum nuchae. 2. Spinous pro- 
cesses of seventh cervical and 
six upper dorsal vertebrae. 
3. Supraspinous ligament. 
Splenius. See above. 
Inserted into (1) head (splenius capi- 
tis); (2) neck (splenius colli). See 
below splenius capitis, splenius colli. 
Nerves: posterior divisions of the 
spinals. 
Inserted into (1) mastoid process of 
temporal bone; (2) occipital bone 
beneath the superior curved line. 
Nerves: posterior divisions of the 
spinals. 344 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion and Nerve-supply. 
Splenius colli (m. splenius 
colli). 
Splenius. See above. 
Inserted into transverse processes of 
first, second, and third cervical ver- 
tebrae, posterior tubercles. Nerves: 
posterior divisions of spinals. 
Fig. 186. 
Muscles in the second layer of the back and on the dorsum of the shoulder. (Gerrish after Testut.) 
Fourth Layer. 
Erector spinae. (Fig. 187.) 1. Spines of eleventh and twelfth See insertions of iliocostalis, longis- 
Opposite last rib ; this dorsal and all the lumbar and simus dorsi, spinalis dorsi and 
muscle divides into the sacral spines and their supra- their continuations to head and neck, 
iliocostalis and longissi- spinous ligaments. 2. Back Nerves: posterior divisions of 
mus dorsi. The spinalis part of inner lip of iliac crest. spinals. 
dorsi is derived from the 3. Posterior surface of sacrum, 
longissimus dorsi (m. external to spinous processes, 
iliocostalis lumborum). 
Iliocostalis (Fig. 187) (m. Outer part of erector spinse. Inserted into the inferior borders of 
iliocostalis dorsi). the angles of the six or seven lower 
ribs by flattened tendons. Nerves: 
posterior divisions of spinals. 
The musculus accessorius Upper borders of angles of the Insertion: (1) upper borders of angles 
ad iliocostalem, is the up- six lower ribs, by separate of six upper ribs; (2) back of trans- 
ward continuation of ilio- tendons. verse process of seventh cervical 
costalis. (Fig. 187.) vertebra. Nerves: posterior divisions 
of spinals. THE BACK. 
345 
Fig.187. 
Fig. 188. 
Erector spinie. The outer series is pulled outward. 
(Gerrish after Testut.) 
Erector spinae. The middle series is pulled outward 
(Gerrish after Testut.) 346 
A MANUAL OF DISSECTION. 
Name. 
Origin. 
Insertion and Nerve-supply. 
Cervicalis ascendens, a 
Angles of four or five upper 
Insertion : posterior tubercles of trans- 
continuation of acces- 
sorius into neck (m. 
iliocostalis cervicis). 
(Fig. 187.) 
ribs. 
verse processes of fourth, fifth, and 
sixth cervical vertebrae. Nerves: 
posterior divisions of spinals. 
Longissimus dorsi, the 
1. Middle part of erector spinae. 
Insertion: (1) tips of transverse pro- 
middle and largest part 
2. Transverse processes of 
cesses of dorsal vertebrae ; (2) lower 
of erector spinae (m. 
lumbar vertebrae. 3. Middle 
ribs (seventh to eleventh) between 
longissimus dorsi). 
(Fig. 187.) 
lamella of lumbar fascia. 
tubercles and angles. Nerves: pos- 
terior divisions of spinals. 
Transversalis cervicis, or 
transversalis colli, the 
cervical continuation of 
longissimus dorsi (m. 
longissimus cervicis). 
(Fig. 188.) . 
Summits of transverse processes 
Insertion : posterior tubercles of trans- 
of six upper dorsal vertebrae. 
verse processes of cervical vertebrae, 
second to sixth inclusive. Nerves: 
posterior divisions of spinals. 
Trachelomastoid, the in- 
1. Transverse processes of five 
Posterior margin of the mastoid pro- 
ternal continuation of 
or six upper dorsal vertebrae. 
cess beneath insertion of splenius 
longissimus dorsi to 
2. Articular processes of three 
and sternomastoid. Nerves : pos- 
cranium (m. longissimus 
capitis). (Fig. 187.) 
or four lower cervical ver- 
tebrae. 
terior divisions of spinals. 
Spinalis dorsi, situated at 
Spinous processes of eleventh 
Insertion : spinous processes of six or 
the inner border of the 
and twelfth dorsal and first 
eight upper dorsal vertebrae. Nerves: 
longissimus dorsi and in- 
timately blended there- 
with (m. spinalis dorsi). 
and second lumbar vertebrae. 
posterior divisions of spinals. 
Spinalis colli, analogous to 
Spinous processes of fifth, sixth, 
Insertion : spine of axis and occasion- 
the spinalis dorsi (m. 
and seventh cervical vertebrae; 
ally spines of third and fourth cer- 
spinalis cervicis). 
occasionally from first and 
second dorsal spines. 
vical vertebrae. Nerves: posterior 
divisions of spinals. 
Complexus (Fig 187) (m. 
1. Tips of transverse processes of 
Inserted into innermost depression of 
semispinalis capitis). 
from two to seven upper dorsal 
vertebrae, and the seventh cer- 
vical vertebra. 2. Articular 
processes of fourth, fifth, and 
sixth cervical. 
occipital bone between the two curved 
lines. Nerves: posterior divisions of 
spinals. 
Biventer cervicis, situated 
Transverse processes of from 
Insertion: superior curved line of 
to inner side of com- 
two to four upper dorsal 
occipital bone. Nerves: posterior 
plexus, and may form 
part thereof. (Fig. 187.) 
vertebrae. 
Fifth Layer. 
divisions of spinals. 
Semispinalis dorsi (m.semi- 
By series of tendons, from trans- 
Insertion : spinous processes of seventh 
spinalis dorsi). (Fig. 
verse processes of fifth, sixth, 
and eighth cervical and first, second, 
third, and fourth dorsal vertebrae. 
Nerves: posterior divisions of 
spinals. 
188.) 
seventh, eighth, ninth, and 
tenth dorsal vertebrae. 
Semispinalis colli (m. semi- 
Transverse processes of upper 
Insertion : spinous processes of second, 
spinalis colli). (Fig. 
188.) 
five or six dorsal vertebrae. 
third, fourth, and fifth cervical ver- 
tebrae. Nerves: posterior divisions 
of spinals. 
Multifidus spinae (m. mul- 
Sacral origin: 1. Back of sac- 
Insertion: laminae and spinous pro- 
tifidus). (Fig. 188.) 
rum, as low as fourth sacral 
foramen. 2. Aponeurosis of 
erector spinae muscle. 3. Pos- 
terior superior iliac spine. 
4. Posterior sacro iliac liga- 
ment. Lumbar origin: arti- 
cular processes. Dorsal ori- 
gin : transverse processes. 
Cervical origin: articular 
processes of three or four 
lower cervical vertebrae. 
cesses of all vertebrae, except atlas. 
Nerves: posterior divisions of 
spinals. 
Rotatores spinae, eleven in 
Upper and back parts of trans- 
Insertion : lower border and outer sur- 
number on each side. 
verse processes in dorsal re- 
face of the first lamina above the 
The first muscle is be- 
tween the first and sec- 
ond ; the last, between 
the eleventh and twelfth 
dorsal spine (m. rota- 
tores). 
gion of spine. 
origin. Nerves : posterior divisions 
of spinals. 
Supraspinales are found in 
Spinous process, and extend to 
Insertion: spinous process immediately 
the cervical region only. 
process immediately above. 
above. Nerves : posterior divisions 
of spinals. THE BACK. 
347 
Name. 
Origin. 
Insertion and Nerve-supply. 
Interspinales, cervical re- 
gion, six pairs; dorsal 
region, three pairs ; lum- 
bar region, four pairs 
(mm. interspinales). 
Spinous process below. 
Insertion: spinous process above. 
Nerves: posterior divisions of 
spinals. 
Extensor coccygis. 
Last sacral or first coccygeal 
vertebra. 
Insertion: lower part of coccyx. 
Nerves: posterior divisions of 
spinals. 
Intertransversales. In cer- 
vical region, most devel- 
oped; in dorsal, least. In 
pairs in lumbar region 
(mm. intertransversales) 
In a transverse process below. 
Insertion: transverse process imme- 
diately above. 
Rectus capitis posticus ma- 
jor (m. rectus capitis 
posterior major). (Fig. 
184.) 
Spinous process of axis. 
Insertion: inferior curved line of occi- 
pital bone and surface of bone below. 
Nerves: posterior divisions of 
spinals. 
Rectus capitis posticus 
Tubercle on posterior arch of 
Insertion: occipital bone beneath in- 
minor (m. rectus capitis 
minor). (Fig. 184.) 
atlas. 
ferior curved line. Nerves : poste- 
rior divisions of spinals. 
Obliquus capitis inferior 
(m. obliquus capitis 
inferior). (Fig. 184.) 
Apex of spine of axis. 
Insertion: lower and back part of 
transverse process of atlas. Nerves : 
posterior divisions of spinals. 
Obliquus capitis superior 
Upper surface of transverse 
Insertion: occipital bone between 
(m. obliquus capitis 
superior). (Fig. 184.) 
process of atlas. 
superior and inferior curved lines, 
external to insertion of complexus 
muscle. Nerves: posterior divisions 
of spinals. 
THE SUBOCCIPITAL TRIANGLE. (Fig. 178.) 
This space, situated in the deep posterior part of the junction of the head and 
neck, is bounded externally by the obliquus superior, below by the obliquus 
inferior, internally by the rectus capitis posticus major. The complexus muscle 
forms its roof ; the floor is formed by the posterior occipito-atlantal ligament and 
the posterior arch of the atlas. Contents : (1) The vertebral artery lies in a groove 
on the upper surface of the posterior arch of the atlas; (2) the suboccipital nerve 
enters the triangle between the vertebral artery and the arch of the atlas; (3) the 
posterior occipito-atlantal ligament and the posterior arch of the atlas are contents as 
well as floor-structures; (4) the deep cervical vein begins in the suboccipital tri- 
angle, by the confluence of small veins, and, as a rule, receives the occipital vein. 
It passes between the complexus and semispinalis colli with the arteria princeps 
cervicis, and becomes tributary to either the vertebral or the innominate vein. 
The great occipital nerve passes through the roof of the triangle-the complexus 
muscle. The occipital artery skirts the external boundary of the triangle and 
rests on the insertion of the complexus muscle. (Figs. 184, 189.) 
BLOODVESSELS OF THE BACK. 
The back is supplied with blood by the occipital, vertebral, intercostal, sub- 
clavian, and lumbar arteries. In the main, the veins correspond to the arteries. 
The occipitals and vertebrals have complicated relations. The vessels of the trunk 
(intercostals and lumbars) are typical angeiotomes, and correspond to the other com- 
ponent parts of an ursegment. Each intercostal artery supplies the skin and sub- 
jacent fascise(dermatome); muscle (myotome); nerve rootsand spinal cord pertain- 
ing thereto (neurotome); vertebrae and ribs (sclerotome). Adjacent segments 
overlap, and on this depends anastomoses of vessels and communications of nerves 
In the following table the source, course, and branches of the arteries supply- 
ing the back are given. With the exception of the vertebral, the veins correspond 
to the arteries. (The vertebral vein is made up in the deep parts of the occipital 348 
A MANUAL OF DISSECTION. 
region. Radicals of the vertebral vein meet in the foramen of the transverse 
process of the atlas, whence there is correspondence between the vertebral artery 
and the vertebral vein. 
Table of Vessels of the Back. 
Name. 
Source. 
Course. 
Distribution and Branches. 
Occipital 
External 
1. Beneath the twelfth nerve, 
and digastric and stylohyoid 
1. The anteria princeps cervicis 
artery 
carotid, 
opposite 
descends and divides into a 
(Figs. 184 
muscles. 2. Crosses the inter- 
superficial and a deep branch : 
and 189) 
facial 
nal carotid artery, internal 
(a) The superficial branch lies 
(a. occipi- 
artery 
jugular vein, vagus, and spinal 
beneath the splenius, and gives 
talis). 
(Fig. 190.) 
accessory nerves. (Fig. 189.) 
3. Lies between the transverse 
process of the atlas and mastoid. 
4. Lies beneath the sterno- 
mastoid, splenius, trachelomas- 
toid, and digastric. 5. Rests on 
the rectus capitis lateralis, supe- 
rior oblique, and insertion of the 
complexus. 6. Pierces the 
fascia between the trapezius and 
sternomastoid. 
off branches which, perforating 
the splenius, supply the trape- 
zius and anastomose with the 
superficial cervical artery (a 
branch of the transversalis colli; 
(6) the deep branch lies between 
the complexus and the semi- 
spinalis colli, and anastomoses 
with the deep cervical artery (a 
branch of the superior inter- 
costal). 2. Muscular, to digas- 
tric, stylohyoid, splenius, and 
trachelomastoid- 3. Sterno- 
mastoid accompanies the spinal 
accessory nerve. 4. Auricular, 
to concha. 5. Posterior men- 
ingeal, accompany internal jug- 
ular vein and supply dura in 
posterior fossa. (Figs. 189 
and 190.) 
Vertebral 
First portion 
1. Enters the foramen in the 
1. Muscular, to deep muscles of 
artery 
of subcla- 
transverse process of the sixth 
the neck. 2. Lateral spinal, 
(Fig. 184) 
vian-the 
cervical vertebra. 2. Ascends 
enter the intervertebral fora- 
(a. verte- 
largest 
to the base of the skull in the 
mina and supply the cord, men- 
bralis). 
branch. 
remaining foramina of the 
transverse processes. 3. Lies 
in a groove on the upper sur- 
face of the posterior arch of the 
atlas. (Fig. 184.) 4. Passes 
beneath the posterior occipito- 
atlantal ligament, pierces the 
dura and arachnoid, and enters 
the skull through the foramen 
magnum. 
inges, vertebrae, and ligaments. 
3. Anterior spinal, one on each 
side, unite in front of the 
medulla and cord, and, rein- 
forced by small arteries in suc- 
cessive segmental regions, form 
a single anterior median artery, 
located in the pia mater along 
the anterior median fissure of 
the spinal cord. 4. Posterior 
spinal branches arise at the side 
of the medulla and pass down 
the cord behind the posterior 
roots of the spinal nerves. They 
receive accessions similar to 
those received by the anterior 
spinals. 5. Bulbar to medulla. 
6. Posterior meningeal, supply 
the dura in the posterior fossa 
and the falx cerebelli. 7. Poste- 
rior inferior cerebellar, crosses 
the restiform body to the under 
surface of the cerebellum. 
Deep cervical 
Posterior 
1. Passes between the transverse 
Anastomoses with the arteria 
artery 
branch of 
process of the seventh cervical 
princeps cervicis, a branch of 
the occipital, and supplies the 
(Fig. 190) 
first inter- 
vertebra and first rib. 2. Lies 
(a. cervic- 
costal (from 
between the complexus and the 
deep muscles of the neck and 
alis pro- 
funda). 
subclavian 
artery). 
semispinalis colli muscles. 
back. THE BACK. 
349 
Name. 
Source. 
Course. 
Distribution and Branches. 
Dorsal 
Intercostal 
1. Given off anterior to space 
1. The muscular branch passes 
branches of 
arteries 
bounded by vertebra, rib, 
through a quadrilateral space 
the inter- 
from the 
transverse process and anterior 
to the back, and divides into 
costal arte- 
thoracic 
costo-transverse ligament. 2. 
external and internal branches. 
ries (Fig. 
aorta (aa. 
Divides into muscular and 
The external branch passes be- 
96) (rami 
intercos- 
spinal branches. 
tween the longissimus dorsi and 
dorsales 
arteriarum 
intercos- 
talium). 
tales). 
iliocostalis muscles, with cor- 
responding nerves from the 
posterior divisions of the spinal 
nerves. The internal branch 
emerges between the longissimus 
dorsi (near the spine) with 
corresponding nerves. 2. The 
spinal branches enter the neural 
canal and supply the cord, men 
inges, bone, and ligaments. 
Fig. 189. 
The occipital artery and its relations. (From a dissection by Mr. Gerald S. Hughes.) (Gray.) 350 
A MANUAL OF DISSECTION. 
Name. 
Source. 
Course. 
Distribution and Branches. 
Dorsal 
Lumbar 
Similar to the dorsal branches of 
Similar in distribution to the 
branches of 
the lumbar 
arteries 
(rami 
dorsales). 
arteries 
from 
abdominal 
aorta (aa. 
lumbales). 
the intercostals. 
dorsal branches of the inter- 
costal arteries. (Fig. 96.) 
Superficial 
Transversalis 
Given off beneath the anterior 
To trapezius, levator anguli scap- 
cervical 
colli from 
margin of the trapezius muscle, 
ulae, cervical glands, and anas- 
artery. 
subclavian 
artery. 
in the subclavian triangle of 
the neck. 
tomoses with the superficial 
branch of the arteria princeps 
cervicis. (Fig. 190 ) 
Fig. 190. 
The internal carotid and vertebral arteries. Right side. (Gray.) THE BACK. 
351 
Fig. 191. 
Superficial and deep distribution of the posterior divisions of the spinal nerves (after Hirschfeld and Leveilhi). 
On the left side the cutaneous branches are represented lying on the superficial layer of muscles. On the right side 
the superficial muscles have been removed, the splenius capitis and complexus divided in the neck, and the erector 
spinae divided and partly removed in the back, so as to expose the posterior divisions of the spinal nerves near 
their origin, a a. Lesser occipital nerve from the cervical plexus. 1. External muscular branches of the first 
cervical nerve, and union by a loop with the second. 2. Placed on the rectus capitis posticus major muscle, marks 
the great occipital nerve, passing around the short muscles and piercing the complexus ; the external branch is seen 
to the outside. 3. External branch from the posterier division of the third nerve. 3'. Its internal branch, some- 
times called the third occipital. 4' to 8'. The internal branches of the several corresponding nerves on the left 
side. The external branches of these nerves, proceeding to muscles, are displayed on the right side, d 1 to d 6, 
and thence to d 12. External muscular branches of the posterior divisions of the twelve dorsal nerves on the right 
side, d V to d 6'. The internal cutaneous branches of the six upper dorsal nerves on the left side, d 7' to d 12'. 
Cutaneous twigs from the external branches of the six lower dorsal nerves. 11. External branches from the pos- 
terior divisions of several lumbar nerves on the right side, piercing the muscles, the lower descending over the 
gluteal region. I' I'. The same, more superficially, on the left side, s s. The issue and union by loops of the poste- 
rior divisions of four sacral nerves on the right side, s' s'. Some of those distributed to the skin on the left side. 
(Gray.) 352 
A MANUAL OF DISSECTION. 
Name. 
Source. 
Course. 
Distribution and Branches. 
Posterior 
Transversalis 
Beneath the levator anguli 
To trapezius, rhomboids, latis- 
scapular 
colli of the 
scapulae to the superior angle 
simus dorsi, and anastomoses 
artery. 
subclavian 
artery. 
of the scapula, thence along the 
posterior border of the scapula 
to the inferior angle beneath 
the rhomboids. 
with the suprascapular, subcla- 
vian, and intercostals (dorsal 
branches). 
Deep cervical 
Superior 
1. Between the first rib and 
1. Muscular, to adjacent muscles. 
artery 
intercostal; 
transverse process of the seventh 
2. Spinal, to neural canal and 
(Fig. 190.) 
occasion- 
ally from 
subclavian. 
cervical vertebra. 2. Upward 
between the 'complexus and 
semispinalis colli. 
its contents. 3. Anastomotic 
to the deep branch of the an- 
teria princeps cervicis. 
NERVES OF THE BACK. 
Posterior divisions of the spinal nerves (rami posteriores) supply (1) the integu- 
ment of the back of the scalp, trunk, and gluteal regions; (2) all muscles of the 
back except those attached to the shoulder-girdle or humerus; (3) joints moved 
by the muscles of the back supplied by the posterior divisions. 
These nerves pursue a definite course to reach the parts they are to supply, and 
in the dorsal region of the spine, in company with corresponding vessels, they 
pass through a four-sided space bounded internally by the body of a vertebra; 
externally, by the anterior costotransverse ligament; above, by a transverse 
process; below, by the neck of a rib. (Fig 96.) 
The general plan of the arrangement of the posterior divisions of the spinal 
nerves is the same throughout; still, some minor variations must be noted and 
studied in the subjoined table. It will be seen in the table (in the third column) 
that the first cervical, the fourth and fifth sacral, and coccygeal nerves do not 
divide into internal and external branches, which, with these four exceptions, is 
the rule. Again, the six upper cutaneous nerves of the back are derived from 
the internal branches; the six lower, from the external branches. (Fig. 185.) In 
other words, there are twelve dorsal nerves; each divides into internal and 
external branches, but the external branches of the six upper and the internal 
branches of the six lower nerves have no cutaneous distribution. The three 
upper lumbar nerves give branches, which, crossing the crest of the ilium, reach 
the gluteal region. (Fig. 141, page 267.) The fourth and fifth sacral and 
coccygeal nerves supply the integument covering the coccyx. (See also table of 
cutaneous nerves of the lower extremity, pages 264-268.) 
(Rami posteriores nervorum spinalium.) 
Name. 
Course. 
Special Feature. 
Distribution and Branches. 
First cervical, 
It passes between the 
It does not divide 
1. A cutaneous branch is occasionally 
posterior 
arch of the atlas 
into internal and 
given off, which accompanies the 
occipital artery and communicates 
division, sub- 
and vertebral 
external branches. 
occipital 
artery, and enters 
(In this regard it 
with the occipitalis major and occip- 
nerve (Fig 
the suboccipital 
resembles the 
italis minor nerves. 2. A communi- 
184) (n. sub- 
occipitalis). 
triangle. 
fourth and fifth 
sacral and coccy- 
geal nerves.) 
cating branch to the second cervical 
nerve. 3. Muscular branches to the 
complexus, rectus capitis posticus 
major and minor, superior and in- 
ferior oblique muscles. 
Table of Posterior Division of Spinal Nerves. (Fig. 96.) THE BACK. 
353 
Name. 
Course. 
Special Feature. 
Distribution and Branches. 
Second cervical 
It emerges from the 
1. It pierces the 
1. The internal branch (called the 
nerve, poste- 
spinal canal be- 
complexus and 
occipitalis major) gives an auricular 
rior division. 
tween the atlas 
trapezius and ac- 
branch to the ear, a muscular branch 
to the complexus, a cutaneous 
The great 
and axis,below the 
inferior oblique 
companies the 
occipital 
occipital artery to 
branch to the scalp, a communicating 
nerve (Fig. 
muscle, divides 
the scalp. 2. The 
branch to the occipitalis minor. 2. 
184) (n. 
into internal 
internal branch 
Has an external branch joined by 
occipitalis 
and external 
passes between the 
the external branch of the third 
major). 
branches, and 
pierces the com- 
plexus muscle. 
inferior oblique 
and complexus, 
pierces the trape- 
zius, and is joined 
by filaments from 
the third cervical 
nerve (posterior 
division). 
occipital nerve ; supplies the splen- 
ius, complexus, and trachelomastoid. 
The third cer- 
It divides into 
The third differs 
1. Internal branch supplies the integ- 
vical nerve, 
internal and ex- 
from the remain- 
ument over the trapezius muscle. 
posterior 
ternal branches. 
ing cervical nerves 
2. External branch of the third, 
division 
1. Internal branch 
in furnishing a 
having joined the external branch 
(Fig. 184) 
passes between the 
filament-the 
of the second, supplies the splenius, 
(n. occipitalis 
tertius). 
complexus and 
semispinalis colli, 
pierces the 
splenius and 
trapezius. 2. Ex- 
ternalbranchjoins 
the external 
branch of the 
second cervical. 
third occipital 
nerve-to the skin 
of the occiput. 
complexus, and trachelomastoid. 
The fourth, 
They emerge from 
1. The internal 
1. Internal branches from the fourth 
fifth, sixth, 
the neural canal 
branches from the 
and fifth supply the skin over the 
seventh, and 
eighth cervi- 
by the interverte- 
fourth and fifth 
trapezius. 2. Internal branches 
bral foramina, 
pass between the 
from the sixth, seventh, and eighth 
supply the semispinalis colli, in- 
cal nerves, 
reach back, and 
complexus and 
posterior 
divide into inter- 
semispinalis, and 
terspinales, multifidus spin®, com- 
plexus, and twigs to the skin near 
division 
nal and external 
perforate the 
(Figs. 185 
and 191) 
(rami poste- 
riores nn. 
cervicalium). 
branches. (Fig. 96.) 
splenius and 
trapezius. 2. In- 
ternal branches 
from the sixth, 
seventh, and 
eighth lie beneath 
the semispinalis 
colli. 
the spinous processes. 3. The ex- 
ternal branches supply the cervicalis 
ascendens, transversalis colli, and 
trach elo m astoid. 
Dorsal nerves, 
They emerge from 
1. The external 
1. Internal branches of the six upper, 
posterior 
the neural canal 
branches of the 
having passed between the semi- 
divisions, 
by the interverte- 
six upper dorsals 
spinalis dorsi and multifidus spin® 
twelve in 
bral foramina, 
are wanting in the 
, (Fig. 96), and pierced the trapezius 
number 
pass through a 
cutaneous nerves. 
and rhomboids, supply the multi- 
fidus spin®, semispinalis dorsi, and 
(Figs. 185 
four-sided space 
2. The internal 
and 191) 
to the back, with 
branches of the six 
integument of the upper region of 
(rami poste- 
dorsal branches of 
lower dorsals are 
the back. 2. The external branches 
riores nn. 
the intercostal 
wanting in the 
of the six upper supply the longis- 
thoraca- 
lium). 
vessels. (Quadri- 
lateral space is 
bounded inter- 
nally by the body 
of the vertebra ; 
externally by the 
anterior costo- 
transverse liga- 
ment ; above by a 
transverse process; 
below by the neck 
of the rib.) They 
divide into inter- 
nal and external 
branches. 
cutaneous nerves. 
simus dorsi, iliocostalis, and their 
continuations to the head. (See 
Gray.) 3. The internal branches of 
the six lower give off no cutaneous 
nerves, but supply the multifidus 
spin®. 4. The external branches of 
the six lower supply the skin of the 
lower region of the back. They 
pierce the serratus posticus and 
latissimus dorsi, in a line with the 
angles of the ribs. 354 
A MANUAL OF DISSECTION. 
Name. 
Course. 
Special Feature. 
Distribution and Branches. 
Lumbar nerves, 
They emerge from 
They contribute 
1. The internal branches supply the 
posterior 
the neural canal 
three cutaneous 
multifidus spinse and interspinales. 
divisions, 
by the interverte- 
nerves to the 
2. The external branches supply the 
five in num- 
bral foramina, 
gluteal region 
erector spin® and intertransversales. 
ber (Figs. 
pass between the 
(Fig. 141.) (Read 
3. The external branches of the 
185 and 191) 
(rami poste- 
riores nn 
lumbalium). 
transverse pro- 
cesses with the 
dorsal branches of 
the lumbar ves- 
sels, and divide 
into internal and 
external branches. 
pages 264-268.) 
first, second, and third give off 
cutaneous branches, which, piercing 
the latissimus dorsi, cross the iliac 
crest, and supply the integument of 
the gluteal region. (Fig. 141.) 
Sacral nerves, 
They emerge from 
The fourth and fifth 
1. The internal branches of the three 
posterior 
the sacral canal 
do not divide into 
upper supply the multifidus spinse. 
divisions, 
(except the fifth) 
internal and ex- 
2. The external branches of the 
five in num- 
by the posterior 
ternal branches. 
three upper unite with the fourth 
ber (Figs. 
sacral foramina, 
(In this regard 
sacral and fifth lumbar on the poste- 
185 and 191) 
and all, except the 
they resemble the 
rior surface of the sacrum and form 
(rami poste- 
fourth and fifth, 
coccygeal and first 
a second series of loops on the outer 
riores nn. 
divide into inter- 
cervical.) The 
surface of the greater sacrosciatic 
sacralium). 
nal and external 
branches. 
fourth and fifth 
sacral unite with 
the coccygeal and 
supply the exten- 
sor coccygis and 
the skin over the 
coccyx. 
ligament, from which three cutane- 
ous nerves (having pierced the glu- 
teus maximus) reach the skin over 
the back of the coccyx. (Fig. 141) 
SUMMARY OF DISTRIBUTION OF NERVES OF BACK. 
The integral parts of the back (including the back part of the scalp, neck, and 
trunk) are supplied as follows : (1) The skin, by posterior divisions of the spinal 
nerves; (2) the trapezius muscle, by the spinal accessory (eleventh cranial nerve) 
and third and fourth cervical nerves (anterior divisions); (3) the latissimus dorsi 
muscle, by the long subscapular, a branch of the posterior cord of the brachial 
plexus; (4) the levator anguli scapulae, by the anterior divisions of the third and 
fourth cervical nerves; (5) the rhomboid muscles, by the anterior division of the 
fifth cervical nerve; (6) the muscles of the third, fourth, and fifth layers, by the 
posterior divisions of the spinal nerves; (7) the occipito-atlantal articulation, by 
suboccipital nerve; (8) the atlanto-axial articulation, by the first and second 
cervical nerves; (9) the costo-central articulations, by the anterior divisions of the 
spinal nerves; (10) the costo-transverse articulations, by the posterior divisions of 
the spinal nerves; (11) the sacrovertebral articulation, by the fourth and fifth 
lumbar and sympathetic nerves; (12) the sacro-iliac articulations, by the posterior 
divisions of the first and second sacral nerves, superior gluteal nerve, and sacral 
plexus; (13) the sacrococcygeal articulation, by the fourth and fifth sacral and 
coccygeal nerves; (14) the ribs and vertebrae, by gray rami communicantes; (15) 
the spinal dura mater, by recurrent branches from the spinal nerves in the several 
regions and by sympathetic fibres from the vertebral ganglia. CHAPTER XXX. 
THE SYMPATHETIC NERVOUS SYSTEM. 
Dissection and Identification. The great prevertebral plexuses-cardiac, solar, and 
hypogastric-have been studied with the viscera which they innervate (pages 186, 187, and 
243). Their branches accompany the arteries, and are distributed with them under the name 
of plexuses; hence, gastric, hepatic, and splenic plexuses refer to sympathetic nerves derived 
from the prevertebral plexuses (accompanying arteries) (Fig. 192), and distributed with them 
to the organs. 
The Gangliated Cord Proper should be studied according to the following steps : (1) Turn 
the viscera to the opposite side of the body-or remove them entirely, if their dissection has 
been completed-and strip off both pleura and peritoneum in the region of the vertebral 
column ; (2) bear in mind the ganglia, interganglionic communicating branches, gray rami, 
connecting the ganglia to the spinal nerves and branches of distribution. 
Cervical Ganglia (superior, middle, and inferior). Identify (1) by the location in the neck, 
behind the carotid sheath; (2) by the superior branches accompanying the internal carotid 
artery and the inferior ganglion communicating with the first thoracic ganglion. 
Superior Cervical Ganglion. Identify (1) by the location behind the internal carotid 
artery, near the base of the skull; (2) by the size, one-quarter of an inch in diameter and 
about one inch in length; (3) by the numerous filaments to the branches of the external 
carotid artery; (4) by the rami communicantes to the spinal nerves and a communicating 
branch to the middle cervical ganglion. 
Middle Cervical Ganglion. Identify (1) by the location opposite the sixth cervical 
vertebra, where the sympathetic crosses the inferior thyroid artery; (2) by communicating 
with the superior and inferior cervical ganglia. 
Inferior Cervical Ganglion. Identify (1) by the location between the neck of the first rib 
and the transverse process of the seventh cervical vertebra; (2) by the attachment to the 
seventh and eighth cervical nerves by rami communicantes. (Fig. 192.) 
COMPOSITION AND FUNCTION. 
Composition. A gangliated cord, having (a) forty-six ganglia, twenty-three on 
each side; (6) ascending and descending interganglionic trunks; (c) rami commu- 
nicantes, connecting the ganglia to the spinal nerves; (d) rami efiferentes, sup- 
plying the bloodvessels and viscera; (e) gray rami communicantes, supplying 
the involuntary muscular fibre in trunk and extremities; (/) sporadic ganglia, on 
the trifacial nerve; (.7) the three great prevertebral plexuses; (A) secondary 
plexuses in the heart, uterus, and intestines; («) white rami, from the motor, 
cranial and spinal nerves. 
. ^Function. To innervate viscera, glands, unstriped muscle fibre, bones, cartil- 
ages, fasciae, and conduits generally not under control of the will. 
The Gangliated Cord consists of two rows of vertebral ganglia, connected by 
interganglionic trunks, situated one on either side of the vertebral column, and 
communicating with each other (1) above, on the anterior communicating artery, 
in the ganglion of Ribes; (2) below, on the coccyx, in the ganglion impar. 
Number of Ganglia in Each Region. Morphologically, there is one ganglion for 
each spinal nerve, thirty-one on each side; in some regions, however, adjacent 
ones fuse, thus making the total number of ganglia on a side less than the number 
of spinal nerves. In the following table the number of ganglia, morphological 
and actual, is given in each region, showing the number lost by fusion. 
Morphological Actual Number 
Region. Number. Number. Lost by Fusion. 
Cervical ... 8 Ganglia . . 8 Ganglia 3 5 
Thoracic . .12 Ganglia . . 12 Ganglia . . 11 1 
Lumbar ... 5 Ganglia . . 5 Ganglia 5 0 
Sacral ... 5 Ganglia . . 5 Ganglia 4 1 
Coccygeal . . 1 Ganglia . . 1 Ganglia 0 1 
Total 31 31 23 8 356 
A MANUAL OF DISSECTION. 
Fig. 192. 
The sympathetic nerve. (Gray.) THE SYMPATHETIC NERVOUS SYSTEM. 
357 
Location of Ganglia in Each Region. The three cervical ganglia and their con- 
necting interganglionic trunks lie behind the carotid sheath, on the rectus capitis 
anticus major muscle; they are connected to the spinal nerves by white rami 
communicantes only. 
The Eleven Thoracic Ganglia and their connecting interganglionic. trunks lie 
posterior to the pleura, in a line corresponding to the heads of the ribs. The first 
thoracic is beneath the first rib; the eleventh is on the side of the twelfth thoracic 
vertebra, connected to the spinal nerves by both white and gray rami communi- 
cantes. 
The Five Lumbar Ganglia, with their connecting interganglionic trunks, lie along 
the inner margin of the psoas magnus muscle, obscured on the right side by the 
ascending vena cava; on the left, by the abdominal aorta. The first and second 
ganglia are connected to the spinal nerves by white and gray rami communi- 
cantes; the third, fourth, and fifth, by gray rami communicantes only. 
The Four Sacral Ganglia and their connecting interganglionic trunks lie internal 
to the anterior sacral foramina, connected to the sacral nerves by white rami com- 
municantes only. These white rami are not indigenous in the sacral region, but 
reach it by descending from the thoracic and lumbar regions. The visceral 
branches of the sacral plexus, arising from the third and fourth nerves, repre- 
sent the white rami of the sacral nerves. 
Recapitulation of White Rami of the Sacral Region. First, the four sacral ganglia 
are connected to the sacral nerves by white rami communicantes, which do not 
originate in the sacral nerves, but descend from the thoracic and lumbar regions; 
second, branches of the sacral nerves themselves (that would have been called 
white rami had they joined the sacral ganglia) are the visceral branches of the 
sacral plexus, and supply vasodilator fibres of the penis, secretory fibres of the 
prostate, inhibitory fibres of the circular muscles of the rectum, and longitudinal 
fibres of the rectum and bladder. 
COMPOSITION OF VERTEBRAL GANGLIA. 
(a) Nerve cells, giving origin to gray rami communicantes; (6) white rami, 
from motor spinal nerves; (c) connective tissue, for sustentation ; (d) vessels for 
nutritional purposes. 
Gray Rami Communicantes originate as axis-cylinder process in the ganglion 
cells of the vertebral ganglia, and are distributed as follows : (1) To neighboring 
ganglia; (2) directly to the viscera and vessels; (3) to the prevertebral plexuses; 
(4) some reach the spinal nerves and accompany the same to the extremities and 
body wall, for the supply of the bones, fasciae, cartilage, periosteum, parietal 
serous membranes, and vessels of these parts. 
(Two examples of gray rami doing terminal work over somatic nerve routes: 
(1) Obturator and anterior crural nerves contribute branches to the femoral artery; 
(2) the branch of the internal popliteal nerve to the popliteus muscle gives a 
gray ramus communicans to the tibia.) 
The Nerve-supply to Bone, cartilage, fascia, and vessels of the trunk and extrem- 
ities is sympathetic, and reaches the same through gray rami, travelling to the 
part with the spinal nerve of this region. Gray rami communicantes arise as 
axis-cylinders of cells in the vertebral ganglia of the gangliated cord of the 
sympathetic. (See Gerrish.) 
WHITE RAMI COMMUNICANTES. 
They originate in the motor roots of the cranial and spinal nerves. Some pass 
through the vertebral ganglia without interruption; others arborize with cells in 
the vertebra] ganglia. The white rami communicantes are indigenous in the 
thoracic and upper lumbar regions only, and are distributed as follows : 358 
A MANUAL OF DISSECTION. 
" The nerves that act on the iris to produce dilatation of the pupil arise as white 
rami in the motor roots of the first, second, and third thoracic nerves, and pass 
up in the sympathetic cord to the superior cervical ganglion, where they arborize 
around their cells, whence fibres pass with the carotid plexus to the Gasserian 
ganglion, and reach the eye through (1) the ophthalmic; (2) the long ciliary 
branches of the nasal division of the ophthalmic." (Gerrish.) 
Motor fibres that supply the involuntary muscle of the eyelids and orbitalis 
muscles of Miiller (a muscle crossing the sphenomaxillary fissure) are supplied by 
white rami communicantes which arise in the motor roots of the fourth and fifth 
thoracic nerves. These rami communicantes pass up the sympathetic cord to the 
superior cervical ganglion, where they arborize around its cells, thence to the 
Gasserian ganglion, from which they reach the eye in a similar manner as set 
forth in the preceding paragraph. Paralysis of these nerves in any part of their 
course may cause (1) narrowing of the palpebral fissure; (2) dropping of the 
upper lid; (3) recession of the globe. " Irritation of the cervical sympathetic 
causes protrusion of the globe, while section of the sympathetic in the neck 
causes retraction of the eyeball." (Treves.) 
Vasomotor fibres to the head, secretory fibres to the submaxillary gland, pilo- 
motor fibres to the head and neck (all of which reach these several areas, accom- 
panying branches of the external carotid artery) are derived from the motor 
roots in the upper thoracic region, and arborize with ganglion cells in the supe- 
rior cervical ganglion. 
The accelerator fibres of the heart are derived from the motor roots of the 
upper thoracic nerves. They arborize around the ganglion cells in the superior, 
middle, and inferior ganglia, whence fibres in the cervical cardiac nerves complete 
the circuit. 
Symptoms in Paralysis of the Cervical Ganglia : (1) Narrowing of the palpebral 
fissure; (2) drooping of the upper lid; (3) recession of the globe and contraction 
of the pupil may ensue on injury to the thoracic region of the spine, since the 
nerves that supply the involuntary muscular fibres of the eye and orbit have their 
origin in the motor roots of the spinal nerves in the thoracic region. 
THE CERVICAL SYMPATHETIC CORD. 
There are three ganglia in this region : (1) The superior, formed by fusion of 
the (morphological) four upper ganglia; (2) the middle, formed by fusion of 
the fifth and sixth ganglia; (3) the inferior, formed by fusion of the seventh and 
eighth ganglia. (See table, page 355.) 
The Superior Cervical Ganglion is behind the internal carotid artery, near the 
base of the skull, on a level with the transverse processes of the second and third 
cervical vertebrae. To expose the ganglion turn the artery aside. The ganglion 
is one and a half inches long, about one-quarter of an inch in diameter, and 
connected to the first, second, third, and fourth anterior primary divisions of the 
cervical nerves by gray rami communicantes. Branches : (a) Superior, which 
accompanies the carotid artery to the cranium, where it divides into a smaller 
or internal branch, which ends in the cavernous plexus, and a larger or external, 
which ends in the carotid plexus; (6) anterior, which are given off from the 
anterior part of the superior cervical ganglion. These nerves accompany the 
external carotid and all its branches-facial, lingual, superior thyroid, ascending 
pharyngeal, posterior auricular, occipital, temporal, and internal maxillary; (c) 
external branches to the third, fourth, fifth, sixth, seventh, ninth, tenth, 
eleventh, and twelfth cranial and the four upper spinal nerves; (d) internal, 
from which pharyngeal branches pass behind the internal and external carotid 
arteries, to join the pharyngeal plexus, which supplies the mucous membrane and 
muscles of the pharynx ; (e) superior cervical cardiac and laryngeal branches are 
given off from the lower part of the ganglion. The right cardiac nerve passes THE SYMPATHETIC NERVOUS SYSTEM. 
359 
behind the subclavian artery, and terminates in the deep cardiac plexus above 
the right pulmonary artery, on the bifurcation of the trachea; the left enters 
the thorax in front of the common carotid, crosses the arch of the aorta, and 
ends in the superficial cardiac plexus in front of the right pulmonary artery in 
the concavity of the aortic arch; (/) inferior, which communicates with the middle 
cervical ganglion. 
The Cavernous Plexus is located in the cavernous sinus, between the internal 
carotid artery and the pituitary body. Its branches are (1) fine twigs to the 
pituitary body; (2) the sympathetic root of the lenticular ganglion; (3) commu- 
nicating, to the third and fourth cranial nerves, and ophthalmic division of the 
fifth cranial nerve; (4).terminal, to the ophthalmic artery and cerebral branches 
of the internal carotid. (Fig. 193.) 
Fig. 193. 
Diagram of the cervical sympathetic. (Gerrish after Testut.) 
The Carotid Plexus is on the outer side of the internal carotid artery, in the 
cavernous sinus, with the sixth nerve. Branches : (1) To the sixth nerve, received 
as this crosses the carotid artery in the cavernous sinus ; (2) to the Gasserian gan- 
glion, received as the artery enters the cavernous sinus; (3) tympanic, or small 
deep petrosal, passes through the carotico-tympanic canal in the petrosa to join the 
tympanic plexus; (4) great deep petrosal branch leaves the cranium through the 
cartilage in the foramen lacerum medium, and joins the great superficial petrosal 
of the facial nerve, to form the vidian. 
The Middle Cervical Ganglion is located opposite the sixth cervical vertebra 
(where the sympathetic cord crosses the inferior thyroid artery) and is connected by A MANUAL OF DISSECTION. 
360 
gray rami communicantes, to the corresponding fifth and sixth cervical nerves. 
Branches: (1) Gray rami communicantes, to the fifth and sixth cervical nerves; 
(2) the middle cervical cardiac to the heart; (3) thyroid, which accompany the 
inferior thyroid artery to the thyroid gland; (4) communicating, to the vertebral 
ganglia above and below-the superior and inferior. 
The Inferior Cervical Ganglion is between the neck of the first rib and the trans- 
verse process of the seventh cervical vertebra, behind the vertebral artery, and 
connected to the seventh and eighth cervical nerves by gray rami communi- 
cantes. Branches : (1) Gray rami communicantes, to the seventh and eighth 
cervical nerves; (2) the inferior cervical cardiac to the heart; (3) to the vertebral 
artery; (4) communicating, to the vertebral ganglia above and below. 
The Thoracic Sympathetic Cord. As previously stated, there are eleven ganglia 
in the thoracic part of the gangliated cord. The last cervical and first thoracic 
ganglia fuse. Branches: (1) To the corresponding spinal nerves, by rami com- 
municantes, gray and white; (2) the upper four or five ganglia give branches to 
the aorta, vertebral ligaments, and posterior pulmonary plexus; (3) the lower six or 
seven form the three splanchnic nerves-great, small, and least. The great splanch- 
nic, formed by the sixth, seventh, eighth, and ninth, pierces the crus of the dia- 
phragm and joins the semilunar ganglion; the small splanchnic, formed by the 
ninth and tenth, passes beneath the diaphragm and joins the renal plexus; the 
least splanchnic, formed by the twelfth, joins the renal plexus. 
The Lumbar Sympathetic Cord. There are four to five ganglia in this region, 
situated along the inner margin of the psoas magnus muscle. They are hidden 
on the left side by the abdominal aorta; on the right by the ascending vena cava. 
Branches : (1) Rami communicantes, white and gray in the upper region (gray 
only in the lower region), by which the ganglia are connected to the correspond- 
ing spinal nerves; (2) to the aortic plexus; (3) to the hypogastric plexus; (4) to 
the vertebrae and their ligaments. 
The Sacral Sympathetic Cord. The ganglia are four in number and lie internal to 
the anterior sacral foramina. The two gangliated cords meet at the ganglion impar. 
Branches : (1) Gray rami, from the corresponding spinal nerves; (2) to the hypo- 
gastric plexus. 
THE PREVERTEBRAL PLEXUSES. 
There are three prevertebral plexuses-cardiac, solar, and hypogastric. Each 
is single and situated near the mid-line of the posterior wall of the trunk, and 
has the following composition: (a) Nerves from the gangliated cord; (6) nerves 
from the brain and spinal cord; (c) ganglion cells and indigenous nerves; (d) a 
connective-tissue meshwork. 
The Cardiac Plexuses. Location : (1) Below the arch of the aorta, internal to the 
ductus arteriosus ; (2) between the bifurcation of the trachea and the arch of the 
aorta; the former is called the superficial, the latter, the deep cardiac plexus. For- 
mation : (1) Cervical cardiac branches of the vagus; (2) a thoracic cardiac branch 
of the vagus; (3) branches from the recurrent laryngeal nerves; (4) cardiac 
branches from the cervical sympathetic cord. This plexus gives off branches 
which accompany the vessels to the heart and lungs. 
The Solar Plexus is formed by (1) two semilunar ganglia; (2) by nerve cords. 
It is located at the commencement of the abdominal aorta, around the coeliac axis. 
Each semilunar ganglion is composed of (a) nerve cells; (6) nerves from the 
vagus; (c) nerves from the great splanchnic; (d) indigenous nerve origins from the 
ganglion cells and (e) connective tissue. Smaller plexuses from the solar plexus. 
(1) The aortic, accompanies the aorta downward; (2) the splenic; (3) the hepatic; 
(4) the gastric; (5) the phrenic; (6) the suprarenal; (7) the renal; (8) the superior 
mesenteric; (9) the inferior mesenteric; (10) the spermatic or ovarian. Branches 
from each plexus accompany the artery to the organ or organs the artery supplies. 
(See Gray.) THE SYMPATHETIC NERVOUS SYSTEM. 
361 
The Hypogastric Plexus is in front of the body of the fifth lumbar vertebra. It 
is formed by two or three branches from the lower part of the sympathetic cord, 
which unite with similar ones of the opposite side. These are joined by branches 
of the aortic plexus. The hypogastric plexus passes into the pelvis and divides 
into two lateral parts, which lie on the side of the rectum. This plexus receives 
branches from the sacral part of the sympathetic and from the third and fourth 
sacral nerves. Smaller plexuses derived from the hypogastric. (1) The middle 
hemorrhoidal; (2) the vesical; (3) the prostatic; (4) the large cavernous, which, 
with the small, supplies the erectile tissue of the generative organs; (6) the 
vaginal; (7) the uterine. Each plexus accompanies the artery of the organ to the 
part. CHAPTER XXXI. 
THE BLOOD VASCULAR SYSTEM. 
By De Lee Shaw, M.D. 
The blood vascular system consists of (1) heart, (2) arteries, (3) capillaries, (4) 
veins, and (5) foetal circulation. 
1. The Heart (cor, cordis), the central organ of the system, is a hollow muscle 
divided by a septum into two halves, right and left, each of which is made up of 
two cavities-an auricle above and behind, a ventricle below and in front. 
Right half of heart contains venous blood and left half arterial blood. Auricles 
receive blood from veins and convey it to ventricles, which force it into arteries. 
Right Auricle (auricula dextra), little larger than left, with thinner walls, 
capacity about two ounces, has projecting, forward and to left, from main portion, 
sinus venosus or atrium, the appendix auriculae which overlaps the aorta. 
Openings, (a) Superior cava (vena cava superior), returning blood from upper 
half of body. (6) Inferior cava (vena cava inferior), from lower half of body, 
(c) Coronary sinus (sinus coronarius), from substance of heart, (d') Foramina 
Thebesii (foramina venarum minimarum), mouths of small veins of heart, (e) 
Auriculo-ventricular, large, oval, establishes communication between auricle and 
ventricle. 
Valves, (a) Eustachian (valvula venae cavae), in foetus, directs blood from 
inferior cava through foramen ovale. (6) Coronary (valve of Thebesius, valvula 
sinus coronarii), protects orifice of coronary sinus, (c) Fossa ovalis, depression in 
septum auricularum, showing position of foramen ovale in foetal heart, (d) An- 
nulus ovalis (limbus fossae ovalis) is the margin of the fossa ovalis. 
Tuberculum Loweri (tuberculum intervenosum) is a projection situated between 
the openings of the venae cavae. 
Musculi Pectinati are parallel ridges of muscle resembling the teeth of a comb 
found on the inner wall of the appendix. 
Right Ventricle (ventriculus dexter), somewhat triangular, forms larger part of 
anterior surface of heart. Below it rests upon the diaphragm. 
Openings, (a) Auriculo-ventricular (ostium venosum dextrum), guarded by 
tricuspid valve, is about one and a half inches in diameter. (6) Opening of 
pulmonary artery, circular, guarded by pulmonary semilunar valves. 
Valves, (a) Tricuspid (valvula tricuspidalis), three triangular segments 
(cuspis anterior, posterior, and medialis), formed by the lining membrane, strength- 
ened by fibrous layer, connected by their bases to a fibrous ring surrounding the 
auriculo-ventricular orifice. Central portion of each cusp is thick and strong, 
lateral margins are thin, (b) Semilunar (valvulae semilunares), three semilunar 
folds, structure same as tricuspid, guarding orifice of pulmonary artery, are 
attached by convex margin to wall of artery at junction with ventricle. Free 
straight margin, projecting upward in lumen of vessel, is thickened by tendinous 
fibres forming the corpus Arantii. Behind each semilunar valve, in pulmonary 
artery, is a pouch or dilatation, sinus of Valsalva (lunulae valvularum semi- 
lunarum), which is filled when blood regurgitates toward the heart. When 
these three pouches are filled the valves are approximated and the opening closed. 
Columns Carne^e, muscle columns, projecting from surface of ventricle, are 
of three varieties: the first are attached by one side as well as by both extremities; 
the second by both extremities, sides being free; the third, musculi papillares, by 
one extremity, the other giving attachment to the chordae tendineae. THE BL OOH VASCULAR SYSTEM. 
363 
Chordae Tendine^e are fibrous bands or strings which pass from musculi papil- 
lares to under surface of valves and prevent them from turning backward into 
auricle. 
Left Auricle (auricula sinistra), like right, consists of principal cavity or sinus 
and an appendix auriculae, which, projecting forward and to right, overlaps 
pulmonary artery. 
Openings, (a) Openings of four pulmonary veins, two from each lung. 
These are not protected by valves. (6) Auriculo-ventricular, large, oval, opens 
into left ventricle. 
Musculi Pectinati are confined to inner surface of appendix. Lunated 
impression (fossa ovalis), on septum auricularum, shows position of foramen 
ovale in foetal heart and is guarded by the valvula foraminis ovalis. 
Left Ventricle (ventriculus sinister), longer and more conical than right, forms 
small part of anterior and large part of posterior surface of heart. It alone forms 
apex, as it projects beyond right ventricle. Walls are three times as thick as 
those of right, and hence on section its cavity appears circular, while cavity of right 
ventricle shows a crescentic form. 
Openings, (a) Auriculo-ventricular (ostium venosum sinistrum), smaller than 
right, is guarded by mitral valve (valvula bicuspidalis).. (6) Aortic, circular, is 
guarded by three semilunar valves (valvulae semilunares, aortae, and individually 
designated valvula semilunaris posterior, dextra and sinistra). 
Valves, (a) Mitral (valvula bicuspidalis), two segments of unequal size, 
thicker than tricuspid, but is of same construction. Two smaller segments are 
usually found at angles of junction of larger. (6) Semilunar (valvulae semilunares 
aortse), guard aortic opening. Similar in structure and action to pulmonary 
semilunar valves. 
Chordje Tendine/E resemble in every way those of right ventricle. Columnse 
carnese, smaller and more numerous than those of right ventricle, are subdivided 
in same manner. 
2. Arteries (arteriae), dense, strong, elastic, cylindrical vessels, carry blood 
from ventricles, and when cut remain open. Vessel wall comprises three coats; 
inner or intima, middle or media, and outer or adventitia. Intima consists of 
endothelial lining, subendothelial layer, and elastic membrane, which constitutes 
the principal portion. Media is muscular coat, consisting of involuntary fibres, 
mostly circular, as well as some fibro-elastic tissue. Adventitia is made up of 
fibro-elastic tissue and forms a protective sheath. 
3. Capillaries (vasa capillares), forming connecting link between arteries and 
veins, consist of single layer of endothelial cells. In these vessels blood under- 
goes changes; in capillaries of lung, venous is changed to arterial blood; in 
capillaries of other tissues, arterial blood is changed to venous. (For exception, 
see portal cin ulation.) 
4. Veins (venae) comprise same coats as arteries, but are thinner and contain more 
connective than muscular tissue. When cut, veins collapse, as elastic property is 
generally absent. Many veins contain valves consisting of crescentic folds of the 
intima strengthened by fibrous tissue, which resemble, in action, the semilunar 
valves of the heart. 
The circulation of blood is best described in two cycles, pulmonary and 
systemic. Pulmonary cycle comprises the passage of venous blood through 
pulmonary artery (from right ventricle) to lungs, in capillaries of which it is 
transformed into arterial blood and is then returned through pulmonary veins to 
the left auricle. It will be noted that pulmonary arteries carry venous blood 
and pulmonary veins carry arterial blood. 
Systemic cycle comprises the passage of arterial blood from left ventricle 
through aorta and its branches to capillaries throughout the body, where it is 
changed to venous blood, and returned by veins to right auricle. 364 
Pulmonary 
Circulation. 
Name. Description. 
Branches. Distribution. 
Pulmonary artery (a. pul- From right ventricle 
monalis). to under surface 
of arch of aorta, 
where it divides. 
Right pulmonary (ramus To right lung, 
dexter). 
Left pulmonary (ramus To left lung, 
sinister). 
Right pulmonary artery Longer and larger 
(ramus dexter). than left. From 
below arch of aorta 
Upper. To upper lobe of 
lung. 
to root of right 
lung. 
Lower. To middle and lower 
lobes of lung. 
Left pulmonary artery From below aorta to 
(ramus sinister). root of left 
Upper. To upper lobe of 
lung. 
lung. 
Lower. To lower lobe of 
lung. 
A MANUAL OF DISSECTION. 
Pulmonary veins (venae pulmonales), two from each lung, pass to and open by 
separate orifices into the left auricle. 
Name. 
Aorta. 
Ascending aorta (aorta 
ascendens). 
Fig. 194. 
Systemic Circulation. Arteries. 
Description. Branches. 
Main trunk from left See below. 
ventricle, divided 
into ascending 
aorta, arch, and 
descending aorta. 
Length two inches, Right coronary (a. coro- 
extending from naria dextra). 
left ventricle to Left coronary (a. coro- 
upper border of naria sinistra). 
second right 
costal cartilage. 
Distribution. 
To entire body. 
To heart muscle. 
To heart muscle. 
/ 4 
1. Ascending aorta. 
2. Right coronary artery. 
3. Left coronary artery. 
4. Left ventricle. 
5. Arch of aorta. 
Arch of ao 
aorta 
I 
S' 
2 
rta (arcus 
e). 
Tg. 195. 
Extends from upper 
border of right, 
second chondro- 
sternal articula- 
tion to left side of 
lower border of 
body of fourth 
thoracic vertebra. 
Upper border 
about one inch 
below upper bor- 
der of sternum. 
Innominate (a. anonyma). 
Left common carotid (a. 
carotis communis sin- 
istra). 
Left subclavian (a. sub- 
clavia sinistra). 
To right upper ex- 
tremity and right 
side of head. 
To left side of head. 
To left upper ex- 
tremity. 
1. Arch of aorta. 
2. Ascending aorta. 
3. Fourth thoracic vertebra 
(lower border). 
4. Innominate artery. 
5. Left common carotid. 
6. Left subclavian. 
7. Right subclavian. 
8. Right common carotid. THE BLOOD VASCULAR SYSTEM. 
365 
Name. 
Description. 
Branches. 
Distribution. 
Innomina 
cephalii 
(Se 
Common 
C( 
te, or brachio- 
(a. anonyma). 
e Fig. 195.) 
carotid (a. carotis 
immunis). 
Fig. 196. 
3 
( 
From aorta to upper 
border of right 
sternoclavicular 
articulation. 
Right, from bifurca- 
tion of innominate 
to upper border of 
thyroid cartilage. 
Left, from arch of 
aorta to same point 
on left side. 
A. thyroidea ima (occa- 
sionally). 
Right common carotid (a. 
carotis communis dextra) 
Right subclavian (a. sub- 
clavia dextra). 
External carotid (a. carotis 
externa). 
Internal carotid (a. carotis 
interna). 
To thyroid gland. 
To right side of 
head. 
To right upper ex- 
tremity. 
To outside of head. 
To brain. 
j 
J 
1. Right c 
2. Right i 
3. Right e 
4. Left co 
5. Left su 
6. Innomi 
7. Right 
ommon carotid, 
nternal carotid, 
xternal carotid, 
mmon carotid, 
bclavian. 
nate. 
ubclavian. 
External c 
10 
1 
1. Extern 
2. Comm 
3. Intern 
4. Tempo 
5. Ascent 
6. Superi 
7. Lingus 
8. Facial 
9. Occipi 
10. Posteri 
arot 
xtei 
Fig. 
1 
J 
J I 
al ci 
an ci 
al m 
ral. 
ling 
or th 
il. 
al. 
or at 
id (a. carotis 
■na). 
197. 
r 
irotid. 
irotid. 
axillary. 
pharyngeal, 
yroid. 
iricular. 
From upper border 
of thyroid cartil- 
age to the space 
between the neck 
of the condyle of 
the jaw and the 
external auditory 
meatus, where it 
divides into the 
temporal and the 
internal maxillary 
arteries. 
1. Superior thyroid (a. 
thyroidea superior). 
a. Hyoid (ramus hyoid- 
eus). 
b. Sternomastoid (ramus 
sternocleidomastoid - 
eus). 
c. Superior laryngeal a. 
laryngea superior). 
d. Crico-thyroid (ramus 
crico-thyroideus). 
2. Lingual (a. lingualis). 
a. Hyoid (ramus hyoid - 
eus). 
b. Dorsalis linguae 
(ramus dorsalis 
linguae). 
c. Sublingual (a. sub- 
lingualis*). 
d. Ranine (a. profunda 
linguae). 
3. Facial (a. maxillaris 
externa) (cervical 
branches). 
a. Ascending palatine (a. 
palatina ascendens). 
b. Tonsillar (ramus ton- 
sillaris). 
c. Submaxillary (rami 
glandulares). 
d. Submental (a. sub- 
men talis). 
e. Muscular (rami mus- 
culares). (Facial 
branches.) 
f. Muscular (rami mus- 
culares). 
To thyroid gland. 
To muscles of hyoid 
bone. 
To sternomastoid 
muscle. 
To larynx. 
To crico-thyroid 
membrane. 
To muscles of hyoid 
bone. 
To dorsum of tongue. 
To muscles and 
mucous membrane 
of mouth. 
To deep parts of 
tongue. 
To soft palate, tonsil, 
and superior con- 
strictor. 
To tonsil. 
To submaxillary 
gland. 
To muscles of floor 
of mouth and chin. 
To internal ptery- 
goid and stylo- 
hyoid muscles. 
To masseter and 
buccinator. 366 
A MANUAL OF DISSECTION. 
Name. 
Superficial temporal (a. tem- 
poralis superficialis). 
Fig. 198. 
Description. 
Extends from the 
division of the 
external carotid to 
a point two inches 
above the zygoma, 
where it divides 
into anterior and 
posterior tem- 
porals. 
4. 
5. 
6. 
7. 
8. 
1. 
2. 
3. 
4. 
5. 
6. 
Branches. 
g. Inferior labial (a. la- 
bialis inferior). 
h. Inferior coronary (a. 
coronaria inferior). 
i. Superior coronary (a. 
labialis superior). 
j. Lateral nasal (a. later- 
alis nasi). 
k. Angular (a. angu- 
laris). 
Occipital (a. occipi- 
talis). 
a. Muscular (rami mus- 
culares). 
b. Sternomastoid (ramus 
mastoideus). 
c. Auricular (ramus 
auricularis). 
d. Meningeal (ramus 
meningeus). 
e. Arteria princeps cer- 
vicis (rami occipi- 
tales). 
Posterior auricular (a. 
auricularis posterior). 
a. Stylomastoid (a. 
stylomastoidea). 
b. Auricular (ramus 
auricularis). 
c. Mastoid (rami 
mastoidei). 
Ascending pharyngeal 
(a. pharyngea ascen- 
dens). 
a. Prevertebral (rami 
prevertebrales). 
b. Pharyngeal (rami 
pharyngei). 
c. Tympanic (a. tym- 
panica inferior). 
d. Meningeal (a. men- 
ingea posterior). 
Superficial temporal 
(a. temporalis super- 
ficialis). (See below.) 
Internal maxillary (a. 
maxillaris interna). 
(See below.) 
Transverse facial (a. 
transversa faciei). 
Middle temporal (a. 
temporalis media). 
Orbital (ramus orbi- 
talis), occasionally. 
Anterior auricular (rami 
auriculares anteriores). 
Anterior temporal (a. 
temporalis anterior). 
Posterior temporal 
(ramus temporalis 
posterior). 
Distribution. 
To lower lip. 
To lower lip. 
To upper lip. 
To side of nose. 
To inner angle of 
orbit. 
To digastric, stylo- 
hyoid, splenius, 
and trachelo- 
mastoid. 
To sternomastoid. 
To back of concha. 
To meninges 
through posterior 
lacerated foramen. 
To muscles of neck. 
Through stylomas- 
toid foramen to 
tympanum and 
mastoid cells. 
To cartilage of ear. 
To posterior part of 
occipitofrontalis 
muscle. 
To longus colli and 
recti muscles. 
To pharynx. 
To tympanum. 
To dura mater 
through several 
small foramina. 
To side of head. 
To deep structures 
of face. 
To parotid gland, 
masseter muscle, 
and integument. 
To temporal muscle. 
To outer angle of 
orbit. 
To anterior portion 
of pinna and ex- 
ternal meatus. 
To forehead. 
To side of head. 
1. Temporal. 
2. Transverse facial. 
3. Middle temporal. 
4. Orbital. 
5. Anterior temporal. 
6. Posterior temporal. 
7. Anterior auricular. THE BLOOD VASCULAR SYSTEM. 
367 
Name. 
Description. 
Branches. 
Distribution. 
Internal maxillary (a. max- 
Extends 
from the 
1. Tympanic (a. tympanica 
To membrana tym- 
illaris interna). 
division of the 
anterior). 
pani. 
external carotid to 
a. Deep auricular (a. au- 
To external auditory 
Fig. 199. 
the sphenomaxil- 
ricularis profunda.) 
canal. 
14 
lary fossa. Di- 
2. Middle meningeal (a. 
To meninges, 
15J) 12 _ 
vided 
into three 
meningea media). 
through foramen 
2 £4 
portions-maxil- 
spinosum. 
lary, 
iterygoid, 
3. Small meningeal (ramus 
To Gasserian gang- 
and sphenomaxil- 
meningeus acces- 
lion and dura, 
lary. 
sorius). 
through foramen 
II 
iw 
4. Inferior dental (a. alve- 
ovale. 
To teeth of lower 
olaris inferior). 
jaw. 
a. Anterior superior 
dental incisor (aa.al- 
To incisor teeth. 
1. Internal maxillary. 
2. Tympani. 
3. Middle meningeal. 
veolares superiores 
anteriores). 
4. Small meningeal. 
b. Mental (a. mentalis). 
To chin. 
5. Inferior dental. 
c. Mylohyoid (ramus 
To mylohyoid 
6. Pterygoid. 
7. Deep temporal. 
mylohyoideus). 
d. Lingual. 
muscle. 
To mucous mem- 
8. Masseteric. 
brane. 
9. Buccal. 
5. Deep temporal (a. tem- 
To temporal muscle. 
10. Alveolar. 
poralis profunda). 
11. Infra-orbital. 
12. Sphenopalatine. 
6. Pterygoid (rami ptery- 
goid ei). 
To pterygoid mus- 
cles. 
13. Descending palatine. 
7. Masseteric (a. masse- 
To masseter. 
14. Vidian. 
terica). 
15. Pterygopalatine. 
8. Buccal (a.buccinatoria). 
To buccinator. 
9. Alveolar or posterior 
To molar and bicus- 
dental (a. alveolaris 
superior posterior). 
pid teeth. 
10. Infra-orbital (a. infra- 
To front teeth and 
orbitalis). 
structures of the 
face anteriorly. 
11. Posterior or descending 
To gums and mucous 
palatine (a. palatina 
membrane of hard 
descendens). 
palate. 
12. Vidian (a. canalis 
To pharynx and 
pterygoidea). 
Eustachian tube. 
13. Pterygopalatine (a. 
To pharynx and 
palatina. major). 
Eustachian tube. 
14. Nasopalatine or spheno- 
To nasal septum and 
palatine (a. spheno- 
mucous membrane 
palatina). 
of lateral wall of 
nose. 
Internal carotid (a. carotis 
From the bifurca- 
1. Tympanic (ramus caro- 
To tympanum. 
interna). 
tion of 
the com- 
tico-tympanicus). 
mon carotid to the 
2. Arterial receptaculi. 
To cavernous sinus. 
Fig. 200. 
fissure of Sylvius, 
3. Anterior meningeal (a. 
To dura of anterior 
10 9 
where 
it divides 
meningea anterior). 
fossa. 
12^// 
7 7^ AZ 
into anterior and 
4. Ophthalmic (a. ophthal- 
middle 
cerebral; 
mica). 
divided 
into cer- 
a. Lacrymal (a. lacry- 
To lacrymal gland. 
5 Ip 
vical, 
petrous, 
malis). 
cavernous, and 
cerebral portions; 
b. Supra-orbital (a. 
To structures above 
supra-orbitalis). 
the orbit. 
passes 
into the 
c. Posterior ethmoid (a. 
To posterior eth moid 
cranial 
cavity 
ethmoidalis poste- 
cells. 
througl 
the caro- 
rior). 
J 
1 
/ 
tid canal, in the 
d. Anterior ethmoid (a. 
To anterior ethmoid 
petrous 
portion of 
eth moidal is anterior). 
cells. 
the temporal bone. 
e. Palpebral (aa. palpe- 
To eyelids. 
brales mediales et 
laterales). 
f. Frontal (a. frontalis). 
To structures above 
/ 
the orbit. 
g. Nasal (a. dorsalis 
To dorsum of nose. 
1. Cervical portion 
nasi). 
2. Petrous portion. 
3 Cavernous portion. 
h. Short ciliary (aa. 
To choroid and cili- 
4. Cerebral portion. 
ciliares posteriores 
ary processes. 
5. Tympanic. 
6. Arterte receptaculi. 
7. Anterior meningeal. 
breves). 
i. Long ciliary (aa. cili- 
To 'iris. 
8. Ophthalmic. 
9. Anterior cerebral. 
ares posteriores 
longse). 
j. Anterior ciliary (aa. 
10. Middle cerebral. 
11. Posterior communicating. 
To iris. 
12. Anterior choroid. 
ciliares anteriores). 368 
A MANUAL OF DISSECTION. 
Name. 
Description. 
Branches. 
Distribution. 
k. Arteria centralis 
To retina. 
retinae. 
1. Muscular (rami mus- 
To muscles of eye. 
culares). 
5. 
Anterior cerebral (a. 
See circle of Willis. 
cerebri anterior). 
a. Anterior median 
See circle of Willis. 
ganglionic. 
b. Inferior internal 
To orbital surface of 
frontal. 
frontal lobe. 
c. Anterior internal 
To marginal, supe- 
frontal. 
rior, middle, and 
descending frontal 
convolutions. 
d. Middle internal 
To corpus callosum 
frontal. 
and its convolu- 
tions ; first and 
ascending frontal 
convolutions. 
e. Posterior internal 
To lobus quadratus. 
frontal. 
6. 
Anterior communicating 
See circle of AVillis. 
(a. communicans ante- 
rior). 
7. 
Middle cerebral (a. 
cerebri media). 
a. Antero-lateral gan- 
See circle of Willis. 
glionic. 
b. Inferior internal 
To inferior frontal 
frontal (ramus 
and outer part of 
frontalis inferior 
orbital surface of 
externus). 
frontal lobe. 
c. Ascending frontal 
To ascending frontal 
(ramus frontalis as- 
cendens). 
convolution. 
d. Ascending parietal 
To ascending parie- 
(ramus parietalis 
ascendens). 
tal convolution. 
e. Parieto-temporal 
To supramarginal, 
superior, and mid- 
(ramus parieto- 
temporalis). 
dle temporal con- 
volutions and an- 
gular gyrus. 
f. Posterior communi- 
See circle of Willis. 
cating (a. communi- 
cans posterior). 
Circle of Willis (circulus 
Formed by the in- 
1. 
Anterior choroid (a. 
To choroid plexus. 
arteriosus). 
ternal carotids and 
choroidea anterior). 
basilar, which is 
2. 
Anterior cerebral (a. 
See above, to ante- 
rior portion of 
ria. zui. 
formed by the 
cerebri anterior). 
1 
junction of the 
brain. 
Jl 
vertebrals. From 
3. 
Anterior communicating 
Connects anterior 
it pass three large 
(ramus communicans 
cerebrals. 
( rll 
trunks for the cor- 
anterior). 
tex of each hemi- 
4. 
Antero-median (a. an- 
To basal ganglia. 
sphere, and the 
tero-mediana). 
9 // 
ganglionic 
5. 
Middle cerebral (a. 
See above, to lateral 
branches for the 
cerebri media). 
areas of brain. 
/ < \ 
basal ganglia. 
6. 
Antero-lateral (a. ante- 
To basal ganglia. 
ro-lateralis). 
/ / 
o 
7. 
Posterior' communicat- 
Connects middle and 
ing (a. communicans 
posterior cerebral 
posterior). 
arteries. 
/A\ 
8. 
Posterior cerebral (a. 
To posterior portion 
cerebri posterior). 
of brain. 
1. 
Anterior cerebral. 
9. 
Postero-median (a. pos- 
To basal ganglia. 
2. 
Anterior communicating. 
tero-mediana). 
3. 
Internal carotids. 
10. 
Postero-lateral (a. pos- 
To basal ganglia. 
4. 
5. 
Antero-median ganglionic. 
Middle cerebral. 
ero-lateralis). 
6. 
Antero-lateral ganglionic. 
7. 
Basilar. 
8. 
Posterior cerebral. 
9. 
Postero-median ganglionic. 
10. 
Postero-lateral ganglionic. 
11. 
Postorior communicating. THE BLOOD VASCULAR ST STEAL 
369 
Name. 
Description. 
Branches. Distribution. 
Subclavian (a. subclavia). 
Fia. 202. 
O' 
1-1-1. Subclavian (right). 
2. Vertebral. 
3. Internal mammary. 
4. Superior intercostal. 
5. Thyroid axis. 
6. Inferior thyroid. 
7. Transversalis colli. 
8. Suprascapular. 
Right, from bifur- 
cation of the in- 
nominate to the 
lower border of 
the first rib. Left 
arises direct from 
the arch of the 
aorta, hence is 
much longer than 
the right. 
1. Vertebral (a. verte- To circle of Willis, 
bralis). 
a. Lateral spinal (rami To spinal cord and 
spinales laterales). membranes. 
b. Muscular (aa. muscu- To deep muscles of 
lares). neck. 
c. Posterior meningeal To dura in posterior 
(a. meningea poste- fossa. 
rior). 
d. Anterior spinal (a. To spinal cord, an- 
spinalis anterior). tenor surface. 
e. Posterior spinal (a. To spinal cord, pos- 
spinalis posterior). teriorsurface. 
f. Posterior inferior To under surface of 
cerebellar (a. cere- cerebellum. 
belli inferior poste- 
rior). 
g. Bulbar. To medulla oblon- 
gata. 
h. Basilar (a. basilaris). See circle of Willis. 
2. Internal mammary (a. Anastomoses with 
mammaria interna). deep epigastric. 
a. Comes nervi phrenici To diaphragm. 
(a. pericard iaco- 
phrenica). 
b. Mediastinal (aa. me- To anterior medias- 
diastinales ante- tinum. 
riores). 
c. Pericardiac (aa. To pericardium, 
thymicae). 
d- Sternal (rami ster- To posterior surface 
nales). of sternum. 
e. Anterior intercostal To upper intercostal 
(rami intercostales). spaces. 
f. Perforating (rami To pectoralis major 
perforantes). and skin. 
g. Musculophrenic (a. To lower intercostal 
musculophrenica). spaces. 
h. Superior epigastric To diaphragm and 
(a. epigastrica supe- rectus abdominis, 
rior). 
(Thyroid axis, truncus Common trunk for 
thyreocervicalis). three following 
arteries 
3. Inferior thyroid (a. To thyroid gland, 
thyroidea inferior). 
a. Inferior laryngeal (a. To larynx, muscles, 
laryngea inferior). and mucous mem- 
brane. 
b. Tracheal (rami trach- To trachea, 
eales). 
c. (Esophageal (rami To oesophagus, 
oesophagei). 
d. Ascending cervical To deep muscles of 
(a. cervicalis ascen- the neck. 
dens). 
e. Muscular (rami mus- To muscles of neck, 
culares). anterior. 
4. Suprascapular (a. cer- To scapular muscles, 
vicalis profunda). 
5. Transversalis colli (a. To neck, 
transversa scapulae). 
a. Superficial cervical To trapezius and 
(a. cervicalis super- skin. 
ficialis). 
b. Posterior scapular (a. To rhomboid, latis- 
scapularis poste- simus dorsi, and 
rior). trapezius muscles. 
6. Superior intercostal (a. To first intercostal 
intercostalis suprema). space 
a. Profunda cervicis (a. To deep muscles of 
profunda cervicis). the neck. 370 
A MANUAL OF DISSECTION. 
Name, 
Axillary (a. axillaris). 
Fig, 203. 
/ 4 
1. Superior thoracic, 
2. Acromial thoracic. 
3. Alar thoracic. 
4. Long thoracic. 
5. Subscapular. 
6. Posterior circumflex. 
7. Anterior circumflex. 
Descriplion. 
From the lower bor- 
der of the first rib 
to the lower bor- 
der of teres major. 
Branches. Distribution. 
1. Superior thoracic (a. To pectoral muscles, 
thora cicalis suprema). 
2. Acromial thoracic (a. To muscles of the 
thoracoacromialis). shoulder. 
3. Long thoracic (a. thora- To serratus magnus. 
calis lateralis). 
4. Alar thoracic (a. thora- To axillary glands, 
cica alaria). 
5. Subscapular (rami sub- To subscapular mus- 
scapulares). cles. 
a. Dorsalis scapulae (a. To scapular muscles, 
circumflexa scap- 
ulae). 
6. Posterior circumflex (a. To deltoid and 
circumflexa humeri shoulder-joint, 
posterior). 
7. Anterior circumflex (a. To deltoid and 
circumflexa humeri shoulder-joint, 
anterior). 
Radial (a. 
A 
1. Recur 
2. Muset 
3. Anter 
4. Super 
5. Poster 
6. Metac 
7. Dorsa 
8. Dorsa 
9. Prine 
10. Radia 
+ Perfoi 
11. Palme 
12. Palms 
13. Deep 
14. Deep 
radia 
Fig. 20 
i 
S' 
S' // 
n 
II 
II 11 
to 
rent, 
lar. 
or cari 
Ocialis 
lor car] 
arpa], 
is polli 
is indi 
jps pol 
lis indi 
ating. 
ir inter 
r recui 
branch 
arch. 
is). 
4. 
f 
LI 
>al. 
vobe 
oal. 
cis. 
cis. 
icis. 
cis. 
osse 
'rent 
of u 
13 
11 
ms. 
Inar. 
From bifurcation of 
brachial, along 
radial side of fore- 
arm to wrist, winds 
backward around 
outer side of car- 
pus to upper end 
of first interosseous 
space, passes for- 
ward between the 
heads of the first 
dorsal interosseous 
muscle to the palm 
of the hand, where 
it crosses the meta- 
carpal bones to the 
ulnar border, 
forming a deep 
arch. 
(In forearm.) To elbow-joint and 
muscles. 
1. Radial recurrent (a. re- 
currens radialis). 
2. Muscular (rami muscu- To radial side of 
lares). forearm. 
3. Anterior carpal (ramus To articulations of 
carpeus volaris). wrist. 
4. Superficialisvolae (ramus To complete super- 
volaris superficialis). ficial arch. 
(In wrist.) 
1. Posterior carpal (ramus Partially forms pos- 
carpeus dorsalis). terior carpal arch, 
which gives off 
dorsal interosseous 
arteries for third 
and fourth spaces. 
2. Metacarpal (aa. meta- To first dorsal inter- 
carpse dorsales). osseous space. 
3. Dorsales pollicis (aa. To dorsum of thumb, 
dorsales pollicis). 
4. Dorsalis indicis (a. dor- To radial side, dor- 
salis indicis). sum of index 
finger. 
(In hand.) 
1. Princeps pollicis (a. To palmar surface of 
princeps pollicis). thumb, 
2. Radialis indicis (a. To palmar surface of 
volaris indicis radi- index finger. 
alis). 
3. Perforating (rami per- Three, to communi- 
forantes). cate with fingers. 
4. Palmar interosseous To interosseous 
(aa. metacarpese vo- spaces, 
lares). 
5. Palmar recurrent (aa. To carpal articula- 
palmares recurrentes). tions. 
6. Deep palmar arch (ar- The preceding five 
cus volarisprofundus). branches are from 
this arch. THE BLOOD VASCULAR SYSTEM. 
371 
Name. 
Description. 
Branches. 
Distribution. 
Brachial (a. br 
Fig. 
7 
□ 
ichialis). 
205. 
f 
^5 
From lower border 
of teres major to 
half inch below 
bend of elbow, 
where it divides 
into radial and 
ulnar. 
1. 
2. 
3. 
4. 
5. 
Superior profunda (a. 
profunda brachii supe- 
rior). 
Nutrient (a. nutricia 
humeri). 
Inferior profunda (a. 
profunda brachii in- 
ferior). 
Anastomotica magna (a. 
collateralis media). 
Muscular (rami muscu- 
lares). 
To triceps, humerus, 
and anconeus. 
To humerus. 
To triceps. 
To anastomosis 
about elbow. 
To coracobrachialis, 
biceps, and brach- 
ialis anticus. 
; J 
1 
$ 
IP 
6 
k 
7 
1. Superior profunda. 
2. Inferior profunda. 
3. Anastomotica magna. 
4. Nutrient. 
5-5-5. Muscular. 
6. Radial. 
7. Ulnar. 
Ulnar (a. ulna 
Fig. 
4 
A'Mi 
1. Anterior re 
2. Posterior re 
3. Posterior in 
4. Anterior in 
5. Muscular. 
6. Posterior ca 
7. Anterior ca 
8. Deep palma 
9. Superficial 
10. Digital. 
11. Superficial! 
ris). 
206. 
10 
curren 
curren 
terossc 
terosse 
rpal. 
rpal. 
r. 
arch. 
volte 
i 
7 
t. 
t. 
OUS. 
ous. 
of radial. 
From bifurcation of 
brachial, crosses 
to inner side of 
forearm, then de- 
scends to wrist, 
crosses annular 
ligament, and 
forms superficial 
arch. 
1. 
2. 
3. 
4. 
1. 
2. 
1. 
2. 
(In forearm). 
Anterior ulnar recur- 
rent (a. ulnaris recur- 
rens anterior). 
Posterior ulnar recur- 
rent (a. ulnaris recur- 
rens posterior). 
Interosseous (a. interos- 
sea communis). 
a. Anterior (a. interos- 
sea volaris). 
b. Posterior (a. interos- 
sea dorsalis). 
c. Recurrent (a. inter- 
ossea recurrens). 
Muscular (rami muscu- 
lares). 
(In wrist.) 
Anterior carpal (ramus 
carpeus volaris). 
Posterior carpal (ramus 
carpeus dorsalis). 
(In hand.) 
Deep palmar or com- 
municating (ramus 
volaris profundus). 
Superficial arch (arcus 
volaris superficialis). 
a. Digital (aa. digitales, 
volares, communes). 
To form anastomosis 
about elbow. 
To form anastomosis 
about elbow. 
To deep structures 
of forearm, ante- 
rior. 
To deep structures 
of forearm, poste- 
rior. 
To anastomosis 
about elbow. 
To ulnar side of 
forearm. 
To wrist, through 
anterior carpal 
arch. 
Helps form posterior 
carpal arch, (a) 
Metacarpal. Is 
dorsal interosseous 
to ulnar side of 
little finger. 
Helps form deep 
palmar arch. 
To ulnar side of 
little and contig- 
uous sides of little,, 
ring, middle, and 
index fingers. 372 
A MANUAL OF DISSECTION. 
A 
Thoracic a 
a< 
J 
t== 
1-=^ 
ame 
arta 
deal 
IG. 
~~~ 
3 
Description. Branches. Distribution. 
(aorta thor- From lower border 1. Pericardiac (rami peri- To pericardium. 
is). of fourth thoracic cardiaci). 
207 vertebra to open- 2. Bronchial (aa. bronchi- To lungs, nutrient 
ing in the dia- ales). vessels. 
- phragm. 3. (Esophageal (aa. To oesophagus. 
~ oesophagese). 
2 4. Posterior mediastinal To glands in medi- 
(rami mediastinales astinum. 
posteriores). 
1 5. Intercostal1 (aa. inter- Nine on each side, 
costales). To intercostal 
~~ 
4 
/ 
called subcostal. 
_' a. Posterior (rami pos- To muscles and skin 
teriores). of back. 
- b. Spinal (rami To spinal cord and 
-g spinales). membranes. 
- c. Collateral (aa. col- To walls of chest, 
laterales). 
_JL__ Muscular (rami muscu- 
lares). 
9) on each side. 
W- 
iiastmal (6). 
Branches and Distribution. 
rta (aorta 1. Phrenic (a. phrenica inferior). To diaphragm. 
From (Coeliac axis) (a. coeliaca). Common trunk for three following 
liaphragm to arteries. 
rth lumbar, 2. Gastric (a. gastrica). To less curvature of stomach. 
rides into 3. Hepatic (a. hepatica). To liver, capsule of Glisson, and gall-bladder. 
s. a. Pyloric. To pyloric end of stomach. 
b. Gastroduodenalis (a. gastroduodenalis). 
a. Gastro-epiploica dextra (a. gastro-epiploica dextra). To 
~08, greater curvature of stomach. 
- ' b. Pancreaticoduodenalis superior (a. pancreaticoduoden- 
I' . 1 alis superior). To pancreas. 
c- Cystic (a. cystica). To gall-bladder. 
4. Splenic. To spleen. 
a. Pancreaticae parvae. To pancreas. 
(y 6 _ b. Pancreatica magna. To pancreas. 
\ 8 c. Gastric (vasa brevia). To stomach. 
yX d. Gastro-epiploica sinistra. To stomach. 
\ y- 5. Superior mesenteric (a. mesenterica superior). 
ci. Inferior pancreaticoduodenalis (a. pancreaticoduodenalis in- 
V r fer or). To pancreas and duodenum. 
\ H b. Vasa intestini tenuis (aa. intestinales). To small intestine. 
\\ c. Ileocolic (a. ileocolica). To right iliac fossa. 
d. Colica dextra (a. colica dextra). To ascending colon. 
- e. Colica media (a. colica media). To transverse colon. 
1 6. Suprarenal (a. suprarenalis). To suprarenal capsule. 
\10 7. Renal (a. renalis). To kidneys. 
\ 8. Spermatic (a. spermatica interna). To testicle. 
14 Ovarian (a. ovarica). To ovary. 
9. Inferior mesenteric (a. mesenterica inferior). 
a. Colica sinistra (a. colica sinistra). To descending colon. 
b. Sigmoid (aa. sigmoidese). To sigmoid flexure of colon. 
c. Superior hemorrhoidal (a. hemorrhoidalis superior). To 
upper portion of rectum. 
1- . 10. Lumbar (aa. lumbales, four on each side). Analogous to intercostals, 
sentenc. a Dorsal (ramus dorsalis). To muscles and skin of back. 
b. Spinal (ramus spinalis). To spinal cord and membranes. 
senteric. c. Abdominal (rami abdominales). To abdominal walls. 
11. Sacramedia (a. sacralis media). To Luschka's gland (coccygeal gland), 
ics. 12. Common iliacs. To pelvis and lower extremity. 
1. Intercos 
2. Bronchi 
3. Pericarc 
4. CEsopha 
5. Posterio 
N 
Abdominal 
abdomini 
opening 
body of 
where it 
common 
J 
12 
6^ 
/ 
tals 
al. 
iac. 
^eal 
r me 
ame. 
ao 
ilis) 
in 
fou 
dr 
iliac 
IG. 
\7 
13 
c. 
axis 
3. 
irena 
>r me 
1. 
natic 
r me 
r. 
nedu 
m ili 
8' 
12= 
9^ 
12- 
14 / 
1. Phreni 
2. Cceliac 
3. Gastric 
4. Splenic 
5. Hepati 
6-6. Supri 
7. Superic 
8-8. Rena 
9-9. Sperr 
10. Inferio 
12. Lumba 
13. Sacra r 
14. Comm< 
i There are eleven intercostal spaces and a region below the twelfth rib occupied by an intercostal artery. The 
first and second spaces are occupied by intercostal arteries, from the subclavian. The succeeding nine spaces are 
occupied by intercostal arteries from the thoracic aorta. The region beneath the twelfth rib is occupied by the 
so-called twelfth intercostal artery, which, in reality, is not an intercostal, because not located between the ribs ; 
hence, as stated in the above table, the twelfth is called the subcostal artery. THE BLOOD VASCULAR SYSTEM. 
373 
Name. 
Description. 
Branches. 
Distribution. 
Common iliac, right and From bifurcation of 
left (a. iliaca communis). aorta to margins 
of intervertebral 
Fig- 209- substance between 
last thoracic ver- 
/ 1 tebra and sacrum. 
Internal iliac (a. iliaca 
interna). (See below.) 
External iliac (a. iliaca 
externa). (See below.) 
To pelvic structures. 
To lower extremity. 
A 
1-1 
2-2 
3-3 
Common iliac. 
Internal iliac. 
External iliac. 
Internal iliac (a. iliaca From bifurcation of 
interna). common iliac to 
upper margin of 
Fig. 210. great sacrosciatic 
foramen, where it 
/!/ divides into an 
anterior and pos- 
terior trunk. An- 
/ / J ~ x terior trunk sup- 
/ / / <2/^715 plies viscera of 
* 7^ I 14 pelvis ; posterior 
\ trunk supplies 
12 
1. Common iliac. 
2. External iliac. 
3. Internal iliac. 
4. Anterior trunk. 
5. Posterior trunk. 
6. Obturator. 
7. Superior vesical. 
8. Middle vesical. 
9. Inferior vesical. 
10. Middle hemorrhoidal, 
11. Internal pudic. 
12. Sciatic. 
13. Iliolumbar. 
14. Lateral sacral. 
15. Gluteal. 
(From anterior trunk). 
1. Superior vesical (aa. 
vesicales superiores). 
2. Middle vesical (a. vesi- 
calis media). 
3. Inferior vesical (a. vesi- 
calis inferior). 
4. Vaginal (in female) (a. 
vaginalis). 
5. Uterine (a. uterina). 
6. Middle hemorrhoidal (a 
hsemorrhoidalis 
media). 
7. Obturator (a. obtura- 
toria). 
a. Iliac (ramus iliacus). 
b. Vesical (ramus vesi- 
calis). 
c. Pubic (ramus pubi- 
cus). 
a. Internal. 
b. Externus. 
8. Internal pudic (a. 
pudenda interna). 
a. Muscular (rami mus- 
culares). 
b. Inferior hemorrhoidal 
(a. hsemorrhoidalis 
inferior). 
c. Superficial perineal 
(a. perinei super- 
ficialis). 
d. Transverse perineal 
(a. perinei trans- 
versa). 
e. Artery of bulb (a. 
bulbi urethrae). 
f. Artery of corpus cav- 
ernosum (a. ure- 
thral is) 
g. Dorsal artery of penis 
(a. dorsalis penis). 
h. Arteria dorsalis clito- 
ridis (in female). 
9. Sciatic (a. glutea infe- 
rior). 
a. Coccygeal (ramus 
coccygis). 
b. Inferior gluteal 
(ramus inferior). 
To apex and body 
of bladder. 
To base of bladder 
and vesicular. 
To base of bladder 
and prostate 
gland. 
To vagina and cer- 
vix uteri. 
To uterus. 
To anus. 
To iliac fossa. 
To bladder. 
To posterior surface 
of os pubis. 
To obturator ex- 
ternus pectineus, 
etc. 
To these muscles and 
hip-joints. 
To muscles outside 
of pelvis. 
To anus. 
To muscles and skin 
of perineum. 
To structures behind 
bulb. 
To bulb of urethra 
and Cowper's 
gland. 
To corpus caverno- 
sum. 
To penis. 
To clitoris. 
To muscles at back 
of pelvis. 
To gluteus maximus. 
To gluteus maximus. 374 
A MANUAL OF DISSECTION. 
Name. 
Description. 
Branches. 
Distribution. 
External iliac (a. iliaca 
From bifurcation of 
c. Comes nervi ischiadici 
(a. comitans nervi 
ischiadici). 
d. Muscular (rami mus- 
culares). 
e. Anastomotic (a. anas- 
tomotica). 
f. Articular (ramus ar- 
ticularis). 
(From posterior trunk.) 
10. Iliolumbar (a. ilio- 
lumbalis). 
a. Lumbar (ramus 
lumbalis). 
b. Iliac (ramus iliacus). 
11. Lateral sacral (a. 
sacralis lateralis). 
a. Superior. 
b. Inferior. 
12. Gluteal (a. glutaea 
superior). 
a. Superficial (ramus 
superior). 
b. Deep (ramus infe- 
rior). 
1. Deep epigastric (a. epi- 
To great sciatic 
nerve. 
To gluteus maximus. 
To branches of 
femoral. 
To hip-joint. 
To psoas and quad- 
ratus lumborum. 
To iliacus. 
To sacral canal. 
To sacral canal and 
structures on dor- 
sum of sacrum. 
To gluteus maximus. 
To glutei and hip- 
joint. 
To abdominal walls. 
externa). 
common iliac to 
gastrica inferior). 
Fig. 211. 
Poupart's liga- 
ment, where it 
becomes the 
femoral artery. 
a. Cremasteric (a. sper- 
matica externa). 
To spermatic cord 
and cremaster. 
d 
d 
b. Pubic (ramus pubi- 
cus). 
c. Muscular (rami mus- 
culares). 
2. Deep circumflex iliac (a. 
circumflexa ilium 
To femoral ring. 
To abdominal mus- 
cles and skin. 
To internal oblique 
and transversalis. 
T 
1. External iliac. 
2. Deep epigastric. 
3. Deep circumflex iliac. 
Femoral (a. femoralis). 
From Poupart's lig- 
profunda). 
1. Superficial epigastric (a. 
To inguinal glands 
Fig. 212. 
ament to opening 
in adductor mag- 
epigastrica super- 
ficialis). 
and skin of abdo- 
men. 
¥ 
nus, where it be- 
comes the poplit- 
eal. 
2. Superficial circumflex 
iliac (a. circumflexa 
ilium superficialis). 
3. Superficial external 
pudic (aa. pudendse 
To skin of groin. 
To skin of groin, 
* penis, and scro- 
externae). 
tum. 
¥ 
T 
1. Superior e 
-4 
t 
Digastric. 
4. Deep external pudic 
(aa. pudendie ex- 
tern as). 
5. Profunda (a. profunda 
femoris). 
a. External circumflex 
(a. circumflexa 
femoris lateralis). 
b. Internal circumflex 
(a. circumflexa 
medialis). 
c. Peforating (four) (a. 
perforans prim a, 
To skin of scrotum 
and perineum. 
To muscles of front 
of thigh. 
To adductors, gra- 
cilis, obturator 
externus, and hip- 
joint. 
To muscles on poste- 
rior surface of 
2. Superior circumflex iliac. 
secunda, tertia). 
thigh. 
3. Superior external pudic. 
6. Muscular (rami muscu- 
To sartorius and 
4. Deep external pudic. 
lares). 
vautus externus. 
5. Profunda femoris. 
7. Anastomotica magna (a. 
To skin and knee- 
6-6. Muscular. 
genu suprema). 
joint. 
7. Anastomolica magna. THE BLOOD VASCULAR SYSTEM. 
375 
Name. 
Description. 
Branches. 
Distribution. 
Popliteal (a. poplitea). 
Fig. 213. 
X' 
Xr 
8 
1. Superior muscular. 
2-2. Superior articular, internal 
and external. 
3. Sural-inferior muscular. 
4. Cutaneous. 
5. Azygos articular. 
6-6. Inferior articular, external 
and internal. 
7. Anterior tibial. 
8. Posterior tibial. 
From opening in 
adductor magnus 
to lower border of 
popliteus, where 
it divides into an- 
terior and poste- 
rior tibial. 
1. Muscular (rami muscu- 
lares). 
a. Superior (aa. muscu- 
lares laterales et 
mediales). 
b. Inferior or sural (aa. 
surales laterales et 
mediales). 
2. Cutaneous (a. cutanea). 
3. Superior articular (aa. 
genu superiores). 
a. Internal (a. genu su- 
perior medialis). 
b. External (a. genu su- 
perior lateralis). 
4. Azygos articular (a. 
genu media). 
5. Inferior articular (a. 
genu inferior 
medialis). 
a. Internal (a. genu in- 
ferior medialis). 
b. External (a. genu in- 
ferior lateralis). 
To adductor magnus 
and flexors of 
thigh. 
To gastrocnemius 
and plantaris. 
To integument of 
the calf. 
To vastus internus, 
inner hamstring, 
and knee-joint. 
To vastus externus 
and knee-joint. 
To knee-joint. 
To popliteus, head 
of tibia, and knee- 
joint. 
To knee. 
To knee-joint. 
Internal plantar ( 
taris medial 
Fig. 214. 
p 
a. p 
is). 
1 
X 
lan- 
Smaller than the ex- 
ternal ; passes for- 
ward along the 
inner side of the 
foot to the inner 
side of the great 
toe. 
Muscular and cutaneous 
branches (rami muscu- 
lares et cutanei). 
To the structures on 
the inner side of 
the foot and great 
toe. 
a6' 
6' 
•1 // ° 
6' 
1. External plantar. 
2. Internal plantar. 
3-3. Posterior perforating. 
4-4. Anterior perforating. 
5. Communicating. 
6-6. Digital. 
External plantar (a. 
taris lateralis). 
plan- 
Passes obliquely 
outward and for- 
ward to the base 
of the fifth meta- 
tarsal bone, then 
turns inward to 
the space between 
the bases of the 
first and second 
metatarsal bones. 
1. Posterior perforating 
(three) (rami per- 
forantes). 
2. Digital (four) (aa. digi- 
tales plantares). 
3. Anterior perforating 
(rami perforantes). 
To muscles, integu- 
ment, and fasciae 
of sole. 
To anastomose with 
interosseous 
branches from me- 
tatarsal artery. 
To three outer and 
half of second 
toes. 
To anastomose with 
interosseous 
branches from me- 
''tatarsal artery. 376 
A MANUAL OF DISSECTION. 
Name. 
Description. 
Branches. 
Distribution. 
Dorsalis pedis (a. 
pedis). 
Fig. 215. 
5 4 2 v 
1. Tarsal. 
2. Metatarsal. 
3. Communicating 
4. Dorsal hallucis. 
5. Interosseous. 
dorsalis 
4 
h 
1st 
From bend of ankle 
to posterior part 
of first intermeta- 
tarsal space. 
1. Tarsal (aa. tarsese medi- 
al es et laterales). 
2. Metatarsal (a. arcuata). 
a. Interosseous (three) 
(aa. metatarsales 
dorsales). 
b. Digital (aa. digitales). 
3. Dorsalis hallucis (a. dor- 
salis hallucis). 
4. Digital (aa. digitales 
dorsales). 
5. Communicating (ramus 
plantaris pro- 
fundus). 
To extensor brevis 
digitorum and 
tarsal joints. 
To dorsum and con- 
tiguous sides of 
four outer toes 
and outer side of 
little toe. 
To great toe. 
To dorsum and con- 
tiguous sides of 
first and second, 
also inner side of 
first toe. 
To complete plantar 
arch by dipping 
between two heads 
of first dorsal in- 
terosseous muscle 
and anastomosing 
with external 
plantar. 
Posterior tibial (a. tibialis 
posterior). 
Fig. 216. 
10 
1. Popliteal. 
2. Anterior tibial 
3. Posterior tibial. 
4. Peroneal. 
5-5. Muscular. 
6. Nutrient. 
7. Communicating. 
8. Internal calcanean. 
9. Internal plantar. 
10. External plantar. 
From bifurcation of 
popliteal to fossa 
between internal 
malleolus and 
heel, where it di- 
vides into internal 
and external 
plantar. 
1. Peroneal (a. peronsea). 
a. Muscular (rami mus- 
culares). 
b. Nutrient (a. nutritia 
fibulae). 
c. Anterior peroneal (a. 
malleolaris posterior 
medialis). 
d. Communicating 
(ramus communi- 
cans). 
e. Posterior peroneal (a. 
malleolaris posterior 
lateralis). 
f. External calcanean 
(ramus calcanei 
lateralis). 
2. Muscular (rami muscu- 
lares). 
3. Nutrient (a. nutritia 
tibiae). 
4. Communicating (rami 
communicantes). 
5. Internal calcanean 
(rami calcanei 
mediales). 
To muscles on poste- 
rior and outer sur- 
faces of leg. 
To fibula. 
Passes to tarsus on 
anterior surface of 
interosseous mem- 
brane. 
Joins with branch 
of posterior tibial. 
To external malleo- 
lus and os calcis. 
To outer side of heel. 
To soleus and deep 
muscles. 
To tibia. 
Join branch of pe- 
roneal. 
To heel and inner 
side of sole of foot. THE BLOOD VASCULAR SYSTEM. 
377 
Nam 
Anterior tibia 
anter 
Fig. 
3 
i 
-f 
e. 
1 (a. tibialis 
ior). 
217. 
Description. Branches. Distribution. 
From bifurcation of 1. Posterior recurrent tibial To popliteus and 
popliteal ; passes (a. recurrens tibialis tibiofibular joint, 
between two heads posterior) (not con- 
of gastrocnemius, stant). 
and through the 2. Superior fibular (ramus To soleus and pero- 
interosseous liga- fibularis). neus longus. 
ment; descends to 3. Anterior recurrent (a. Assists in anasto- 
bend of ankle, and recurrens tibialis mosis about 
becomes dorsalis anterior). patella. 
pedis. 4. Muscular (rami muscu- To muscles on ante- 
lares). rior surface of leg. 
5. Internal malleolar (a. To inner side of 
malleolaris anterior ankle 
medialis). 
6. External malleolar (a. To outer side of 
malleolaris later- ankle, 
alis). 
1. Posterior recurrent tibial. 
2. Superior fibular. 
3. Anterior recurrent tibial. 
4. Muscular. 
5. Internal malleolar. 
6. External malleolar. 
Systemic Veins. 
Name. Description. 
Superior vena From junction of 
cava (vena right and left in- 
cava superior). nominates to right 
(See page 185.) ventricle, two and 
one-half to three 
inches in length. 
Right innomi- From junction of in- 
nate or ternaljugular and 
brachiocephalic subclavian on 
(v. anony- right side to oppo- 
ma dextra). site first costal 
(See page 185.) cartilage of right 
side, one inch in 
length. No 
valves. At 
angle of junction 
receives right 
lymphatic duct. 
Tributaries. Source. 
1. Right innominate (v. Right side of head and right 
anonyma dextra). upper extremity. 
2. Left innominate (v. anon- Left side of head and left 
yma sinistra). upper extremity. 
3. Mediastinal. From mediastinal space. 
4. Pericardiac (vv. pericar- From pericardium. 
diacee). 
5. Azygos major (v. azygos From lower ten intercostal 
major). spaces of right side. 
a. Azygos minor (v. azygos From four or five lower inter- 
minor). costal spaces of left side. 
a. Left upper azygos. From three or four upper 
spaces in left side below 
superior intercostal. 
b. (Esophageal (vv. From oesophagus, 
cesophagese). 
c. Mediastinal (vv. From mediastinal space, 
mediastinales). 
b. (Esophageal (v. oesoph- From oesophagus, 
agea). 
c. Mediastinal (vv. medi- From mediastinum, 
astinales). 
d. Pericardiac (vv. peri- From pericardium, 
cardiacse). 
e. Right bronchial (vv. From right lung, 
bronchiales dextrse). 
f. Right superior inter- From two or three upper in- 
costal (v. intercostalis tercostal spaces of right 
superior dextra). side. 
1. Internal jugular (v. jugu- 
laris interna). (See 
below.) 
2. Right subclavian (v. sub- 
clavia dextra). (See 
below.) 
3. Inferior thyroid (v. thy- From thyroid gland, 
roidea inferior). 
4. Right vertebral (v. verte- From cranial cavity, spinal 
bralis dextra). canal, and deep muscles of 
the neck. »• A MANUAL OF DISSECTION. 
378 
Name. 
Description. 
Tributaries. Source. 
Left in nomin ate 
(v. anonyma 
sinistra). 
(See pages 185 
and 197.) 
Internal jugular 
(v. jugularis 
interna). 
(See pages 26 
and 106.) 
From junction of in- 
ternal jugular and 
subclavian on left 
side to opposite 
first costal carti- 
lage of right side, 
two-and-one-half 
inches in length. 
No valves. At 
angle of junction 
receives thoracic 
duct. 
From jugular fora- 
men to root of the 
neck. Formed by 
junction of lateral 
and inferior pet- 
rosal sinuses. One 
pair of valves. 
Lies in sheath 
with carotid ar- 
tery and pneu mo- 
gastric nerve. 
5. Right internal mammary From phrenic nerve, medias- 
(v. mammaria interna tinal glands, pericardium, 
dextra). sternum, anterior portion 
of intercostal spaces, and 
upper part of abdominal 
walls. 
1. Left internal jugular (v. 
jugularis sinistra). (See 
below.) 
2. Left subclavian (v. sub- 
clavia sinistra). (See 
below.) 
3. Left inferior thyroid (v. a. From thyroid gland, 
thyroidea inferior sinis- 
tra). 
4. Left vertebral (v. verte- b. From cranial cavity, spinal 
bralis sinistra). canal, and deep muscles 
of the neck. 
5. Left internal mammary c. From phrenic nerve, medi- 
(v. mammaria interna). astinal glands, pericar- 
dium, sternum, anterior 
portion of intercostal 
spaces, and upper part of 
abdominal walls. 
6. Left superior intercostal From two or three upper in- 
(v. intercostalis superior tercostal spaces of left side, 
sinistra). 
a. Left bronchial (v. From left lung, 
bronchialis sinistra). 
b. Superior phrenic (v. From phrenic nerve, 
phrenica superior). 
1. Lateral sinus. From brain. 
2. Inferior petrosal sinus. From brain. 
3. Facial (common) (v. From face, 
facialis communis). 
a. Anterior division of See external jugular vein, 
temporomaxillary). 
b. Facial (v. facialis). 
a. Angulai' (v. angu- From side of nose, 
laris). 
b. Frontal (v. fron- From forehead, 
talis). 
c. Supra-orbital (v. From above orbit, 
supra-orbi talis). 
d. Deep facial (v. From muscles of face, 
facialis profunda). 
e. Internal palpebral From lower lid. 
(v. palpebralis 
inferior). 
f. Superior labial (v. From upper lip. 
labialis superior). 
g. Inferior labial (v. From lower lip. 
labialis inferior). 
h. Buccal (v. buccalis). From side of mouth. 
i. Masseteric (v. mas- From masseter muscle, 
seterica). 
j. Submental (v. sub- From chin, 
mentalis). 
k. Inferior palatine (v. From soft palate, 
palatina inferior). 
J. Submental, maxil- From submaxillary gland, 
lary (v. submax- 
il laris). 
m Ranine (v. dorsalis From tongue, 
linguae). 
4. Lingual (v. lingualis). From tongue. 
5. Pharyngeal (v. pharyn- From pharyngeal plexus, 
gea). 
6. Superior thyroid (v. thy- From thyroid gland, 
roidea superior). 
7. Middle thyroid (v. thy- From thyroid gland, 
roidea media). 
8. Occipital (p. occipitalis). From posterior surface of 
head. THE BLOOD VASCULAR SYSTEM. 
379 
Name. 
Description. 
Tributaries. 
Source. 
Lateral sinus 
(sinus later- 
alis). 
Venous channel, in- 
side of cranial 
cavity; outer coat 
1. Superior longitudinal sinus 
(sinus sagittalis super- 
ior). 
From brain and pericranium. 
(See Figs. 26 
formed by dura, 
inner by lining 
a. Superior cerebral veins. 
From upper surface of brain. 
and 27, pages 
b. Veins of diploe. 
From bones of cranium. 
54 and 55.) 
membrane of vein. 
Situated in at- 
tached margin of 
tentorium cere- 
belli. From tor- 
cular Herophili to 
jugular foramen. 
2. Straight sinus (sinus 
rectus). 
a. Inferior longitudinal 
(sinus sagittalis 
inferior). 
b. Median cerebral veins 
(vv. cerebrates 
medianae). 
c. Vense Galeni (v. cerebri 
magna). 
a. V. corporis striati. 
b. Choroid vein. 
c. Basilar. 
d. Superior cerebellar. 
3. Occipital (v. occipitalis). 
4. Superior petrosal (sinus 
petrosus superior). 
From free margin of falx 
cerebri. 
From surface of brain along 
longitudinal fissure. 
From ventricles of brain. 
From corpus striatum. 
From choroid plexus. 
From base of brain. 
From upper portion of cere- 
bellum. 
From falx cerebelli. 
From base of brain. 
i 
5. Inferior cerebellar vein. 
From lower portion of cere- 
bellum. 
Inferior pet- 
• 
6. Petro-squamous. 
7. Veins of diploe (vv. diplo- 
icae). 
From lower portion of brain. 
From bones of cranium. 
From termination of 
1. Cavernous sinus (sinus 
From base of brain. 
rosal sinus. 
cavernous sinus to 
cavern us). 
(See Fig. 26, 
page 54.) 
jugular foramen. 
Lies along lower 
border of petrous 
portion of tem- 
poral bone. 
a. Inferior cerebellar veins 
(vv. cerebelli infe- 
riores). 
b. Ophthalmic (v. ophthal- 
mica). 
a. Superior ophthal- 
mic (v. ophthal- 
mica superior). 
b. Inferior ophthalmic 
(v. ophthalmica 
inferior). 
2. Circular sinus (sinus cir- 
cularis). 
a. Anterior. 
b. Posterior. 
3. Small veins (vv. minimae). 
From base of cerebellum. 
From orbit. 
From contents of orbit. 
From floor of orbit. 
Connect two cavernous sin- 
uses. 
From internal ear, medulla, 
and pons. 
Emissary veins. 
Pass through aper- 
tures in cranial 
wall and connect 
outside veins and 
sinuses). 
4. Transverse sinus (sinus 
transversus). 
See emissary system, Eck- 
ley's Anatomy of Head and 
Neck, pp. 100-102. 
Connect two inferior petrosal 
sinuses. 
Subclavian. 
Is continuation of 
1. External jugular (v. jugu- 
From exterior of cranium and 
(See Fig. 104, 
axillary from 
laris externa). 
deep portion of face. 
page 197.) 
outer border of 
first rib to inner 
end of clavicle, 
where it unites 
with the internal 
jugular to form 
the innominate. 
2. Posterior division of tem- 
poromaxillary. 
a. Temporal (v. tempor- 
alis). 
I. Parotid (v. paro- 
tidea). 
II. Articular (v. arti- 
cularis). 
III. Anterior auricular 
(v. auricularis an- 
terior). 
IV. Transverse facial (v. 
transversa). 
V. Middle temporal (v. 
tem poralis media). 
VI. Orbital (v. orbit- 
alis). 
b. Internal maxillary (v. 
maxillaris interna). 
From anterior division. (See 
fascial.) 
From temporal region. 
From parotid gland. 
From articulation of inferior 
maxillary. 
From ear. 
From side of face. 
From side of head. 
From eyelids. 
From sphenomaxillary fossa. 380 
A MANUAL OF DISSECTION. 
Name. 
Description, 
Tributaries. Source. 
Axillary (v. 
3. 
4. 
5. 
6. 
7. 
8. 
. Continuation of 1. 
I. Middle meningeal From meninges. 
(v. meningea 
media). 
II. Deep temporal (v. From temporal muscle, 
perforans). 
III. Veins of diploe. From bones of cranium. 
IV. Pterygoid (v. ptery- From pterygoids. 
goidea). 
V. Masseteric (v. mas- From masseter. 
seterica). 
VI. Buccal (v. buc- From buccinator. 
calis). 
VII. Alveolar (v. alveo- From alveolar process of 
laris). superior maxillary. 
VIII. Palatine (v. pala- From hard and soft palate, 
tina). 
IX. Inferior dental. From inferior maxillary 
bone, teeth, etc. 
Posterior auricular. From behind ear. 
Posterior external jugular. From upper and back part of 
neck. 
Suprascapular. From posterior scapular 
region. 
Transversalis colli. From side of neck. 
Anterior jugular (v. jugu- From submaxillary region. 
laris anterior). 
Branch of cephalic. From arm. 
Cephalic (v. cephalica). From superficial portion of 
axillaris). 
Brachial (v. 
basilic from lower 
border of teres 
major to outer 
border of first rib. 
Basilic passes from 
bend of elbow up- 
ward, pierces deep 2. 
fascia half-way up 3. 
arm, and then lies 
in relation with 4. 
brachial vessels. 
5. 
6. 
7. 
8. 
9. 
10. 
11. 
Venae comites _ 1. 
arm. 
a. Median cephalic (v. Connects median and cephalic 
mediana cephalica). veins. 
b. Radial (superficial) (v. From dorsal surface of fingers, 
radialis). wrist, and radial side of 
forearm. 
Superior thoracic. From walls of thorax. 
Acromial thoracic (v. From muscles about the 
thoracoacromialis). shoulder. 
Long thoracic (v. thora- From side of thorax and ax- 
cicalis lateralis). illary glands. 
Alar thoracic. From lymph glands of axilla. 
Subscapular (v. subscapu- From muscles about scapula, 
laris). 
Posterior circumflex (v. From deltoid and shoulder- 
circumflexa posterior). joint. 
Anterior circumflex (v. From humerus and shoulder- 
circumflexa anterior). joint. 
Basilic (v. basilica). From superficial structures of 
forearm. 
a. Common ulnar (super- From forearm and hand 
ficial) (anterior ulnar, through anterior and pos- 
posterior ulnar). terior ulnar. 
b. Median basilic (v. me- Connects median and basilic 
diana basilica). veins. 
Median (v. mediana). From superficial structures on 
front of forearm. 
Brachial. 
Superior profunda (v. pro- From muscles on posterior 
brachialis). 
Radial (vv. 
radiales). 
formed by junc- 
tion of deep radial 2. 
and ulnar veins 3. 
just below bend of 
elbow, extend up- 4. 
ward witli brach- 
ial artery, and 
empty into axil- 5. 
lary vein near 
teres major 6. 
muscle. 
7. 
Venae comites from 
right side of hand 1. 
funda superior). surface of arm. 
Nutrient (v. nutricia). From humerus. 
Inferior profunda (v. pro- From structures back of 
funda inferior). elbow-joint. 
Anastomotica magna (v. From elbow-joint, 
collateralis ulnaris in- 
ferior). 
Muscular (rami muscu- From muscles on anterior 
lares). surface of arm. 
Radial (deep) (vv. radi- 
ales). (See below.) 
Ulnar (deep) (vv. ulnaris 
profundse).(See below.) 
(In forearm.) 
Radial recurrent (ramus From elbow-joint. 
and forearm to 
elbow in relation 2. 
with radial artery. 
recurrens). 
Muscular (rami muscu- From deep muscles, 
lares). THE BLOOD VASCULAR SYSTEM. 
381 
Name. 
Description. 
Tributaries. Source. 
Ulnar (vv. 
Venae comites from 
3. Anterior carpal (rami From anterior surface of 
carpeae anteriores). wrist and hand. 
4. Superficialis volae. From anterior surface of the- 
nar eminence. 
(In wrist.) 
5. Posterior carpal (rete From posterior surface of 
carpi dorsale). wrist and hand. 
6. Metacarpal (vv. meta- From second interosseous 
carpeae dorsales). space and fingers. 
7. Dorsalis pollicis (v. dor- From posterior surface of 
salis pollicis). thumb. 
8. Dorsalis indicis (v. dor- From posterior surface of in- 
salis indicis). dex finger. 
(In hand.) 
9. Princeps pollicis (v. prin- From thumb. 
ceps pollicis). 
10. Radialis indicis (v. vol- From index finger, 
aris indicis radialis). 
11. Perforating (vv. perfbr- Communicate with dorsal in- 
antes). tero.-seous veins. 
12. Palmar interosseous (vv. From interosseous spaces, 
digitales volaris com- 
munes). 
13. Palmar recurrent. From carpal articulations. 
(In forearm.) 
ul nares) 
ulnar side of hand 
1. Anterior ulnar recurrent From elbow-joint. 
Inferior vena 
to elbow, where 
they empty with 
radial into brach- 
ial. Are in rela- 
tion with ulnar 
artery. 
Formed by junction 
(ramus recurrens). 
2. Posterior ulnar recurrent From elbow-joint, 
(rami recurrentes ante- 
riores). 
3. Anterior interosseous From deep muscles on ante- 
(vv. interosseae ante- rior surface of forearm, 
ri ores). 
4. Posterior interosseous From deep muscles on poste- 
(vv. interosseae poste- rior surface of forearm, 
riores). 
5. Muscular (rami muscu- From muscles on ulnar side 
lares) of forearm. 
(In wrist.) 
6. Anterior carpal (rete From anterior surface of 
carpi volare). wrist and hand. 
7. Posterior carpal (rete From posterior surface of 
carpi dorsale). wrist and hand. 
(In hand.) 
8. Deep palmar (communi- Communicates with deep 
eating) (ramus com radial veins. 
municans). 
9. Superficial palmar arch From palm of hand and 
(arcus volaris super- fingers. 
ficialis). 
1. Hepatic (three usually) From liver. 
cava (vena 
of the common 
(vv. hepaticae). 
cava inferior). 
iliac veins on right 
2. Phrenic (v. phrenica in- From diaphragm. 
(See Figs. 112 
side of fifth lum- 
ferior). 
and 122, pages 
bar vertebra, and 
passes upward, 
3 Suprarenal (vv. supra- From adrenal tissue. Left 
212and 232.) 
renales). vein usually empties into 
emptying into 
right auricle. 
left renal or phrenic. 
4. Renal (v. renalis). From kidney. Left renal 
receives left spermatic. 
5. Right spermatic (v. sper- From right testicle. 
matica dextra). 
(Ovarian vein, right (v. From ovary. 
ovarica) forms plexus 
in broad ligament and 
terminates same as 
spermatic vein). 
6. Lumbar (four on each From muscles and integument 
side) (vv. lumbales). of loins. 
7. Right common iliac. From pelvis and right lower 
extremity. 
8. Left common iliac. From pelvis and left lower 
extremity. 382 
A MANUAL OF DISSECTION. 
Name. 
Description. 
Tributaries. 
Source. 
Common iliac 
(vena iliaca 
Formed by union of 
external and in- 
1. Lateral sacral (vv. sac- 
rales) (occasionally). 
From pelvic wall. 
communis). 
ternal iliac veins 
2. Iliolumbar (v. iliolum- 
From iliacus and quadratus 
(See Fig. 134, 
in front of sacro- 
balis). 
lumborum. 
page 255.) 
iliac articulation, 
and terminate in 
inferior vena cava. 
(Left common iliac also 
receives middle sacral.) 
3. Internal iliac (v. hypo- 
gastrica). 
a. Gluteal (vv. glutese su- 
periores). 
b. Sciatic (v. glutere infe- 
rior). 
c. Internal pudic (v. pu- 
denda interna). 
d. Obturator (vv. obtura- 
toriae). 
e. Hemorrhoidal plexus 
(plexus hemorrhoid- 
al is). 
/. Vesicoprostatic plexus. 
Dorsal vein of penis or 
clitoris. 
g. Hemorrhoidal plexus 
(plexus hemorrhoid- 
alis). 
h. Uterine and vaginal 
plexus. 
4. External iliac (v. iliaca 
externa). (See below.) 
From posterior wall of pelvis. 
From muscles and integument 
of gluteal region. 
From posterior surface of 
thigh. 
From perineum and external 
genitals. 
From pelvis and inner sur- 
face of thigh. 
From rectum. 
From bladder and prostate. 
From erectile tissue of 
penis. 
From rectum.' 
From uterus and vagina. 
External iliac 
From termination 
1. Deep epigastric (v. epi- 
From anterior abdominal 
(v. iliaca 
of femoral at Pou- 
gastrica inferior). 
wall. 
externa). 
part's ligament to 
2. Deep circumflex iliac (v. 
From abdominal wall in iliac 
(See Fig. 134, 
page 255.) 
sacro-iliac articu- 
lation. 
circumflexa ilium pro- 
funda). 
3. Pubic (v. pubica) (occa- 
sionally). 
region. 
Small branch from pubic 
region. 
Femoral (v. 
From opening in 
1. Internal saphenous (v. 
From inner side find dorsum 
femoralis). 
(See Figs. 150, 
adductor magnus 
to Poupart's liga- 
saphena magna). 
of foot and inner side of 
leg and thigh. 
151, and 152, 
pages 288 and 
291.) 
ment. 
a. Superficial epigastric (v. 
epigastrica superfici- 
alis). 
b. Superficial circumflex 
iliac (v. circumflexa 
ilium superficialis). 
c. External pudic (v. pu- 
denda externa), 
2. Profunda femoris (v. pro- 
funda femoris). 
a. External circumflex (v. 
circumflexa externa). 
b. Internal circumflex. 
c. Perforating. 
d. Nutrient. 
3. Muscular (rami muscu- 
lares). 
From abdominal wall-super- 
ficial. 
From upper portion of thigh 
and abdominal wall. 
From inner side of thigh 
and pubic region. 
From deep structures of 
thigh. 
From muscles on front of 
thigh. 
From adductor muscles. 
From muscles on posterior 
surface of thigh. 
From femur. 
From muscles of anterior 
surface of thigh. 
Popliteal (vv. 
Formed by junction 
1. Sural veins (vv. surales). 
From gastrocnemius. 
popliteae). 
(See Fig. 164, 
page 308.) 
of anterior and 
posterior tibial 
venre comites, at 
lower border of 
popliteus muscle ; 
extends upward to 
opening in adduc- 
tor magnus. 
2. Articular (several) (vv. 
genu, laterales et me- 
diales superiores ac 
inferiores). 
3. External saphenous (v. 
saphena parva). 
4. Anterior tibial (vv. tibi- 
ales anteriores). (See 
below.) 
5. Posterior tibial (vv. tibi- 
ales posteriores). (See 
below.) 
From knee-joint. 
From outer side and dorsum 
of foot, and outer and pos- 
terior portions of leg. THE BLOOD VASCULAR SYSTEM. 
383 
Name. 
Description. 
Tributaries. 
Source. 
Anterior tibial 
Continuation up- 
1. Muscular (rami muscu- 
From muscles on anterior sur- 
(vv. tibiales 
ward of venae 
lares). 
face of leg. 
anteriores). 
comites of dorsalis 
2. Internal malleolar (v. mal- 
From inner side of ankle. 
(See page 312.) 
pedis artery to 
j unction with pos- 
leolaris medialis). 
3. External malleolar (v. 
From outer side of ankle. 
Dorsalis pedis 
terior tibial. 
Venae comites from 
malleolaris lateralis). 
1. Tarsal (vv. tarsae). 
From tarsal articulations. 
(vv. dorsales 
base of first inter- 
2. Metatarsal (v. metatar- 
From joints and muscles. 
pedis). 
(See page 314.) 
osseous space to 
bend of ankle, 
sae). 
a. Interosseous (v. perfor- 
From interosseous spaces. 
where they be- 
come anterior 
tibial. 
antes). 
I. Digital (vv. digitales). 
3. Dorsalis hallucis. 
From toes. 
From great toe. 
Posterior tibial 
Venae comites from 
4. Communicating (ramus 
plantaris profundus). 
1. Peroneal (page 322). 
Connects with plantar veins. 
(vv. tibiales 
junction of inter- 
a. Muscular. 
From muscles on fibular side 
posteriores). 
(bee page 322.) 
nal and external 
plantar between 
b. Nutrient. 
of leg. 
From fibula. 
Internal plantar 
heel and internal 
malleolus to lower 
border of popli- 
teus, where they 
unite with ante- 
rior tibial to form 
popliteal. 
Venae comites along 
c. Anterior peroneal. 
d. Communicating (vv. 
communican tes). 
e. Posterior peroneal. 
f. External calcanean. 
2. Muscular (rami muscu- 
lares). 
3. Nutrient (vv. nutriciae). 
4. Communicating (vv. com- 
municantes). 
5. Internal calcanean. 
6. Internal plantar (v. plan- 
taris medialis). (See 
below.) 
7. External plantar (v. plan- 
taris lateralis). (See 
below.) 
Superficial digital branches 
From deep structures on an- 
terior surface of leg. 
Connects with posterior tibial 
venae comites. 
From behind external mal- 
leolar. 
From outer side of heel. 
From muscles on posteiior 
surface of leg. 
From tibia. 
Connects with peroneal venae 
comites. 
From inner side of heel. 
From great toe and inner 
(v. plantaris 
inner side of foot 
(vv. digitales superfici- 
side of foot. 
medialis). 
(See pages 329 
and 330.) 
External plan- 
to junction with 
external plantar to 
form posterior 
tibial. 
Venae comites which 
ales). 
1. Posterior perforating (vv. 
Communicate with metatarsal 
tar (v. plan- 
extend across the 
perforantes) (three). 
veins on dorsum of foot. 
taris later- 
bases of metatarsal 
2. Digital (vv. digitales) 
From interosseous spaces and 
alis). 
bones and along 
(four). 
toes. 
(See pages 329 
the outer side of 
3. Anterior perforating (vv. 
Communicate with interosse- 
and 330.) 
foot, with external 
plantar artery, to 
join internal plan- 
tar to form poste- 
rior tibial. 
From behind upper 
perforantes anteriores). 
ous veins on dorsum of 
Portal vein 
1. Superior mesenteric (v. 
foot. 
From small intestines. 
(vena portae). 
(See Fig. 125, 
border of head of 
pancreas to trans- 
mesenterica superior). 
a. Colica media (v. colica 
From transverse colon. 
page 240.) 
verse fissure of 
liver; lies be- 
tween layers of 
lesser omentum 
behind common 
media). 
b. Ileocolic (v. ileocolica). 
c. Colica dextra (v. colica 
dextra). 
2. Splenic (v. lienalis). 
From caecum. 
From ascending colon. 
From spleen. 
duct and hepatic 
artery, three or 
four inches in 
length. 
a. Pancreatic (vv. pancre- 
aticae). 
b. Vasa brevia (vv. gas- 
tricae breves). 
c. Gastro epiploica dextra. 
d. Inferior mesenteric (v. 
mesenterica inferior). 
a. Colica sinistra. 
b. Sigmoid (vv. sig- 
moideae). 
From pancreas. 
From stomach. 
From greater curvature of 
stomach. 
From colon. 
From descending colon. 
From sigmoid flexure. A MANUAL OF DISSECTION. 
384 
Name. 
Description. 
Tributaries. 
Source. 
Spinal veins 
3. 
4. 
5. 
Numerous plexuses 1. 
c. Superior hemorrhoidal 
(v. hemorrhoidalis 
superior). 
Cystic (v. cystica) (occa- 
sionally). 
Coronary. 
Pyloric. 
Dorsi spinal (venae spin- 
From hemorrhoidal plexus. 
From gall-bladder. 
From lesser curvature of 
stomach. 
From pylorus. 
From skin and muscles of 
(venae 
spinales). 
placed upon and 
within spinal col- 2. 
ales dorsales). 
Meningorachidian. 
back. 
From between vertebrae and 
Cardiac veins 
umn. Terminate 
in vertebral in 
neck, intercostal 
in thorax, lumbar 
and sacral in loins 
and pelvis. 3. 
4. 
Veins which return 1. 
a. Anterior longitudinal. 
b. Posterior longitudinal. 
Venae basis vertebrarum. 
Medulli spinal. 
Coronary (vv. coronaria). 
membranes of cord. 
From whole length of spinal 
canal behind bodies. 
From whole length of canal 
behind cord. 
From bodies of vertebrae. 
From spinal cord. 
From both ventricles and left 
(vv. cardi- 
acae). (See 
blood from sub- 
stance of heart. 2. 
Posterior cardiac (v. car- 
auricle. 
From both ventricles. 
Fig. 98, 
page 185.) 
3. 
4. 
5. 
6. 
7. 
diaca posterior). 
Left cardiac (three or 
four) (v. cardiaca sin- 
istra). 
Anterior cardiac (three or 
four) (vv. cardiacae an- 
teriores). 
Kight coronary (v. coron- 
aria dextra. 
Coronary sinus (sinus cor- 
onarius). 
Venae Thebesii (numer- 
ous). 
From left ventricle. 
From right ventricle. 
From back part of right au- 
ricle and ventricle. 
Dilated portion of coronary 
vein. 
From walls of right auricle 
-open directly into cavity. 
THE F(ETAL CIRCULATION. 
1. The foramen ovale, situated in the posterior wall of the right auricle, 
establishes a free communication between the auricles of the heart, and is usually 
closed in the adult by a membrane proceeding from below upward, called the 
valvula foraminis ovalis. 
2. The Eustachian valve (valvula vense cavse inferioris) is large, formed of 
endocardium and muscular fibres, and directs blood from the inferior vena cava 
through the foramen ovale into the left auricle. In the adult it is commonly 
small and identified by its cribriform appearance, situated between the anterior 
margin of the inferior vena cava and the right auriculo-ventricular orifice. 
3. The ductus arteriosus (Botalli) forms a direct opening between the pulmonary 
artery and the aorta. Through it venous blood is deflected into the arterial circula- 
tion. Its period of usefulness is during intra-uterine life. In the adult it obtains 
as a fibrous connective-tissue cord. It occasionally remains open in the adult. 
4. The hypogastric arteries (aa. umbilicales), one on either side, pass from the 
internal iliac arteries to the upper surface of the bladder, thence through the 
umbilical opening (annulus umbilicalis) to the placenta, through the umbilical cord. 
The portions of these vessels remaining patulous after birth are the superior 
vesical arteries. 
5. The umbilical vein (vena umbilicalis) passes from the placenta through the 
umbilical opening, through the umbilical cord to the transverse fissure of the 
liver. This vessel returns aerated blood from the placenta, and, obliterated after 
birth, forms the round ligament of the liver. 
6. The ductus venosus (Arantii) forms a communication between the umbilical 
vein and the inferior vena cava. It obtains in the adult as a fibrous cord in the 
fissure for the ductus arteriosus, on the posterior surface of the liver. 
Course of foetal circulation : Blood passes from the placenta, where it is puri- 
fied, to the transverse fissure of the liver through the umbilical vein. Here a THE BLOOD VASCULAR SYSTEM. 
385 
part is mixed with the blood of the portal vein (ramus sinistra venae portae), and 
follows the usual course of this vessel. The remainder passes through the ductus 
venosus to the inferior vena cava, and is mixed with blood coming from the lower 
portions of the body. This blood reaches the right auricle, and is partially 
Fig. 218. 
Plan of the foetal circulation. In this plan the figured arrows represent the kind of blood, as well as the 
direction which it takes in the vessels. Thus, arterial blood is figured >- ->; venous blood > > 
mixed (arterial and venous) blood > ■ ->. 
mixed with the contents of the superior vena cava, and directed by the Eustachian 
valve through the foramen ovale to the left auricle. From here it passes into the 
left ventricle, thence through the aorta, principally to the head and upper extrem- 
ities; that which does not leave the vessel through the branches of ihe arch of the 386 
A MANUAL OF DISSECTION. 
aorta is mixed with venous blood, which has passed from the superior vena cava, 
right auricle, right ventricle, and pulmonary artery, where the ductus arteriosus 
empties into the aorta. From this point the blood (principally venous) is dis- 
tributed to all other portions of the body, and part of it passes to the placenta 
through the internal iliac and hypogastric arteries. It will be noticed that the 
liver receives purified blood direct from the placenta, hence its large size in the 
foetus. The head and upper extremities receive richer blood than the lower 
extremities; this accounts for the relatively large size of these members. The 
lungs receive blood only for nourishment (this through the bronchial arteries), 
hence practically all blood which passes into the pulmonary artery reaches the 
aorta through the ductus arteriosus. (Fig. 218.) CHAPTER XXXII. 
SENSORY AND MOTOR CONDUCTION PATHS BETWEEN THE SPINAL 
CORD AND THE CEREBRAL CORTEX. 
By C. M. Jackson, M.D. 
1. Sensory (afferent) conduction paths from the spinal cord to the cerebral 
cortex. 
A. Direct route (without traversing the cerebellum). 
a. Via tracts of Goll and Burdach (fasciculus gracilis et cuneatus). 
b. Via anterolateral ground bundle (fasciculi proprii). 
c. Via tract of Gowers (anterolateral ascending). 
B. Indirect route (via cerebellum). 
a. Via tracts of Goll and Burdach (fasciculus gracilis et cuneatus). 
b. Via direct cerebellar tract (fasciculus spinocerebellaris dorsolateralis). 
c. Via tract of Gowers (fasciculus spinocerebellaris ventrolateralis). 
2. Motor (afferent) conduction paths from the cerebral cortex to the spinal cord. 
A. Direct route (without traversing the cerebellum). 
a. Via pyramidal tract. 
b. Via corpus striatum and mid-brain. 
B. Indirect route (through cerebellum). 
a. Via pyramidal tract, nuclei pontis, cerebellum, and bulbar nuclei. 
The conduction paths within the central nervous system have, as yet, been very 
incompletely worked out. Of the paths between the periphery of the body (exclu- 
sive of the cranial nerve regions) and the cerebral cortex, the more important of 
the well-established afferent and efferent conduction paths are given in the above 
list. These paths are indicated in a diagrammatic way in Fig. 219, page 389. 
Each path is made up of a chain of neurone systems (a neurone system including 
a group of homologous nerve fibres and their cells of origin). Each system, 
as a rule, is indicated in the figure by a single neurone. 
Let us first consider the sensory (afferent) paths from the periphery to the cere- 
bral cortex. Sensory impulses pass into the spinal cord over the neurones, whose 
cell-bodies are located in the dorsal ganglia (sensory neurones of the first order). 
From the spinal cord to the cerebral cortex there are six paths over which the im- 
pulse may pass, three indirect (via cerebellum) and three direct (not traversing the 
cerebellum). 
In the direct sensory route, A a (see list above), the fibres pass up the tracts of 
Goll and Burdach, fasciculus gracilis et cuneatus (ff over neurones of the first 
order, to end in the nuclei gracilis et cuneati. (These tracts transmit the muscle 
and joint sensations, not the cutaneous or painful.) Neurones of the second order, 
arising in the nuclei gracilis et cuneati, continue the sensory path upward through 
fibres of the mesial fillet (m), which cross to the opposite side and give off col- 
laterals to the bulbar nuclei (inferior olive, formatio reticularis, etc.) and to the 
mid-brain, the axones terminating in the optic thalamus. A few axones continue 
uninterrupted to the cerebral cortex. In general, however, the path is continued 
by sensory neurones of the third order, arising in the optic thalamus and extend- 
ing to the cerebral cortex. Thus, in route A a three neurone systems transmit 
the impulse from the periphery to the cortex. 
In sensory route, A b, the impulse is transmitted from the neurones of the first 
order, via collaterals, to the gray matter of the anterior horn. Jfeurones of the 
second order, arising here, continue the path upward through the anterolateral 388 
A MANUAL OF DISSECTION. 
ground bundle (fasciculi proprii), h, of the spinal cord, thence into the posterior 
longitudinal bundle {fasciculus longitudinalis medialis}, giving off collaterals (and 
partly ending) in bulbar nuclei and mid-brain, terminating in optic thalamus. 
Neurones of third order continue path to cortex, as in A a. 
In sensory route, A c, the impulse is transmitted, via collaterals, to cells of gray 
matter of spinal cord. Neurones of the second order continue the path upward 
through the anterolateral ascending tract, g (Gowers'), through dorsal region of 
medulla and pons, to end in mid-brain and optic thalamus, etc. From the optic 
thalamus, neurones of the third order continue to cerebral cortex, as in A a and 
A b. Routes A b and A c probably transmit cutaneous and painful sensations. 
In the indirect route, B a, the impulse passes upward, as in A a, to the nuclei 
gracilis et cuneati. From these, neurones of the second order ascend through the 
inferior peduncle, k, of the same and opposite side, to the vermis, giving off col- 
laterals to the nucleus dentatus, etc. From the vermis, neurones of the third order 
pass to the nucleus dentatus; and neurones of the fourth order proceed from the 
nucleus dentatus, via superior peduncle, to the red nucleus of opposite side (a few 
fibres proceeding uninterrupted to the thalamus). From the red nucleus, neurones 
of the fifth order ascend to the optic thalamus; and thence neurones of the sixth 
order to the cerebral cortex, as in direct routes. 
In indirect sensory route, B b, the neurones of the first order transmit the im- 
pulse, via collaterals, to the cells of the column of Clarke. These, the neurones of 
the second order, send axones upward in the direct cerebellar tract {fasciculus spino- 
cerebellaris dorsolateralls'}, via inferior peduncle, to the vermis of same and oppo- 
site sides, giving off collaterals to the nucleus dentatus, etc. From the vermis, 
neurones of the third, fourth, fifth, and sixth orders proceed to the cerebral cortex, 
just as in route B a. 
In indirect sensory route, B c, neurones of the first order give collaterals to cells 
of gray matter. From these, the neurones of the second order, the path is con- 
tinued up Gowers' tract {fasciculus spinocerebellar is ventrolateralis}, as in direct 
route, A c. On reaching the mid-brain, however, the fibres here concerned leave 
those of the direct route and curve upward, reaching the superior vermis via the 
superior peduncle of the cerebellum. Thence to the cerebral cortex the path is 
continued by neurones of the third, fourth, fifth, and sixth orders, as in routes B a 
and B b. 
It will be observed that the indirect sensory routes are more complex, involving, 
in general, six neurone systems, while the direct routes require only three. 
Having traced the various paths of a sensory impulse ascending to the cerebral 
cortex, let us now consider the various paths by which a motor impulse may pass 
from the cerebral cortex downward through the spinal cord to the peripheral 
muscles. We may classify these efferent paths, as we did the afferent, as indirect 
{via cerebellum) and direct (not traversing cerebellum). 
Direct motor route, A a, begins with motor neurones of the first order, the 
pyramidal cells in the motor areas of the cerebral cortex. The axones from these 
descend in the corona radiata, internal capsule, and pyramidal tracts to the lower 
end of the medulla oblongata. Here they diverge into three separate paths: (1) 
The majority of the fibres cross to the opposite side (pyramidal decussation) and 
descend in the crossed pyramidal tract {fasciculus cer ebro spinalis lateralis}, ending 
in the gray matter of the anterior horn; (2) a small proportion of the fibres 
descend in the direct pyramidal tract {fasciculus cer ebro spinalis ventralis}, ending 
in the gray matter of the anterior horn, chiefly of the same side; (3) a few 
fibres descend in the crossed pyramidal tract of the same side, to end in gray 
matter of anterior horn. In all three cases, neurones of the second order are the 
motor cells of the anterior horn, whose axones pass out of the spinal cord in the 
ventral (motor) roots of the spinal nerves, to end in the peripheral muscles of the 
body. Thus only two neurone systems are necessary to carry a motor impulse 
from the cerebral cortex to a peripheral muscle. (The same holds good for motor 
cranial nerves.) SENSORY AND MOTOR CONDUCTION PATHS. 
389 
In direct motor route, A b, the neurones of the first order are cells of the cere- 
bral cortex (chiefly the frontal region), sending axones downward, to end in the 
corpus striatum. From the corpus striatum, neurones of the second order descend 
to the mid-brain (Edinger). From the mid-brain, neurones of the third order 
descend to the spinal cord in various ways, chiefly via anterolateral descending 
tract, to end in the gray matter of the anterior horn; thence via the motor cells 
Fig. 219. 
of the anterior horn (in this case acting as neurones of the fourth order) over the 
ventral roots of spinal nerves to peripheral muscle, as in motor route, A a. 
In indirect motor route, B a, the neurones of the first order are cells of the motor 
area of the cerebral cortex, similar to those in motor route A a. The axones, after 
descending through internal capsule and pyramidal tracts to the pons, end in (or 
give collaterals to) the nuclei pontis. These, the neurones of the second order, 390 
A MANUAL OF DISSECTION. 
proceed via middle peduncle to the cortex of cerebellar hemisphere of the opposite 
side; thence, via neurones of third order, to nucleus dentatus (some fibres not 
interrupted here). From nucleus dentatus, neurones of fourth order descend to 
bulbar nuclei (formatio reticularis, inferior olive, etc.). From the bulbar nuclei, 
neurones of the fifth order descend in various ways, to end in gray matter of the 
anterior horn; thence, via motor anterior horn cells (in this case, neurones of the 
sixth order), to muscles, as in motor routes A a, and A b. Thus it will be seen 
that the same neurones may act as a system of one order in one path and of a 
different order in another path. 
SOME GENERAL PROPOSITIONS CONCERNING NERVE IMPULSES. 
1. All nerve impulses conform to the reflex type. 
2. A reflex path is provided connecting every sensory point of the body with 
every motor point. 
3. Between any given sensory point and motor point of the body a reflex im- 
pulse may pass over many different paths. For example, between the peripheral 
sensory and motor points shown in Fig. 219, page 389, reflex paths may readily 
be traced as follows : 
a. Directly across the cord, via collaterals, to motor cells. 
b. Indirectly across the cord in many ways, via association neurones. 
c. Reflected from medulla, returning via bulbar nuclei. 
d. Reflected from cerebellum, ascending over various paths, returning via 
bulbar nuclei. 
e. Reflected from mid-brain, ascending in various ways, returning via antero- 
lateral descending tract. 
f. Reflected from basal ganglia, via thalamus and corpus striatum, etc. 
g. Reflected from cerebral cortex (as stated above). 
Description of Fig. 219, page 389. 
Diagram to represent some of the principal paths between the spinal cord and the cerebral cortex. 
1,1. Cell-bodies of sensory neurones of the first order. Their axones give off collaterals : (a) To motor cells (6) per- 
mitting direct spinal reflex ; (6) to association cells, permitting indirect spinal reflex ; (c) to cells of Clarke's column 
sending axones through direct cerebellar tract to cerebellar cortex; (d) to cells whose axones ascend through 
Gowers' tract to the cerebellum, etc.; (e) to cells whose axones ascend through the anterolateral ground bundle and 
posterior longitudinal bundle to optic thalamus; (/) the main trunks terminating above in the nuclei gracilis and 
cuneati. 
2. Cell of Clarke's column, sending axone through direct cerebellar tract to cer .bellar cortex. 
3. Sensory cells of gray matter, whose axones ascend through Gowers' tract (7) to the cerebellar cortex or to the 
optic thalamus. 
4. Sensory cell of anterior horn, whose axone ascends through the anterolateral ground bundle (A) and posterior 
longitudinal bundle to reach the optic thalamus, giving collaterals to the nuclei of the bulb and mid-brain. 
5. Association cell of spinal cord, connecting afferent and efferent neurones. 
6, 6. Lowest motor neurones, whose axones emerge through motor roots of spinal nerves. 
7, 8, 9,10. Cells of nuclei gracilis and cuneati, whose axones ascend to the cerebellar cortex (via inferior peduncle, 
k); and to the optic thalamus, via mesial fillet (m), giving collaterals to bulbar and mesencephalic nuclei. 
11. Motor cell of bulbar nuclei (formatis reticularis, olive, etc.), whose axone descends in anterolateral descending 
tract (o) to the motor cells in anterior horn of cord. 
12,13. Cells of cerebellar cortex, sending axones to nucleus dentatus. 
14. Cell of cerebellar cortex, whose axone descends to bulbar nuclei. 
15,16. Cells of nucleus dentatus, sending axones to red nucleus and thalamus, respectively. 
17. Cell of nuclei pontis, sending axone to cerebellar cortex, via middle peduncle, 
18. Motor neurone from corpora quadrigemina to spinal cord, via anterolateral descending tract (similar neurones 
occur in red nuclei). 
19. Neurone from corpora quadrigemina to optic thalamus. 
20. Neurone from red nucleus to optic thalamus. 
21. Neurones from optic thalamus to cerebral cortex. 
22. Neurone from optic thalamus to corpus striatum, 
23. Pyramidal motor neurones from cortex to spinal cord and nuclei pontis via pyramidal tracts (p). 
24. Neurone from cerebral cortex to corpus striatum. 
25. Neurone from corpus striatum to corpora quadrigemina, etc. METAMERISM. 
391 
METAMERISM. 
C. M. Jackson, M.D. 
The human body, like that of most of the lower animals, exhibits a segmental 
type of structure; that is to say, the body is built up of a number of successive 
segments (metameres), which, although modified in the various body regions, 
present each the same fundamental plan of structure. This segmentation (metam- 
erism) is somewhat masked in the adult human body, but is very clearly shown 
in the embryonic development, and especially in the structure of the lower 
animals. In many of the worms, for example, the body is almost entirely made 
up of segments, which are exactly alike. Each metamere has its own distinct 
muscular segment (myomere, myotome), skeletal segment (scleromere, sclerotome), 
vascular segment (angeiomere), neural segment (neuromere), intestinal segment 
(enteromere), excretory segment (nephromere), and segmental reproductive organs. 
In the development of the human embryo a similar arrangement appears, ex- 
cept that the alimentary and reproductive systems show but slight traces of seg- 
mentation. Each primitive metamere (ursegment of the Germans) includes 
typically myomere, scleromere, neuromere, angeiomere, enteromere, nephromere, 
Fig. 220. 
Diagram of cross-section through a metamere in the trunk region. On the left side of the figure the rib is 
omitted, and branches of the nerve and artery are shown. Veins not shown in the figure. 
D. Dorsal division of myomere. V. Ventral division of myomere, s c. Spinal canal, containing spinal cord and 
roots of a pair of spinal nerves, db, vb. Dorsal and ventral branches of spinal nerves and corresponding arteries. 
d c, I c, v c. Dorsal, lateral, and ventral cutaneous nerves and vessels, s. Sympathetic ganglion, r. Recurrent 
branch, b. Visceral branch. A. Section of aorta with branches (angeiomere). mes. Mesentery. E. Section of 
alimentary canal (enteromere). 
and is enclosed in its own skin segment, or dermatomere. Aside from the head, 
in which the number of segments is uncertain, there are about thirty-five to 
thirty-eight primitive metameres in the human embryo, of which eight are cervical; 
twelve, thoracic; five, lumbar; five, sacral; and five to eight, caudal. The 
primitive segmental arrangement of the embryo is modified in the adult body by: 
(1) The reduction or disappearance of certain portions (as in coccygeal region); (2) 
excessive development of special regions (head, extremities, etc.); (3) fusion of 
successive segments (spinal cord, various muscles, etc.), and (4) migration of cer- 
tain structures (muscles, nerves, etc.). 392 
A MANUAL OF DISSECTION. 
Iii the trunk region, however, the adult body still exhibits characteristic metam- 
erism. If we except the limbs, which are budded off laterally in the pectoral 
and pelvic regions, the relations of the various constituents of a typical metamere 
are indicated in Fig. 220. The skeletal segment (scleromere) is represented by 
the vertebra dorsally, and the ribs laterally. The muscular segment (myomere), 
aside from the visceral constituent in the intestinal wall, appears in two divisions, 
dorsal and ventral. The dorsal division (P) forms the muscular group, filling 
the costo-vertebral groove on each side. The ventral division (F) splits into 
several layers in the ventrolateral body-walls, and is represented (in part) by the 
intercostal and abdominal oblique muscles. The neural segment (neuromere) 
includes the corresponding section of the spinal cord, a pair of spinal nerves with 
their branches, and a pair of sympathetic ganglia. The spinal nerve on each side 
is formed by a dorsal (posterior) sensory root bearing a ganglion, and a ventral 
(anterior) motor root. The two roots unite to form a mixed trunk which passes 
out through the intervertebral foramen, and, often giving off a small recurrent 
meningeal branch, divides into the dorsal (posterior) and ventral (anterior) 
divisions. The dorsal division supplies the dorsal muscular division and the 
overlying skin. The ventral division supplies the remainder of the body-wall, 
and sends a branch (ramus communicans) to join the sympathetic ganglion. The 
sympathetic ganglion on each side gives off a recurrent branch to the meninges, 
and sends branches ventrally through the mesentery to supply the visceral seg- 
ment. The vascular segment (angeiomere) includes the corresponding section of 
the aorta, a visceral branch to the intestine, and a pair of lateral arteries. Each 
of the latter (e. g., intercostals) divides into a dorsal (posterior) and a ventral 
(anterior) branch. These branches accompany the corresponding branches of the 
spinal nerves, and agree with them in distribution. The corresponding veins are, 
of course, included in the angeiomere, although not shown in the diagram. The 
enteromere and dermatomere include the corresponding segments of the alimentary 
canal and skin, respectively. INDEX. 
A. 
Abdomen, pelvis, organs of, 
220 
Abdominal aorta, 238, 372 
arteries, 372 
muscles, general, 201 
organs, identification of, 209 
nerves of, 243 
ring, internal, 213 
external, pillars of, 202 
topography, 215 
vessels, dissection of, 238 
walls, dissection of, 200 
nerves of, 204 
vessels of, 204 
Abducens nerve, 93 
Abducent nerve, 63 
Abductor hallucis muscle, 328 
minimi digiti muscle, 328 
Abscess, psoas, 273 
Absorptive function of peri- 
toneum, 216 
Accelerator muscle of back, 344 
urinae, 251 
Accessory obturator nerve, 277 
sinuses, 49 
Acromion process, 139 
Adductor brevis muscle, 294 
longus muscle, 294 
magnus muscle, 294 
minimi digiti muscle, 61 
muscles, 293 
obliquus hallucis muscle, 
332 
pollicis muscle, 161 
pollicis muscle, 161 
transversus hallucis muscle, 
332 
pollicis muscle, 161 
Alcock's canal, 254 
Alimentary canal, 220 
Alveolar artery, 367 
veins, 380 
Anal muscles, dissection, 251 
Analysis of kidney, 231 
of ligament, triangular, 253 
of stomach, 221 
of sympathetic nerve, 355 
of uterus, 235 
Anastomotica magna, 371 
artery, 149 
femoral, 292 
vein, 380 
Anastomosis of neck, deep, 343 
of neck, superficial, 343 
Angeiomere, 391 
Angular vein, 378 
Annular ligament, anterior, 152 
311 
external, 324, 325 
internal, 317, 321 
Annular, posterior, 167, 169 
Ansa hypoglossi, 107, 135 
Anterior ciliary arteries 86 
commissure, 71 
crural nerve, 277 
mediastinum, 184 
perforated space, 61 
pillar of palate, 76 
spinal artery, 75 
Antero-lateral arteries, 160 
ganglionic arteries, 368 
Antero-median arteries, 59, 
368 
Antihelix, 95 
fossa of, 95 
Antitragus, 95 
Antrum of Highmore, 46 
mastoid, 50 
Anus, 227 
Aorta, abdominal, 238, 372 
branches of, 238 
arch of, 194 
relations of, 195 
ascending, 194 
bifurcation of, 269 
thoracic, 196, 372 
relations of, 196 
Aortic arch, 185 
plexus, 244 
valve, 191 
Apertura scabe vestibuli coch- 
lea}, 102, 103 
Apex of heart, 186 
of sacrum, 259 
Aponeurosis, vertebral, 341 
Apparatus, lacrymal, 87 
Appendices epiploicse, 224 
Appendicular artery, 241 
Appendix vermiformis, 210, 
225 
Aquseductus cochleae, 103 
Fallopii, 101 
Sylvii, 72 
vestibuli, 102 
Aqueous humor, 93 
Arachnoid membrane, 57, 75 
Arantius, ductus, 384 
Arch of aorta, 194 
aortic, 186 
crural, 202 
dorsal, of foot, 262 
palmar, deep, 155, 165 
superficial, 155, 165 
plantar, 330 
Armpit, 139 
Area of Broca, 62 
cribrosa media, 101 
superior, 101 
of smell, 63 
Areas, peritoneal, kidneys, 232 
Arteria centralis retinae, 92, 
368 
I Arteria comes nervi ischiadici, 
374 
phrenici, 369 
dorsalis indicis, 370 
pedis, 376 
pollicis, 370 
scapulse, 370 
gastro-epiploica sinistra, 372 
pancreatica magna, 372 
parva, 372 
princeps pollicis, 370 
receptaculi, 367 
Arteriosus, ductus, 384 
Artery or arteries, abdominal, 
372 
acromial thoracic, 146 
alar thoracic, 146 
alveolar, 120, 367 
anastomotica magna, 149, 
371, 374 
anterior spinal, 75 
antero-lateral, 60 
antero-median, 59 
appendicular, 241 
articular of knee, 375 
ascending pharyngeal, 119 
auricular, 366 
anterior, 366 
deep, 367 
posterior, 119, 366 
! axillary, 145, 370 
basilar, 369 
brachial, 139, 148, 371 
branches of, 148 
bronchial, 194, 372 
buccal, 120, 367 
of bulb of urethra, 373 
bulbar, 369 
calcanean, external, 376 
internal, 376 
carotid, common, 109, 115 
external, 109 
internal, 59, 109, 367 
carpal, anterior, 370, 371 
posterior, 370, 371 
cerebellar, anterior-inferior, 
60 
posterior-inferior, 60 
superior, 60 
cerebral, anterior, 59, 368 
middle, 59, 368 
posterior, 59, 368 
cervical, ascending, 369 
deep, 348, 352 
superficial, 369 
choroid, anterior, 60, 368 
postero-lateral, 60 
postero-mesial, 60 
ciliary, anterior, 86, 92, 367 
long, 92, 367 
short, 92, $67 
circumflex, anterior, 146 394 
INDEX. 
Artery, circumflex, external, 
.374 
iliac, superficial, 292 
internal, 374 
posterior, 140, 146 
coccygeal, 373 
colica dextra, 241, 372 
• media, 241 
sigmoidea, 242 
sinistra, 342 
collateral, 372 
comes, 271 
common carotid, 195 
communicating, anterior, 
59 
of brain, 368 
ophthalmics, 368 
posterior, 59 
coronary, left, 186 
of lips, 78 
right, 186 
corpus cavernosum, 373 
cremasteric, 374 
crico-thyroid, 117 
cystic, 372 
dental, inferior, 367 
posterior, 367 
posterior-anterior, 367 
posterior-superior, 120 
digital, of hand, 371 
dorsal, of clitoris, 373 
lumbar, 350 
of penis, 373 
dorsalis hallucis, 376 
pedis, 315 
duodenum, 222 
ear, 96 
epigastric, deep, 207, 374 
superficial, 291 
superior, 369 
ethmoidal, anterior, 92, 367 
posterior, 92, 367 
external circumflex, 292 
facial, 24, 108, 118, 365 
transverse, 366 
femoral, branches, 291 
table of, 290 
'fibular, superior, 377 
frontal, 90, 93, 367 
anterior, internal, 368 
ascending, 368 
internal, inferior, 368 
middle, 368 
posterior, internal, 368 
funicular, 237 
ganglionic, antero-lateral, 
368 
antero-median, 368 
postero-lateral, 368 
postero-median, 368 
gastric, 209, 221, 239 
gastroduodenal, 221, 372 
gastro-epiploica dextra, 221, 
372 
sinistra, 221 
gluteal, 270, 300 
inferior, 373 
superior, 374 
hemorrhoidal, inferior, 373 
middle, 271, 373 
superior, 372 
hepatic, 239, 372 
branches of, 239 
physiology of, 241 
hypogastric, 270, 384 
Artery, ileocolic, 241, 372 
ileolumbar, 374 
iliac, 373 
circumflex, 374 
common, 372 
right, 269 
external, 269, 270 
internal, 269 
internal, 377 
inferior, 369 
infra-orbital, 18, 120, 367 
innominate, 195 
intercostal, 177, 372 
anterior, 369 
dorsal branches of, 349 
superior, 369 
internal circumflex, 292 
mammary, 177, 185 
maxillary, 37, 119 
interosseous, anterior, 371 
common, 371 
palmar, 370 
posterior, 371 
recurrent, 371 
of kidneys, 233 
lacrymal, 367 
lingual, 109, 117 
long thoracic, 146 
lumbar, 243, 372 
malleolar, external, 377 
mammary, internal, 369 
masseteric, 120, 367 
mastoid, 366 
maxillary, internal, 366 
median spinal, 75 
mediastinal, 369, 372 
meningeal, 56 
anterior, 56, 367 
middle, 56, 367 
posterior, 56, 367 
small, 367 
table of, 57 
mental, 17, 367 
mesenteric, inferior, 242, 372 
superior, 241, 372 
metacarpal, 370 
metatarsal, 376 
muscular, brachial, 371 
ophthalmic, 92 
musculophrenic, 369 
mylohyoid, 367 
nasal, 92, 367 
nasopalatine, 120 
nutrient, 149 
of femur, 149 
of humerus, 371 
of tibia, 321 
obturator, 271, 295, 373 
occipital, 348, 118, 340 
oesophageal, 372, 369 
ophthalmic, 367 
table of, 92 
orbital, 366 
ovarian, 237, 243, 372 
palatine, descending, 120 
posterior, 120 
palpebral, 367 
inferior, 92 
superior, 92 
pancreaticoduodenalis, 372 
inferior, 241 
superior, 372 
parietal, ascending, 368 
parieto-temporal, 368 
perforating, 292 
Artery, perforating, femoral, 
' 374 
mammary, 369 
radial, 370 
pericardiac, 369, 372 
perineal, superficial, 373 
transverse, 373 
peroneal, 323, 324, 376 
posterior, 376 
pharyngeal, 366 
ascending, 366 
phrenic, 372 
left, 239 
right, 239 
plantar, external, 3.30, 375 
internal, 375 
of pleura, 193 
of pons varolii, 60 
popliteal, 308, 375 
articular branches, 309 
posterior auricular, 119 
spinal, 75 
postero-lateral, 60 
postero-median, 60 
prevertebral, 366 
profunda cervicis, 369 
femoris, 374, 292 
inferior, 149, 371 
superior, 148, 149, 371 
prostate, 234 
pterygoid, 120, 367 
pterygopalatine, 120, 367 
pubic, 373, 374 
pudic, 271, 301 
deep, 292 
external, 374 
external, 292 
internal, 373, 374 
superficial, external, 374 
pulmonary, 186, 198 
pyloric, 221, 372 
radial, 155, 165 
radialis indicis, 370 
recurrent palmar, 370 
radial, 370 
renal, 242, 372 
sacra media, 243, 372 
of scalp, 52 
sacral, lateral, 270, 374 
scapular, posterior, 342, 352, 
369 
sciatic, 271, 301, 373 
sigmoid, 372 
spermatic, 213, 242, 246 
sphenopalatine, 367 
spinal, 75, 327 
anterior, 369 
lateral, 369 
posterior, 369, 372 
splenic, 230, 241, 372 
sternal, 369 
of stomach, 221 
stylomastoid, 366 
subclavian, 135, 369 
left, 191 
subscapular, 146, 371 
superficial temporal, 119 
superficialis volse, 370 
superior hemorrhoidal, 242 
thoracic, 146 
thyroid, 108, 117 
supra-orbital, 19, 89, 92, 367 
suprarenal, 242, 372 
suprascapular, 143, 369 
tarsal, 376 INDEX. 
395 
Artery, temporal, anterior, 366 
deep, 120, 367 
middle, 366 
superficial, 366 
thoracic, acromial, 370 
alar, 370 
long, 370 
superior, 370 
thyroid axis, 369 
inferior, 369 
tibial, anterior, 313, 314, 377 
posterior, 317, 321 
recurrent, anterior, 377 
posterior, 377 
trachial, 369 
transversalis colli, 341, 369 
tympanic, 366, 367 
of tympanum, 99 
ulnar, 155, 165 
recurrent, anterior, 371 
posterior, 371 
uterine, 271, 373 
of uterus, 236 
vaginal, 271, 373 
vasa brevia, 221 
vertebral, 348, 369 
vesical, 373 
inferior, 271, 373 
middle, 271, 373 
superior, 271, 373 
Vidian, 120, 369 
Articular artery, inferior (of 
knee), 375 
superior, of knee, 375 
branches, 306 
crural nerve, 277 
popliteal artery, 309 
recurrent, 305 
veins, 382 
Articulation, temporomandib- 
ular, 34 
Aryteno-epiglottideus muscle, 
128 
Arytenoid cartilage, 128 
Ascending aorta, 194 
colon, 210 
pharyngeal artery, 119 
vena cava, 186, 269 
Attachments, mesentery, 219 
Attrahens aurem muscle, 23 
Auditory canal, internal, 101 
meatus, external, 96 
nerve, 63 
ganglia of, 104 
Auricle of heart, 186 
left, 190 
openings of, 190 
right, function of, 189 
Auricular artery, 366 
anterior, 366 
deep, 367 
posterior, 119, 366, 380 
fissure, 36 
nerve, vagus, 138 
vein, anterior, 379 
Auricularis magnus nerve, 107, 
131 
Auriculo-ventricular groove, 
186 
valve, 191 
cusps, 190 
Axillary artery, 145, 372 
relations, 145 
space, 144 
vein, 145, 380 
Axis, coeliac, 239, 372 
thyroid, 369 
Azygos uvulse, 84 
vein, major, 186, 197, 377 
minor, 198, 377 
B. 
Back, dissection of, 340 
fascia of, deep, 340 
superficial, 340 
nerves of, 352 
summary of, 354 
vessels of, 347 
table of, 348 
Bands, longitudinal, of intes- 
tine, large, 224 
Basilar artery, 369 
vein, 60, 379 
Basilic vein, 156, 380 
median, 156, 380 
Bauhin valve, 225 
Biceps femoris muscle, 303 
muscle, arm, 131, 143 
Bicuspid valve, 191 
Bifurcation of aorta, 269 
Bile-duct, common, 229 
Bladder, 213 
dissection of, 233 
female, 237 
ligaments of, 233 
location of, 233 
surface of, intestinal, 233 
Blood-supply, of intestine, 
small, 223 
of lumbar plexus, 277 
of penis, 249 
of peritoneum, 216 
Bloodvessels, great, 194 
Body, internal geniculate, 72 
olivary, 73 
perineal, 259 
restiform, 73 
thyroid, 109, 123 
blood-supply of, 123 
Bone, hyoid, 107 
nerve-supply of, 357 
pubic, 260 
Bony pelvis, 259 
Border of liver, anterior, 228 
posterior, 228 
Borders, grooves, of heart, 186 
Botalli, ductus, 384 
Boundaries of neck, 113 
Boundary of neck, inferior, 114 
posterior, 114 
superior, 114 
Brachial artery, 139, 148, 371 
plexus, 110, 131, 132 
vein, 380 
Brachio-cephalic vein, 377 
Brain and cord, dissection of, 
59 
dura of, 56 
removal of, 52 
Branches of abdominal aorta, 
238 
Broad ligament, 235 
Broca, area of, 62 
lobe of, 76 
Bronchi, 191 
Bronchial arteries, 194, 372 
vein, left, 378 
right, 377 
Brachialis anticus muscle, 140, 
143 
Buccal artery, 120, 367 
nerve, 28 
vein, 378-380 
Buccinator fascia, 23, 32 
muscle, 23, 29, 32 
Bulb, olfactory, 62 
of urethra, artery, 373 
Bulbar artery (brain), 369 
Bulbi vestibuli, 257 
Bursae of knee, 309 
C. 
Caecum, 210, 225 
Calcanean artery, external, 376 
internal, 376 
veins, internal, 383 
Calcaneo-cuboid ligament, 
long, 333 
! Calcarine fissure, 66 
Calloso-marginal fissure, 64, 
66 
Camper's fascia, 200 
Canal, Alcock's, 254 
alimentary, 220 
auditory, internal, 101 
carotid, 96 
of Huguier, 34 
Hunter's, 296 
inguinal, 206 
contents of, 201, 207 
pudic, 273 
semicircular, 102 
Canaliculi, 87 
Canalis spiralis modioli, 102 
Canthi, 86 
Capsule, external, 70 
internal, 70 
of kidney, 232 
suprarenal, 212, 233 
Caput coli, 225 
Cardiac plexus, 186, 360 
veins, 187, 384 
anterior, 384 
left, 384 
posterior, 384 
' Carotid artery, common, 109 
arteries, 115 
external, 109, 117 
internal, 109, 116, 367 
left common, 195 
canal, 96 
plexus, 55, 359 
sheath, 109 
triangle, inferior, 114 
superior, 114 
vessels, line of, 109 
Carpal arteries, anterior, 370 
posterior, 370, 371 
veins, anterior, 381 
posterior, 381 
Cartilage, arytenoid, 128 
cricoid, 127 
of larynx, 126 
thyroid, 126 
Caruncula lacrymalis, 86 
Cauda equina, 75 
Caudate nucleus, 69, 70 
Cavernous plexus, 56, 359 
sinus, 55, 37Q 
Cavities, abdominal, peritoneal 
214 396 
INDEX. 
Cavities of peritoneum, 216 
Cavity, pleural, 184, 192 
Cavum oris, 78, 79 
Cells, ethmoidal, 45 
fronto-ethmoidal, 49 
lacrymo-ethmoidal, 49 
mastoid, 46 
maxillo-ethmoidal, 49 
palato-ethmoidal, 49 
spheno-ethmoidal, 49 
Central artery of retina, 92, 
368 
lobe, 65 
point of perineum, 252 
Cephalic vein, 139, 156, 380 
median, 156, 380 
Cerebellar artery, inferior, 60 
inferior posterior, 60 
posterior inferior, 369 
superior, 60 
veins, 60 
inferior, 379 
superior, 379 
Cerebellum, dissection of, 72 
table of, 72 
Cerebral artery, anterior, 59, 
368 
middle, 59, 368 
posterior, 59, 368 
veins, inferior, 60 
median, 60, 379 
superior, 60, 379 
Cervical artery, deep, 348, 352 
superficial, 369 
cardiac nerve, 138 
fascia, deep, 107, 122 
ganglia, 355 
paralysis of, 358 
ganglion, inferior, 355, 360 
middle, 355, 359 
superior, 355, 358 
nerve, first, 352 
fourth, fifth, sixth, sev- 
enth, eighth, 353 
second, third, 353 
table of, 130 
pleura, 192 
plexus, 109, 130, 131 
Cervicalis ascendens muscle, 
346 
Cheek, 76, 78, 79 
Chondroglossus muscle, 85 
Chorda tympani nerve, 28 
Choroid artery, anterior, 60, 
368 
postero-lateral, 60 
postero-mesial, 60 
plexuses, 70 
tunic, 93 
vein, 379 
Cilia, 86 
Ciliary arteries, anterior, 92, 
367 
long, 92, 367 
short, 92, 367 
ganglion, 40, 92 
muscle, 93 
nerves long, 92 
short, 92 
processes, 93 
Circle of Willis, 69, 368 
Circular sinus, 379 
Circulation, collateral, of knee, 
309 
foetal, 384 
Circumflex artery, anterior, 
370 
external, 292, 374 
internal, 292, 374 
posterior, 140, 370 
iliac artery, 292 
nerve, 134, 140, 144, 156 
vein, anterior, 380 
external, 382 
internal, 382 
posterior, 380 
Circumvallate papillae, 77 
Claustrum, 70 
Clavicle, 107, 139 
Cleft, interlabial, 258 
Clitoris, 258 
Coats of intestine, small, 223 
Coccygeal artery, 373 
Coccygeus muscle, 262 
Coccyx, 260 
Cochlea, 102 
bony, 103 
Cochlear duct, 104 
Cceliac axis, 239, 372 
Colica dextra artery, 241, 372 
vein, 383 
media artery, 241, 372 
vein, 383 
sigmoidea artery, 242 
sinistra artery, 242, 372 
vein, 383 
Collateral arteries, 372 
circulation of knee, 309 
fissure, 66 
Colles' fascia, 250 
Colon, ascending, 210 
descending, 211 
extent of, 225 
subdivisions of, 225 
transverse, 211 
extent of, 225 
Columella, 102 
Columnse carnese, 189 
Comes nervi ischiadici artery, 
374 
phrenici, 369 
Commissure, anterior, 71 
optic, 62 
Common carotid artery, left, 
195 
iliac artery, 372 
tendon, inner, 154, 160 
Communicating artery, ante- 
rior, 59, 368 
posterior, 59, 368 
Complexus muscle, 342, 346 
Compressor naris muscle, 23 
narium minor muscle, 23 
urethrae, muscle, 254 
Conarium epiphysis cerebri, 71 
Concha, 95 
Conduction paths, Jackson, 387 
Condylar process, 34 
Congenital hernia, inguinal, 
206 
Conjoined tendon, 202 
Conjunctiva, 86 
Conjunctival sac, 86 
Constrictors of pharynx, 85 
Convolution, fourth temporal, 
67 
frontal, inferior, 64 
middle, 64 
superior, 64 
marginal, 65 
Convolution, occipital, 65 
orbital, 67 
paracentral, 66 
parietal, ascending, 65 
inferior, 65 
superior, 65 
sub calcarine, 67 
temporal, inferior, 65 
middle, 65 
superior, 65 
Coracobrachialis muscle, 139, 
143 
Coracoid process, 139 
Cord, cervical, 75 
lumbar, 75 
spermatic, 200, 246 
composition of, 246 
spinal, 74 
sympathetic, 358 
ganglia of, 355 
lumbar, 360 
sacral, 360 
thoracic, 360 
vocal, false, 129 
true, 128 
Cornea, 86 
Coronary arteries of lips, 78 
left, of heart, 186 
right, of heart, 186 
sinus, 189, 384 
vein, right, of heart, 384 
of stomach, 384 
Corpora albicantia, 62 
cavernosa, 248 
geniculata, 72 
quadrigemina, 71 
Corpus callosum, 66, 67 
peduncles, 61 
cavernosum artery, 373 
spongiosum, 248 
striatum, veins of, 379 
Corrugator cutis ani muscle, 
227, 251 
supercilii muscle, 23 
Corti, organ of, 105 
Costal pleura, 192 
Costo-coracoid membrane, 142 
Coverings of penis, 248 
of peritoneum, 217 
of testicle, 245 
Cranial foramina, table of, 58 
nerve, fourth, 90 
sixth, 90 
table of Kitterman, 53 
third, 91 
Cremaster muscle, 202 
Cremasteric artery, 374 
Crest, falciform, 101 
inferior vertical, 101 
superior vertical, 101 
Cricoid cartilage, 127 
Crico-arytenoideus muscle, lat- 
eralis, 128 
posticus, 128 
Crico-thyroid artery, 117 
membrane, 128 
muscle, 128 
Crista falciformis, 101 
terminalis, 189 
vestibuli, 102 
Cristse acusticae, 105 
Crural arch, 202 
nerve, anterior, 276 
articular, 277 
Crureus muscle, 289 INDEX. 
397 
Crusta cerebri, 62 
Crystalline lens, 93 
Cubital fossa, 155, 162 
Cul-de-sac of Douglas, 215 
Cuneate lobe, 66 
Cupola, 103 
Curves urethral, 250 
Cusps, auriculo-ventricular, 190 
Cutaneous nerves, anterior, of 
abdomen, 200 
of thorax, 177 
of arm, 151, 166 
dorsal, six lower, 340 
six upper, 340 
internal, 134, 148, 156 
lateral, of abdomen, 200 
of leg, table of, 265 
lesser internal, 134, 148 
median, 156 
perforating, 279, 282 
of ulna, 156 
veins of arm, 150, 166 
vessels, 340 
Cystic artery, 372 
vein, 384 
D. 
Deep fascia of arm, 166 
of thorax, 139 
palmar, 370, 371 
Deltoid muscle, 139, 143 
Dental arches, 76 
artery, inferior, 367 
posterior superior, 120 
superior anterior, 367 
posterior, 367 
vein, inferior, 380 
Depressor alee nasi muscle, 23 
anguli oris muscle, 22 
labii inferioris muscle, 22 
Depressors of hyoid bone, 111 
of mandible, 37 
Descending colon, 211 
extent of, 225 
vena cava, 186 
Descent of testicle, 204 
Development of testicle, 204 
Diameter of duodenum, 222 
Diaphragm, 182, 183, 184 
Diaphragmatic pleura, 192 
Digastric muscle, 112 
Digital arteries of hand, 371 
veins, 262 
of foot, 383 
plantar, 383 
Dilator naris anterior, 23 
posterior, 23 
Diploic veins, 379, 380 
Dissection of abdominal ves- 
sels, 238 
of bladder, 233 
of duodenum, 222 
of intestine, large, 224 
of jejunum, ileum, 223 
of kidneys, 231 
of liver, 227 
of pancreas, 229 
of penis, 247 
of peritoneum, 216 
of spermatic cord, 246 
of spleen, 230 
of testicle, 245 
of uterus, 234 
' Diverticulum, Meckel's, 223 
Dorsal arch of foot, 262 
artery of clitoris, 373 
of penis, 373 
nerves, 353 
of penis, 382 
thoracic, 180 
vein of clitoris, 382 
of penis, 382 
Dorsalis hallucis artery, 376 
vein, 383 
indicis muscle, 370 
vein, 381 
linguae vein, 378 
pedis artery, 315, 376 
vein, 383 
pollicis muscle, 370 
vein, 381 
scapulae artery, 370 
Dorsi spinal veins, 74, 384 
Douglas, cul-de-sac of, 215 
semilunar fold of, 204 
Duct, cochlear, 104 
common bile, 229 
ejaculatory, 250 
gall, 228 
nasal, 45, 87 
Stenson's, 20 
thoracic, 199 
Ductus Arantii, 384 
arteriosus, 384 
Botalli, 384 
venosus, 384 
Duodenum, arteries of, 222 
diameter of, 222 
dissection of, 222 
embryology of, 223 
extent of, 222 
fixity of, 222 
morphology of, 222 
parts of, 222 
portion of, descending, 223 
superior, 222 
reflexes of, 223 
relations of, pancreas 222 
Dura mater of brain, 56 
of cord, 74 
Dural sinuses, 54 
E. 
Ear, internal, 100 
external, dissection of, 95 
Ejaculatory ducts, 250 
Elevation, sublingual, 77 
Embryology of duodenum, 223 
of intestine, small, 220 
of liver, 229 
of pancreas, 229 
of spleen, 231 
of stomach, 222 
Eminentia articularis, 34 
Emissary system, 379 
veins, 379 
Endolymph and spaces, 104 
Endothoracic fascia, 193 
Enteromere, 390 
Epigastric artery, deep, 207, 
374 
superficial, 291, 374 
superior, 369 
plica, 214 
vein, deep, 382 
superficial, 382 
Epiglottis, 128 
J Erectile masses of penis, 248 
Erector penis muscle, 251 
spinae muscle, 344 
Ethmoidal artery, anterior, 92, 
367 
posterior, 92, 367 
cells, 45, 49 
Eustachian tube, 100 
valve, 189, 384 
Expression muscles, 27 
Extensor brevis digitorum 
muscle, 313 
pollicis muscle, 168, 171 
brevior muscle, 168, 173 
carpi radialis longior muscle, 
168, 173 
ulnaris muscle, 168, 170 
communis digitorum muscle, 
168, 170 
| indicis muscle, 168, 171 
longus digitorum muscle, 
313 
pollicis muscle, 168, 171 
minimi digiti muscle, 168, 
170 
ossis metacarpi pollicis mus- 
cle, 168 
proprius hallucis muscle, 
313 
External abdominal ring, 200, 
202 
capsule, 70 
cutaneous nerve, 275, 276 
ear, arteries of, 96 
dissection of, 95 
nerves of, 96 
malleolus, 324 
oblique muscle, 201 
petrosal nerve, 27 
plantar nerve, 280 
rectus muscle, 89, 90 
Extravasation of urine, 250 
Eye, identification of, 86 
muscles of, dissection of, 88 
nerves of, 93 
Eyeball, dissection of, 93 
Eyelids, composition of, 86, 88 
dissection of, 87 
F. 
Face, dissection of, 17 
Facial artery, 24, 108, 118 
stages and branches of, 25 
transverse, 366 
canal, 37 
muscles, nerves of, 24 
nerve, 27, 63 
branches of, 28 
course of, 97 
vein, 26, 108, 121 
common, 378 
deep, 378 
superficial, 378 
transverse, 379 
Falciform crest, 101 
Fallopian tube, 235 
Fallopius, aquaeductus, 101 
hiatus, 96 
Fascia of back, deep, 340 
superficial, $40 
buccinator, 23 
Camper's, 200 398 
INDEX. 
Fascia, Colles', 250 
deep, of arm, 166 
cervical, 107, 122 
of forearm, 150 
palmar, 153, 157 
of thorax, 139 
transverse, of leg, 319 
endothoracic, 193 
iliac, 272 
lata, 287 
lumbar, 203, 341 
masseteric, 29 
obturator, 262, 273 
orbital, 89 
pelvic, 273 
of female, 237 
plantar, 327 
popliteal, 317 
rectovesical, 273 
Scarpa's, 200 
superficial abdominal, 200 
of arm, 166 
of forearm, 150 
of neck, 106 
of thorax, 139, 177 
temporal, 29 
of thigh, deep, 286 
superficial, 285 
transversalis, 203, 269, 272 
transverse, of leg, 317 
Fauces, isthmus, 76, 81 
Female bladder, 237 
pelvis, dissection of, 234 
outlet of, 256 
rectum, 237 
ureter, 237 
urethra, 237, 258 
Femoral artery, branches of, 
291 
table of, 290 
region, anterior, 285 
posterior, 303 
sheath, 273, 290 
vein, 382 
profunda, 382 
table of, 290 
Fenestra ovalis, 102 
rotunda, 103 
Fibres, intercolumnar, 202 
Fibular artery, superior, 377 
head, 324 
region, dissection of, 324 
Filiform, 77 
Filum terminale, 75 
Fissura palpebrarum, 86 
prima, 62 
vestibuli, 103 
Fissure, auricular, 36 
calcarine, 66 
calloso-marginal, 64, 66 
collateral, 66 
Glaserian, 34 
hippocampal, 66 
of liver, left longitudinal, 
209 
right longitudinal, 209 
transverse, 209 
longitudinal, of brain, 63 
parieto-occipital, 64, 66 
petrotympanic, 34 
of Rolando, 63 
of Sylvius, 62, 63 
transverse, of brain, 64 
Flexor accessorius muscle, 330 
brevis hallucis muscle, 331 
Flexor brevis minimi digiti 
muscle, 161, 332 
pollicis muscle, 161 
carpi radialis muscle, 154, 
160 
ulnaris muscle, 155, 160 
longus digitorum muscle, 
317, 319, 331 
hallucis muscle, 317, 3 
331 
pollicis muscle, 155, 160 
muscles of thigh, 302 
profundus digitorum mus- 
cle, 155, 160 
sublimis digitorum muscle, 
155, 160 
Flexure, sigmoid, 211, 226 
Floor, pelvic, dissection of, 261 
Foetal circulation, 384 
Folds, palpebral, 86 
Foot, sole of, 327 
Foramen ovale, 384 
singulare, 101 
of Winslow, 209, 278 
Foramina, base of skull, 57 
constant, 58 
cranial, table of, 58 
inconstant, 58 
primary, 58 
secondary, 58 
Forceps, anterior posterior, 68 
Forearm, deep fascia of, 150 
superficial fascia of, 150 
Fornix, 69 
anterior pillar of, 69 
posterior pillar of, 69 
Fossa, antihelix, 95 
cochlearis, 102 
cubital, 155,162 
glenoid, 34 
helix, 95 
inguinal, external, 214 
internal, 214 
middle, 214 
ischiorectal, 254 
nasal, 45 
navicularis, 250 
ovalis, 189 
of peritoneum, 217 
Fourth ventricle, 74 
Fovea hemispherica, 102 
semielliptica, 102 
Framum linguae, 77 
Frontal artery, 90, 93, 367 
anterior, internal, 368 
ascending, 368 
inferior, internal, 368 
internal, inferior, 368 
middle, internal, 368 
posterior, internal, 368 
convolution, inferior, 64 
middle, 64 
superior, 64 
lobe, 64 
nerve, 40, 89 
sinuses, 45 
sulcus, inferior, 64 
superior, 84 
vein, 378 
Fronto-ethmoidal cells, 49 
Functions, mesenteric, of peri- 
toneum, 217 
omental, of peritoneum, 217 
of peritoneum, 211 
of pleura,193 
Fungiform papillae, 77 
Funicular artery, 237 
G. 
Galen, veins of, 60, 379 
Gall-bladder, 209, 228 
Gall-ducts, 228 
Ganglia, auditory nerve, 104 
cervical, 355 
hemisphere, 70 
spinal, 75 
sympathetic, 357 
vertebral, composition of, 357 
Gangliated cord, 355 
Ganglion arteries, antero-lat- 
eral, 368 
antero-median, 368 
cervical, inferior, 355, 360 
middle, 355, 359 
superior, 355, 358 
ciliary, 40, 92 
Gasserian, 40 
geniculate, 27 
Meckel's, 27, 42 
otic, 44 
of Scarpa, 104 
spirale, 104 
submaxillary, 44 
Gasserian ganglion, 40 
Gastric artery, 209, 221, 339, 
372 
nerves, 138 
Gastrocolic omentum, 217 
Gastroduodenal artery, 221, 
372 
Gastro-epiploica dextra, 372 
artery, 221 
sinistra, 372 
artery, 221 
Gastrohepatic omentum, 217 
Gastrosplenic omentum, 218 
Gastrocnemius muscle, 317 
Gemellus inferior nerve, 281 
muscle, inferior, 300 
superior, 300 
superior nerve, 281 
Generalization of ligaments, 
309 
Geniculate body, internal, 72 
ganglion, 27 
Geniohyoglossus muscle, 78, 
84 
Geniohyoid muscle, 78 
Genitocrural nerve, 274, 276 
Genito-urinary muscles, 251 
Gimbernat's ligament, 202, 214 
Glands, lacrymal, 87 
lymphatic, inguinal, 287 
Meibomian, 86 
of Moll, 86 
parotid, 19 
prostate, 234 
mediastinal, 199 
sublingual, 78, 109, 125 
submaxillary, 109, 124 
thymus, 184 
Glandulse Molli, 86 
Glaserian fissure, 34, 36 
Glenoid fossa, 34, 36 
Glossopharyngeal nerve, 63, 78 
Gluteal artery, 270, 300 
inferior, 373 
superior, 374 INDEX. 
399 
Gluteal nerve, inferior, 279, 
282 301 
superior, 278, 282, 300 
region, 297, 298 
veins, 382 
Gluteus maximus muscle, 299 
medius muscle, 299 
Gracilis muscle, 293 
Gray rami communicantes, 134, 
289, 294, 357, 
Groove, auriculo - ventricular, 
186 
anterior, 186 
Growths of intestine, unequal, 
220 
Gubernaculum, 204 
Gustatory nerve, 77 
Gyrus fornicatus, 65 
hippocampal, 65 
H. 
Hard palate, 76 
Hassner, valve of, 45 
Hearing, organs of, 95 
Heart, apex of, 186 
auricles of, 186, 188, 190 
borders and grooves of, 
186 
currents of, 189 
dissection of, 188 
posterior surface of, 186 
ventricle of, 186 
Helicotrema, 103 
Helix, 95 
fossa, 95 
Hemisphere, ganglia, 70 
Hemorrhoidal artery, 271 
inferior, 373 
middle, 373 
superior, 372 
nerve, inferior, 282 
plexus, 227 
of veins, 382 
vein, superior, 384 
Hepatic artery, 239, 372 
physiology of, 241 
veins, 239, 381 
Hernia, congenital inguinal, 
206 
infantile, congenital, 206 
inguinal, 206, 207 
direct, 208 
indirect, 208 
Hesselbach's triangle, 207, 214 
Hiatus Fallopii, 96 
Highmore, antrum of, 46, 49 
Hilton's law, 265 
Hilum of kidney, 231 
Hippocampal fissure, 66 
gyrus, 65 
Homologies, sexual, 256 
Huguier, canal of, 34 
Humor, aqueous, 93 
vitreous, 93 
Hunter's canal, 296 
Hydrothorax, 192 
Hyoglossus muscle, 84 
Hyoid bone, 107 
Hypochondria, right and left, 
215 
Hypogastric artery, 270 
plexus, 236, 244, 361 
plica, 214 
Hypogastrium, 215 
I Hypoglossal nerve, 63, 78, 015, 
'135 
I. 
Ileoceecal junction, 210 
valve, 225 
Ileocolic artery, 241, 372 
vein, 383 
Ileocostalis, 344 
Ileum, 223 
Iliac artery, circumflex, 374 
common, 373 
right, 269 
external, 269, 270, 373 
internal, 269, 270, 373 
fascia, 272 
lata, 287 
region, dissection of, 269 
muscles of, 273 
veins, 382 
circumflex, deep, 382 
superficial, 382 
common, 269 
left, 381 
right, 381 
external, 270, 383 
internal, 270, 382 
vessels, 269 
Iliacus muscle, 274 
Iliohypogastric nerve, 201, 
274, 276 
Ilioinguinal nerve, 201, 274, 
276 
Iliolumbar artery, 374 
veins, 382 
Impulses, reflex, 389 
Incisura intertragica, 95 
Infantile hernia, inguinal, 206 
Inferior oblique muscle, 89, 
90 
rectus muscle, 89, 90 
vena cava, 238 
Infracostal muscles, 182 
Inframandibular nerve, 28 
Infra-orbital artery, 17, 120, 
367 
nerve, 17, 28 
Infraspinatus muscle, 143 
Infundibulum, bony, 45 
Inguinal canal, 206 
contents of, 201, 207 
fossse, 214 
hernia, 206, 207, 208 
direct, 208 
indirect, 208 
regions, 215 
Innominate artery, 195 
vein, left, 197, 377, 378 
right, 197, 377 
Intercolumnar fibres, 202 
Intercostal artery, 177, 349, 
369, 372 
superior, 369 
muscles, external, 177, 182 
internal, 177, 182 
nerves, 177, 180 
veins, 177 
superior, left, 378 
right, 377 
Intercostohumeral nerve, 156 
Interfascial spaces, cervical, 
123 
Interlabial cleft, 258 
Intermuscular septa, 140, 285 
Internal auditory meatus, 96 
capsule, 70 
ear, 100 
maxillary vein, 39 
rectus muscle, 89, 90 
Interossei, muscles of foot 
332 
Interosseous artery, anterior, 
371 
common, 371 
palmar, 370 
posterior, 371 
recurrent, 371 
nerve, posterior, 168, 171 
veins, anterior, 381 
palmar, 381 
posterior, 381 
Interparietal sulcus, 65 
Interpeduncular space, 62 
Interspinales muscles, 347 
Intertransversales muscles, 
347 
Interventricular groove, ante- 
rior, 186 
Intestines, distinction of, 210 
growth of, unequal, 220 
large, 211 
small, 211, 220 
Intramural sinuses, nerves, 48 
Intra-orbital dissection, 89 
Iris, 87, 93 
Ischial spine, 260 
tuberosity, 260 
Ischiorectal fossa, 254 
region, 254 
Ischium, 260 
Island of Reil, 65 
Isthmus of fauces, 76, 81 
Iter, 72 
J. 
Jacobson's nerve, 27 
Jejunum, 223 
Joint, knee, 309 
Jugular vein, anterior, 107, 
120, 380 
external, 107, 121, 379 
internal, 109, 121, 377 
posterior, 107, 121 
superficial, 120 
Junction, ileocrecal, 210 
K. 
Key, foramina of, 57 
Kidney, analysis of, 231 
capsule of, 232 
dissection of, 231 
hilum of, 231 
left, 212 
anterior surface of, 232 
nerves of, 233 
peritoneal areas of, 232 
posterior surface of, 232 
right, 211 
anterior surface of, 232 
ureter, 233 
Knee, bursae of, 309 
collateral circulation of, 309 
joint, 309 
nerves of, 30§ 
table of, 310 INDEX. 
400 
L. 
Labia majora, minora, 257 
Labial veins, inferior, 378 
Labyrinth, dissection of, 100 
membranous, 103 
Lacrymal apparatus, 87 
artery, 92, 367 
gland, 87 
nerve, 40, 90 
sac, 87 
Lacrymo-ethmoidal cells, 49 
Lacus lacrymalis, 86 
Lamina cribrosa, 101 
spiralis ossea, 103 
secundaria, 103 
Lancisi, nerves of, 68 
Large intestine, 211 
bands of, 220 
dissection of, 224 
Laryngeal nerve, superior, 109, 
369 
pouch, 129 
Larynx, 109, 125, 126 
blood-supply of, 129 
interior, 128 
muscles of, 128 
Lateral ligament of knee, ex- 
ternal, 310 
sinus, 378 
ventricles, 68 
Latissimus dorsi muscle, 340, 
343 
Layers of peritoneum, 216 
Left kidney, 212 
ventricle, 190 
Leg, fascia of, deep transverse, 
319 
muscles of, deep group, 319 
table, 334 
Lens, crystalline, 93 
Lenticular nucleus, 70 
Lesser omentum, 209, 217 
Levator anguli oris muscle, 22 
scapulae muscle, 341 
ani muscle, 252 
labii inferioris muscle, 22 
superioris muscle, 22 
alaeque nasi, 22 
menti muscle, 22 
palati muscle, 81, 84 
palpebrse muscle, 23, 88, 90 
Levatores costarum, 182 
Ligament, annular, anterior, 
311 
external, 324 
internal, 317, 321 
anterior annular, 152, 157 
of bladder, 233 
broad, 235 
calcaneo-cuboid, 333 
generalized, 309 
Gimbernat's, 202, 214 
of knee, external lateral, 310 
of liver, 209 
phrenocolic, 211 
posterior annular, 167, 169 
Poupart's, 202, 214 
round, 235 
sacrosciatic, greater, 261 
lesser, 261 
triangular, 214, 253 
of uterus, false, 214 
true, 235 
Ligamentum denticulatum, 75 
nuchae, 341 
Ligamentum patellae, 289 
Limbic lobe of Broca, 66 
Line, pelvic, white, 262 
Linea alba, 201 
Lines, semilunar, 201 
Lingual artery, 109, 117 
lobe, 67 
nerve, 77, 78 
vein, 109, 121 
Lingualis muscle, divisions of, 
85 
Lips, 76, 78 
Lithotomy, perineal, 252, 253 
Liver, 209 
borders of, 228 
dissection of, 227 
embryology of, 229 
ligaments of, 209 
location of, 227 
posterior surface of, 229 
reflexes of, 229 
root-structures of, 227 
surfaces of, 228 
transverse fissure, 209 
Lobe, central, 65 
cuneate, 66 
frontal, 62, 64, 67 
limbic of Broca, 66 
lingual, 67 
occipital, 65 
olfactory, 61, 62 
parietal, 64 
quadrate, 66 
temporal, 62, 65 
Lobule of ear, 95 
Longissimus dorsi, 346 
Longitudinal fissure, 63 
of liver, 209 
sinus, inferior, 55, 379 
superior, 54, 379 
vein, anterior, 384 
posterior, 384 
Longus colli muscle, 113 
Lower extremity, cutaneous 
nerves of, 262, 265, 268 
cutaneous vessels of, 262 
jaw, ligaments of, 34, 35 
Lumbar arteries, 243, 350, 372 
fascia, 203, 341 
nerves, 354 
plexus, 269, 274 
arteries of, 277 
table of, 274 
regions, 215 
veins, 381 
Lumbrical muscles, 331 
Lungs, dissection of, 184, 193 
root-structures of, 185, 193 
Lymphatic glands, inguinal, 
287 
M. 
Macula acustica, utricle, 104 
Majendie, foramen of, 57 
Malar nerve, 28 
Malleolar artery, external, 377 
internal, 377 
vein, internal, 383 
Malleolus, external, 324 
Mammary artery, internal, 177 
185, 369 
veins, internal, 180 
internal, left, 378 
right, 378 
j Mammary veins, left, 378 
i Marginal convolution, 65 
i Maxillary artery, internal, 37, 
119, 366 
nerve, inferior, 43 
sinus, 49 
vein, internal, 379 
j Maxillo-ethmoidal cells, 49 
Masseter muscle, 29, 30 
Masseteric artery, 120, 367 
fascia, 29 
nerve, 43 
vein, 378, 380 
Mastoid antrum, 50 
artery, 366 
cells, 46 
process, 107 
I Meatus, auditory, external, 96 
internal, 96 
Meatuses, 45, 47 
Meckel's diverticulum, 223 
ganglion, 27, 42 
Median nerve, 133, 146, 155, 
162 
spinal artery, 75 
vein, 156 
Mediastinal arteries, 369 
posterior, 372 
glands, 199 
pleura, 192 
veins, 377 
Mediastinum, anterior, 184 
middle, 184 
posterior, 184 
superior, 184 
Medulla oblongata, 62, 73 
pyramids, 62 
Medulli spinal veins, 74, 384 
' Meibomian glands, 86 
Membrana tympani secundaria 
103 
Membrane, arachnoid, 57 
costo-coracoid, 142 
crico-thyroid, 128 
thyrohyoid, 109, 128 
Membranous labyrinth, 103 
Meningeal arteries, 56 
artery, anterior, 56, 367 
middle, 56, 367 
posterior, 56, 366, 369 
small, 367 
nerve, 138 
vein, middle, 380 
Meningorachidian veins, 74, 
384 
Mental artery, 17, 367 
foramen, 17 
nerve, 17 
Mesenteric artery, inferior, 242 
372 
superior, 241, 372 
function of peritoneum, 217 
vein, inferior, 383 
superior, 242, 383 
Mesentery, attachment of, 219 
contents of, 219 
jejunum, ileum, 223 
proper, 211, 218 
Mesocolon, transverse, 211 
Metacarpal arteries, 370 
veins, 381 
Metamere, 391 
Metamerism, 391 
Metatarsal arteries, 376 
veins, 383 INDEX. 
401 
Middle ear, tympanum of, 96 
mediastinum, 184 
Mid-line of neck, structures in, 
115 
Migration of testicle, theories 
of, 205 
Modiolus, 102 
canal of, central, 102 
Moll, glands of, 86 
Mons veneris, 256 
Morphology of duodenum, 222 
Motor oculi nerve, 63 
Mouth, 76 
Muller's muscle, 88, 89 
Multifidus spinae, 346 
Muscles, abdominal, 201 
abductor minimi digiti, 328 
adductor brevis, 294 
hallucis, 328 
longus, 294 
magnus, 294 
minimi digiti, 161 
obliquus hallucis, 332 
pollicis, 161 
pollicis, 161 
transversus hallucis, 332 
pollicis, 161 
anal, 251 
arm, table of, 173, 174, 175, 
176 
arytenoideus, 128 
aryteno-epiglottideus, 128 
attrahens aurem, 23 
biceps, 139 143 
femoris, 303 
biventer cervicis, 346 
brachialis anticus, 140, 143 
buccinator, 23 
cervicalis ascendens, 346 
chondroglossus, 85 
ciliary, 93 
coccygeus, 262 
complexus, 342, 346 
compressor naris, 23 
narium minor, 23 
urethral, 254 
constrictors of pharynx, 85 
coracobrachialis, 139 
corrugator cutis ani, 251 
supercilii, 23 
cremaster, 202 
crico-arytenoideus lateralis, 
128 
posticus, 128 
crico-thyroid, 128 
crureus, 289 
deltoid, 139, 143 
depressor alae nasi, 23 
anguli oris, 22 
labii inferioris, 22 
digastric, 112 
dilator naris, anterior, 23 
posterior, 23 
of ear, external, 96 
erector penis, 251 
spinae, 344 
of expression, 21 
table of, 24 
extensor brevis digitorum, 
313 
pollicis, 168, 171 
carpi radialis brevior, 168, 
173 
longior, 168, 173 
ulnaris, 168, 170 
Muscles, extensor communis 
digitorum, 168, 170 
indicis, 168, 171 
longus digitorum, 313 
pollicis, 168, 171 
minimi digiti, 168, 170 
ossis metacarpi pollicis, 
168, 171 
proprius pollicis, 313 
extensors of thumb, 168, 171 
external oblique, 201 
rectus, 89, 90 
of eye, table of, 88 
flexor accessorius, 330 
brevis digitorum, 328 
hallucis, 331 
minimi digiti, 161, 332 
pollicis, 161 
carpi radialis, 154, 160 
ulnaris, 155 
longus digitorum, 319, 331 
hallucis, 320, 331 
pollicis, 155, 160 
profundus digitorum, 155 
sublimis digitorum, 155 
of thigh, 303 
gastrocnemius, 317 
gemellus inferior, 300 
superior, 300 
geniohyoglossus, 78, 84 
geniohyoid, 78 
genito-urinary, 251 
gluteus maximus, 299 
medius, 299 
minimus, 299 
gracilis, 293 
of hand, palmar, 161 
radial, 161 
ulnar, 161 
hyoglossus, 84 
inferior oblique, 89, 90 
rectus, 89, 90 
iliacus, 274 
ileocostalis, 344 
of iliac region, 273 
infracostales, 182 
infraspinatus, 143 
intercostal, external, 177, 
182 
internal, 177, 182 
internal oblique, 203 
rectus, 89, 90 
interossei, 162 
dorsal, 333 
of foot, 332 
interspinales, 347 
intertransversales, 347 
latissimus dorsi, 340, 343 
of leg, deep group, 319 
table of, 334-339 
levator anguli oris, 22 
scapulae, 341, 343 
ani, 252 
labii inferioris, 22 
superioris, 22 
alaeque nasi, 22 
menti, 22 
palati, 81, 84 
palpebrae, 23, 89 
levatores costarum, 182 
longissimus dorsi, 346 
longus colli, 113 
lumbricales, 161, 162, 331 
masseter, 29, 30 
of mastication, 29 
Muscles of mastication, nerves 
of, 29, 33 
table of, 32 
Muller's, 88, 89 
multifidus, 346 
mylohyoid, 78, 112 
of neck, 110 
obliquus capitis inferior, 347 
superior 347 
obturator externus, 300 
internus, 299 
occipitofrontalis, 23 
omohyoid, 107, 111 
opponens minimi digiti, 161 
pollicis, 161 
orbicularis oris, 21 
palpebrarum, 22 
palatoglossus, 78 
palatopharyngeus, 78, 84 
palmaris brevis, 161 
longus, 155 160 
pectineus, 294 
pectoralis major, 139, 141 
minor, 139 
peroneus brevis, 324, 325 
longus, 324, 325 
tertius, 313 
plantaris, 317 
platysma, 106, 110 
myoides, 22 
popliteus, 317, 319 
pronator quadratus, 155, 
160 
radii teres, 154, 159 
psoas magnus, 269, 273 
parvus, 273 
pterygoid, external, 29- 
internal, 29 
pyramidalis, 204 
nasi, 23 
pyriformis, 262, 299 
quadratus femoris, 300 
rectus abdominis, 203 
capitis anticus major, 113 
minor, 113 
lateralis, 113 
posticus major, 347 
minor, 347 
femoris, 287 
rhomboid, 341, 343 
rhomboideus major, 343 
minor, 343 
risorius, 22 
rotators, external, 299 
spinae, 346 
sartorius, 287 
scalenus anticus, 110, 113 
medius, 110, 113 
posticus, 110, 113 
semimembranosus, 305 
semispinalis colli, 346 
semitendinosus, 304 
serratus magnus, 142 
posticus inferior, 182, 342 
superior, 182, 342 
small, of hand, 162 
soleus, 317, 319 
sphincter ani, external, 251 
spinalis colli, 346 
dorsi, 346 
splenius, 342, 343 
capitis, 343, 344 
colli, 344 
sternohyoid, 107, 111 
sternomastoid, 107, 1111 402 
INDEX. 
Muscles, sternothyroid, 107, 
111 
styloglossus, 84 
stylohyoid, 78, 107, 112 
stylopharyngeus, 85 
subclavius, 142 
superior oblique, 89, 90 
rectus, 89, 90 
supinator brevis, 155, 161 
longus, 169, 173 
supraspinalis, 346 
supraspinatus, 143 
temporal, 29 
tensor palati, 81, 84 
vaginae femoris, 287 
teres major, 167, 168 
minor, 143 
thyro-arytenoideus, 128 
thyro-epiglottideus, 128 
thyrohyoid, 107, 111 
tibialis anticus, 312 
posticus, 317, 320 
trachelomastoid, 346 
transversalis, 203 
cervicis, 346 
transversus perinei, 252 
trapezius, 341, 343 
triangularis sterni, 182 
triceps, 168 
of tympanum, 99 
vastus externus, 288 
internus, 288 
zygomatic, 22 
Muscular veins (femoral), 382 
Musculi pectinati, 189 
Musculocutaneous nerve, 133, 
140, 146, 156, 281, 306, 324 
Musculophrenic artery, 369 
Musculospiral nerve, 156, 167, 
169 
Musculus accessorius of back, 
344 
Mylohyoid artery, 367 
muscle, 78, 112 
nerve, 108, 113 
Myomere, 391 
Myotome, 391 
N. 
Nares, posterior, 45, 46 
Nasal artery, 92, 367 
duct, 45, 87 
fossae, 45, 46 
nerves of, 48 
nerve, 40, 91 
Nasopalatine artery, 120, 367 
Neck, anastomosis of, 343 
boundaries of, 113 
dissection of, 106 
fascia of, superficial, 106 
deep, 122 
muscles of, 110 
triangles of, 113 
veins of, 120 
Nephromere, 391 
Nerve or nerves of abdominal 
organs, 243 
of abdominal walls, 204 
anterior, 46 
crural, 276, 277 
table of, 289 
recurrent, 305 
auditory, 63 
ganglia, 104 
Nerves, auricular vagus, 138 
auricularis mangus, 107 
auriculo-temporal, 43, 44 
of back, 352 
summary of, 354 
of bone, 357 
buccal, 28 
cervical, 353 
cardiac, 138 
chorda tympani, 44 
ciliary, long, 92 
short, 92 
circumflex, 134, 140, 156 
cranial, table of, 53 
cutaneous, anterior, of abdo- 
men, 200 
of thorax, 177 
of arm, 151, 166 
external, 275, 276 
internal, 134, 148 
lateral, of abdomen, 200 
of thorax, 177 
of leg, 262, 264 
table of, 265 
lesser internal, 134, 148 
perforating, 279 
dental, inferior, 43 
superior, 41, 42 
dorsal cutaneous, six lower, 
340 
six upper, 340 
of penis, 282 
external cutaneous, musculo- 
spiral, 156 
ear, 96 
of eye, 93 
facial, 27, 63 
course of, 97 
branches in petrosa, 98 
first cervical, 352 
fourth cranial, 90 
frontal, 40, 89 
gastric, 138 
glossopharyngeal, 63, 78 
gemellus superior, 281 
genitocrural, 274, 276 
gluteal, inferior, 279, 282, 301 
superior, 278, 282, 300 
great occipital, 340 
hemorrhoidal, inferior, 282 
hypoglossal, 63, 78 
iliohypogastric, 201, 274, 276 
ilio-inguinal, 201, 274, 276 
infra-orbital, 17, 28 
inframandibular, 28 
intercostal, 177, 180, 181 
inter costohumeral, 156 
internal cutaneous, musculo- 
spiral, 156 
interosseous, posterior, 168 
Jacobson's 27 
of kidneys, 233 
of knee, 309 
lacrymal, 40, 90 
Lancisi, 68 
laryngeal, inferior, 109 
superior, 109 
lingual, gustatory, 43, 44 
long buccal, 43 
lumbar, 354 
malar, 28 
maxillary, inferior. 43 
superior, 41 
median, 133, 155, 162 
cutaneous, 156 
Nerves, meningeal, 138 
masseteric, 43 
mental, 17 
motor oculi, 63, 93 
musculocutaneous, 133, 281, 
306, 324, 325 
musculospiral, 134, 148 
mylohyoid, 108, 113 
nasal, 40, 91 
obturator, 275, 277, 294 
accessory, 275, 277 
internus, 281 
occipital, lesser, 107 
small, 107 
oesophageal, 138 
ophthalmic, 40, 93 
optic, 92, 93 
orbital, 41 
of penis, 249 
of peritoneum, 216 
petrosal, great superficial, 27 
small superficial, 27 
phrenic, 109, 131, 185, 198 
plantar, external, 280, 329 
internal, 280, 329 
of pleura, 193 
pneumogastric, 63, 109, 136 
polymeric, 277 
popliteal, external, 280, 283, 
305 
internal, 279, 283, 306, 307 
of prostate, 234 
pterygoid, external, 43 
pudic, internal, 254, 279, 282, 
301 
pulmonary, anterior, 138 
pyriformis, 281 
quadratus femoris, 281 
radial, 156, 166 
sacral, 354 
saphenous, short, 280, 316 
of scalp, 52 
sciatic, great, 279, 282, 305 
table of, 283 
small, 279, 282, 303 
sixth cranial, 90 
of sole, 329 
spinal accessory, 63, 341 
posterior divisions of, table 
of, 352 
suboccipital, 340 
subscapular, 134, 148 
superficialis colli, 107 
supra-acromial, 107, 131 
supraclavicular, 107, 131 
supramandibular, 28 
supra-orbital, 19, 89 
suprascapular, 134, 143 
suprasternal, 107, 131 
supratrochlear, 89 
sympathetic, dissection of, 
355 
temporal, 28 
deep, 43, 44 
of testicle, 245 
third cranial, 91 
thoracic cardiac, 138 
external anterior, 133 
internal anterior, 133 
tibial, anterior, 280, 305, 313 
posterior, 279, 317, 321 
of tongue, 83 
trifacial, 39, 63 
trochlear, 63, 72, 93 
of tympanum, 99 INDEX. 
403 
Nerve, ulnar, 133, 148, 155, 164 
cutaneous, 156 
of uterus, 236 
vagus, 109, 136, 198 
of vena cava, 239 
Vidian, 27 
Neuro-epithelia, otic, 104 
Neurovasal region, 329 
Notch, sacrosciatic, greater, 
261 
lesser, 261 
Nucha, 341 
Nucleus caudatus, 70 
lenticularis, 70 
Nutrient artery (humerus), 371 
vein (femur), 382 
(fibula), 383 
(humerus), 380 
O. 
Obliqui muscle, internal, 202 
Obliquus capitis inferior mus- 
cle, 347 
superior muscle, 347 
Obturator artery, 271, 295, 373 
fascia, 262, 373 
muscle, internal, 262 
nerve, 275, 281, 294 
accessory, 275 
vein, 295, 382 
Occipital artery, 118, 340, 348 
convolutions, 65 
lobe, 65 
nerve, great, 340 
lesser, 107 
small, 107 
sinus, 55 
triangle, 115 
veins, 121, 378, 379 
Occipitalis minor, 131 
Occipitofrontalis muscle, 23 
Oculomotor nerve, 93 
(Esophageal artery, 369 
nerve, 138 
veins, 377 
(Esophagus, 199 
Olfactory bulb, 62 
tract, 62 
Olivary body, 62, 73 
Omenta, stomach, 221 
Omental function, peritoneum, 
217 
Omentum, gastrocolic, 217 
gastrohepatic, 217 
gastrosplenic, 218 
great, 209, 217 
lesser, 209, 217 
Omohyoid muscle, 107, 111 
Openings, left auricle, 190 
ventricle, 190 
Ophthalmic artery, 367 
nerve, 40, 93 
veins, 379 
Opponens minimi digiti muscle, 
161 
pollicis, 161 
Optic commissure, 62 
nerve, 92, 93 
thalamus, 71 
tracts, 62, 63, 72 
Orbicularis oris muscle, 21 
palpebrarum, 22 
Orbital artery, 366 
convolutions, 67 
Orbital fascia, 89 
nerve, 41 
periosteum, 89 
vein, 379 
Organ of Corti, 105 
abdominal, 209, 220 
of hearing, 95 
pelvic, 220 
Orifices, submaxillary, 77 
Os innominatum, 260 
Ossicles of tympanum, 99 
Osteologic points, pubic, 201 
Ostium maxillare, 45 
Otic ganglion, 44 
vesicle, 104 
Oval foramen, 384 
Ovarian artery, 237, 243, 372 
vein, 381 
Ovary, 237 
P. 
Palate, hard, 76 
pillars of, 76, 77, 80 
soft, 76, 78 
Palatine artery, posterior, 367 
vein, 380 
inferior, 378 
Palato-ethmoidal cells, 49 
Palatoglossus muscle, 78 
Palatopharyngeus muscle, 78, 
84 
Palmar arch, deep, 155, 370, 
371 
superficial, 155 
fascia, deep, 153, 157 
vein, deep arch, 381 
recurrent, 381 
superficial arch, 381 
Palmaris brevis, 161 
longus muscle, 155 
Palpebrse, 86 
Palpebral artery, 367 
inferior, 92 
superior, 92 
folds, 86 
vein, internal, 378 
Pancreas, 211 
dissection of, 229 
embryology of, 229 
location and characters of, 
229 
Pancreatic veins, 383 
Pancreatica magna artery, 372 
Pancreaticse parvae arteries, 372 
Pancreaticoduodenalis arterv, 
372 
inferior, 241 
superior artery, 372 
Papillae circumvallatae, 77 
fungiformes, 77 
lacrymales, 86 
Paracentral convolution, 66 
Paralysis, cervical ganglion, 358 
Parietal artery, ascending, 368 
convolution, ascending, 65 
superior, 65 
lobe, 64, 65 
pericardium, 184 
pleura, 184 
Parieto-occipital fissure, 64 
Parieto-temporal artery, 368 
Parotid gland, 19 
vein, 379 
Patellar ligament, 289 
Pectineus muscle, 294 
Pectoralis major muscle, 139 
minor muscle, 139 
Peduncle, cerebellar inferior, 72 
middle, 72 
superior, 72 
Peduncles, corpus callosum, 61 
Pelvic fascia, 273 
of female, 237 
floor, 261 
outlet, boundaries of, 245 
female, 256 
plexuses, 244 
Pelvis, bony, 259 
female, dissection of, 234 
Penis, blood-supply of, 249 
coverings of, 248 
dissection of, 247 
erectile masses of, 248 
nerve-supply of, 249 
Perforating arteries, femoral, 
292 
(mammary), 369 
(profunda), 374 
radial, 370 
veins, femoral, 382 
of foot, 383 
radial, 381 
Pericardiac arteries, 369, 372 
veins, 377 
Pericardium, description of, 167 
dissection of, 187 
parietal, 184 
prolongations of, 187 
surfaces, relations, 187 
visceral, 184 
Perilymph, 104 
spaces, 104 
Perineal artery, superficial, 373 
transverse, 373 
body, 259 
lithotomy, 252, 253 
muscle, superficial, 252 
space, contents of, 254 
deep, 253 
superficial, 250 
veins, 383 
Perineum, central point of, 252 
Periosteum, orbital, 89 
Peritoneum, blood-supply of, 
216 
cavities of, 216 
characters of, 216 
coverings of, 217 
dissection of, 216 
fossse of, 217 
functions of, 216 
absorptive, 216 
ligatory, 216 
mesenteric, 217 
omental 217, 
plicate, 216 
secretory, 216 
greater sac of, 211 
layers of, 216 
lesser sac of, 211 
nerves of, 216 
pelvic wall of, 214 
retentive medium, 216 
sac, lesser, 218 
Peroneal artery, 323, 324, 325, 
376 
nerve, 282 
Peroneus brevis muscle, 324, 
325 404 
INDEX. 
Peroneus longus muscle, 324, 
325 
tendon, 333 
tertius muscle, 313 
Petrosa, 96 
Petrosal nerve, external, 27 
sinus, 378, 379 
inferior, 56, 379 
superior, 56 
Petrosquamous vein, 379 
Petrotympanic fissure, 34 
Pharyngeal artery, 366 
plexus, 84 
veins, 121, 378 
Pharynx, 84 
Phrenic arteries (aorta), 239 
artery, 372 
nerve, 109, 131, 185 
veins, 378, 381 
Phrenocolic ligament, 211 
Pia mater, 57, 75 
Pillars of palate, 76, 77, 80 
Pineal gland, 71 
Pinna, 95 
Pituitary body, 62 
Plantar arch, 330 
artery, external, 330, 375 
internal, 375 
fascia, 327 
interossei muscles, 332 
nerves, 280 
external, 329 
internal, 329 
vein, external, 383 
internal, 383 
Plantaris muscle, 317 
Plates, tarsal, 88 
Platysma myoides, 26, 106, 110 
Pleura, 192 
arteries of, 193 
cervical, 192 
characters, 193 
costal, 192 
diaphragmatic, 192 
functions of, 193 
mediastinal, 192 
nerves, 193 
parietal, 184 
retentive medium, 193 
visceral, 184 
Pleural cavity, 184, 192 
Plexus, aortic, 244 
brachial, 110, 131, 146 
cardiac, 360 
superficial, 186 
carotid, 55, 359 
cavernous, 56, 359 
cervical, 109, 130 
choroid, 70 
hemorrhoidal, 227, 382 
hypogastric, 236, 244, 361 
lumbar, 269, 274 
table of, 274 
pelvic, 244 
pharyngeal, 84 
prevertebral, 360 
pterygoid (veins), 18 
pulmonary, anterior, 138 
sacral, 269, 277 
table of, 278 
visceral branches of, 284 
solar, 244, 360 
veins of, hemorrhoidal, 256 
venous, anterior, hand, 155 
dorsal, hand, 155 
Plexus, vesicoprostatic, 382 
Plica, epigastrica, 214 
fimbriata, 77 
hypogastrica, 214 
semilunaris, 86 
urachi, 214 
Pneumogastric nerve, 63 
Pneumothorax, 192 
Polymeric muscles, 277 
Pons Varolii, 62 
Popliteal artery, 308, 375 
fascia, 317 
nerve, external, 283 
internal, 279 
space, 306 
vein, 309, 382 
vessels, 317 
Popliteus muscle, 317, 319 
Portal vein, 240, 383 
Postcentral sulcus, 65 
Posterior auricular artery, 119 
mediastinum, 184 
spinal artery, 75 
surface of heart, 186 
Postero-lateral arteries, 60, 368 
Postero-median arteries, 60, 368 
Postglenoid tubercle, 34 
Pouch, laryngeal, 129 
rectovesical, 214 
utero-vesical, 214 
Poupart's ligament, 202, 214 
Precentral sulcus, 64 
Prevertebral artery, 366 
plexus, 360 
Princeps pollicis artery, 370 
vein, 381 
Process acromion, 139 
condylar, 34 
coracoid, 139 
mastoid, 107 
styloid, 34 
Processes, ciliary, 93 
Profunda artery, inferior, 371 
superior, 371 
cervicis artery, 369 
femoris artery, 292, 374 
vein, inferior, 380 
superior, 380 
Pronator quadratus, 155 
radii teres, 154, 159 
Prostate, arteries of, 234 
gland, 234 
nerves of, 234 
Psoas abscess, 273 
magnus muscle, 269, 273 
Pterygoid artery, 120, 367 
muscle, external, 29 
internal, 29, 31 
plexus, 18 
vein, 380 
Pterygopalatine artery, 120, 
367 
Pubic artery, 373, 374 
bone, 260 
fascia lata, 287 
symphysis, 261 
vein, 382 
Pudic artery, deep external, 374 
external, deep, 292 
superficial, 292 
internal, 271, 301, 373 
superficial external, 374 
canal, 223 
nerve, internal, 279, 301 
vein, external, 382 
Pudic vein, internal, 301, 382 
Pulmonary artery, 186, 198 
plexus, anterior, 138 
veins, 186, 198 
vessels, 198 
Puncta lacrymalia, 86 
Pyloric artery, 221, 372 
vein, 384 
Pyopneumothorax, 192 
Pyothorax, 192 
Pyramidalis muscle, 204 
nasi muscle, 23 
Pyramids, medulla, 62 
Pyriformis muscle, 262, 281, 
'299 
Q. 
Quadrate lobe, 66 
Quadratus femoris, 281, 300 
Quadrilateral space, 134, 143, 
167 
R. 
Radial artery, 155, 165, 370 
nerve, 156, 166 
recurrent artery, 370 
vein, 155 
deep, 380 
recurrent, 380 
superficial, 380 
Radialis indicis muscle, 370, 381 
Rami communicantes, 277 
gray, 134, 262, 295, 357 
white, sacral region, 357 
Ranine veins, 77, 378 
Receptacular arteries, 367 
Recess, tonsillar, 77, 78 
Rectovesical fascia, 273 
pouch, 214 
Rectum, 255 
extent of, -223 
female, 237 
vessels of, 227 
Rectus capitis anticus major 
muscle, 113 
minor muscle, 113 
lateralis muscle, 113 
posticus major muscle, 347 
femoris muscle, 287 
muscle, 203 
sheath of, 204 
Recurrent artery, ulnar, ante- 
rior, 371 
posterior, 371 
laryngeal nerve, 129 
palmar artery, 370 
vein, 381 
Reflex impulses, 389 
Reflexes of duodenum, 222 
of liver, 229 
of spleen, 231 
of stomach, 222 
Regions, abdominal, 215 
fibular, dissection of, 324 
gluteal, 298 
hypochondriac, 215 
hypogastric, 215 
iliac, 269 
inguinal, 215 
ischiorectal, 254 
of leg, anterior, 311 
posterior, 316 
lumbar, 215 INDEX. 
405 
Regions, neurovasal of foot, 
329 
subtrapezial, 341 
of thigh, anterior, 285 
internal, 293 
posterior, 303 
umbilical, 215 
Reil, island of, 65 
Relations of duodenum, 222 
of spleen, 231 
of stomach, 222 
of trachea, 192 
Removal of brain, 52 
Renal arteries, 242, 372 
veins, 242, 381 
Restiform body, 73 
Retentive medium of peri- 
toneum, 216 
Retina, 93 
Retzius, foramina of, 57 
Rhomboid muscles, 343 
Rhomboideus major muscle, 
343 
minor muscle, 343 
Rima glottidis, 129 
Ring, abdominal, external, 200, 
202 
internal, 213 
Right kidney, 211 
ventricle, 186, 189 
Risorius muscle, 22 
Rolando, fissure of, 63 
Root-structures of liver, 227 
of lungs, 185, 193 
Roots of spinal nerves, 75 
Rostrum, 68 
Rotator muscles, external, 299 
Rotatores spinae muscles, 346 
Round ligament (uterus), 235 
S. 
Sac, conjunctival, 86 
lacrymal, 87 
peritoneum, greater, 211 
lesser, 211, 218 
Sacculus, 104 
Sacra media artery, 243, 372 
Sacral arteries, lateral, 270, 374 
nerves, 354 
plexus, 269, 277, 284 
table of, 278 
veins, 382 
Sacrosciatic ligaments, 261 
notches, 261 
Sacrum, 259 
Saphenous nerve, short, 280, 
• 316 
vein, long, 246, 311 
external, short, 382, 
internal, long, 382 
short, 264, 316 
Sartorius muscle, 287 
Scala media, 104 
vestibuli, 103 
tympani, 103 
Scalenus anticus muscle, 110, 
113 
medius muscle, 110, 113 
posticus muscle, 110, 113 
Scalp, arteries, nerves of, 52 
composition of, 51 
Scapular artery, posterior, 369 
Scarpa's fascia, 200 
Scarpa's triangle, 295 
Sciatic artery, 301, 373 
nerve, great, 279, 305 
small, 279, 303 
table of, 283 
vein, 382 
Sclerotica, 86 
Sclerotome, 391 
Secretory function, peritoneum, 
216 
Semicircular canals, 102, 104 
Semilunar folds of Douglas, 204 
lines, 201 
valve, pulmonary, 190 
Semimembranosus muscle, 305 
Semispinalis colli, 346 
dorsi muscle, 346 
Semitendinosus muscle, 304 
Septa, intermuscular, 140, 285 
Septum lucidum, 69 
nasi, 45 
Serratus magnus muscle, 142 
posticus muscle, inferior, 182, 
342 
superior, 183, 342 
Sexual homologies, 256 
Sheath, carotid, 109 
femoral, 273, 290 
of rectus muscle, 204 
Sheaths, tendons of hand, 153, 
158 
Shoulder, region of, 139 
Sigmoid artery, 372 
flexure, 226 
of colon, 211 
vein, 383 
Sinus, cavernous, 55, 379 
circular, 379 
coronary, 189 
inferior longitudinal, 55 
lateral, 378 
longitudinal, inferior, 379 
superior, 379 
maxillary, 49 
occipital, 55 
petrosal, inferior, 56, 378 
superior, 56, 379 
pyriformis, 129 
straight, 55, 379 
superior longitudinal, 54 
transverse, 379 
Sinuses, accessory, 49 
dural, 54 
frontal, 45, 59 
sphenoidal, 46, 49 
Valsalva, 191 
Small intestine, 211, 220 
blood-supply of, 223 
coats of, 223 
Smell, area of, 63 
Soft palate, 76 
Solar plexus, 244, 360 
vessels and nerves of, 329 
Sole, dissection and table of, 
327 
Soleus muscle, 317, 319 
Space, anterior perforated, 61 
axillary, 144 
interpeduncular, 62 
perineal, contents of, 254 
deep, 253 
superficial, 250 
popliteal, 306 
posterior perforated, 62 
quadrilateral, 134, 143, 167 
Space, subarachnoid, 75 
subdural, 75 
Spaces, endolymphatic, 104 
interfascial, cervical, 123 
perilymphatic, 104 
Spermatic artery, 213, 242, 246 
cord, 200 
composition of, 246 
dissection of, 246 
veins, 213, 243 
right, 381 
Spheno-ethmoidal cells, 49 
Sphenoidal sinuses, 46, 49 
Sphenopalatine artery, 367 
Sphincter ani, 251 
Spinal accessory nerve, 63, 341 
artery, 75, 369 
anterior, 369 
posterior, 369 
cord, 74 
ganglia, 75 
nerves, posterior divisions, 
table of, 352 
dorsal, 384 
veins, 74, 384 
dorsal, 384 
Spinalis colli muscle, 346 
dorsi muscle, 346 
Spine, ischial, 260 
Spleen, 211 
class of, 230 
dissection of, 230 
embryology of, 231 
reflexes of, 231 
relations of, 231 
Splenic artery, 230, 241, 372 
veins, 230, 241, 383 
Splenium, 68 
Splenius capitis muscle, 343 
colli, 344 
muscle, 343 
Stenson's duct, 20 
Sternal arteries, 369 
Sternohyoid muscle, 107, 111 
Sternothyroid muscle, 107, 111 
Sternum, 107, 139 
Stomach, 209 
analysis of, 221 
arteries of, 221 
dissection of, 220 
location of, 220 
omenta of, 221 
reflexes of, 222 
relations of, 222 
size of, 220 
Straight sinus, 55, 379 
Striae longitudinales, 68 
Styloglossus muscle, 84 
Stylohyoid muscle, 78,107, 112. 
Styloid process, 34 
Stylomastoid artery, 366 
Stylopharyngeus muscle, 85 
Subarachnoid space, 75 
Sub calcarine convolution, 67 
Subclavian artery, 135, 196, 369 
triangle, 115 
veins, 379 
left, 378 
. right, 377 
Subclavius muscle, 142 
Subdivisions of colon, 225 
Subdural space, 75 
Sublingual elevation, 77 
gland, 78, 109 
Submaxillary ganglion, 44 406 
INDEX. 
Submaxillary gland, 109, 124 
orifices, 77 
Submental vein, 378 
Suboccipital nerve, 340 
triangle, 347 
Subscapular artery, 370 
vein, 380 
Subtrapezial region, 341 
Sulcus, frontal, inferior, 64 
superior, 64 
intraparietal, 65 
postcentral, 65 
precentral, 65 
temporal, first, second, third, 
65 
triradiate, 67 
Supercilia, 86 
Superficial fascia of abdomen, 
200 
of arm, 166 
of thorax, 139, 177 
petrosal nerve, great, 27 
small, 27 
Superficialis colli nerve, 107 
volte artery, 370 
veins, 381 
Superior maxillary nerve, 41 
mediastinum, 184 
oblique muscle, 89, 90 
rectus muscle, 89, 90 
vena cava, 196, 377 
Supinator brevis muscle, 155 
longus muscle, 169 
Supra-acromial nerve, 107, 131, 
156 
Supraclavicular nerve, 107, 131, 
156 
Supramandibular nerve, 28 
Supra-orbital artery, 19, 89, 92, 
367 
nerve, 19, 89 
vein, 378 
Suprarenal arteries, 242, 372 
capsule, 212, 233 
Suprascapular artery, 143, 146, 
369 
nerve, 143, 168 
vein, 380 
Supraspinales muscles, 346 
Supraspinatus muscle, 143 
Suprasternal nerve, 107, 131, 
156 
Supratrochlear nerve, 89 
Surfaces of kidneys, 232 
of liver, 228 
posterior, 229 
Sylvian fissure, 63 
Sylvius, aqueduct, 72 
Sympathetic cord, cervical, 358 
lumbar, 360 
sacral, 360 
thoracic, 360 
ganglia, location of, 357 
nerve, analysis of, 355 
dissection of, 355 
Symphysis pubis, 261 
System, emissary, 379 
Systemic veins, 377 
T. 
Tapetum, 68 
Tarsal artery, 376 
plates, 88 
veins, 383 
Tegmen tympani, 96 
Temporal artery, anterior, 366 
deep, 120, 367 
middle, 366 
posterior, 366 
superficial, 119, 366 
bone, embryology of, 36 
convolutions, 65, 67 
fascia, 29 
lobe, 65 
muscle, 29, 30 
nerve, deep, 43, 44 
superficial, 28 
sulci, first, second, third, 65 
vein, deep, 380 
middle, 379 
superficial, 379 
Temporomandibular joint, 34 
Temporomaxillary vein, 378, 
379 
Tendo Achillis, 317 
oculi muscle, 22 
Tondon, Achillis, 319 
common inner, 154, 160 
conjoined, 202 
peroneus longus, 333 
tibialis posticus, 333 
Tenia semicircularis, 71 
Tensor palati muscle, 81, 84 
vaginae femoris muscle, 287 
Teres major muscle, 167, 168 
minor muscle, 143 
Testicle, coverings of, 245 
descent of, 204 
development of, 204 
dissection of, 245 
migration of, 205 
nerves of, 245 
vessels of, 245 
Testis, tunica vaginalis, 206 
Thigh, deep fascia of, 286 
superficial fascia of, 285 
Third ventricle, 71 
Thoracic aorta, 196, 372 
artery, acromial, 146, 370 
alar, 146, 370 
long, 146, 370 
superior, 146, 370 
duct, 199 
nerve, cardiac, 138 
external anterior, 133, 146 
internal anterior, 133, 148 
region, 139 
vein, acromial, 380 
alar, 380 
long, 380 
superior, 380 
walls, dissection of, 177 
Thorax, divisions of, 184 
Thymus gland, 184 
Thyro-arytenoideus muscle, 128 
Thyro-epiglottideus muscle, 128 
Thyrohyoid membrane, 128 
muscle, 107, 111 
Thyroid artery, 369 
superior, 108, 117 
axis, 369 
body, 109, 123 
embryology of, 124 
cartilage, 126 
vein, inferior, 377, 378 
middle, 121, 378 
superior, 108, 121, 378 
Tibia, nutrient artery of, 323 
Tibial artery, 313, 314 
Tibial artery, anterior, 377 
posterior, 317, 321, 376 
recurrent anterior, 377 
nerve, anterior, 280, 305 
posterior, 279, 317, 321 
veins, anterior, 382, 383 
posterior, 382 
Tibialis anticus muscle, 312 
posticus muscle, 317, 320 
Tibiofibularj region, anterior, 
311 
posterior, 316 
Tongue, 77, 81 
mucous membrane of, 81 
muscles of, 83 
nerves of, 83 
vessels of, 78, 83 
Tonsil, 78, 81 
Tonsillar recess, 77 
Topography of abdomen, 215 
Trachea, 109, 129 
dissection of, 191 
relations of, 192 
Tracheal artery, 369 
Trachelomastoid muscle, 346 
Tract, olfactory, 62 
optic, 63, 72 
Tractus spiralis foraminosus, 
101, 102 
Tragus, 95 
Transverse colon, 211, 225 
fissure, great, 64 
mesocolon, 211 
sinus, 379 
Transversalis cervicis muscle, 
346 
colli artery, 369 
muscle, 341 
vein, 380 
fascia, 203, 269, 272 
muscle, 203 
Trapezius muscle, 341, 343 
Triangle, Hesselbach's, 214 
of neck, 113, 114 
anterior, 114 
carotid, inferior, 114 
superior, 114 
contents of, 115 
occipital, 115 
posterior, 114 
roof-structures of, 115 
subclavian, 115 
submaxillary, 114 
Scarpa's, 295 
suboccipital, 347 
Triangular ligament, 214, 253 
Triangularis sterni muscle, 182 
Triceps muscle, 168 
Tricuspid valve, 189 
Trifacial nerve, 39, 63 
Trigonum olfactorium, 62 
Triradiate sulcus, 67 
Trochlear nerve, 63, 72, 93 
j True vocal cords, 128 
Tube, Eustachian, 100 
Fallopian, 235 
Tuber cinereum, 62 
Tuberosity ischial, 260 
Tunica vaginalis testis, 206 
। Turbinate bones, 45, 47 
Tympanic artery, 366, 367 
plate, 34 
Tympanum, 37, 96 
1 arteries of, 99 
I clinical, 99 INDEX. 
407 
Tympanum, dissection of, 96 
muscles of, 99 
nerves of, 99 
ossicles of, 99 
relations of, 99 
roof, floor, walls of, 97 
U. 
Ulnar artery, 155, 165 
nerve, 133, 148, 155 
vein, anterior, 155 
common, 155, 380 
deep, 380 
posterior, 155 
recurrent, anterior, 381 
Umbilical region, 201, 215 
vein, 384 
Urachal plica, 214 
Ureter, 212, 233 
arteries of, 233 
female, 237 
Urethra, curves, 250 
female, 237, 258 
Urine extravasation, 250 
Ursegment, 390 
Uterine artery, 373 
and vaginal plexus veins, 382 
veins, 237, 382 
Uterovesical pouch, 214 
Uterus, analysis of, 235 
arteries of, 236, 271 
dissection of, 234 
ligaments of, 235 
false, 214 
masculinus, 250 
nerves of, 236 
Utricle, 103 
Uvula, 76, 78 
V. 
Vagina, 258 
Vaginal artery, 271, 373 
veins, 382 
Vagus nerve, 109, 136, 198 
Valsalva sinuses, 191 
Valve, aortic, 191 
auriculo-ventricular, 191 
of Bauhin, 225 
bicuspid, 191 
Eustachian, 189, 384 
Hassner's, 45 
ileocsecal, 225 
pulmonary semilunar, 190 
tricuspid, 189 
of Vieussens, 72 
Vasa brevia, 383 
arteries, 221 
veins, 383 
intestini tenuis, 372 
Vas deferens, 213, 247 
Vastus externus, 288 
internus, 288 
Vein, alveolar, 380 
anastomotica magna, 380 
arch: palmar, superficial, 381 
articular (knee), 382 
auricular, 379 
anterior, 379 
posterior, 380 
axillary, 145, 380 
azygos minor, 198 
basilar, 60, 378 
Vein, basilic, 380 
median, 380 
brachial, 380 
brachio-cephalic, 377 
bronchial, left, 378 
right, 377 
buccal, 378, 380 
calcanean, internal, 383 
cardiac, 187, 284 
anterior, 384 
left, 384 
posterior, 384 
carpal, anterior, 381 
posterior, 381 
cephalic, 139, 156, 380 
median, 380 
cerebellar, 60 
inferior, 379 
superior, 378 
cerebral, middle, 378 
superior, 60, 378 
choroid, 378 
circumflex, anterior, 380 
external, 382 
iliac, deep, 382 
posterior, 380 
colica dextra, 383 
media, 383 
sinistra, 383 
colli, transversalis, 380 
coronary, right, 384 
of stomach, 384 
cutaneous, of arm, 150, 166 
cystic, 384 
dental, inferior, 380 
digital, 262 
plantar, 383 
of diploe, 378 
diploic, 379 
dorsal, of hand, 155 
of penis, 382 
dorsalis hallucis, 383 
indicis, 381 
linguae, 378 
pedis, 383 
pollicis, 381 
dorsi spinal, 74, 384 
emissary, 379 
epigastric, deep, 382 
superficial, 382 
facial, 108, 121, 378 
common, 378 
deep, 378 
transverse, 379 
femoral, 382 
profunda, 382 
table of, 290 
frontal, 378 
of Galen, 60 
Gastro-epiploica dextra, 383 
gluteal, 382 
hemorrhoidal, plexus of, 256 
superior, 384 
hepatic, 239, 381 
iliac, circumflex superficial, 
382 
common, 269, 382 
left, 381 
right, 381 
external, 270, 382 
internal, 270, 382 
ileocolic, 383 
iliolumbar, 382 
innominate, left, 197, 377, 
378 
Vein, innominate, right, 197, 
377 
intercostal, 177 
superior, left, 378 
right, 377 
internal mammary, 180 
interosseous, 383 
anterior, 381 
palmar, 381 
posterior, 381 
jugular, anterior, 107, 120, 
380 
external, 107, 121, 378 
internal, 109, 121, 377 
left, 378 
posterior, 107, 121 
superficial, 120 
posterior, 380 
labial, superior, 378 
lingual, 109, 121 
longitudinal, anterior, 384 
posterior, 384 
lumbar, 381 
malleolar, external, 383 
internal, 383 
mammary, internal, left, 378 
right, 378 
maxillary, internal, 39, 379 
median, 156 
basilic, 156 
cephalic, 156 
mediastinal, 377 
medulli spinal, 74, 384 
meningeal, middle, 380 
meningorachidian, 74, 384 
masseteric, 378, 380 
mesenteric, inferior, 242, 383 
superior, 242, 383 
metacarpal, 381 
metatarsal, 383 
muscular (femoral), 382 
of neck, 120 
nutrient (femur), 382 
(fibula), 383 
(humerus), 380 
obturator, 295, 382 
occipital, 121, 378 
oesophageal, 377 
ophthalmic, 379 
inferior, 379 
superior, 379 
orbital, 379 
ovarian, right, 381 
palatine, 380 
inferior, 378 
palmar, deep, 381 
of hand, 155 
recurrent, 381 
palpebral, internal, 378 
pancreatic, 383 
parotid, 379 
perforating femoral, 382 
plantar, 383 
radial, 381 
pericardiac, 377 
peroneal, 383 
anterior, 383 
posterior, 383 
petrosquamous, 379 
pharyngeal, 121, 378 
phrenic, 381 
superior, 378 
plantar, external, 383 
internal, 383 
i popliteal, 309, 382 408 
INDEX. 
Vein, portal, 240, 383 
princeps pollicis, 381 
profunda, inferior, 380 
superior, 380 
pterygoid, 380 
pubic, 382 
pudic, 301 
internal, 382 
pulmonary, 198 
radial, 155 
deep, 380 
superficial, 380 
radialis, 381 
indicis, 381 
ranine, 77, 378 
recurrent, radial, 380 
renal, 242, 381 
sacral, 382 
lateral, 382 
saphenous, long, 262, 264, 
311, 382 
short, 264, 316, 382 
sciatic, 382 
sigmoid, 383 
spermatic, 213, 243 
spinal, 74, 384 
splenic, 231, 241, 383 
subclavian, 378 
right, 378 
submental, 378 
subscapular, 380 
superficialis voire, 381 
supra-orbital, 378 
suprarenal, 381 
suprascapular, 380 
systemic, 377 
tarsal, 383 
temporal, deep, 380 
external, 379 
middle, 379 
temporomaxillary, 378 
thoracic, acromial, 380 
alar, 380 
long, 380 
Vein, thoracic, superior, 380 
thyroid, 124 
inferior, 377 
middle, 121, 378 
superior, 108, 121, 378 
tibial, anterior, 382, 383 
posterior, 382, 383 
ulnar, anterior, 155 
common, 155, 380 
deep, 380 
recurrent, anterior, 381 
posterior, 381 
posterior, 155 
umbilical, 384 
uterine, 237, 382 
vaginal, 382 
ventricular, 60 
vertebral, left, 378 
right, 377 
Velum interpositum, 70 
Vena azygos major, 186, 197, 
377 
minor, 377 
cava, ascending, 186, 269 
descending, 186,196 
inferior, 238, 381 
nerves of, 239 
superior, 377 
tributaries of, 239 
corporis striati, 378 
Venae basis vertebrae, 74, 384 
Galeni, 378 
Thebesii, 384 
Venosus ductus, 384 
Ventricle, fourth, 74 
of heart, 186 
lateral, 68 
left, 190 
right, 189 
third, 71 
Ventricular veins, Galen, 60 
Vermiform appendix, 225 
Vertebral aponeurosis, 341 
artery, 348, 369 
Vertebral, ganglia, composition, 
357 
veins, 377, 378 
Verumontanum, 250 
Vesical artery, 373 
inferoior, 271, 373 
middle, 271,373 
superior, 271, 373 
otic, 104 
Vesicoprostatic plexus, 382 
Vesiculse seminales, 247 
Vessels of back, 347 
carotid, 109 
dorsal cutaneous, 340 
iliac, 269 
popliteal, 317 
pulmonary, 198 
of rectum, 227 
of sole, 329 
suprascapular, 168 
of testicle, 245 
of tongue, 78 
Vestibule, 102 
of vulva, 257 
Vieussens, valve of, 72 
Vidian artery, 120, 367 
nerve, 27 
Visceral pericardium, 184 
pleura, 184 
Vocal cords, false, 129 
true, 128 
Vulva, vestibule of, 257 
W. 
Walls, abdominal, 200 
thoracic, 177 
White rami, 357 
Willis, circle of, 368 
Winslow, foramen of, 218 
Z. 
Zygomatic muscles, 22