•V;r#; ■:/;,! ir^i.':'-^/;::^;:::^:':;.;'1''--'''; ; ■ ;.:;;'£-4..,.;• xr- t; ■■'. -■ ■■■ v-:>'' «xmgm&x\■'•>■.■ ■■ ■■ ■■•-■ ■■:■ •■:. ■ - !- ?$$?&'$ yfx :f^%^^^mm: ■ :.W-;.'.'.':;:'•:■:'. ' ■-'";: >'. ■■;; ' +J§ i^KJKl'V-'ii-^,:!'.?'.■ |Bpi!X-\''. .1-: ■■■■■w ■■.: .V;|| NATIONAL LIBRARY OF MEDICINE Washington a^MIftlw k.t. Lk*+% T &o\% • A SYSTEM OF DISSECTIONS. EXPLAINING THE ANATOMY OF THE HUMAN BODY, WITH THE spanner of ^tepfapingtfje IParts?, THE DISTINGUISHING ^ TIE NATURAL FROM THE DISEASED APPEARANCES, And pointing otit to the Student tlie objects most worthy of attention : DURING A COURSE OF DISSECTIONS. VOLUME II. BY CHARLES BELL. First American from t/ie third Lmidun Edition. BALTIMORE : Published by Samuel Jefferis, No. 212, Market-Street. P. Mauro, {winter. 1814- /■ A SYSTEM OF $hl$$teti#n$. DISSECTIONS OF. THE NECK. BEFORE the student proceeds to the dissection of the neck and face, besides having laid down ceitain important practical points to be the subject of his more particular attention during his progress, he ought to consider, or endeavour to learn, what are the pecu- liarities to which his attention should here be turned, and in what he is to expect this dissection to differ from that of the arm or leg. He will have learned that the extremities are cover- ad with strong fascia, that their vessels are pi otccted by this fascia, and strong condensed cellular memb aue, which invests them. In the neck, howeve,, he will find no such fascia, but only an extended web of muscular fibres, which is stretched from the chest 4 obliquely over the side of the neck to the cheek, and which, mingling with the common cellular membrane immediately under the akin, embiaces and compresses the important vessels beneath. He will, of course, in- quire into the necessity and effect of this peculiarity. It may, therefore, be observed, that the neck, having a great breadth or thickness in proportion to its lengtti, the seve al parts are necessarily more upon the stretch in the various easy turns of the head , and that there is here an ease and variety of motions, which could not be allowed, were the parts bound down by strong fascia.* Again, not only is theiea necessity for fiee motion in the head and neck, but the motions of the throat are so extensive, that they could not have free- dom, unless the uniform compression (which is re- quired to every part of the body) were yet so moderate as ti ce.y to relax, whilst it kept a degree of tension on the parts. Partly for thee reasons, and partly for the accom- plishment of other purposes, which we shall presently notice, the neck is not invested with a firm and un- elactic fascia, but with a cutaneous muscle, the pla- tysma myoides. When the dissector makes his incision down the middle of the throat, and carelessly dissects back the integuments, he is apt to lift back this cutaneous mus- cle with them, because, where the muscles of either side meet in the middle of the neck, the fibres are ex- tremely thin, and confounded with the sheath of cellu- lar membrane which covers the veins and stiaight muscles. But, by taking little of the integuments off, except the cutis vera, and drawing his scalpel, in the *When the neck is peculiarly short, and when the fat de- posited still further separates t/ie muscles, then are the turnimg motions of ttie head impeded, and the straining to t/ie aUempt has the effec t of compressing the veins returning (he blood from tfie head. a length of the fibres from the clavicle to the chin, he will recognise the loose fibres, and be able gradually, by a nice dissection, to display the superiiicial anatomy of the neck, a most important part to the surgeon. When you have dissected back the integuments from the side of the neck, and behind the mastoid muscle, the connecting membrane becomes looser, and here it is interwoven with the extremities of the cervi- cal nerves, and theii connexion with the sub-occipit»l and portio dura. Theie will be found here also nume* rous meshes of veins, the occipital and ceivical veins forming ai eolai with the axillaris and jugnlaris externa. On the throat too, there are many superficial rami fications of the external jugular vein, which inosculate with the thyioid veins. Here also we find seveial.de- , licate nerves, t e branches of the anastomoticus coi!i descendens, and the extremities of the descending di- vision of the ninth pair, or descendens noni. DISSECTION OF THE MUSCLES OF THE NECK. The fv-st muscle you have to dissect is the platysma myoides. It arises from the integuments which cover the pectoralis major and clavicle ; and t'escends ob- liquely upon the side of the neck to the base of the jaw. It is called a tutaneous muscle ; but impro- perly. This name however, implies the membran- ous nature of the muscle, and that it is to be found immediately under the skin. The integuments are to be lifted from it by carrying the knife in the direction of the fibre. When displayed in all its extentwfrom the deltoid and pectoral muscles to the cheek and base of the jaw, you will be satisfied that it has no connexion with the skin, and readily conclude that there is no truth in the explanation of its action, which supposes a muscle to arise on the foejat of the chest, to j.ull back the angle of the mouth. YflH 6 will also see that it is superfluous as a muscle for drawing down the lower jaw, considering how little force is necessaiy for that operation, and the numerous muscles which lie beneath. The use of this muscle is to compress the veins, and to impel the blood into the chest. It is in oction wherever there is straining of the muscles of the chest, as in difficult breathing, in coughing, or vomiting. During this first part of the dissection, you have to obseive, that the external jugular vein lies under this muscle ; the small nerves which you find upon the side of the neck are branches of the decendens noni, and of the cervical nerves. On raising the platysma myoides (which is to be done by taking up its origin, and throwingthe muscle upwards, having it connected with the face,) you see the beautiful muscle, the sterno-cleido-mastoideus. After dissecting carefully the origin from the ster- num and from the clavicle, and following up these portions towards their insertion into the temporal bone, you have to consider them as subject to disease. The wry neck is produced by a disease of this muscle; a portion of it loses its natural structure, and degene- rates into a kind of cartilage, which of course is equally incapable of contraction or of being stretched. The consequence is, that the head is tied down to one side, the mastoid process brought towards the sternum, and the chin pitched diicctly upwards. Sometimes this disease affects the clavicular, some- times the sternal portion ; and by observations on the dead body in the course of this dissection, the student will learn to distinguish these portions in the living body, and to avoid the error of cutting more, in ope- ration, than the portion which is i'iseascd. During the dissection of this muscle, a considera- ble nerve will be observed, perfoiating it in its upper part. This is the spinal accessory nerve, a branch of tHe eighth pair. 7 SECOND DISSECTION. THE MUSCLES OF THE JAW, THROAT, AND TONGUE. Before proceeding to this dissection, you must take the cartilages of the throat in your hand, and make yourself familiar with them. Os hyoides. 1. Its base; that part which is felt at the root of the tongue. 2. Its greater cornua, which stretch the bag of the pharynx, as the fingers do the mouth of a purse. 3. The lesser jcornua. 4. The ligament which connects this bone with the styloid process. Thyroid cartilage. ,1. Its broad shield-like part. 2. The prominent part near the os hyoides, called the ponum adami. 3. The, inferior cornua. \. The superior cornua. 5. The ligament which connects the corner of the os hyoides and thyroid car- tilage. Cricoid cartilage. You have principally to observe : 1. That the ring is narrow at its fore' part, and that there is a space between this and the lower part of the thyroid, occupied only by a membrane. 2. That the cartilage rises remarkably on the back part. 3. That on this prominence there are two articulating surfaces for the arytenoid cartilages. Arytenoid cartilages. These are not at all like peas. They aie of a singular and very irregular form. You will obseive : 1. Thier base and articu- lating surface. 2. The apex or tip. 3. Their poste- rior angle. Epiglottis. This is a broad triangular cartilage, of the shape of, an artichoke leaf. It is connected w ith the other cartilages of the larynx, and with the • 8 root of the tongue. In swallowing, it falls down ' like a valve upon the opening of the larynx. The dissector proceeds to the dissection of the mus- cles, which cover the fore part of the throat, and which arise from the scapula and sternum, and are inserted into the os hyoides and thyroid cartilage. These are muscles which draw down the throat : viz. 1. The sterno-hyoideus, 2. omo-hyoideus, and 3. sterno-thyroideus. (See Appendix.) ] He has then to dissect the muscles which lie be- twixt the lower jaw and os hyoides : viz. Th« digastricus, or biventer maxilla. mylo-hyoideus. genio-hyoideus. genio-hyo-glossus. lingualis. These two last classes of muscles are antagonists to each other. In the degree of permanence of con- traction, I consider the long muscles of the throat to resemble the sphincter muscles. The throat is moved upwards in swallowing by the second class, during which these of the first class relax ; but when the secdud have ceased to act, these resume their slation- aiy tension and action, which is to keep down the cartilages of the throat. When the platysma myoides is taken off, if the veins have been injected, we shall be astonished with the irregularly dilated state of the internal jugular vein ; but we shall perceive that it is so in a particular manner, where it is under the influence of the mastoid and cutaneous muscles, which by their alternate and spasmodic action, force the blood from the head j into the thorax, during coughr.ng or other violent inspiration ; and we may perceive that without this provision, the blood would actually stagnate in the head when there was a stiain upon the lungs, and an inten option to the blood entering the chest. For , 9 the same reason (the occasional difficulty of the re- turn of the blood into the thorax,) we see that even what may be considered as the cutaneous veins, are still under the platysma myoides. The effect of this muscle on them may be at any time observed during the violence of a cough. This muscle is, therefore, quite unlike the cutaneous muscles of quadrupeds, and mustnot be classed with them. Neither is it a muscle, the principal use of which is to pull down the corner of the mouth, or to act on the lower jaw ; but its real effect is to compress the veins. Bronchotomy, here, forms the first subject to which the attention is naturally attracted in this dissection. Observe the thickness of the integuments over the tiachea, the veins which cover it, the small muscles which are to be held aside : obsei've, also, the extent of the thyroid gland, the profussion of veins and arteries which supply it, the motion of the trachea, the rings of the trachea, the size of tne passage of the tube, and that the space for the operation is bound in by the carotids, sternum, and thyroid gland. In short, all those circumstances ought to be noted and observed, which have proved fatal during the operation, or which are, by our best writers, conceived to threaten suffo- cation, viz. the danger of blood falling into the wind- pipe, and causing suffocation ; the motion of the throat throwing out the tube, and causing sudden ob- struction, with the risk of transfixing the trachea by the trochar, and the possibility of accidents from the swelling of the integuments, &c. Letthe student make up his mind now to the difficulties, the dangers, and the uses, of this operation ; for when the call is made upon him, and his patient is in danger of immediate suffocation, the mind will not be free for delibera tion. 10 FARTHER DISSECTIONS OF THE MUSCLES OF THE THROAT. To proceed with the dissection of the muscles of the throat, you ought now to take away the lower jaw : or, if you do not wish to preserve the skeleton, «aw through the jaw at the symphysis, and dislocate one side of it from its articulation. You then get a lateral view of the throat. You dissect tnes e mus- cles : 1. The 3TYLO-GLOSSUS. 2. The STYLO-HYOIDEOS. 3. The STYLOPHARYNGEUS. 4. The CONSTRICTOR pharyngis superior, medius, and inferior. For these muscles see the Appendix. The throat and tongue being washed with a little vioeger and water, you should attend to these parts : 1. Velum pendulum palati. This you find to be a soft fleshy membrane, eking out the soft palate in the roof of the mouth, and hanging from the pa- late bone; behind it and above it you see the pos- terior nates. This velum you may consider in the first place as a valve, which falling against the back part of the pharynx prevents the food or drink from passing out of the mouth into the nostrils : it is also an organ of the voice; if I had ever doubted this, I lately had an opportunity of assuring myself of it, for 1 examined a man who had so entirely lost the bones of the face that I could look down into the throat from the nose, and as he spoke I saw this membrane rising and falling, and changing its degree of tension, so as to modulate the voice. 2. Uvula. This is the part which hangs down in the centre of the velum palati. It is a very sensible part, and is in some degree a centinel to call into ac- u tion the surrounding parts, for as soon as the morsel passes the uvula, it is grasped by the arches of the palate and pharynx. It no doubt also assists in mo- dulating the voice. 3. Towards the root of the tongue youjfind two arched with an intermediate space, somewhat'like the gothic arch. The anterior one is made by the constrictor isthmi faucium drawing the membrane : the posterior one in the same way by thepalato pharyngeus. 4. Amygdala. In the hollow between these arch- es, they receive a large mucous gland, the amygdala. You observe a member of follicles here, in which the mucus lodges. This gland is one of many for co- vering the morsel with mucus, that it may glide from the cesophagus into the stomach. 5. Iter ad aurem. The last thing I wish you to obsei've is the Eustachian tube, or the iter a palato ad aurem. You have now the following muscles to dissect; 1. AZYGOS UVULAE. 2. CONSTRICTOR ISTHMI FAUCIUM. 3. PALATO-PHARYNGEUS. 4. CIRCUMFLEXUS PALATI. 5. LEVATOR PALATI MOLLIS. See the Appendix, p. 1. The names imply the actions of these raus cles. Some further remarks upon the dise «r?. From what has been said, it will be readily under- stood, that, if the curtain of the palate be destroyed by ulcer, the voice will be affected, and in swallowing, fluids will regurgitate into the nose. By inflammation the velum may attach and adhere to the back part of the pharynx. This I have seen as the consequence of ribbens. The amygdala?, as every one knows, swell enormously in inflmmation of the throat; so as to threaten suffocation. 'I'hey suppurate, or rather, as 1 12 imagine, the suppuration is in arches of the palate. These glands are subject to a hardness like callosity, and require to be extirpated on account of the un- pleasant effect which is thus produced on the voice. The uvula is subject to relaxation: and by this too the voice is affected. Sometimes the uvula degene- rates into tumour, and requires to be cut off. The student should accustom himself to the natural appear- ance of all these parts, so that he may not fall into the error which I have known to be committed, of giving a course of mercury, under the persuasion of the throat being ulcerated when there was nothing un- natural, nothing but glandular irregularities, the foveae of the amygdala. As the communication between the throat and the cavity of the ear is for supporting the bal- lance of the air in the cavity of the tympanum, so that the membrane of the tympanum may vibrate easily; the deafness from cold is explained when we know that the swelling and relaxation of the membrane at that place closes the communication through the Eusta- chian tube. And so we may understand how tumours of the polypous kind, overspread ng the upper part of the pharynx and posterior nares, produce deafness. In swallowing, the parts act in this succession : When the morsel is masticated, there is as yet an un- gratified appetite : and to gratify the palate completely, the morsel must be thrust back into the pharynx: this is done by the dorsum of the tongue, by the muscles which raise and draw back the tongue. At this time the velum is pressed up, to prevent the mat- ter from passing into the nostrils. The morsel is then seized by the constrictor pharyngis and palatopharyn- geus, which by their action push it down into the phar- ynx : it is then pressed by the upper portion of the constrictor pharyngis, and successively by the middle and by the inferior portion of that muscle until it is delivered to the grasp of the tunica vaginalis guls, which by the successive action of its fibres, carries it into the stomach. 13 A singular disease has been produced by the lodging of a cherry stone or such small body, in some inequal- ity of the bag of the pharynx, perhaps originally an ulcer or a lacuna, whenever lodged here, it is by each subsequent aciton of tiie throat pushed deeper. The fasciculi of the fibres of the surrounding muscle yield to it ; and every time the food passes, some part of it is deposited so as to encrease the distention of the lit- tle sac, till gradually it becomes an immense bag, re- ceiving a great part of every meal : at last by its size it presses on the oesophagus, and finally obstructs deglutition. The pharyngeus and tunica vaginalis guise being the muscular covering of a tube connected directly with the stomach, and further united by sympathy with that organ though the branches of the great pair of nerves, arc subject to spasm, as well as to paralysis, from disorders of the stomach. This leads me to point out the propriety of attending to the anatomy of the parts, as the directors in the introduction of the tube into the stomach for conveying nourishment dur- ing obstructed deglutition. Cut up the side of the gullet and pharynx, and ob- serve once more the velum, the root of the tongue, the opening of the larynx, and the epiglottis. You will observe that the epiglottis is connected with the root ef the tongue, that it is raised from the larynx when thetongue is thrown forward, and it falls down to co- ver the glottis when the root of the tongue is drawn backward : with the present view before you, if you think of introducing the flexible tube, the propriety will occur to you of forcing it again >t the back part of the pharynx, and of making the patient pull the tongue back, as in the action of swolling, so that the glottis may be protected, and the point of the tube prevented from being introduced into the larynx. Vol. II. B 14 DISSECTION OF THE LARYNX. You now take out a portion of the trachea along with the larynx ; that is, the cartilages which have already been enumerated, and which form the upper part of the trachea. Dissect the following muscles; On the fore part : 1. THE THYRO-HYOIDEUS. 2. THE CRICO-HYOIDEUS. On the back part : 1. THE CRICO-ARYTJENOIDEUS POSTICUS. 2.----------------------------LATERALIS. 3. THE THVRO-ARYT./ENOIDEUS. 4. THE ARYT.1ENOIDEUS OULIftUUS. 5.------------------------TRANSVERSUS. 6. THE THYRO-EPIGLOTTIDEUS. 7. THE ARYTiENO-EPIGLOTTIDEUS. Having dissected these muscles, slit up the larynx upon the back part, and observe, 1st. The soft and delicate nature of the mucous membrane, which covers all these parts. 2d. The sacculus laryngeus. 3d. The rima glottidis ; and the manner in which it is formed : a tendon passes from the back and middle part of the thyroid cartilage towards the base of the arytaenoid cartilage, and membrane of the throat being drawn over that ligament, a chink or slit is formed, which is enlarged or diminished by the operation of the small arytaenoid muscles ; these operating on the upper and outer part of the arytaenoid cartilages move their base, and draw tense, or relax the tendon of the glottis. DISEASED APPEARANCES IN THE LARYNX. 1. Inflammation of the membrane of the laiynx is very frequent. While in a less degree, the mucous secretion is only made more viscid, and lodges abo it 15 the sacculus laryngeus. In violent inflammation, the nature of the secretion is changed, and a membranous sul stance is formed : for example, in the cynanche trachealis, or croup, a complete tube of membrane is formed. In examining this diseased appearance, you will generally find a serous effusion on the outside of the larynx : if the child has died early in the disease, much inflammation about the inside of the larynx, and a yellowish cinerttious membrane lining the larynx and trachea : the child dies in consequence of effusion in the lungs, and you have to observe during dissection whether the lungs, collapse upon opening the thorax, or whether there is this membranous production or effusion in the branches of the trachea, the bronchiae, and cells. 2. I have frequently of late found ulcers in the larynx. 3. 1 have found the epiglottis entirely eaten away. 4. Abcesses form in the outside ofthe larynx ; many of these have opened internally so as to cause suffo- cation. When the parts are before the student, he has to consider the effect of bodies entering the chink ofthe glottis, or lodging about the larynx ; of a bit of bone ■ticking in the throat near the larynx ; the operation of bronchotomy as it relates to the internal structure. In the consideration of all these subjects, the leading fact is this, that there is scarcely such a thing as me- chanical obstruction to respiration, but that if a husk or shell lodge about the larynx; or if inflammation excites it to a more irritable state ; or if an ulcer is formed in these parts ; the sense of suffocation and the coughing come in successive paroxysms, be- cause they proceed from the contraction ofthe glottis and the action of these lesser muscles. It too often happens that the surgeon thinks he has done enough when he has learned to count the branches ofthe external carotid artery, and their con. lo nections with the glands ; and, with these thoughts, he confidently undertakes all kinds of operations on this part ofthe body. But I haveso oftenseen, during an operation, mistakes and hesitation, proceeding from ignorance of the outward appearance ofthe parts, and particularly from inattention to the effect ofthe platys- ma myoides, that I feel myself called upon to solicit the student's attention to it. In dissecting out a small superficial tumour from the neck or cheek, we often find a few fibres encumbering us, and embracing the tumour with a firmness, which will readily be ascribed to the fibres of the plafysma myoides, only by those who recollect the wide differ- ence betwixt the muscle acting as a living part, and the relaxed and feeble state in which it is found in dis- secting the dead body. Again, I have seen surgeons experience much diffi- culty in dissecting round the base of a tumour seated in the neck, or above the angle ofthe jaw, merely from forgetting the effect of this cutaneous muscle in bind- ing it down, and in more particularly connecting the base with the surrounding parts ; for thus misled he has to dissect wide, deep, and irregularly, to destroy the adhesion of the tumour to the parts beneath. To dissect out a diseased gland, we ought to lay the skin cellular membrane, and fibres of this muscle, freely open, and reach fairly down through the bed of fat or membrane in which it lies. By getting thus to the immediate surface of the tumour, which is generally •mooth and uniform, the dissection will in almost every instance be very easy; and often the gland may be turned out with the point of the thumb or handle of the knife, so as to hang by its vessels, the artery supplying the tumour being the only one which will re- quire to be cut. By attending to this it will be pos- sible to dissect tumours from parts surrounded with im- portant vessels, without haemorrhage or other danger ?7 FIRST DISSECTION OF THE MUSCLES OF THE FACE. The knife should be carried from the occiput to the nose ; then carried above the eye-brow. The dissection is to he begun on the forehead, by carrying the scalp • oft towards the ear. The anatomist must take care only to raise the skin, and not go ;too near the bone. Fie will find the fibres of the anterior portion of the occipito-frontalis running down to be inserted into the eye-prow ; and a strong slip passing down on the nose. When he has dissected the frontal and occipital portion of this muscle, he will raise the lower part of it near '. the inner extremity of the eye-brow, and then he will '* find the corrugator supercilii ariing from the nasal portion of the frontal bone, and inserted into the eye- brow. « The second partfof this dissection will comprehend the muscles of the eye-lid and the oblique mus- cles of the eye-ball. In dissecting tor the orbi cularis muscle, the eye-brow ought to be preserv- , ed in its place. The knife must still be carried in the direction of the fibres of the muscle, in this in- stance, in a circular direction round the eye-lid. The eye-ball and recti muscles are now to be dis- sected out, and displayed, when if the student is de- siious of comprehending something of the use and function of these muscles, he has these subjects of enquiry before him. 1. The action ofthe muscles ofthe eye-brow, as bestowing a capacity of expiession. 2. The action of the orbicularis, in gently closing the eye-lids and in weeping, in opposing the occipito-frontalis, in com- bining with the corrugator supeicilii. 3. The ques- tion ; are these obliqui muscles to roll the eye-ball, or merely to suspend it, and prevent the recti from dragging the eye-ball into the socket ? 4. Then B 2 IS comes an enquiry regarding the action of the recti muscles on the optic nerve and on the ball of the eye.' 5. And, lastly, the distinction of squinting, as it pro- ceeds from a weakness iu the sensations of the retina, or an irregular action ofthe muscles of the e\c SECOND DISSECTION OF THE MUSCLES OF THE FACE, VIZ. THOSE WHICH SUR- ROUND THE LIPS AND ACT ON THE NOSTRIL. The anatomy of these muscles is sufficiently ex- plained in the Appendix ; they require niceness and care in the dissection ; an incision is carried down- the side ofthe nose from the inner angle of the eye, this is iu the direction of the levator labii suuerioris, alaequc nasi. By the side of this muscle towSrd the nose, is the constrictor nasi. The levator labii supe- rioris comes down from the edge of the orbit so as easily to be found, and beneath it lies the levator anguli oris. The dissection ofthe muscles on the lower part of the face must be begun by carrying the integuments off* the neck and dissecting the platysma myoides. As this cutaneous muscle of the neck ascends over the corner of the jaw, it runs forward to the angle ofthe mouth, under the name of risorius santorini. This risorius muscle, being superficial, may be dis- sected away, and then a clearer view may be had of the zygomaticus, the buccinator, the depressor anguli oris, and the depressor labii inferior's. The dissector in the last place makes the dissection of the orbicularis oris, and the levator menti. N. B. This last class of muscles are to be considered, I. As muscles of mastication. 2. As muscles of ex- pression in modulating sound. 3. As muscles of ex. predion in moving the features. 4. The enquiry mav 19 be carried to the comparison of the muscles of man, with the two classes of brutes, the carnivorous and granivorous, and lastly to the observance of what is peculiar to the human face, and indicative of human character. DISSECTION OF THE ARTERIES OF THE NECK. The student having injected the arteries ofthe head and made himself master of the plan ofthe carotid artery, which he will find in the Appendix, proceeds to the most important dissection of the whole body. The virst dissection ought to be the outer mus- cles on the fore part of the neck, the thyroid gland, its veins and artei ics. The second dissection is begun by turning off the platysma. myoides, and clearing the mastoideus muscle. Then the sheath ofthe trunk of the carotid artery is" to be opened, and the jugular vein and the par vagum displayed. •THE DISSECTOR WILL BE LED TO CONSIDER THESE POINTS. 1. He will attend to the direction of the carotid artery, and howitjretires behind the cartilages of the throat, and receives protection from the mastoid mus- cle. 2. Seeing the deep situation of the carotid, and the manner in which it is surrounded by the sheath of membrane, and under the compression of muscles, it will be easily comprehended how it is supported, after its coats have given way and are dilated in aneurism ; and observing how it must be supported and compressed on the outside, the effects of its •■.icurieinal dilatation in obstructing the muscles of 20 J the throat, and compressing the trachea, will be un, ' derstood. <• : 3. No part of anatomy can; more interest the sur- J gical student than this intricate intertexture of vessels. J and nerves under the angle of the jaw. 1 We observe how the platysma myoides covers and * embraces all the vessels, even the commencement of the external jugular vein : Again, how the vessels recede under the protection of the edge of the mas- ;" toid muscle. We find a mass of cellular membrane mingled with the glanduke concatenatae, or lympha- • tic glands of the neck, lying on the outside of the » jugular vein, and connected with the sheath ofthe great vein and artery. These are the. glands which f are so often diseased, and form large ' hard tumours, requiring operation. Observing their situation in this. their natural state, we may learn how far they must compress and encroach upon the vessels before they • torment the patient with the alarms of suffocation j i and being under the pressure of muscles before thejp * distend the integuments, they have generally sent their roots very deep. When a gland enlarges from disease, it pushes aside the cellular membrane, and i condensing it, forms a firm sheath or bed in which j the gland lies ; by getting through this cellular mem- *1 brane, as I have observed, and cutting fairly down to ! the surface of the gland, or raising up by dissection layer after layer the surrounding celluar membrane, ' the surgeon will often be able to dissect it out from its bed with ease. But these glands, we may observe, during dissection, are close upon the processes of the cervical vertebrae. During their enlargement, there- fore, they press down upon the bone, and form an adhesion so broad and intricate, that it is impossible to take the gland away with any certainty of eradicat- ing the disease. 4. When these glands under the angle ofthe jaw, and before the mastoid muscle, enlarge, they push 21 up thelobe of the parotid^gland before, form firm con- nexion with it, and are nearly incorporated with it. Hence, I have no doubt has frequently arisen the mistake of the surgeon, that he was extirpating the parotid gland, when he was merely taking out the lymphatic gland, and perhaps along with it the ex- tended lower lobe ofthe parotid. Twice I have seen in operation the lower part of the parotid gland dis- *ucted off wich much trouble and nicety from the enlarged glands beneath, and the diseased lymphatic gland taken out. In these several operations being assistant, I have found it necessary to observe to the mirgeon, that the surface of the tumour consisted ofthe natural granulated parotid gland, and to show him how to turn up the parotid gland to take out the tumour ofthe lymphatic gland. * 5. Observing in the first and superficial dissection of the side of the neck, the manner in which the platysma myoides covers all and sends its slips up- wards on the cheek, we shall understand how, by these means, it firmly braces down the lower part of the parotid gland ; and that before we can come to the surface of a tumour seated here, we have in general to make a free incision through this muscular expan- sion. It may befu the remarked, that the embracing of the fibres of this muscle has, during operation, a strength which the relaxed state of the parts in the dead body cannot explain. 6. Observing the numerous branches of arteries and veins here, the surgeon, digging in this deep cavity, will perhaps endeavour to insulate the connexions of the gland rather by the finger than by the knife. But I have found the root of such tumours striking so deep by the side ofthe vessels, that there was actually in this attempt danger of lacerating the internal ju- gular vein. 7. It will be observed from the dissection, that the arteries which are in danger from the extirpation of 22 tumours behmd the angle of the jaw, are the continu- ed trunk ofthe external carotid, or the temporal ar- tery, the internal carotid at its acute turn, and the oc- cipital artery ; observe the relations of these points ac- curately. The most exposed is the temporal artery, as it ascends under the lower part ofthe parotid gland. The occipital artery will be observed to lie very deep under the mastoid process, defended by the transverse process ofthe atlas ; and no surgeon will attempt to go within the sheath of the carotid and juglar vein, so as to endanger the internal carotid artery. See Rules for tying arteries when divided in wounds, and a d«- scription of the manner of dissecting for them. Operative Surgery, Vol. 11. 8. Surgeons, in common practice, often extirpate tumours with merely a general knowledge ofthe arte- ries, and after feeling and examining the tumour, they cut it out by merely going round the diseased part*. W« cannot but shudder to think how many operators of this kind there have been in this country, and how many there still are, giving themselves out as opera- tors, with an intention of establishing themselves in the superior ranks of the profession, with the sin of a conscious deficiency both of knowledge and expert- ness.* Here in the neck the surgeon can use no tonrniquet to stem the torrent of blood, until he have cut round the diseased parts : he must have an accu- rate knowledge ofthe parts, and dissect so as to avoid danger. The want of a knowledge of this part of anatomy does not so much lead to rash and fearless operations ; but as the parts are really of so essential importance, and errors so fatal, the patient is put off from time to time with frivolous pretexts, until the disease becomes so extensive, or the adhesions of the * Tlie author is happy to say that these remarks do not now apply to what is within his sphere ofohn'rvation. 23 tumour so deep, and so widely spread, that no other surgeon can venture upon an operation. ^ 1". Observe also that sometimes there is found lying on the parotid, or in its substance, a lymphatic gland, which may be diseased, and which 1 have seen diseased, and taken out from its socket in the gland. We ought also to attend to the vessels passing through the parotid gland, particularly the continued branch of the external carotid, the going off of the internal maxillary, and (he transversalis faciei. We shall be convinced from the actual view of the parts, that it is impossible to extirpate the parotid gland. I assisted my brother formerly in this operation. The whole gland was diseased ; it was dissected all round, until it remained attached only at that deep point which is behind the jaw bone, where it en- circles the artery. A ligature was put upon its root, and in a few days it dropt off, more completely era- dicated than could have been possible with the knife. The following day I assisted Mr. J. Walker, sur- geon, to dissect out a tumour from the same place. It would have appeared to a superficial observer to be the same disease of the parotid gland ; but, though the tumour was firmly rooted behind the angle of the jaw, its degree of lateral motion convinced us that it was a diseased lymphatic gland, rolling under its bed of cellular membrane, and the lobe of the pa- rotid gland. Mr. Walker, therefore, laid his account with going through the cellular membrane, cutaneous muscle, and the lobe ofthe patrotid gland, before he touched the surface of the diseaseu gland. By these means, without haemoirhage, he was enabled com- pletely to insulate it ; but finding its roots to run very deep, and the artery pulsating strongly, (the tumour being in actual contact with the external ca- rotid,) he put a ligature round the root of the gland, which came away on the following day. 24 1 also assisted Mr. Renton on a similar occasion.* When we dissect up the pa.olid gland, we observe the strong cord of nerves (the portio dura) which passes up through it, branching to the side of the face. These nerves will retain the ligatures for a very long time, unless they are, after a few days, snipt across. We ought to explain to the patient that there is often a slight distortion of the mouth, or a falling down of the eyebrow, from taking out tumours about the jaw. 10. The student must not leave the dissection of the carotid arteries, the thyroid and lingual arteries, with- out turning his attention to the circumstance of wounds in the neck, and state of those who have at- tempted suicide. II. And having examined the thyroid gland and its four arteries, he ought to think of its enlargement and the conseqnences of the attempt to extirpate it. DISSECTION OF THE ARTERIES OF THE HEAD. The student proceeds with the dissection of the ar- teries of the jaws and face, and the first thing which arrests him is the anatomy of the salivary glands. 1. He observes the place ofthe parotid gland, its great extent from the jugum to the mastoid process of the temporal bone. He observes the character of its substance ; he notices the socia parotidis ; the course and exact plan of the duct. He will take into his consideration the necessity of avoiding this duct in operations on the face, and the consequence of wound- ing it, viz. a fistulous opening, discharging saliva co- piously during meals. 2. He will next turn his attention to the sub- maxillar gland—notice its place and the lymphatic Tfiese cases occurred some years ago in Scotland. 25 glands which are attached to it. These lymphatic glands are often diseased ; the salivary gland rarely. 3. He will then dissect the genio and mylo-hyoidei muscles, and expose the sublingual gland, thus tracing large salivary glands lound the whole lever jaw. He will next attend to the opening of the salivary ducts under the tongue, and think of the effect of their ob- struction, and place and appearance of salivary con- cretions. 4. The student now traces the branches ofthe caro- tid artery, marking their exact place, that they may be avoided in operation, or secured in the event of being wounded. THE DISSECTION OF THE EYE.j Before the student proceeds to the dissection of those coats of the eye, which are called the proper coats, he must observe what is meant by the accessoiy or adventitious coats, viz. the tunica conjuctiva, or adnata ; the albuginea, foimed by the expanded ten- dons of the muscles. In studying these he takes also into consideration the appaiatus for secreting the tears, and for absorbing and conveying them into the nose. The tunica conjunctiva he finds to be the inner membrane of the eye-lid, reflected over the surface ofthe eye, so as to prevent foreign bodies from pass- ing deep into the socket. He ought to attend to the seat of the lachrymal glands, by dissecting down the upper eye-lid, and pulling it from its situation un- der the roof of the orbit. He ought to examine the ducts of this gland which open on the suiface ofthe inner eye-lid. He ought also to observe the pitneta lacrymalia on the edge of the eye-lids, near the inner angle, for absorbing the tears after they have washed the surface of the eye ; the carwncula Vol. 11 C 2G lacrymalis; the membrana semilunaris will be cxa-N : mined. A careful observation should also he made of the ' situation of the lacrymal sac and duct; the relation it bears to the ligament of the tarsus, to the angular ar- ^ tery, to the stro.ig point of the nasal process of the upper maxillary bone, and its seat in the os unguis, j An opportunity must be taken of tracing the duct .;; down to its opening in the nose, under the lower spongy bone, and of observing particularly the direc- tion of the stilct in the operation for the fistula lacry- malis. Upon taking out the eye, the ducts of the lacrymal gland should be examined ; the Meibomian ducts and glands. The surgical student will now enquire what is the nature of the Ptery^ion and Pannus and Kncanthis, and the effect of inflammation on the conjunctiva and cornea. , He will think of the nature of the disease called ' fistula lacrymalh, and the operation for its cure. Having dissected the eye-ball free of all parts exter- nal to the sclerotic coat, I should advise this method of proceeding : lay the eye in a flat dish, and pour round it warm jelly, so that just the surface of the sclerotic coat be above the jelly, and a small part of the margin of the cornea. When the jelly has con- gealed, it keeps the eye-ball uniformly supported and steady, and prevents the necessity of such pressure on the coats as would make the vitrious humour burst through the choroid coat or retina, upon making the incision of the strong outer coat. The instru- ments must be nice and sharp ; two pairs of small forceps, a lancet, pointed knife, and very delicate- scissors, and blow-pipe. With the sharp lancet, by repeated scratches, cut*: up a portion of the sclerotic com; »hen insinuating the point ofthe scissors under it, raise a triangular .22 flap. Under the sclerotic, the choroid coat, of a dark brown colour, will be recognised ; vessels and ncivCs will be seen passing from the sclerotie to the choroid coat; the nerves running forward betwixt the sclei otic and choroid coats to the iris : the arteries of the cho- roid will be distinguished from the veins, by their run- ning forward, and in a direction nearly parallel; while the larger veins, when followed through the sclerotic coat are seen to send out their branches, di- verging from the centre, and at the same time making circles in their course, so as to have the name of ] asa Forticosa.* A general black colour will be observed to pervade the substance of the choroid coat ; and upon teazing up this outer suiface of the choroid coat, we have what is considered as the proper choroid coat, while the inner surface is the ttimca Huy^.chiana. Upon turning back a portion' of the dark choroid coat, you find a black pigment on its under suiface, the Pi;rmcntum Aigri/m. If the subject is not peiiectly fresh, the black matter willJbe loose and floating ; part of it will also adhere to the surface of the retina, which is now seen lying under the choroid, and under the Pigmentum JSigrum. The retina will be found whitish, or having a con- siderable degree of opacity. By dropping a little weak acid upon it, it will become more opaque and stronger, and the vessels upon the inside will be more obscurely seen ; but if we turn up a portion of the retina, we see the vessels on its inner surface still distinct, and running apparently without any membrane to support them. This, however, is owing to the per- fect transparancy of the inner surface ofthe retina; and these ramifications are a proof that there is a * This is on the presumption that the veins and arteries ofthe eye are injected; if they are not, t/tey will appear like a fibrous structure in this choroid coat. 28 membrane here, the lamina vascutosa tunica retina ; while that which is external, and contiguous to the pigmentum nigrum, is the medullary portion of this internal coat, called retina, and the seat of the sense. Returning to the sclerotic coat, and cutting it fur- ther up towards the cornea, we have to attend to the connexions ofthe iris and ciliary processes, and cham- bers oftue aqueous humour. We find, upon carefully dissecting up the most anterior part of the sclerotic coat, that there is a whitish kind of band which con- nects the oute. circle of the iris and the ciliary circle with the sclerotic coat. This circular connexion best deserves the name of ciliary ligament. When we have taken up a considerable piece of the pellucid cor- nea, we can then observe the size of the anterior cham- ber of the aqueous humour ; and the situation of the iris, the nature ofthe pupil and the situation ofthe lens. The lens will be seen with its anterior convexity close upon the pupil, or perforation of the iris ; and the greater posterior convexity will also be observed, when you look from behind. Now, the student ought to turn in his mind all the precepts he has received regarding the operations of extracting and couching the cataract; for now he can understand that the great principle of extracting the opaque lens is, that the vitrious humour being com- pressed, protudes the lens through the dilated pupil. He may now convince himself, by observing the nearness of the lens to the iris, of the very small quan- tity ofthe aqueous humour contained behind the iris, and the impossibility of depressing the lens (by the operation of couching) into the posterior chamber of the aqueous humour, there being no such cavity. He will observe also, the point at which the needle for couching ought to be introduced, and the direction of the needle,soas to transfix the cataract. In short, he must now study the parts, and trust to no verbal de- scription ; for such is the use ofdissection. 29 We will observe further in this view, that where the choroid coat advances forward, it is, as it were, colifined, so as to form plicae ; and these passing inward, touch themaigin ofthe lens. Now observ- ing the place of these ciliary processes, introduce your hook, transfix the lens', and bring it away ; and now you will observe that these ciliary processes aie very short ; are like one circle within the larger circle ofthe iris ; and that there is no space betwix, these and the iris ; that when the lens is depressed, it is unsocketed from these connexions, and lies under the vitrious humour. OF PREPARING THE RETINA FOR DEMONSTRATION. Suppose that we make sections ofthe eye, with the intention of studying the structure of the optic nerve and retina, we dissect and follow the coals ofthe nerve until we find them terminating in the coats of the eye. In making a section ofthe optic nerve, we can now trace the arteiia centralis retinas through the porus opticus ; and the medullaiy matter of the nerve itself through the lamina cribrosa. When we have made a section of the eye, so as to see the back of lens and the ciliary processes, we may obseive that the retina seems to terminate at the loot of the circle of the ciliary body, or coiona ciliaris, as 1 have called it. But here the opaque and medullary part of the retina only terminates; the transparent part of it is continued inward ; not only touches the lens, but passes over its back part., by pouring a little vine- gar on the retina, the opaque medullary part will become more opaque, but the vessels on the in- side will not be obocuied. To demonstiate the vascularity and membraneous natuie of the retina further, float it in water, so that its outer surface may be exposed ; then take a solution of the caustic alkali, and with a hair pencil wash away the outer medullaiy suiface; then only will theie remain the 30 web of membrane, which serves as a base to the medullary part : or float the whole retina in a very weak solution of the alkali, and then it will appear that the medullary part is gradually dissolved, and there only remains the delicate and transparent web of membrane, full of vessels ; which transparent membrane is the base upon which the medullary part is as it were superimposed. When the web of the retina is minutely injected, and thus prepared, it may be hung in spirits, and then the vessels are seen beautifully ramifying : while the membrane which conveys them being transparent, is not discernible ; and this I conceive must have been the manner in which Ruysh must have prepared the vessels of the retina, so as to represent them as he has done in his works. To examine the iris the eye is put in jelly until it is all covered but the cornea. The cornea is then to be punctured with a lancet, and cut off. The iris is then seen to be a delicate membrane perforated in the centre, which perforation is the pupil: directly be- hind, the lens is felt, not seen, because of its extreme transparency. In the living eye the depth of the posterior chamber of the aqueous humour is just' enough to prevent the lens and iris from being in contact. The iris is properly the anterior part of this perforated membrane ; the back part of it is some- times called uvea. It will be best to look for the muscular fibres of the iris in the eye of some of the larger animals. Ofthe petitian canal.—To demonstrate this canal, we may cut off an anterior segument from the eye, leaving the lens seated on the fore part of the vitrious humour. To do this, the sclerotic coat must be carefully cut in the circle, a little behind the cornea ; then the choroid coat, with the ciliary body and iris, raised carefully rom the connexion to the fore part of the vitrious humour. Observing now the 31 margin of the lcn3, \*c perceive that the membrane of the vitrious humour appears to be reflected over it. Puncturing at this place, and blowing gently with the blow-pipe, you find that the air passes the circle round the margin of the lens, forming a canab/ like a chain of regular vesicles : or, instead of using the blow-pipe, to adapt it for demonstration, the point of the mercurial injecting tube may be forced into the angle betwixt the lens and vitrious humour, and a few drops of quicksilver allowed to fall into it, when they will show a connected chain ofjfglobules running round the lens. The Membrana Papillaris is seen in the foetus of from seven to nine months. It is a web of mem- brane which is hung across the pupil. To show this membrane, we may cut across the eye, keeping the anterior segment, then gently separate the vitrious humour and lens. But this is a slovenly way of displaying the membrane : we ought carefully to cut away tbe cornea also, so as to show the ciliary circle and the iris, and membrana pupillaris on both sides. If the eye of the fcetus be injected, we may socket the eye ball in a small cup with jelly, and then open the sclerotic coat, the choroid and retina. When we have done this, and look down into the vitrious humour, we shall see the arteria centralis retina send forward an artery, which is distributed to the back of the capsule ofthe lens. It the capsule of the lens be injected, we shall be able to trace the connexion of the foetal system of vessels in the eye, from the arteria centralis retinarto the branches of the ciliary arteries on the membrana pupillaris. 32 DISSECTION OF THE SERVES OF THE , ORBIT AND FACE. To have a distinct vciw of the nerves passing through the orbit, and to the eye, we niu.-t laise the upper part of the orbit, so as to have easy access to the parts within. Observing the points at which the 4th, 5th, and Gtli paiisof nci vis pas>s through the dm a mater, we have to dissect the duia mater up, so as to show the further couise of these nei ves. We have particularly to attend to the Gasserian ganglion of the fifth pair, and the passage of the sixth pair through the curvcrnous sinus. \Ve must dissect the dura mater from the fore part of the petrous bone, and from the sphenoid bone, show- ing the cavity which it forms heie for the lodgment of the ganglion of the fifth pair. We have to dis- tinguish betwixt the iutei lacing ofthe membiane of the duiamaler, and the blanching of neives. We ought also to lay open, with caution, the cavernous sinus, and display the turns of the carotid artery, and the couise of the sixth pair, and the beginning of the great sympathetic nerve. To pio.-ecute the dissection of these nerves, the fiontal bone must be cut down to the oi bit, so as to Jay open all the outside of the orbit; and thcsj.henoid and temporal bones must be cut down, so as to lay open the foiamen laceiuin, and the foramina roluiiduiu and ovale. The check bone ought also to be cut down, and the lower jaw cut through at iis symphysis, and the j.ortion uf the side \ou are dis- secting ought to be toni back, and left attached'at the articulation. Now you have free access to the dissection ofthe whole couise of the neives of the face. 1. You have to attend to the nerves passing into the oi'cit, viz. the 3d, or motor oculi, the 4th, or tro- chk-aiis, the opthalmic blanch of the Oth, .aid the Gth, or abductns. 33 The distribution of those nerves, or at least thejgr general cou se, is to be traced by dissecting very care- fully at the outer side of the optic neive, where tney are apparently in much confusion. You ought then to attend to the further and ml* nute distribution of these nerves in the orbit : 1st, The subdivisions of thefifth paii, viz. To the lachry- mal gland ; to the forehead ; to the lenticular gan* glion ; to the nose (by passing again into tlie cranium through the internal orbital foramen.; 2dly, Tne distribution of the third, or motor oculi, to the muscle=. 3dly, The formation ofthe lenticular gan- glion by the 3rd and 5th pairs, and the course of the fasciculi of ciliary nerves into the eye-ball. Having followed the nerves of the orbit, you may trace the nasal branch through the foramen, by breaking up the cells of the frontal and cethmoid bones until you find it passing down again with the first pair into the nose, or sending its branches into the frontal sinuses. Certain phenomena are now to be considered : 1. The languor in the eye and eye-lids ; the squint- ing in approach of death ; in hydrocephalus ; in the drunken man ; after fever, &c. 2. The convul- sions and nervous symptoms which have resulted from a wound oi the eye-brow. 3. The connexion established betwixt the eye and membrane of the nose. 4. Betwixt the iris and retina. 5. Betwixt the viscera and senses. Having the Gasserian ganglion and first great divi- sion of the fifth pair already dissected, it remains to follow the distribution of the superior and inferior maxillary nerves. To do this, there is much careful dissection and patience required, particularly for the dissection of the superior maxillary nerve ; for we find it lodged in the deep fossa, behind the maxillary sinus of the upper jaw amongst loose fat. Here it sends off many branches ; and the ganglion of mcikel, with the retrograd e \'idcan nerve, and the branches to the nosC and palate, are exceedingly difficult to follow. The whole of this dissection must be done by breaking up the bones, and their accidental fracture may tear away the chief point of demonstration. The dissector turns to the other side of the head and traces the portio dura of the seventh nerve, pro- perly enough called the nerrus communicans faciei, sometimes the letter sympathetic ; he finds it coming out from the sylo mastoid for an en, and forming the pes anserinus under the parotid gland. He finds it connected with the supraorbital nerve, with the branches ofthe fifth on the t emple, with the infia orbitary nerve on the cheek, with the niandibula labralis on the chin, with the ninth and the eighth, and sympathetic and cervical nerves under the lobe of the ear. To follow the lower maxillary nerve (the third di- vision of the fifth pair is easier,) you i.iu:t recollect, 1. The great branch to the lower jaw : '.'. The gus- tatory nerve into the substance of the tongue, and finally to the gustatory papillae ; and, 3. The reflected branch passing into the ear, the chorda tynipani. 4. The connexions which it forms with the ninth nerve, and its twigs to the submaxillary gland. Last- ly, the ninth nerve is to be followed and traced in its distribution to the muscles of I he tongue. After these directions there arc several things vfhich ought to be noticed, and which may be ex- plained from the circumstances of the anatomy: i. Paralysis of the tongue takes place, and taste remains. 2. Hemicrania. 3- Ticdoloureux. 4. The sensibility of the teeth. 5. The extreme pain in fracture and caries of the lower jaw. 6. Distinct sensation in the classes of the papillae of the tongue. 7. Pain in the ear in affections of the teeth and throat. 8. Pain in the integuments of the head, and 35 those symtoms which arc called nervous, of the head and sense.:, indera.igemcnt ofthe abdominal viscera. DISSECTION OF THE NERVES OF THE NECK.. The side of the scull is now to be cut down, and the lower jaw taken away. The dissector seeks the ninth nerve under the angle of the jaw, traces it into the tongue, and follows the descendens noni. This- branch of the ninth nerve he finds passing down upon the side ofthe neck to the muscles ofthe throat, and forming connexions with the cervical nerves. He then seeks the pur vagum the glosso-pharyngeal * ne;:ve, the spin-it accessory nerve, being the three divi- sions of the eighth pair. Hiving followed the lesser divisions to their destina- tions, he returns and follows the par vagum down the neck, tracing its branches to the throat and larynx, to the heart. He follows it into the thorax, returns upon the recurrent branch, traces it round the great.artcry, and backwards behind the trachea to the larynx. Here he naturally pauses to consider the distribu- tion of these nerves, as they explain certain circum- stances in the living .'vstem. 1. How tickling the throat produces vomiting. 2. How the secretions ofthe tongue and Pharynx arc affected'by the state of the stomach. 3. How the viscid secretions of the fauces and larynx will be changed by the operation of an emetic. 4. How it is explained that there is pain in the shoulder when there is inflammation of the throat. 5. How expe- riments on the par vagum and its branches affect the voice. Tnc djssectiuu being resumed, the knife is carried I 36 rearer the spine, and the great sympathetic nei vc is traced downwards to the chest. Tlien the cervical nerves aieto be dissected, and with particular care, the origin of the phrenic is to be demonstrated from the ceivical neives. When the phrenic nerve is dissected, the external respiratory nerve should also be displayed, viz. that nerve which, arising from the neives of the neck, like the phrenic, passes through the axilla, past the axil- lary plexus, and to the muscles clothing the chest, a nerve which 1 have described as c rnbining together the action ofthe internal and external muscles of respiration. PROSECUTION OF THE DISSECTION OF THE LONG NERVES INTO THE THORAX AND ABDOMEN. The dissector having perused the classification, and general description of the couise of the pai vagum, sympathetic, and phrenic nerves, proceeds to the dis- section of tbe thorax. There a»e two principal dis- sections, 1st. The neives to the heait, viz. from the sympathetic, par vagum, and recur.tns : the . hrtnic, in its course through the thorax to the diaphragm. 2d. The prosecution ol the par vagum on the oeso- phagus and to the lungs. 3. The sympathetic nerve and splanchnic branches. To do this last dissection, itw ill be necessary to cut down the ribs; preserving only the lower margin of the thorax to keep the dia- hragm distended ; or the trunk may be opened, the iaphragm cut from its connexion with the ribs, and the sides pressed down to the table. This dissection explains some obvious sympathies. 1. Seeing the net-work formed by the par vagum around the oesophagus, and considering their distri. bution to the stomach, we cannot wonder that in 5 37 hysterical women, with affections ofthe stomach,there should be spasm or paralysis of the oesophagus, or that sensation which is called globus hystericus. 2. By the circumstances of the anatomy, we are drawn to ob- s4i\e the connexion betwixt the stomach and lungs, and the asthmatic attack, from mere affection of the stomach, since we see the pulmonic plexus of nerves to be a division ofthe oesophageal plexus. 3. The same circumstance of connexion explains the effect of an antispas. iodic draught instantly relieving spasm ofthe chest, or difficult breathing. 4. Seeing that the nerves ofthe heart are supplied by the sympathetic nerve and par vagum, we are prepared to expect that in the dis- order of the viscera, the pulses of the heart may inter- mit, and the action be otherwise deranged. 5. Now it will be understood how a man, being wounded low in the spinal marrow, survives for a time paralytic ; but being woundell low in the neck, and the spinal marrow injured, he dies. Because the wound in the neck being above the oi igin ofthe. phrenic nerve, the muscles of respiration cease to act. 6. Seeing the derivation of the phrenic nerve to be from nerves whose branches are sent to the shoulder, and considering the proximity of the liver and dia- phragm, we may conceive how disease of the liver i6 attended with pain in the shoulder. DISSECTION OF THE NERVES OF THE ABDOMEN. When we have dissected the par vagum in its course through the thorax, and have traced its branches on the oesophagus, we see them passing the diaphragm with the oesophagus, to be distributed upon the sto- mach (the corda vcntriculi;) we may oberve also Vol. 11. D 33 that the right nerve becomes the more anterior ofthe two. To prosecute these nerves we must now follow their course in the abdomen, elevate the diaphragm, and press down the stomach, and shew the manner of their distribution to the superior orifice, and along the arches of the stomach. Here the student natu- lally recurs again to the consideration of the various sympathies, explained by the course of this n^ye, and its distribution to the throat, lungs, and stomach, &c. Having dissected the branches of the par vagum, which are sent to the upper side of the stomach, and down to the solar plexus, he ties the lower orifice of the stomach, and cuts away all the length of the intestines, excepting a part of the duodenum and rectum. Raising the stomach, he seeks the splanchnic nerve (the anterior branch of the sympathetic in the thoiax) where it comes into the belly by the side of the lesser muscle of the diaphragm. He finds the semilunar ganglion formed by this splanchnic nerve; it is likean irregular gland, being red and fleshy. The solar plexus or great central ganglion of the abdomen is formed by numerous branches from the two semilunar ganglions, and a plexus descends to it from the nerves of the stomach. Having found the two glanglia and traced them into the great solar plexus which lies before the aorta, and at the root of the cceliac artery, the lesser division of nerves is to be traced from this centre. We do not however now follow individual branches out meshes or plexus—viz. the hepatic plexus, along; the veins tand arteries of the biliary ducts, splenic plexus along the splenic artery, the superior mesenteric plexus, the inferior mesenteric plexus on the upper and lower mesenteric vessels. The next dissection, or division of this labour is 3.9 prosecuted by lifting up the kidney and its vessels, and tracing down the continued trunk ofthe sympathetic nerve, which continues its course from the thorax into the abdomen, keeping close on the side of the spine. Here are to be observed the branches which it receives from the lumbar nerves ; the plexus which it gives to the kidney; the additional branches it throws to the mesenteric plexus. From the plexus of the kidney are to be traced the nerves to the testicle or ovaria and womb, and finally the hypogastric plexus is to be shewn. The connexion or consent of parts which will na- turally recur to us during this dissection are, 1. Thit consent betwixt the stomach, and every other part of the living body, particularly betwixt the head and stop mach, and the sickness from affection of the brain. 2. The consent of the stomach with the liver, exem- plified in the sickness from disease, of the liver and in the increased discharge of bile during the excitement of the stomach. 3. With the testicle as shown in the sickness and lowness, the consequence of injury of the testicle, 4. With the womb as shown in th« sickness ond retching during any change taking place in the uterus. 5. With the diaphragm as in vomit- ing. 6. We must admire tooi the extraordinary sen- sibility of the stomach, independent of the conscious exercise of the mind. 7. We must consider the sto- mach as the most vital part, for a blow on the stomach kills more suddenly than when the injury falls on the brain or heart. In dissecting the nerves ofthe loins, and especially in tracing them round upon the walls ofthe abdomen, and down upon the fore part of the thigh, and to the testicle, we cannot close our eyes to the evident con- nexion of parts established through them. 1. A numbness and stiffness in the thigh, is some- times to be attributed to the accumulation of hardened fceces in the colon. 2. Nephritic chohc is a spas- 40 niodic state af the colon, affected by the contiguity of the inflamed kidney, or sympathising through the con- nexion of nerves. 3. When we inject the coats of the testicle for hydrocele, we enquire of the patient if he has numbness in the loins and back, or if he has a weary numb sensation passing down the thigh. 4.- Rheumatic affection of the thigh or loins, gives the sensation of pain in the testicle. 5. When there is stone in the kidney or ureter, there is numbness and pain of the thigh, and retraction of the testicle. 6 When there is disorder of the womb, there is a weight and pain of the loins. All these symptoms are to be explained by considering the common Biigin of the ntives from the loins. DISSECTIONS OP THE UPPER EXTREMITY. DISSECTION OF THE MUSCLES OF THE SHOULDER. I MIGHT refer my reader entirely to the Appendix" containing a history of the muscles, for this part of the anatomy ofthe muscles, did I not consider that it was too often considered as a mere 'esson of dissection, in which there was no knowledge of surgery to be obtained. 1. The first thing which claims the attention ofthe student after making the dissection of the pectoralis major, the deltoides and latissimus dorsi, is to be able to answer intelligibly that question which is so fre- quently put, what are the muscles which surround the shoulder joint ? you will not be satisfied with run- ning over the names, deltoides, supra and infra-spina- tus, subscapularis, teres major and minor, brachialis and triceps. 2. But you will observe that the pector- alis major, the latissimus dorsi and the teres major, are the greatest protection to the joint by command- ing the humerus, for there cannot be a dislocation of the shoulder joint without the humerus be previously raised. 3. Then it is expected that you will be able to say where the head of the humerus bursts through; betwixt what muscles its neck is embraced; and where the head ofthe bone commonly lies when it is dislocated. 4. And as of moat consequence of all, what are the impediments to reduction. In the dissection of the muscles of the arm, there is nothing to detain the student's attention, but when he comes to the fore arm he must make careful ob- servation of the fascia, and the connexion of the ex- pansion of the biceps flexor cubili wjth it. He will have to notice that there is a very tolerably strong membrane covering the belly of the biceps muscle, but that the facia of the foi e arm is of a tendinous strength. Having observed how it is connected with the spines and condyles ofthe humerus, he will trace it down to the wrist, and observe its connexion with the ligaments there ; and in dissecting it up he will no- tice the strong partitions which descend betwixt the muscles ofthe fore arm. On the back ofthe arm as the facia is more distinctly provided for the attachment or origin of muscles he will find it stronger, and the partitions more distinct than on the fore part of the arm. In dissecting on the palm ofthe hand, let him observe the peculiar nature of the fat, and the strong and regular aponeurosis which is under it. All these circumstances are worthy ofthe regard ofthe surgeon, CLASSIFICATION OF THE MUSCLES OF THE FORE ARM. There is no remembering the muscles ofthe fore arm and hand without an arrangement. 1 use the fol- lowing. We have first to observe the extreme simplicity of the muscles which lie on the arm, resulting from the simplicity ofthe motions performed at the elbow joint. In the same way we find that the muscle? 43 which lie on the fore arm hold a relation to the move- ment of the hand ant. wrist. To know the motions to be performed, is to obtain a key to the anatomy of the muscles ofthe fore aim. Belore proceeding to the dissection of the muscles ofthe aim, the stuuent should once moie put the skeleton before him, and take note of the points of origin and insertion, and the nature of the joins, and the motions performed , he will on this occasion no- tice : 1. The prominence of the inner condyle. 1. The excavation, as it wee, ot the bone ofthe foie arm, for the lodgment of the stronger clas. of muscles, the flexors. 3. He will see that the hand bends on the wrist joint. 4. That the radius rolls and carries with it the whole hand. 5. That the fingers and thumb must have their flcxois and extensors. I. Class, flexors, they arise from the inner con- dyle:----they are flexors ofthe wrist, or flexors of the thumb and lingers. II. Class, extensors, they arise from the external condyle :----they are extensors ofthe wrist, or ofthe thumb and fingers. III. Class, rotators of the band, they are pecu- liar in their insertion, viz. into the radius. They aic pronatois, (carrying the palm downwards,) or supina- tois, (laising the palm supine.) A kind of artificial memory of the mu- cles of the fore aim may be had by arranging them in numbers ; for example, if we take the biceps flexoi as supinator in this imtance, which it truely is ; and the mass of the flexor muscles, as one great pronator for ^uch is their conjoint operation; then the muscles go in thiees, thus : 1. For the motion ofthe wrist three flexors, the ulnaris, radialis, and medius, commonly called pal- mares longus. — Three extensors, the ulnaris, the radialis longior, and brevior.—Three pronators, the teres, the quadratus, and the mass of flexor muscles. 44 —Three supinators, the supinator longus, brcvis, and the biceps cubiti.—There are also three extensors of the fingers, the extensor communis, the indicator, the extensor minimi digiti.—Three extensors of the thumb ; the extensor primus, sccundus, and tcrtius— Three flexors ofthe fingers and thumb ; the flexor digi- torum sublimis, flexor digitorum profundus, the flexor pollicis longus. For the anatomy of these muscles, and of those lying on the hand, 1 may refer the reader to the Appendix. DISSECTION OF THE ATTER1ES OF THE ARM. The arm should not be cut from the trunk until observations are made upon the exact situation of the subclavian and axillary arteries. Having made yourself acquainted with the divisions of the great artery into subclavian, axillary brachial, 8tc. and of the several branches (see Appendix,) you commence your dissection by a particular attention lo the relations of the subclavian artery : you dissect above the clavicle and clear the lower part of the sterno- cleido-fhastoideus, and the scalcni muscles. 1. The dissector has to observe how the subclavian artery rises from the chest. 2. How the axillary nerves de- scend from the side ofthe neck to meet it. 3. He is to judge whether he can compress the artery here with his finger above the clavicle. 4. He has to ob- serve that the nerves may be wounded by the cut of a sabre, but the edge being stopped by the clavicle, the main artery may escape. 5. In a surgical view he has to look to the manner in which the lower thyroid ar- tery rises, and how the transvciialis humeri passes across the root of the neck to the shoulder. The dissection is prosecuted by turning off the in- 4j teguments of tht deltoid and pectoral muscles. Then the clavicular portion of the pectoralis may be raised, and avoiding the branch of the artery you see heie (the thoiacica humeraria,) you also raise a kind of fascia, and taking care not to wound the cephalic and subclavian veins, you find the subclavian artery deeper than the vein, and coming obliquely from under the clavicle. 1. Here the artciymay he com- pressed in any case of dangerous bleeding from the axilla; or even so as torestrain the haemorrhage din- ing amputation at the shoulder joint. 2. The stu- dent will now be well employed in considering the place of this artery, and the shape ofthe thorax. He will now be aware that to the superficial observer, a ball will seem to enter ths thorax when it has only wounded the shoulder. The consideiation of this subject will lead him to the anatomy of the axilla. ANATOMY OF THE AXILLA. The intricacy ofthe anatomy of the axilla, with the > danger of wounds, and the occasional necessity for opeiations in it, make this a very important dissection ; a piece of anatomy, of which no surgeon can be ig- norant, without risking the safety of his patients, and feeling in himself a state of mind far from envi- able. It is evident enough, that during an operation in the axilla, the surgeon cannot distinguish parts ; he is operating among deep parts, feeling rather than seeing ; endeavouring to insulate the glands with his fingers, and tearing rather than cutting;* but a */ recollect thistofiave been written after cutting out large diseased glands from the axilla in theca c of cancerous breast. I now beiievc thjs-operalivn in the axilla to be insufficient to restrain the course of a cancerous disease. 46 thorough knowledge of the parts is necessary toghe him boldness and decision; which are most of all required in operations upon parts so ncarHhe great trunks, wncrc the smaller branches bleed with an im- petuous jet, and where the tourniquet cannot be applied. In making this dissection of the axilla, we must be especially careful to keep all the parts in their natural situation, so as to be able to judge accurately of their relation to each other in the. living body. We have but a small space to dissect; but our success so much depends on our more general knowledge of the branch- ing of the arteries, and the course and proximity of the nerves of the arm, that the student can scarcely expect to make an elegant dissection, or thoroughly to understand the relation of the parts, till he have first dissected for the general anatomy of the arm. He should at least have dissected the muscles and nerves before he makes his dissection of the axilla. The integuments are to be dissected off the outer surface ofthe pectoralis major and latissimus dorsi, but the fat in the pit betwixt these tendons ought not to be taken away, as in muscular dissection. 1. You have to observe the place ofthe axillary glands, jthe size of the branches of the thoracic ar- teries, or of the subscapular which supplies them, the nerves which come out from the intercostal spaces which pass amongst them. 2. The whole plexus of nerves and the axillary artery will be found to be braced down by a web of aponeurosis. 3. This being lifted, we "now find that the nerves closely sur- round the artery, and hence we conclude that this artery must not be attempted to be secured by diving with a needle here. For the surgeon would in that case include the nerves, and the ligature would not come away until it was cut from the bundle of nerves. 4. When yon have disentangled the nerves 47 and artery, and traced the divisions of the plexus, you recognise the radial nerve running upon the fore part of the humeral artery ; the ulnar nerve taking its couise towards the inner condyle of the humerus ; the muscular spiral nerve passing through the triceps and behind the bone ; the external cuta- neus nerve passing before the humerus and through the coraco brachialis. You turn your attention to the circumstance of wounds penetrating the axilla ; for often when a ball has passed through the arm-pit, or ' lodges, the tract or the seat of it may be discovered by the numbness in the part of the arm supplied by the extremities ofthe nerve. If there should happen to be a wound ofthe axilla,attended with great hae- morrhage, and yet it is not evident whether the axil- lary artery or the subscapular artery be wounded ; if we find the muscles supplied by the radial nerve, paralytic, and the sensibility of the thumb, and tore and middle fingers lost, it is evident that the ball has passed through the main artery, since the radial nerve clings around it. 5. You con- sider how the head of the hnmerus being dislocat- ed, may press on the plexus of nerves or the ar- tery, and cause a symptom announcing the disloca- tion. 6. The question may pass through your mind, Does a punctui ed wound of the axillary artery call for amputation? Does a wound where the artery and the whole plexus of nerves are cut through require am- putation ? 7. You consider the part in the axilla and the muscles of the shoulder in relation to the ampu- tation of the arm at the shoulder-joint. 8. Of the glands in the axilla you have to observe the great group of lymphatic, or absorbent glands of the axilla, which, when diseased, and clustering together, form a tumour, which it is dangerous to extirpate. Other more solitary glands will be noticed. 48 SOME FURTHER OBSERVATIONS ON THE TWO LAST DISSECTIONS. 1. No one who knows the strength required in screwing a tourniquet on a limb, will think lightly of the difficulty of compressing the subclavian ai lery with his linger. An instrument might be made to press strongly on the first rib above the clavicle, which might stem the impetuosity of the blood, but the finger or thumb is preferred. The common tour- niquet may undoubtedly be applied much farther up than usually is conceived to be practicable, by placing the pad deep in the axilla, and resting the screw of the tourniquet on the acromion process of the sea* pula, an additional strap crossing the breart, and preventing the belt of the tourniquet from slipping off" the shoulder. 2. To this edition 1 must add that I have seen the operation of amputation at the shoulder-joint per- formed, and have been filled with admiration at the boldness and dexterity of the surgeon, Mr. Vance of Haslar. But it is a hazardous operation, where the assistant must be equal if not superior to the surgeon ; he has to stand behind the prtient and compress the subclavian artery, by pressing above the clavicle. It is with a view ijo your situation as an assistant that 1 now advise you to look to the relation of the subclavian artery, the clavicle, and the insertion of the cucullaris muscle, and the place of the scaleni. In the next edition of my Operative Surgery 1 will offer a substitute for this operation. 3. It morbid matter be absorbid by the lymphatics in the arm, buboes aic formed in the axilla, as in the lymphatic glands ofthe groin. But if the sore be in the course of the distribution of the ulnar nerve, there are small glands a little above the internal com 49 dylc which may previously swell. It is from partak- ing of the disease of the mamma, the most frequent source of cancerous matter, that these axillary glands become so often diseased; and it is thisdrca-e ot these glands chielly, which occaisions the necessity of ope- rations in the axilla, and gives importance to the anatomy of the part- If, when these glands arc not far advanced in the disease, only feeling through the integuments hard *!id enlarged, a small incision be made, there is danger of their eluding us, slipping amongst the loose cellular bubstar.ee. They should be firmly fixed with the two lingers, so that when the inei-ion is made, they may start out; and the fingers; should not be removed from them, when small and move- able, until they are taken up by the assistant's hook. When the glands become more enlarged, they form adhesions with the surrounding cellular mem- brane ; they group together, and form a fixed indu- rated mass. When these glands inflame, become enlarged, and suppurate, numbness of the arm arises from the ab- scess involving the nerves ; and when the abscess heals, the indurated itool includes or presses upon the plexus ofthe nerves. Since those arteries which are passing through the glands are the same which pioceed to supply theN mamma, it might be thought, that if we were first to extirpate the axillary glands, we should not have to take up with the tenaculum the same arteries twice. But this is no object. The extirpation of the breast is a simple operation. 11 the breast be small, the arteries which bleed during liie operation can be stopped with the point of the assistant's finger. If it be large, they can be easily tied as they are cut : and in this case it is better to tie them when they '- fttbt bleed ; for being stopped by the finger, they do 1 not bleed when the finger is lifted, and are with dil- Vol. 11. E 56 ftculty found; and if not found, bleed when the woman is laid to rest, and begins to recover from I her apprehensions. The arteries which bleed in the extirpation of the breast, arc those coming from the interstices of the three first ribs, viz. branches ofthe internal mammary, and those thoracic arteries which we see in this "dissection coming round from the axilla, the thoracica longior and branches from the subscapular. In wounds here, we have sometimes a resource in- dependent of the ligature of the bleeding arteries. Two or three firmly compressed sponges, with lig*. tures attached, should be in readiness ; the sponge is to be thrust into the axilla, another, if it should be required, and one or more compresses above it. The roller is applied round the breast and nek, and firmly upon the compresses in the axilla, and then the arm is bound down to the side. When the sponges come away, they leave a clean surface, which easily unites, or fills up. I have said that it is dangerous to dive with the needle in this part ; for you observe the proximity of the great arteries and nerves ofthe arm ; yet it has hap- pened, that the needle has been struck round the ulnar nerve, which was marked by the pain, the numbness and contraction of the ring finger and little-finger. We see how imminent the danger was of striking through the axillary artery. It is inded difficult to conceive how the nerve could be struck without the ' artery. Dissection of the arteries of the arm prosecuted.—The dissection may now be prose- cuted by taking the integuments off the inside ofthe forearm. After recognising the muscles in this more partial view you trace the branches of the humeral artery; you trace the radial nerve in company with, .'. the main artery ; the ulnar nerve, and its accompany. .* 51 ing artery from the profunda humer ; and also the course of the muscular spiral nerve. You may perhaps now see why surgeons will sometimes say that arteries have acute feelin°\ You are careful to observe the manner in which the hu- meral artery, and radial nerve, and venae comites, are involved in a sheath and bound down by a membrane, and particularly how they pass under the stronger fascia near the bend of the arm. You notice that to cut for the humeral artery, you have only to lay bare the edge of the biceps flexor cubiti, to open the sheath, and avoid the radial nerve, that high in the arm the nerve is superficial to the artery, that towards the bend of the aim it is on the inside of the artery ; what difference will there be in a wound of the artery before and after it has passed under the aponeurosis pf the biceps ? The full anatomy of the bend of the arm is veiy important. The following are the chief cir- cumstances to be noticed. On the fore part ol the fore arm you have to save I. The superficial veins, viz. the cephalic vein, which is coming up the radial edge of the fore arm ; the basilic, on the ulnar edge ; the median, in the centre. You have further to notice that the median splits, and that the division which passes to the cephalic vein is called the' median cephalic, and that the division which passes towards the inside of the arm, and unites with the basilic, is called the me- dian basilic vein. I have to call your attention par- ticularly to these divisions of the median vein, as they are commonly selected for bleeding. You have now to notice the two superficial or cutaneous nerves. 2. Betwixt the supinator longus and the outer edge of the biceps muscle, you find the external cuta- neous ncive, that which passes before the arm-bone and perforates the coracQ-brachialis muscle ; you may trace its branches under the cephalic and median 52 cephalic veins. 3. The internal cutaneous nerve is . found coming directly down from the inside of th* ■ arm over fascia and under the median barilic vein; J while the p incipal branch goes under the vein, some- -times a small filament passes over it. k You may now lift the fa. Yo.-i ought to draw a line from the inner condyle across the bend of the arm, and observe how far the bifurcation of the humeral artery is nclow this. G. Next obsci ving the radial, the ulnar, and the interosseous arteries, you attend to the it- current branches^ and their inosculations. REMARKS CONNECTED WITH THE SU. PERFICIAL DISSECTION OF THE BEND OF THE ARM. 1. Let the student, in the first place, mark well the connexions of the cutaneous veins, and nerves, and fascia, and arteries ; let him not confound, as some authors do, the description of deep-seated and superficial veins ; let him note the extreme delicacy of these superficial nerves, and not think of looking for them in the midst of a bloody operation ; let him not <4 confound the symptoms of the injured nerves with the effect of inflammation under the fascia ; and, above all, it is important that he should consider the appearance of these parts in the aneurism of the biachial artery, and in other diseases which may afr feet them. 2. The median basilic vein, is above the expansion of the biceps muscle, or the place at which the broad tendon ofth.it muscle expands into the general 53 fascia ofthe fore arm. You notice the edge ofthe fascia, where it is reflected towards the internal con- dyle (or perhaps we should say where it takes its origin from that bone ;) you see that the vein is a very little removed from the artery. We find, upon examining the arm of the subject, that the artery (at the point where the vein ciosses it obliquely,) is covered by the fascia only ; and that at this point it is thrown up more superficially by the bulging of the joint.* • 3. With the parts before us, we can be at no loss to understand the peculiar appearance which the parts assume in forming the aneurismal tumour, when the artery has been wounded in bleeding. By the firm compress and roller, the external wound, and that ofthe facia, soon heals ; but the artery continues to bleed, though not outwardly : the blood is impelled s under the fascia ; the connexions ofthe fascia are torn up ; a regular tumour is formed, occupying the bend of the arm ; and this tumour stretching the facia, con- tractsthefingers, and keeps the fore arm atarightangle with the arm ; as in other diseases in which the fascia-is contracted, or the biceps muscle swelled or contracted, or the muscles under the fascia inflamed. 4. In the aneurism of the bend ofthe arm thus regularly formed, the first incision of the operation lays bare the fascia ; for the integuments contract, and the glistening fascia appears forming the distended sac of the aneurism with the dark-coloured coagu- lum under it. * This superficial seat of t/ie ariery, and contiguity to the rein, causes tlie blood to flow from the vein, someimes in phlebotomy, per saltum ; which circumstance has given a pale face to many a youth, conceiving it to be tlte blood leaping from a wound of the artery. This ceases upon Uwdii/g the arm a little. 54 j. Sometimes the aneurism takes a very different form, viz. when the artery punctured by trauMiixing the vein, bleeds through the vein. It has thus hup- pened, that the stream of blood has continued into the vein, and the parts inflaming and thickening round this communication, it has formed an establish- ed and permanent opening from the artery into the vein; while the outer wound ofthe vein healing, the proper aueurismal varix is formed. In this case, the effect of the impulse of the arterial blood sent in up- on the veins is, that, in the first place, the median basi- lic vein is raised into a tumour, and the other veins be- ing also successively enlarged, the whole veins ofthe arm become varicose, and assume a very peculiar character. If we press the blood from the vein, we can feel the arterial blood rushing through the com- munication ; it can be stopped by the point ofthe finger. Notwithstanding the very distinct characteristic marks ofthe aneuiismal varix, I have heard surgeons boldly maintain, for their own credit, a common aneurism to. be a case of aneuiismal varix, though there was not a varicose or enlarged vein in the whole arm ; and this merely because, in the commencement ofthe tumour, the blood could be forced back, or the tumour made to disappear ; nay, even after the operation was perform- ed, and the artery was seen lying in the bottom oftha wound, fai.-ly punctured cio^sways, they would main- tain, that it had been an aneuiismal varix, but that it had bursi ! 6. We may observe, that the internal cutaneous nerve passes down upon the inside ofthe fore arm ; but although its branches are very numerous, wc see that they take, in general, a course under the veins ; and we observe a very considerable branch taking a course directly under the median basilic vein.* Some * This or even the radial nerve ikelf, nu>r'-'. bt> punc- tured by tramfixmg the win. i 55 vf the external cutaneous nerves, take sometimes « course over the veins. This, in bleeding in the me- dian vein, makes the danger of puncturing the nerve much greater than when the operation is perfoimcd in the median basilic : in bleeding in the median basi- lic, on the contrary, thci c is moie dangerof wounding the artery. But with a delicate hand a wound ofthe artery is scarcely possible ; while the most dexterous surgeon cannot be sure of avoiding the puncture of the nerve. 7. Effects of puncture of the nerve.—When a nerve is wounded in bleeding, the patient feels a more actuate pain than usual iu lhat operation ; has a sense of numbness communicated to the shoulder, and down to the fingers, or is distuibed and alarmed in a manner he cannot account for, and has a sense as of trilling of water down the arm. These, in the worst cases, are but p: eludes to along train of mi- serable feelings, spasm about the neck and jaw, frightful dreams, and a general loss of health from the extremely irrilable staie in which the patient is left after the accident. These spasmodic affections attack chiefly when the patient is going to sleep, when the system is exhausted. I have known a young man in this situation, that when just falling asleep, his jaw was sometimes suddeny and violently clenched toge- ther, and a violent spasm of the muscles ofthe back of the neck, and trunk, seized upon him, which did not leave him till he was again roused and awake ; thus exhausting him with watching and fatigue. In this state of body, the slightest scratch, or ruffling of the skin, was attended with an aggravation of all the dis- tressing symptoms. The complaint had existed for severalyeais. 8. Another and more frequent occurrence after bleeding, is a swelling, and inflammation of the punc- ture ; i n erysipelatous inflammation spreading all over the a' m, and a bad suppuration. % - 'k 56 9. The inflammation ofthe internal coat of the vein itself is also an alarming occurrence, as it may spread along the vessels to the heart itself. 10. Sometimes inflammation from bleeding, with successive suppuration and inflammation, extend under the fascia, or affect the fascia it>clf, or cause an obstinate hardening and contraction of the biceps muscle. In these accidents, we are enabled, byobserv- ing the peculiar connexion ofthe la.cia, to understand the effect, and often to remedy the evil: From inflam- mation and abscess in the fore arm, 1 have seen the most obstinate contractions in consequence of the neivly formed connexions and thickening ofthefascia. After the inflammation has subsided, 1 have cured the contractions by poultices, with camphor, and a splint laid alongst the fore arm, padded, and adapted to the curvature, so as to keep the arm always gently on the stretch. REMARKS UPON THE FULL DISSECTION OF THE ARTERIES AND NERVES OF THE ARM AND FORE ARM. The place of the wound of the brachial arterv In bleeding, was long misunderstood ; and we find aua- tonnstis arguing the propriety of operating for aneurism here, not from tiie probability of the collateral arteries being sullicieut to carry on the circulation, but on account ofthe probability of only one of the branches being wounded. Having the parts now before us, we see, that in the natural distribution ofthe arte- ries, by transfixing the median basilic vein, we should wound the tiunk of the brachial artery a full inch above the bifurcation into the radial anil ulnar ar-.- teries. "■•* Of the variety of the distribution in the brvciiial artery.—But the confusion on this point had arisen from the frequent irregularities of the dis- tiihution ol the brachial artery : very frequently the artery does not descend in one trunk under the fascia of the foi e arm ; on the contrary, it sometimes divides into the two arteries ofthe fore- arm, even in the axilla; in which case they run parallel, the radial branch taking a spiral turn round the- other, and instead of dipping deep under the expanded tendon of the biceps muscle, and under the protection of the muscles, it takes a superficial course upon the forearm ; some- times the brachial artery divides in the middle of the arm, sometimes near to the edge of the expansion of the biceps : When the radial artery runs thus superfi- cially, it lies sometimes above the fascia, and immedi- ately under the cutaneous veins ; but still it is tied down by the crossing fibres ofthe fascia, appearing rather as if included in it than running above it. This distribution ofthe arteries is to us no motive for the operation ; it does not come into our calcula- tion ; we operate with the expectation of the trunk be- ing wounded ; but wc have to attend to the probable consequences of a wound of this superficial radial branch, lilies superficially, so as even in the living body to be traced by its pulsation evident to the eye. The trunk of the brachial artery can be hurt only by so rude a wound as to have pierced the fascia ; but in the case of a high bifurcation, the radial artery lies. in immediate contact with the vein, and may be touched even in a delicately performed operation.* We have no cases of the wound of this branch on * Yet it is not in every vibjeet having this distribution ofthe artery, that we find it so entirely superficial, for ge- nerally it is fairly covered with the expansion ofthe biceps muscle, und it has always shreds of fibres binding it down. .** 58 record ; such a wound might, more than the prick- ing of the deep artery, be apt to form the aneurisinal rarix. If this more superficial artery should happen to be punctured, perhaps a general echymosis will bt the consequence, from the driving of the blood into the cellular membrane. Op the arteries which surround the joint. — Those are what are called the collateral arteries; that is, the smaller branches which run parallel with the trunks. Those from the brachial artery are the extremities ofthe profunda, the lesser profunda, the anastomaticus major, and some lesser anastomosing branches. These lesser anastomosing branches either follow the direction and general course of the ana- stomaticus major, »r pass towards the outside branch- ing betwixt the biceps and brachialis internus muscles, and inosculate with the recurrens radialis, or a braneh ofthe main artery, which takes a retrograde course, and which is sent off immediately before the separation of the radial and ulnar arteries. The branches of the arteries ofthe fore arm which correspond with these, are, the recurrens radialis, the recurrens ulnaris anterior and posterior, the re- curres interossea. To make a dissection of these, we present the back of the arm ; we must carefully dissect the muscular branches of the profunda superior from the flesh and tendon of the triceps; we find it sending down a branch upon the back of the external condyle, which forms a net-work of vessels on the ligaments, and which chiefly communicates with the recurrens interossea. The profunda inferior, being a smaller and more superficial branch, comes down upon the inner edge of the triceps, turns over the back ofthe internal condyle, inosculates with the profunda ma- jor, and with the recurrens ulnaris posterior. The anastomoticus major turns likewise round the pro- jecting bone, but does not keep its course upon the 59 back part ofthe arm ; it again turns to the fore part, and inosculates with the recurrens ulnaris anterior. The retrograde branches ofthe arteries of the fore arm seen upon the back part, are, the recurrens in- terossea and the recurrens ulnaris posterior. The re- currens interossea comes off from the interosseous ar- tery ; immediately after it has perforated the mem- brane, it ascends backwards to the joint, lying betwixt the ulna and the mass ofthe extensor muscles, as they arise from the outer condyle of the humerus. The re- currens ulnaris comes out from betwixt the heads of the flexor muscles. \ All those arteries form a net-work of inosculations, which surround the elbow-joint, and which continue the circulation in the fore arm, when the main arteiy, at the bend of the arm, is tied in the operation for aneurism. But this is so in the beginning, only, not in the end; for those arteries do not all continue to be enlarged ; on the contrary, some one of superior size, or more direct communication, takes the lead, enlarges becomes tortuous, and seems to annihilate others. As far as my observation goes, this is the busi- ness of the anastomosis, betwixt that branch of the brachial artery, which is called the anastomoticus major, and the recurrens posterior ulnaris. This ar- tery becomes wonderfully enlarged, and is felt pulsa- ting strongly behind the inner condyle soon after the operation. Of the ulnar and radial arteries at the wrist.—There is no part ofthe body in which it is more necessary to connect the anatomy with the accidents, than here at the wrist ; for, from appa- rently slight accidental wounds of these arteries, there come great pain, inflammation, deep driving of the blood, unskilful operations, and bad surgery, and danger of losing the arm, and even'the life ofthe patient. The danger is from these vessels,—the ulnar artery, as it turns over the wrist and the ra«: 60 1 dial arterv, as it turns over the root of the thumb, or the palinar arch in the hand not being neatly tied at first. The consideration of this department ofsur- gcry would lead us too far ; 1 only say look to it now when the parts are befoie you. I have required you also to look to the peculiar appearance of the fat, and the aponeurosis on the palm. In a wound ofthe artery in the palm, we put in a large pad, or compi ess, and close the hand, and bind it Irmly ; but if the arch of the palm be cut, this does not completely stem the blood, or the pain and iuflam- malion are such, as will not allow the bandage to be drawn sufficiently tight ; we must then undo the ban- dage, and endeavour to find the artery ; but the ap. pearance of the wound is changed; it is tumid, and" , the cellular membrane stuffed with blood, so that, from ' the confusion, we probably cannot see the mouth ofthe artery. In this state of things, the patient getting weak J from loss of blood, and the vessels, perversely bleed- 1 ing only when the dressings are applied, and stopping I when they are undone, the surgeon is tempted to fol- low the artery with Incisions, fruitless perhaps, be- cause he is still amongst th e disordered parts. He is at last tempted to dive for the roots of those vessels with his needle. And now let us observe the conse- quence of this : Suppose that a surgeon does not dis- sect neatly for the radial or ulnar artery at the wrist, but plunges for it with his needle, the .kin, tendons, and nerves are included, and the ligature is drawn tight upon them; there may be most dangerous ner- vous symptoms from the including of the nerve, or more certainly, the n xt day, !,y the fading ofthe parts, the ligature slackens, and the artely bleeds a- gain. When the student, then, is studying this part of the anatomy, let him not run with too much rapidity • over this important lesson. I would recommend it i to him to read Mr. John Bell's Principles of Surgery , 61 upon this point, where he will find surgical cases so \pictured and represented to him, that he will not quickly forget them; let him return then again to his subject ; let him examine the fascia at this forepart of the wrist, and the manner in which it covers the artery ; let him observe the palmar aponeurosis, and mark accurately the place at which the arteries turn over the wrist; let him mark the connexion ofthe ulnar artery and nerve, where they lie connected, and observe the radii 1 nerve free from the arteries, passing under the ligament ofthe wrist, and then he will not be guilty of seeking (as I have seen surgeons do) the radial nerve, in order to separate it from the radial ar tery. i Vol. II. F DISSECTIONS OF THE LOWER EXTREMITY. DISSECTIONS OF THE THIGH. THE order of the student's dissecting the lower limb should be this : 1. He ought to have part of a subject to teach himself the anatomy of the fascia, and of the muscles ofthe thigh and leg. 2. He ought particularly to dissect the joints of the hip, knee, and ankle. 3. He ought next to attend to the anatomy of the arteries only. ■*. And in the last place he ought to dissect the arteries, veins, and nerves of the lower extremity together, attending, in this hist instance, particularly to the places of the arteries as thoy hold relation to the other more prominent parts, and to the mutual relations of arteries, veins and nerves. Remark* intradictory to the Direction of the Extremi- ties ; tfie Effects of tlie Muscles a?ui Fania upon the Vessels; and the Pecu/iuriiti in the Ut.tribution of the Feins and Arteries. In the dissection of the thigh, the method of inves- tigation, as well as the object of it, is essentially different from lhat which is followed in the di^sec- tions of the belly and thorax. We find the limbs made up of a solid muscular flesh, which surrounds the bones, gives symmetry and action to the limbs, and poises the trunk upon them : and, besides the integuments common to every part of the body, we find them covered with strong fasciae, or the aponeu- rotic expansion of tendons ; which not only support and brace the muscles in their action, but gives the limbs a defensive strength, by forming them into a firm concentrated pillar. The fibres of the fascia, too, mingling with the common cellular membrane, dive amongst the deeper muscles, and divide and class them. We find the arteries branching amongst the muscles, and exposed, we might at first suppose, to be interrupted in th en- actions amongst those active and contractile parts; but these arteries have energy and force to overcome and resist the contraction of the muscles of the limbs. The more languid flow of blood in the veins is indeed left exposed to casual interruption by compression of the muscles ; but this pressure upon the veins is counteracted, or its bad effects avoided, by their pe- culiar distribution. In the legs and arms, and in the neck am. all fleshy parts, there are two sets of veins : the venae comites, accompanying the arteries through their whole course amongst the muscles ; and the cutaneous veins, which though like the others they receive the returning blood from the ar- teries, take a different course to the heart, emerge from the oppression of the muscles, and return their blood by a superficial distribution to the great veins of the trunk. We observe no such variety of distribu- tion in the chest or belly—no valves to counteract the retrograde impulse of the blood ; because in these cavities there is no occasional and partial action of parts by which the return of the blood can be re- tarded, the pressure being uniform through the whole 64 cavity—and became, from this uniform pressure, no distribution of the veins could free them. Wncn any pressure is made upon the upper part of the thigh, if the pregnant uterus, tor example, should press upon the vessels of the pelvis, or a schirrous tumour should arise from the glands of the groin surrounding the crural vessels, the veins are the first to suffer ; the supply of blood is not diminished, but the free return of the blood is retarded, causing oede- ma. In the case of an adventitious tumour, both arteries and veins pissing through it, the arteries, by the strength of their pulsation remain free, and possessed of full room for action, however large the tumour, while the veins, being more passive, having no action, arc encroached upon by the tumour, and compressed, and the blood is consequently retarded in their dilated extremities. YVc learn from this the importance of making the pressure uniform over all the lower part of the limb, when we apply bandages or compress an artery. Were it possible so uniformly to compress a limb, from the toes to the top of the thigh, as to Uave no part unincluded or unsupported (unless in inflam- mation of the parts,) almost any degree of compres- sion might be used ; for in that case the blood would flow uniformly over the whole limb ; and though stifled in a degree, no part would be overloaded with stagnant blood. Further peculiarities in the anatomy of the extre- mities will naturally come to be noticed in the couise of the history of each dissection. 65 FIRST DISSECTION OF THE THIGH. Of the fascia of the thigh, the inguinal glands and superficial vessels, the lym- phatics and cutaneous nerves. In acquiring a knowledge of the economy of the body, of the peculiarities in the distribution of the vessels of the extremities, of the use and effect of the fascia, and of the characteristic difference betwixt the limbs and cavities of the trunk and head, this forms an important dissection. With a view to sur- gery it is no less important; since a knowledge ofthe point* of anatomy, which it includes, is extensively applicable to practice. It is almost impossible, by description alone, to give such an idea of the appear- ance ofthe vessels and membranes, as to enable any one readily to distinguish them in the dissection ; yet surely something may be done so to point out the character of the parts, that when once seen, the- recollection of them will not be quickly effaced. Precautions necessary in conducting the dissection—We lay the subject on the side, and begin the dissection on the outside of the thigh ; here the fascia is stiong and cannot be mistaken, or its layers lifted. The dissection is continued up towards the back ofthe ilium, and here it covers thefascialis and the gluteus medius, but the gluteus maximus is not under a fascia. That muscle is to be carefully dissected ; then the dissection of the fascia is to be continued towards the fore part of the tnigh. In dissecting the integuments of the fore part ofthe thigh, we should not cut too deep, nor look for the smooth and strong fascia, which, from description, we may naturally have been led to expect; for upon the fore part, and above the tract of the important F 2 GO vessels, tha fascia is of a loose and cellular texture; and the gradual change whicti it undergoes is to be observed only by tiacing it from its stronger expan- sion on the outer part of the tnign. We begin anew o,i the abdomen near the groin. We dissect the true skin back, leaving much of the subjacent cellular membrane. The parts wnich then come into view, mav be now described as a general insiancc. The lymphatic vessels are immediately under the true skin. They are more superfical than the veins and nerves. They run in straight lines ; are only partially seen, or seem to be abruptly biokcn off by the intei vemag pellicles of fat. They a. c very laigo and varicose in appearance, when distended, especially in the course of the saphena vein ; more numerous upon the middle part of the thigh, and more thinly scattered, but more distinctly seen upon the outer part. In colour and appearance, when in their na- tural state and collapsed, they lesemble loose muscu- lar fibres; being flat reddish lines, most distinctly and strongly muscular in their colour, ond pellucid only when distended with air. When the.-e vessels are snipped obliquely with their scissors, or puntured wilh the lancet and blown up, or injected with mer- cury, they take a very peculiar appea;ance ; for they swell onTy betwixt their valves, whilst the valves seem to cut them into beads i, regularly joined. Lymphatic glands.—At the groin, immediately under the skin, on a level w ith the lymphatics, and above the fas ia ond cutaneous veins, we find the congeries of lymphatic glands. But all the inguinal glands are not thus superficial ; on the contrary, many are sunk amongst the condensed cellular membrane xvhic:i mingled with the aponeurotic membranes! forms a bed covering the femoral artery and vein We have particularly to notice such as belong to the lymphatic:, ofthe penis. Veins.—The saphena vein, we are told, lies above 67 the fascia ; the great femoral vein below it. This is true ; but it must at the same time be understood with some limitation. About six inches from the groin (if merely the skin have been dissected back) we can only see the saphena vein shining faintly through the fascia, even in the leanest subject. It comes up upon the inside of the knee and thigh, and does not dive suddenly under the fascia, but is gra- dually enveloped, and more firmly embraced, by th* fibres of the fascia ; which at the fore part of the thign is split into layers, and so filled with the adi- pose membrane and fat, that it might be more justly eatimated as condensed cellular membrane. _ Far- ther down upon the thigh, again, on the inside of the vastus internus muscle, the more natural con- nexion of this vein is with the cellular membrane, being immediately attached to the skin, and having no protection but a very thin layer of cellular mem- brane. Nerves—Above the fascia of the thigh several delicate and extensively prolonged nerves are,seen. 1st, Upon the inner and upper part of the thigh, branching to the scrotum, testicle, and pubes, is the inguinal nerve, consisting of delicate twigs, which come by a circuitous course, and are derived by very delicate twigs from the fi;st and second lum- bar nerve. Within the belly it may be seen coming out betwixt the psoas and iliacus internus muscles : it winds round part of the spine of the os ilium and inside of the ligament, and pierces the ligament, and appears upon the pubes, -idly, The internal cutaneous n^rve comes out from Poupart's ligament above the crural vesseto, and is largely distributed upon the inside ot ihe Ui.gh, extending its branches round upon the internal con. dyle ofthe os femoris and patella. It is a branch of the anterior crui-al nerve. 68 3dly, The middle cutaneous nerve,* from the »-imc source wiih the last, comes out from the point marked by the sartorius muscle, crossing the head of the rectus muscle. It is distributed upon the fore and middle part of the thigh. •Uhly, The external cutaneous nerve, de- rived fiom tue third lumbar nerve, appears upon the outside of the thigh, a little below the lower spinous process, ofthe os illium ; and dividing into blanches, one runs round the back and outer part of the thigh, and the other runs down the fascia, where it covers the vastus extcrnus and outside of the rectus muscles. These \essels and nerves have been mentioned be- fore describing the fascia more particularly ; as we must be aware of them in the first cut of the knife, or they arc lost to us. OF THE SUPERFICIAL PARTS SEEN IN THE FIRST DISSECTION OF THE THIGH CONSIDERED AS SUBJECT TO DISEASE. It has been already explained, that, in treating of morbid anatomy, il is intended, not merely to include the diseased state of the viscera, but also the deiange- ment ci thenatuial anatomy of the extnmities and external parts, whether by violence or by disease, with the consequences of their derangement to health and lite. In the review ofthe parts before us now, we have more to observe than might -een. strictly to belong to so limited a direction ; for I shall here consider the diseases of the cutaneous veins, and r. > < ts, anu k.scia in general. tC^T- verymi"utc ™,vesform the deeper branches of tZ Z <™U' 1'""',,,m l/'ose > but4/ may 66 ovel looked in the general arrangement. * 69 Mr. Hunter pointed out the effect of inflammation upon veins ; shewed, by dissection, how inflamma- tion propagated alongst their cavities after amputation, bad compound fractures, and extensive abscesses; proved that matter was sometimes formed in them ; and that, in general, the consequence of the inflam- mation was to produce partial or interrupted adhetions of ttieir inner coats, preventing the matter from pass- ing into the tide of blood. At the same time, the possibility of matter thus formed mixing with the blood, and being driven to the heart, was explained. "I have seen (says he,) from a wound in the foot, "the vena saphena inflamed all up the leg and thigh, " nearly as high as the groin ; and 1 have been " ooliged to open a string o. abscesses almost through « its whole length." In other instances, after similar injuries, he found the inner surface of the veins furred over with coaguluble lymph.* These observa- tions of M'. Hunter are given in illustiation of the effects produced by accidents in blood-letting, and as establishing a new principle upon which to explain the st.ange series of symptoms which sometimes take place after bleeding. It has already been explained how the pressure of the uterus, or of an adventitious tumour in the pelvis or groin, may distend the veins of the leg, merely by increasing the resistance to the circulation without any disease or failure in the coats of the veins. In old people, again, such distention has an evident connexion with the general plethora of the venous system, and, in all probability, with a failure of that greater degree of resistance which the veins of the Tower extremities should possess, and which ii requited in them to keep the balance or th« *The inner coat of arteries has, in some in-Lances, slmwn a degree of inflammation,propagaU din a retrograde Course to the heart, as after tlie operation for aneurism. 70 system, and counteract the pressure of the column of blood. But the dilatation of the cutaneous veins is not confined to such cases as these ; for we find,that in younger men and women tb<> veins are often diseased ; that sometimes they arc varicose, not unfrequently dcgenciating into iuoiours, which, amassing the blood, affect the neighbouring parts, and form a dan- gerous disease. Sometimes, again, influenced by the contiguity of disease, tncy become tortuous and en- larged, round the base of some tumours, or the mar- gin of callous ulcers, forming in many instances the most characteristic feature of such tumours. Since we know that the natural capacity of the veins must depend upon the just mean of their resist- ance to the action of the heart and arteries, we cannot be at a loss to conceive how disease should so weaken the elasticity and power of resistance of their coats ai to allow them to dilate ; and (as their dilatation is in length as well as in diameter) to become conse- quently varicose and tortuous. But I suspect there is something more than this ; there is some specific in- fluence exerted on the vascular system of the part, which becomes apparent in the dilatation of the veins only, though receding equ illy in tiie arteries. We are often consulted by patients with varicose en- largements of the veins ofthe spermatic chord and of the thigh, where there appeared no tendency to disease in the venous system, or in the vessels of the lower part ofthe body ; where it proceeds from a sedentary life and slowness of the bowels, and is a mere me- chanical effect. The exertion in going to stool, and the pressure on the veins of the abdomen, gradually dilates the veins in the groin until the valves lose their office, and the column of blood presses down on the veins of the thigh and leg. When the veins ot the thigh and leg become varicose, there is a de- ficiency felt at intervals, pitts with hard incom- 71 Picssible edges, into which the fingers sink. These induratinos are formed by the indurated coats in the abrupt angles of the branches, in consequence of the deposition of coagulable lymph. The stimulus of distention which the veins suner seems to be the cause of this. A state of the veins, not, however, analogous to the last case, sometimes takes place without anv ap- parent cause. Tumours will gradually arise from veins, which, upon dissection, are found to contain only a confused mass of coagulated blood and mucus, blending all distinction of bones, membranes, and muscles. Such tumours will sometimes seem to take their origin from the bones, being small, inert, firm tumours, at first ; but by slow progression, assisted perhaps by the means used to bring them to suppura- tion, increasing, till, upon a rash attempt to extir- pate them, it will be found that they are intersected" with lamellae of bone, and that it is absolutely ne- cessary, from the confusion of diseased parts, to finish the operation by the amputation ofthe limb. We should perhaps class with these last, such tu- mours as, appearing at birth hardly raised above the common integuments, gradually dilate as childhood advances, and form spongy varicose tumours, which have an irregular tuburculated surface, and increasing in the brightness of their hues, purple and red, bleed in their advanced stage, and require operation. Such spongy tumours being allowed to increase too much, and take a firm seat upon the bones, will generally, though extirpated, regenerate. In the operation there is much bleeding ; the tumour is, when cut into, like a honey-comb ; and the arteries, as if emptying into these sacs, send out their blood with great fo. ce\ 1 have seen such tumours on the head, uuder.'hc chin, i and on the belly ; though they occur, I believe more commoniy on the spine, in the back or neck. Tik- ,e ueral opinion seems to or, that they arise from ik- 72 jury done to the child in the womb ; an opinion having no foundation but in the desire to explain every thing. But la me not be understood to say, that such a tumour is simply a congeries of varicose veins ; for it is evident, that in these cases, as in other more familiar examples, theve is a local disease acting upon the neighbouring veins, and drawing them into dis- ease, allied in its nature to proper cancer. Thus we shall find a tumour growing from some fleshy part, hard and knobular, with distorted veins, with a fretting soie upon its most piominent part, and bleeding, scinetimes an acknowledged cancer, yet differing in no very definite character from those of with"it wc have been speaking.* Diseases of the lymphatics.—The superfical lymphatics point out to us, in some instances, the nature of disease ; for, being extiemely susceptible of inflammation, they apprize us of infection, and lead us by a hard inflamed line to the neighbouring glands. This effect of local poison and inflammation on the alisoi bent vessels has been long observed ; being con- sidered as one of the great proofs ofthe theory of absorption. But l)r. Ferrier of Manchester, has endeavoui cd to prove a more general affection of the lymphatics ofthe leg and thigh in those swelling! incident to women after child;.irth. It has appeared to me that, in the welling of the thigh and leg after child' irth, there is niore of the nature of a critical swelling, than a meiely local affection; and that the * J let tfiese observations stand in this Edition (though J confess t/tey are somewhat out of place now, )asa proof of wluit /had seen of tlie: e diseases before t/tey obtained so generaf notke, and because I think still the ojnnion that the vessels are influenced to this peculiar character by a 2' e-ious disease, and are not t/temselves to be considered a* constituting the disease is the correct view of the pat/tology. I 73 obstruction and inflammation of the lymphatics of the limb may be more naturally explained upon the idea that this inflammation is sympathetic, and communicated from the extremities of the lympha- tics to their trunks, than that the disease is pri- marily in the lymphatics, and that their affection is the cause of the swelling of. the limb, else why should one leg begin to swell after the other subsides, and perhaps at the distance of three weeks frOm deli- very, as I have seen it. After violent and long continued exercise, where any part of a limb has been exposed to continued friction (as the inside of the leg or thigh after having been long on the saddle,) the lymphatics are liable to inflame; when a hard chord may be traced in t^ieir course alongst their limb to the neighbouring glands. This takes place without any lesion of the cuticle or the smallest ulceration; but it seems to be the mere effect of the continued friction which frets- and inflames the coats of the vessel. In a case of a riding groom, which occurred in the Infirmary here, the inflamed lymphatics were so swelled and tender in their course upon the inside ofthe t'.iigh, and in the glands of the groin, that the man could not move without excruciating pain. A rugged sore at the root of the nail of the toe, or a fretting sore on the shin, will sometimes produce a red line all the way up the leg, and a tumour in the groin. What the appearance of tne lymphatics in such inflammations may be, . e can say only from analogy; for they have been little attended to in morbid dis- section: but when we consider that 'heir activity must be influenced by a stimulus propagated from their absorbing mouths to the trunks of the system, we have rather to wonder that inflammation and dis- ease should be so seldom excited in them. Accident shews what from theory we are led to eonceive, viz. that the fluids in the lymphatics are accelerated by Vol. II. O 74 the action of the muscles ; for when in wounds a large lymphatic is laid open, and continues to dis- charge after the suiface is healed, we may observe a gush or acceleration of the discharge upon any eNe.tion of the limb. This accident, from the punc- turing of a lymphatic, must happen in even the most superficial incision, but is not generally ob- served till the sore is healing ; when, from the tume- fied extremity of the vessel, the fluid is seen discharg- ing as from the head of a pimple, and so abundantly as quickly to moisten the dressings. Upon the con- tinuance of this discharge, astringents are generally applied ; but. they sometimes fail : and n any cases in collections shew, that the discharge continues obsti- nate under these remedies. We have only to apply a compress in the course of the vessel below the orifice, this stops the discharge, and gives time for the healing of the ulcer. Op the fascia.—Every one is aware of the bad consequence ol tight bandaging in inflammation ; and that where the parts are swelling under an unelastic bandage, the inflammation is increased, great pain is excited, and the member is veiy apt to fall into a angrene. Nearly the same consequences, in a lesser egree, are frequently to be looked for from the bind- ing of the fascia in deep seated inflammation. For the muscular parts swelling, as after penetrating wounds, and being confined by the strong imbrace of the fascia, especially in the thigh and fore arm, it causes excruciating pain, with contractions of he limb. The elastic feeling which this tension of the parts gives to the touch in the first stage of inflam- mation, conveys the sensation of matter beneath, and the surgeon is apt to mistake the case. In ab- scess, the fascia being of a more inert texture, not so readily partaking of inflammation and suppuration as the subjacent softer parts, it confines the matter, and eauses it to spread more extensively amongst the loose cellular membrane. It was long believed, that in punctured wounds the bad symptoms were owing to the extreme sensi- bility in the tendinous parts when wounded ; butthey are now more universally attributed to wounds of the cutaneous nerves ; while another and distinct train of symptoms follow the swelling of the inflamed parts, embraced by the fascia. The fascia possesses less life, will die and slough when the parts above and beneath remain alive. DISSECTION OF THE FEMORAL ARTERY IN THE GROJN. In proceeding to dissect away from the groin the glands and fat, we shall find a few delicate superfi- cially distributed nerves coming from under the liga- ment of the thigh. We shall find also, that the cellular membrane which surrounds the great vessels forms a condensed bed, independent of an aponeu- rosis upon the subjacent muscles. The inner surface of this cellular membrane is strong from the inter- lacing of fibres. It covers and invests the great artery and vein. The same condensed cellular membrane is continued behind the vein and artery ; and by pull- ing up these vessels, after dissecting it back from be- fore them, their branches may be seen piercing it like the vessels of the heart going out from the pericardium. All the vessels in the body are more or less supported in this manner by sheaths of cellular membrane ; but it is at such places as this in the groin, that it be- comes a great object in surgical anatomy to obverve it. If the subject be in a favourable condition, very large lymphatic vessels may be observed coursing obliquely over the great artery, and passing through a net-work of ligament under the P.uipart ligament. 76 The dissector next traces the femoral artery and vein unucr the ligamcn. 01 the thigh, and observes the exiurc ol ligamentous choids thiough which these vessels and the lymphatics pa-s into the trunk. He looks again to the place where the femoral heinia comes out. I advise him, on this occasion, to cut thiough the integuments and abdominal muscles, near the Pau- pau ligament, and to push up ihe peritoneum, and dig down upon the exte. nal iliac arte y, that he may comprehend tlie natuie ofthe operation lor femoral aneurism. The disease which may be mistaken and con- founded at the place of this last dissection are, femo- ral oi crmal heinia with inguinal heinia; bubo with femoral heinia; common sciofulous abscesse.s of the inguinal glands with the lumbal abscess ; and lumbar abscess with disease of the hip-joint. It is not at eveiy point unuei the ligament of the thigh that tne femo. al heinia is found to protrude ; but only at that point wheic the ligament is less firmly tied oown by ligamentous lacing, and where the cellular membiane is looser, betwixt the temoral ar- tery and vein on one side, and the os pubis and in- seition of ligament of the thigh on the other. 'I his, it may be. obseived, is a small outlet, strictly em. braceu by the cruial vessels and epigastric artery on the outsiue, and' by the acute edge of a semicircular process ol the ligament of the thigh. It is immedi. ately in the bend of the groin, and towards the in- side ; so that it is very near the seat of the inguinal heinia. And when a femoral hernia, in the male con.es down suddenly, and is attended with much inflammation and tumefaction, especially if the pa- tient be corpulent, the tumour so spieads towards the ring, and is at the same time so tender, that it cannot be t.eely handled ; and so it is sometimes a uifficult matter to say precisely whether it be a femo- 77 ral or an inguinal hernia. In all the other instances of disease in this part, and in general in the femoral hernia, the ring and the spermatic chord remain free, so that no room is left for doubt. This rising ofthe femoral hernia is owing to the difficulty it has to make its way downward, and to the motion of the thigh, which presses it up. Although the tumour rises, yet the neck ofthe sac being deep and coming out from under the Paupart ligament, we have to take into consideration, while the parts are before us, the proper direction of the force necessary to reduce this kind of hernia. If a patient with a bubo or glandular swelling, immediately in the seat of kernia, should at the same time be attacked with symptoms resembling those of strangulation, as vomiting or want of pas- sage by stool (a case by no means unlikely,) it may become extremely difficult to determine upon the case, notwithstanding the lightness with which it is commonly mentioned. I have not seen a bubo mistaken for a hernia ; but what is more extraordi- nary, 1 have seen a hernia, and an inguinal hernia too, mistaken for a bubo. The tumour extended down from the ring upon the groin ; was small and circumscribed ; and so violently inflamed, that it seemed upon the point of suppuration. But the most deceiving circumstance was, that the patient was not reduced ; he was strong, and walked stoutly, inso- much as to make his escape from the surgeons. It was naturally conceived, that if it had been a hernia so far advanced, the patient must have been more re- duced, and every symptom of strangulation more ur- gent. But the man died afterwards, and 1 saw the dissection. Herniary tumours are soft and elastic at first, and become firm and more incompressible upon the ap- proach of strangulation. Glandular tumours are in general very hard in their commencement, circum- b * Gi ;s scribed, and moveable ; and before they have attained a size which can be mistaken, become sollei, more prominent, and discolouicd : when matter is formed, it is suhiCiently evident. 1 suspect 'hut in the case of hemia which 1 have mentioned, abjve, the inflam- mation, which occuriedso ea.ly, hid been an cry i- pehitOMs affection, occasioned ly the altemps to reduce the gut. ltappca>ed daik, and like inflam- mation verging to suppuiation. The hi'toiy of synip- to.ns, the distinctions evident to the touch, the occasional retiring ol the swelling, its diminution on the patient's lyitv down, the percusMon communi- caicd by coughing, &.c. will sufficiently distinguish the leino.al he:nia. The lumbar abscess appears in the groin, com- monly upon the outside of the iemoal ailery, under the .-.liongc pa t of the fascia, and nearer the os ilium. When the tumour forms slowly and regulaily, the fascia can be plainly felt ; and when it is far advanced, and the fascia gives way, the deficiency is plainly felt with the lente edges of the fascia. The lumbar abscess, however, does not always point thus regu- larly, but is mo e extensively diffused in the groin, even surrounding and including the iemoral vessels; or it runs so deeply amongst the muscles, th.it the lancet or trochar cannot reach it with safety. In the dead body, upon laying open the abscess in the thigh, mid freeing it of matter, a new dischaige is seen to conic "from within the belly. Upon following this sinus, it is found to run up behind the psoas muscle, upon the vertebra of the loins ; and these bones are often carious. In some instances the a; sccss conti- nues its course by the spine and side of the intestinum rectum, and points by the ride of the anus ; rarely it marks its way up into the thoiax. The patient will sometimes suivive until a string of abscesses are continued from the thoiax to the groin, and down upon the rectum, and roundthe hip. 79 The suppuration of the inguinal glands simply, where there is no communication with the internal parts, may be known by the history of the dis- ease. A scrophulous disease of these glands will commence by their induiation and clustering, and advance slowly to suppuration, and will not become fuller and tensei in I he erect postuie, as takes place in lumbar abscess. Collections in the hip-joint may protrude in such a manner upon the gioin, as to be mistaken for ab- scess oi the glands, or lumbar abscess. The affections of the joint aie so peculiar, however, that they can- not be lnisundetstood. Inflammation and disease of the joint is of necessity attended with lameness, dis- tinctly referable to the hip-joint, vvilh a lengthening or shortening of the leg. OF THE ANATOMY OF THE FEMORAL* HERNIA. The frequent occurrence of the femoral herniamusr. impress us still moie forcibly with the importance of this piece of anatomy. When the subject presents for dissection, the student should not be without some advice to enable him to improve by the oppor- tunity. In a recent hernia of the thigh, the tumour is in general small. Indeed sometimes during the life of the patient it is to be discoveied only by the symp- toms, not by the swelling in the groin ; and these herniae are the most dangerous and suddenly fatal. If the rupture have been suddenly fatal, then pro- portionally there is less derangement of the natural anatomy ; for it is little alterated but by the effect of inflammation. Theie will be found a membiane of condensed cellular substance coming down from the 80 belly, and covering the tumour ; under this the fasria will be found tense and stretched ; the tu- mour is formed in a bed of inflamed cellular mem- brane, and the fibres ot the fascia, mingling with the condensed cellular substance, required to be cut thiough before we arrive at the sac which is formed by the peritoneum. In the substance of the cellular bed which inverts the proper sac, the inguinal glands will be found involved. 1, the thigh have been in- jected, and (he tumour be cousiierable, we find the external pudic artery, and inguinal cutaneous branches, ramifying upon the sac. The femoral hernia, com- ing from under Paupart's ligament, does not stretch down upon the thigh, but turns up upon the belly, as I have said. The dissector has to observe this fact, and think of the proper means of relaxing the con- nexions ofthe femoral ligament with the fascia lata of tlie thigh, and of the propor direction of the force in the operation of the taxis. A celebrated author has said, that the femoral hernia is less apt to be strangulated than the hernia of the ring : but it is evident, that the latter is com- paratively less liable to occasional derangement. For not only is the strangulation of the spermatic choid p. evented by the mechanism of the parts when in their natural state, but even in hernia (especially where it has continued for some time) the exten- sion of the fibres of the externa) oblique, round the margin of the ring or neck of the sac, is such, that before the action of tiie abdominal muscle can pull them, so as to compress the sac, it is held in check by those fibres, which continue in a direct line. Or, in other words, the passage through the tendon of the abdominal muscle is not such as we should conceive from a rupture splitting the parallel fibres, and obtaining a passage liable to compression, by th: extension and consequent approximation of those fibres ; but on the contrary, the fibres are gra- dually elongated as the rupture protrudes and^in- 81 creases ; thus forming a circular opening, extending outwards and downwards conically, so as not to be liable to compression by the action of the muscles. In the femoral hernia the thigh, forcing the tumour upwards, encreases the sudden angle of the neck, when almost of necessity strangulation must follow. In operating for the femoral hernia, there are two points of the anatomy of much importance : First, the knowledge of the membranes which invest the tumour, and which must be carefully attended to in the external incision : And, secondly, the danger which attends the second stage of the operation in cutting the ligaments of the thigh, to free the gut from stricture. If therefore the dissector possess the opportunity, he ought to examine very particularly the manner in which the ligament binds down the neck of the sac, with a view to the manner of cut- ting it during operation. Unless the person has died of the hernia, the colours of the contained parts are of no importance. FURTHER DISSECTION OF THE ARTE- RIES AND NERVES OF THE THIGH. It is needless to speak of the importance of this dissection : the next division of our sjbject, which treats of the accidents and diseases, will sufh- cienlly evince it. As we have now to dissect back the general fascia, and as in separating the muscles we have much of their connexions to attend to, it may be well to point out such circumstances as may illustrate the general description ofthe fascia. In carrying an incision through the fascia above the tract of the fe moral artery, and dissecting back that portion which covers the outside of the thigh, 82 the direction of the fibres on the outer and on the inner surfaces of the fascia will be found very dif- ferent, shewing the two plates of which it is com- posed. Upon the outer surface its fibres run in circles round the thigh ; upon the inside they run in the l.-ngth, and are more silvery and closer. Upon the inside of the thigh, besides the coat of cellular membrane which involves the veins, there is a more appropriated sheath, though by no means like the fascia on the outside of the thigh in strength. Upon .'issecting this part of the fascia from the more slender muscles which come down from the os pubis, it will be found to send down interlacing fibres be- twixt the muscles, keeping them in some measure distinct from each other. Of this we have an ex- ample in the gracilis muscle ; for, when we slit up and dissect back the fascia which covers it, we still find a condensed membrane separating it from the triceps. The femoral artery, as it descends from the groin, gets betwixt the tendinous insertion of the triceps and the origin of the vastus internus muscles. Be- twixt these two muscles there is such an interlacing of tendinous filaments, that they form the bottom ui a deep groove in which the artery runs. Observe the tciidmou* sheath which covers this part ofthe artery. The great accompanying vein keeps on the inside ©f the artery, and turns more and more under the artery as it descends to pass through the triceps muscle. The vein is very strong in its coats ; and perhaps in an operation it might be mistaken for the artery, it the surgeon should be left to judge by the feeling betwixt his fingers, which in many cases is a good criterion. Tne student will no doubt turn here to the Appen- dix, and make ni.nself thoroughly master of the arrangement of the branches of the femoral artery ; but Mere is a knowledge to be gained by the eye, 83 Wu ,u T0^8 Wl11 not convey« After noticing the sheath of the great artery, and the passing off of the esser branches, he must retire a step from the body, look to the general figure of the limb, and notice caretuUy the course of the artery down the thigh • the probability of its being wounded by stabs in such and such places and direction, the situation of the trunk of the profunda, as distinguished from the great artery, and the probability of wounds of the descending branches ofthe profunda being mistaken for wounds, of the femoral artery itself, will now be thought of. NOTE OF THE NERVES WHICH ARE TO BE TRACED AMONG THE MUSCLES ON TIIE FORE PART OF THE THIGH. Of the trunk of the anterior crural nerve.—This nerve commences by a twig from the second lumbar nerve. The third is almost entirely expen-led upon it. It receives likewise a twig from the fourth. The body of the nerve lies betwixt the psoas and iliacus internus muscle. It comes from under the ligament of the thigh, by the outside of the femoral artery, and is in part covered by the ves- sel. As it lies betwixt the muscles, it splits into numerous branches, which tend downwaid upon the thigh. It here receives twigs from the lumbar nerves ; and it sends delicate branches to the internal iliac muscle, and to the psoas muscle, viz. recurrenles netvipsoae. Or the distribution of the anterior crv- Ral nerve—A very minute knowledge of muscu- lar branches will add little to our practical knowle ge. In dissection, when we find a branch of this nerve going to a muscle, we knew its origin and distribu- 84 tion, and consequently its name. Thus, three branch- es to tiie sartorious muscle : Nervus niusculi sartorii brevis vel superior, -----.-----------------medius, __________.____________. longus vel inferior. In the same manner the three neives ofthe vastus externus : Nervi lividi, or pectenules, going down upon the pectenalis ; nervus niusculi crural is ; nervus niusculi recti, Ate. From a branch ofthe anterior crural nerve, going to the vastus internus, is sent off'the nervus saphe- nus, orcuTANEUs loncus. This nerve runs down under the sartorius, and is joined by some minute twigs from the deeper muscular branches of the ob- turator nerve. Continuing its couise, it appears as a cutaneous nerve upon the inside ofthe knee. From this proceeding downwards, it is largely distributed over the tibia ; is connected with the saphena vein ; nid, finally, ends on the inner ankle and fore part of the foot and toes. Obturator nerve.—This nerve commences with a twig from the second lumbar nerve ; as it passes the third lumbar nerve, it is joined hy some delicate twigs; it has also additional twigs from the fourth lumbar nerve. It comes out from the pelvis by the thyroid hole, consequently in the middle of the muscular flesh of the thigh, and is chi fly distributed to the adductor muscles ; one branch descends to- wards the knee. In opposition to the last mentioned nerve, it is sometimes called the posterior crural nerve, but improperly. « 85 OF THE ACCIDENTS AND DISEASES OF THE ARTERIES IN THE THIGH, AND OF THE POPLITEAL ANEURISM. It has been already mentioned, in treating of the diseases of the arteries, how frequent their enlarge- ments are at the flexures of the groin and ham ; and the explanation which appeared to be tho most natu- ral of this circumstance was there fully detailed. (See Vol. 1. page 181.) But it is not merely the structure •r situation of those parts which occasions the many diseases of these arteries ; they are besides exposed to many accidents. "A wound of the great artery high in the thigh is suddenly fatal. If by a slighter puncture, or the ex- ternal wound healing quickly in consequence of com- pression, an aneurismal, tumour should be formed, those connexions amongst the muscles, which have been carefully pointed out, cannot withstand the con- tinued impulse ofthe blood ; but in a shorttime, the blood driving amongst the muscles insulate* them ; and upon operation an extensive irregular cavity is found. It must be a much more difficult operation to tie a wound of the lesser branches of arteries, than where the trunk is pierced ; for if the wound be deep, others are, in searching for the wounded artery, unavoidably cut, and even the great trunk endangered ; and on enlarging the wound, there is such confusion of the effused coagulated blood in the interstices ofthe mus- cles, that the artery is with difficulty found, and ex tensive incisions are necessary; which, if not very cautiously made, increase the evil. In the encysted aneurism the progress of the tumour is slow. A case of aneurism in the groin, Vol. II. H 86 Which I saw latelv, may serve us as a general example. A small tumo i. "arose immediately below the ligament ofthe ugh. It remained stationary a long* time ; but upon some slight exei lion it suddenly enlarged, stretch* ing down the thigh. Here its progress seemed again ar estcd for some time ; but it again increased, and showed, by the knobular figure of its surface in its last stage, these three successive changes which it had un- dergone. The smaller division of the tumour which first arose, gradually lost its pulsation ; whilst the beating was very great in the more extensive tumours further removed from the ligament. When the two hands were extended over the tumour (for its size was so great,) the beating of the collateral arteries was distinctly felt on each side round the base of the tumour. Though the veins of the thigh were much enlarged (the aneuriMii compressing them as they go up under Paupait's ligament,) the limb was not eedemaious, which generally happens in such cases. The dissection showed exactly what the preced- ing views of the anatomy would lead us to expect. Upon the most proininet part of the tumour, and where the pulsation had been more distinctly felt, the skin and fascia and sac ofthe aneurism were blended together. Upon the outside of the thigh, the firm and tendinous aponeurosis tied down the aneu- ri-.m;il sac. The aneurismal sac was distinct, and separated the clots of blood from the surroutiding parts; but still it was impossible to distinguish* whence it was derived. The external iliac artery was much enlarged and ossified ; and along the whole track ol the aorta several enlargements and ossifica- tions were found. He cannot be at a loss to account for the succes- sive stages of the growth ofthe tumour, nor for the want of pulton "„, that first formed. The tumoin- 111 the beginning was probably formed by the di'ated coats ol the artery, and they were sustained bv the 87 uniform resistance ofthe surrounding parts ; but up- on the failure of some ofthe connexions of the fascia, a sudden dilatation was allowed, and thetumour spread irregularly to the weaker points, and down the thigh, in the direction ol the original impulse ofthe blood. While the dilataiion is so small, that the blood keej s moving in the sac there is probably no eoagulum foim- ed ; but w hen it stretches into distinct sacs, the stream is diverted from the original channel, and the tumour firs t founed fills with fiim eoigula, and the pulsation is con- sequently suppressed.* Since this was written 1 have had many other examples ofthe disease before me. When the operation for aneurism is peiformed in the groin for a case like the present, it cannot suc- ceed ; and the practice of the most expeit surgeons shows us the confusion which is likely to follow. Upon the first incision for laying bare the sac, so many collateral arteries (which we have noticed to be much enlarged,) and the veins, too, which are like- wise enlarged in that direction, in consequence of the obstruction and pressure ofthe tumour, pour out so much blood, that the whole operation is to be done upon parts covered with blood, where tie only guide is the feeling. In regard to the ligature of the great artery, we must be undci perpetual alarm ; and for the space of two weeks we cannot be assured that the failuic ofthe ligature, or rather the ulceration of the coals ofthe artery by the ligature, will not be instantly fatal. Or, if the bleeding should for this time be stopped by the surgeon, the repeated failure of liga- trnes, and the endeavour to follow up the trunk of the artery below the ligament of the thigh, with the deluge of blood, and faint exertions of a patient dying *■' See an interesting paper upon diseased blood-vessels, by Dr. I'at/iie, in the 7 rainactions of a Su-ietyjor the iwj to ement of Mediculand Surgical Knowledge. in your hands, make a terrible scene. Wc are ther* fore much indebted to Mi. Abemelhy for shewing u» ^ the practicability of cutting above the Paupart hgt- . ment, pushing aside the peritoneum, and tying th« '1 trunk of the external iliac artery. In considering the propriety of these operations for aneurism in the groin, axilla, and neck, we ought neT vcr to lose sight of the fact that they are sometimes spontaneously cured, as happened in a case in the Vork Hospital lately. As the femoral artery descends, is approaches the bone; and especially as it turns round to go into the ham, it lies very near it, which exposes it to be punc- tured by the spiculae ofthe bone in fractures. As the artery here is much more firmly embraced by ihe muscles than in the upper part of the thigh, there is presented, in such an accident, upon dissection, a very curious appearance; for the large muscles, the vasti, are undermined, and they cover the acquired sac of the aneurism with a layer of fibres, causing it to re- semble a strong muscular bag. 1 have had a second case of this kind under my knife lately. OF THE OPERATION ON THE FORE PART OF THE THIGH FOR THE POPLITEAL ANEURISxM. Particular attention should be paid to the anatomy •fthe crural artery, as it pierces the triceps muscle; with a view especially to the high operation for the popliteal aneurism. We cannot study surgical ana- tomy by dissection alone ; but by a careful examina- tion and comparision with the points of the living body, which are to be our guides. Here, for instance the course ofthe sartorious muscle is of infinite im- portance. It is not easily brought into such action as 89 will show its ccurse on the limb ; but if a weight 1,4 placed upon the ground, and wcatlenpt to shove it rice wise with the ball ofthe great toe, or if we turn the heel over the knee of the other leg, it will be brought to swell and show its course. In the event ofthe examination of a patient this is to be done with the sound limb. The incision is to 1 e made upon llie outer margin ofthe li.usele, beginning a little below the middle of the thigh, Mm following the curve of the muscle. In pui suing this first incision nnt'er the sartoiius (its upper surface being kept cdhpected with the integuments,; belwixt the ori- gin of the vastus internus and the insertion of the adductor longus into the thigh bone, we find the ai'U'iv covered by irregular fibres ofthe fascia. There appears to be no foresight nor method of operating which can ensure success in this operation, except by guarding against too large an incirion ; by the accu- lacy with which it is made to correspond with the point of the artery to be tied ; and by taking care that, in uncovering the artery, the parts are not too much loosened, especially the sartoiius muscle; and bv cutting the artery betwixt the two ligatures, and allowing it to contract and bury itself amongst the cellular membrane. When the wound is extensive (and it is perhaps impossible to avoid it in a big and fat man,) a large suppuiating sore is the consequence ; and there will be a greater chance of the sinuses forming up along the side of the artery, which some- times takes place even in the most dexterous opera- tion. The consequence of this state ofthe aitcry is, that instead of being supported by the surrounding p?rt«, if lies surrounded with matter; the ligatures, Jibe SCtons, keep up the discharge ; and the vessel ulcerating, the patient dies by the loss of blood, if not l»y one gush, at least by successive smaller bleed- ings. Another circumstance with regard to the sar- 112 » 90 tonus muscle h, that when it is left loose in the wound, it swells and fills up the opening, so that the matter is confined. « OF THE ANATOMY OF THE HAM, AND OF THE ANEURISM AT THIS PLACE. As the anatomy of the ham, and the disease of the artery, have so strict a connexion with the subject of which we have now been treating, it will be better to finish the consideration of them here, than to leave it for separate explanation after the dissection ofHhe hip and back part ofthe thigh. Upon laying aside the true skin and superficial cellular membrane from the back part of the knee- joint, we have first to observe, as ofthe utmost ^im- portance in the diseases and operations, the strong fascia which covers the muscles and great vessels and nerves. We find a strong layer of fibres coming down obliejuely from the outside, derived from the' fascia lata ol the thigh. From the projecting head ofthe fibula there runs upwards a layer of silvery fibres crossing the first. From the tendon of the semi- membranosus muscle an aponeurosis comes down, which, gaining additional fibres as it descends, forms a veiy strong sheath, covering all the back part.of the leg. In other words, betwixt the two condyles of the thigh bone, and fiom the head of the fibula and be- twixt the ham-1 ing tendons, a strong fascia of inter- woven fibres is extended, and this i^ prolonged down upon the origin ofthe gastrocneniii muscles and back ofthe leg. Upon slitting up and dissecting back the fascia,- the great nerve appears. It comes down betwixt the, bi- ceps and scmi-membranosus muscles, on a level with the top oi' the trochanter. It splits into two great 9 91 tranches : the greater continues its course betwixt tiSe fc*ads of the gastrocnemii muscles ; whilst the lesser got, outwardly and obliquely downwaids superfici- ary (f'ut under the fascia ;) this lesser branch, split- ting into brunches, gives off' directly in a middle course betwixt the gastiocnemii muscles and fascia, » small ne.ve, which is accompanied by a consider- able vein. liefow the nerve, and the superficial vein and long slender artery which accompanies it, there is much cellular membrane and fat. Under this fat, and close to- luebone, lie the popliteal artery and vein. They arc inibeded in this tissue, and are intimately connect- ed together ; the vein more outwardly in its uninfect- ed; state clinging round the artery, and the lesser tranches of veins striding over it. It the parts be accurately retained in Qieir natural si- tuation during dissection, it will be seen, that in order tuilind the easiest access to the artery in operation, our iocisiwn should be made rather towards the outer bajii.sti ing than immediately in the middle. By this Bw.iiis we keep to the outside of the ischiatic nerve. Wu shall find the artery lying deep and covered with the -vein, and to tie it separately, it must be disentan- gled from under the* vein. But let us consider the *Ute of tiie parts in disease. bl'ATE OE THE PARTS IN FOFLITEAL ANEURTSM The liinb is generally cedematos ; sometimeus so much so as to make the pulse at the inner ankle to be tell with difficulty, independently of its faintness f em Lie aneurism. The limb is in general considerably iueiat. Round the whole knee-joint there is much swelling; so that the tumour in the ham is not very distinct, but has more the feelling of general tension. c'pon laying open the integuments, the tumour paii.ee more distinctly into view, distending the fascia, 9i With regard to the appearance and situation of the parts, particularly of the nerve, and great vein, and lesser saphena, it must depend upon the direction in which the coats of the artery fiisl give way. If the artery shall have given way towards the inside, then the tumour will increase in that direction clue.ly ; while the artery itself will, in some degree, be pushed in the opposite direction, and the nerve and the vein will be crowded towards the outer ham-strings. For the same reason, when the tumour, while yet small, has got to the outer side of the vessels, as it enlarges it pushes them towards the inside ; or the nerve may even be carried directly forward upon the lumour. The natural anatomy, therefore, can only leach us the appearance of the parts, enabling us quiclriy to recognize them. In viewing the tumour we should immediately determine, that the tumour could not originate from the coats ofthe artery, nor be an extension of them, since the tumour is so ab- rupt and circumscribed, and the artery immediately above partakes so little of the enlargement. It is only • by observing the progress of similar tumours in the breast and belly, that we are convinced ofthe great dilatation, I should rather say growth which mem- branes will allow. They acquire t>o gradually additi- onal strength and increase of thickness, that unless we were in a manner witness of the gradual change in the ( nature and properties of the arterial coats, we could not doubt that these tumours were formed by the cel- lular membrane gradually condensing, in conseqeuence of inflammation and the impulse of the blood. The popliteal aneurism takes place exactly in that part of the artery which must accommodate itself to the flexure ofthe joint. It would appear, however, that sometimes it occurs lower, in consequence of some violent action of the heads of the gastrocnemii 93 muscles, or where the arteries of the leg are given olf. The ostensible reason for the new method of opeiating, viz. on the fore part of the thigh, is, that the aie.y may be supposed to partake more ofthe disease, in proportion to its proximity to the tumour. But this io putting the merit ofthe operation upon an insecure fooling; for we know that the diseased state of the arterial system is always greater towards the trunks, and that it is gradually encroaching upon the extremities ; that the disease is common to all the system, though the peculiar situation of the artery at ihe joint subjects it to additional risks. These may even be increased by the circumstances of a patient's general habits or way of life ; but especially u.is disease is frequent in such as keep the joint ha- bitually bent, but are liable to occasional violent efforts of the limb, and chiefly of the gastrocnemii muscles. It. was formerly observed that horsemen were more especially exposed to it; and that class of men still continue to be the great suffeiers by this disease. Whatever may be our reasoning upon this fact, it is evidently to be attributed to some cause which affects the portion of the artery which is sub- ject to the flexion ofthe joint only ; and if the liga- ture can be as easily and effectually secured three inches above the joint as upon the fore part of the thigh, it will be as effectually removed from those • caus es of failure ofthe artery which are peculiar to the joint, and there will be less chance of the general affection of the trunks having reached so far. The better reasons for preferring the new operation seem to be, the difficulty of operating in the ham ; the debth at which the artery lies ; and consequently the dil'.iculty of drawing the ligature accurately: the ex- tensive suppuration which follows, and the greater risk of haemorrhage : and when the operation suc- ceeds, a permanent contraction of the limb is apt to remain, arising from the adhesion among the parts, 94 aud perhaps in some measure from the great nerve being so much exposed in the operation, that it must partake of the inflammation, and remain in the midst of the parts condensed and hardened. The power, or conveniency rather, which the higher operation gives of tying the artery again arrd again, following it up the thigh as the ligature successively gives way, is but a forlorn hope. I'nis is not the merit of the ope- ration. It is, that it allows us at once, with a small incision, to tie the artery; and when firmly secured with ligatures in the extremities ofthe incision, to cut in the middle portion, which allows the ends to shrink, and bury themselves amongst the cellular membrane, without interfering with the diseased and disordered parts. Even in the modern operation, when the dis- ordered parts suppurate, the limb, or even the life of the patient is often lost. OF THE CHANGES WHICH TAKE PLACE IN THE CAPACITY AND ACTION OF ARTERIES WHEN TIED, AND THE CIRCUMSTANCES WHICH INFLUENCE THESE CHANGES. As morbid anatomy, or the changes which disease • ccasions, and the effect of operations upon the neigh- bouring parts, deserve so much of our attention ; and as the laws by which the arteries in these case's are influenced, prove so useful and curious an inquiry, and so necessary to be remembered in determining upon every operation, I shall here endeavour to lay before the reader a few of the more important cir- cumatances which influence the arteries. What 1 now most anxiously wish to explain is, the connexions and sympathies oi" the trunks of 95 vessels supplying a limb, with the changes in the limb or part ofthe body which they supply. When part of a limb is amputated, the trunks ofthe arteries which supplied it rapidly diminish in size, and contract their diameter. If the lower part of a limb mortify, and the disease gradually encroach upon the limb, and spread upwards, the activity of the arteries is found proporti- onally decreasing, and their diameter shrinking ; in- somuch, that if it be thought fit to amputate the limb above the diseased part, the size of the arteries will be found diminished, and the bleeding consequently less. In these circumstances, the leg has been amputated without the necessity of tying the arteries on the stump ; and, upon dissection, it is found that the arte- ries in mortified parts are stopped with coagulated blood. In contrast with this, we have to contemplate the changes to which the arteries are subject in the na- tural growth of the body, or when an adventitious tumour grows upon a limb. As a limb enlarges in the course of nature, the arteries supplying it increase in size and strength. No one in these days will say, that this is merely a dilatation ofthe artery; on the contrary, it is an increase of size, strength of .coats, and energy of action. In the case of an adventitions tumour growing upon a member, we find the arteries of that member gaining strength and increase of ca- pacity, and enlarging their diameter, and becoming more tortuous proportionally as the tumour increases in size. In reasoning upon these facts, Dr. Hunter writes thus :* " Every body must see, that in this onse the trunk ofthe artery would dilate till it became proportionable in capacity to its branches ; for till then the trunk would be the narrowest part of the canal, the part where there would be the most re- sistance ; and therefore the yielding coats of the * See Medical Observations, Vol. II. 96 artery would give way till the just proportion was established between the trunk and all its branches." This explanation proceeds upon a false principle ; for although the trunk of the artery may be supposed proportionally narrower than the branches, yet as it is not narrower now than formerly, why should it give noreresistance than formerly ? Should not the greater diameter ofthe extremities rather lead to the inference, that since the resistance to the passing forward of the blood is diminished, the force of the blood laterally upon the trunk of the vessel is like- wise diminished ? But this is not the way in which the difficulty is to be solved: It is evident that an increase of blood is sent to the limb ; and the ques- tion is, How is this bestowed ? It is observable by eve -y one in any degree conversant with the trifling accidents and local diseases of the body, that where there is an injury, an inflammation, a swelling, whe- ther inflammatory or indolent, there is, according to the importance of the tumour, a strict connexion and sympathy betwixt the diseased part, and the vessels more or less remote by which it is supplied. Where there is a smart inflammation, there is a very perceptible increase of action quickly ceasing with its cause. Where there is an indolent tumour, there is a more imperceptible, but permanent change in the size and acti vity of the vessels. In this view, I hope, it will appear that the explanation, which rests merely upon the distention and dilatation ofthe arteries by the blood, is but lame and imperfect; and it will be evi- dentthat in the vessels of a limb, when influenced by a great tumour growing uponit, the same changetakes place as under the influence of the natural growth ofthe limb from childhood, Let us take the question in another light. Let us trance the observations of Dr. Hunter to the pheno- mena which gave rise to his most ingenious reflec- 97 tions, viz. the case of varicose aneurism, in the second volume ofthe Medical Observations. in that species of aneurism in which a communi- cation betwixt the artery and vein is formed in the bend of the arm, and by which a proportion of the blood which should circulate in the arm is drawn aside from the trunk of the artery into the basilic vein, and finds a less circuitous route back to the heart, it seems invariably to happen that the brachial artery is enlarged from the axilla down the arm to the communication. It becomes larger, and more tor- tuous, and its pulsation is more distinctly felt. This increase of diameter and strength, Dr. Hunter ascribes to the derivation of blood by the aperture, and reasons upon it in the words already quoted; conceiving this derivation of blood to act in a manner analogous to the adventitious tumour growing upon the limb. Did the motion ofthe blood in the arteries depend upon the laws of hydraulics simply—this breach iu the vessel, this less circuitous route back to the heart, giving an easier circulation than through the extreme vessels, the supply of blood to the forearm would be permanently diminished. But the laws ofthe econo- my have directly a different tendency: for as the natu- ral growth of a limb has an immediate effect (by what sympathies, or mode of action, we must remain ignorant,) in enlaging the parent trunk, soliciting a greater action and supply of blood; and as after the natural increase of the limb is arrest, a pre- ternatural tumour growing upon the member will still farther in crease the agency of the vessels, it is natural to infer, from such strong analogy, that it is the in- fluence of the forearm which occasions the increase of stength in the brachial artery; that the breach in the artery has withdrawn a quantity of blood from the arm, which is supplied by a more vigorous action in the trunk ofthe artery. Of THE COLLATERAL ARTERIES IN ANEURISM Vofa. II. I 98 But it is only from a more extensive view of the changes which take place in arteries, that we can form a decided opinion respecting the circumstances which affect them. We should naturally conceive, upon a superficial view, that when the trunk of an artery is ti- ed, the collateral arteries enlarge merely as a conse- quence of the greater impulse of blood into them. But it is evident, that it is not the force of the blood upon their coats which distends them ; since, when their ex- tremities are tied, as after amputation, they do not di- late : and from an examination ofthe collateral arteries in aneurism, we see, that there is not a dilatation or extension of the coats merely, but at the same time an increase of strength and thickness of the coats, as in the natural growth of the arteries. We have to show how the arteries become tortuous, also, as they increase in power; and we hope to show, that this tortuous figure of the artery is the great means of the additional exertion. In Dr. Hunter's remarks upon the case already quoted, there are several instances of the serpentine course which arteries take, as illustrating the increase and convolutions of the artery of the arm in aneu- risinal varix. This change he supposes to happen, " because the artery is lengthened, and therefore can- not preserve its course ;" and that it is lengthened by the distension of the blood. Mr. John Bell, in his Anatomy of the Heart and Arteries, has objected to the reasoning of Dr. Hunter, but has come nearly to the same conclusion. " It is merely (says he) a consequence of the long continued pressure of the blood: it is this only which can account for the slowly increasing tortuosity in the temples or hands of an old man, or the sudden tortuosity which the newly dilated artery assumes after the operation for aneurism." (p. 291.) When the functions of an artery are considered, this matter will appear in a different light. As the artery possesses a power of accelerating the blood, or of circulating it by an 99 action alternating with the heart, the force exerted by an artery upon the blood must be in proportion to the length of the artery. A portion of an artery, of the length of three inches, will have a greater power of accelerating the blood than one of two inches, though they are equal in diameter, there being in the one a greater force of action than in the other. The combina- tion of the muscular reaction ofthe first artery, exerted to accelerate the blood, will, when compared with that ofthe other, be as three to two. It follows, therefore, that the increased length of an artery, which has assumed the serpentine zig-zag course which arteries take in the several instances already mentioned, as in the temporal arteries when a great tumour grows upon the head, in the collateral arteries in aneurism, and in the brachial artery in the aneuiismal varix, is a means of additional force and power to the circulation. It seems to depend upon the same principle, and to be consonant with the same laws, which influence the natural increase of the artery in diameter and in muscular strength. That part of the member which remains beyond the ligature of the artery in theopera- tion for aneurism, comes to act upon the collateral branches in a manner strictly analogous to the way in which a great tumour growing upon a limb, or upon the head, acts upon the arteries of the part. The arteries become enlarged and tortuous, with an increase of pulsation and force ; or the limb acts upon its collateral arteries as its growth did upon the trunk, there being such an effect mutually existing betwixt the increase ofthe member in bulk, and the capacity and energy of the arteries which supply it. The ser- pentine form of the arteries in old age is the natural course ofthe economy acting in a uniform tenor from childhood. It is a mark of the gradual failure of the activity of the muscular fibre, but is attended with a proportional increase of the contractile substance sus- taining the powers of the system to a longer period. The increase of the collateral arteries after the 100 operation for aneurism, which from experience we know to be the harbinger of a successful termination, and of the closing of the trunk, is to be accounted for upon the same p.inciple. It shows a degteeof youthful pliancy in the branches; it proves that the influence of the limb has succeeded: that the current of blood has changed; and that the trunk of the artery is left dormant to take those changes,which are completely to preclude the flow of blood in that direction. (See Of the State ofthe Vessels in Ab- scess, &.c. Vol. 1 page 155.) The numerous melancholy instances of the death of patients liom the operation of aneurism, teach U3 the importance of attention to the state of the system jn determining upon the operation. If the patient be young, and the aneurism have been produced by an accident, as a violent strain and twisting of the knee-joint, the spiculae of a fractured bone punctur- ing the artery, &c. to tie the artery, even by an operation apparently bold or fool-hardy, will be at- tended with success; and so all experiments upon animals will be. But we must not be misled to con- ceive that, without regard to circumstances, an opera- tion, il done after a certain manner, and with such and such precaution, shall be universally successful. It is to the state of the patientthat we are chiefly to look. A man far advanced in life, with adi eased state ofthe arteries, will often fall a sacrifice however dexte ously the operation may be perfomed. The collateral ar- teries will not be in a state to take an increased action, and to enlarge, so as to give a new route to the blood, and make a complete derivation from the trunk, which is tied. But the blood making an effort to keep in the old channel, will retain the ar- tery unsealed by the coagula, which should form in it; and in a few days tlie ligature cutting its way out by the ulceration of the artery, there will be a profuse bleeding. 101 It may be useful to observe the consequences of amputation to such a patient, and the changes which we know to take place. After amputation, there is a diminished energy of action in the whole remaining arteries of the limb, and a real permanent contraction of the trunk ofthe artery and ofthe smaller blanches, the extremities of which were distributed to the am- putated parts. When we consider that, in general, in aneurism the arteries are in a diseased state, and that their partial failure is to be taken as a proof of this ; is not the diminution of the diameter of the artery, and of the velocity of the blood, the most likely way to secure the remaining part of the artery from the farther effects of disease ? Is it not most likely that, by allowing it a more quiet state, this may secure the patient from the formation of succes- sive aneuiismal tumours in the arteries connected with that limb ? Thus differently do facts prove the case to stand from what a superficial observation would lead us to infer. We should conceive, that the amputation of a limb would endanger the remain- ing stump by the greater impulse communicated to the obstructed extremities. On the contrary, if it were by any accident to happen, that there was a necessity of amputating below the knee in a case of aneurism in the ham, I have no hesitation in saying, that the tumour would diminish and the aneurism surffer a kind of spontaneous cure. In offering these remarks, I mean only to illustrate the laws ofthe animal economy in these diseases ; not to draw |a practical conclusion : for in determining upon the propriety of amputation, even after the ope- ration foraneuiism has failed, there a re circumstances to be attended to which do not fall under our consi- deration. 12 102 After the lessons which the reader has received on more difficult dissections, he can be at no loss to prosecute the dissection of the leg and foot. The knowledge of the bones, fascia, and ligaments, and of the actions of the muscles of the lower extre- mity are very necessary to the surgeon ; and after making himself acquainted with these as I have ad- vised, he will prosecute the dissection of the arte- ries. In doing this, let him take particular notice of the course of the arteries and nerves, and of their re- lations to each other and to the surrounding parts; he will think ofthe practicability of tying them when wounded in the living body. APPENDIX SYSTEM OF DISSECTIONS. DESCRIPTION OF THE MUSCLES THE ORDER OF DISSECTION DISSECTION 1* MUSCLES SITUATED ON THE FORE PART OF THE ABDOMEN. There are fivepair, consisting of three broad mus- cles on each side of the belly, and two in the central part. LATERAL MUSCLES. 1. OBLIQUUS EXTERNUS DESCENDENSi Origin. From the lower edges of the ei,rht inferior ribs, at a little distance from their; cartilac-' 10* Its origins are serrated, and mix with portions of the serratus major anticus ; the pcctoralis major, sometimes, sends down fibres which unite with it; the fibres run down obliquely forwards, and terminate in a thin and very broad tendon. Insertion. 1. Into the whole length of the linea alba. 2. By the pillars of the ring into the os pubis. 3. Into the Paupart ligament. 4. Into the spine of the ilium. The minute anatomy and the action of this muscle must be learned from the text, Vol. I. page 42. 2. OBMftUUS internus abdominis. Oe. 1. The spine of the ilium; the whole length between the posterior, and superior anterior spinous process. 2. The os sacrum and the three undermost lumbar vertebra, by a tendon common to it, and to the serratus posticus in- ferior muscle. 3. From Paupart's ligament. I.v. The cartilago ensiformis. 2. The cartilages of the seventh and of all the false ribs. 3. The linea alba. 4. The os pubis. i the text, Vol. I. page 46, 105 3. transversalis. Oe. 1. The inner 6r concave surface ofthe cartilages ofthe seven lower ribs, where some of its fibres are continued with'those of the diaphragm. 2. From the transverse processes of the last ver. tebra of the back and the four superior verte- brae of the loins. 3. The whole spine of the os ilium internally. In. The cartilago ensiformis and the linea alba. THE CENTRAL MUSCLES ARE THE RECTI AND PVRAMIDALES. 4. RECTUS ABDOMINIS. Or. The ligament of the symphisis pubis. In. 1. The cartilages of the three inferior true ribs. 2. Ensiform cartilage. It somestimes intermixes with the fibres of the pectoralis. It is divided by tendinous intersections, and at these places it adheres firmly to the anterior part of) the sheath, in which the muscle is included. 106 Use. To compress the fore part, but more particu- larly the lower part of the belly; to bend the trunk forwards, or to raise the pelvis. By its tendinous intersections, it has been supposed that it is enabled to contract at any of the in- termediate spaces ; and, by its connexion with the tenuons of the other muscles, it is pre- vented from changing place, and from rising prominent when in action. 5. FYRAMIDALI9. Or. The os pubis and ligament of the symphisis. In. Into the linea alba and inner edge of the rectus muscle, half-way between the os pubis and umbilicus. It is often wanting. Use. To assist the last muscle. 107 DISSECTION II. MUSCLES OF THE PERINEUM MUSCLES ABOUT THE MALE ORGANS OF GENERATION. This appears to be no more than a condensation of the cellular membrane lining the scrotum ; yet the skin here is capable of being corrugated and relaxed in a greater degree than in other places. The muscle proper to each testicle is the v 6. cremaster. Or. The internal oblique sends down a few fibres; these, near the junction of the os ilii and pu- 101 hi*," pierce the ring of the external oblique, and then descend upon the spermatic chord. In. The tunica vaginalis ofthe testicle, upon which it spreads, and is insensibly lost. Use. To suspend and draw up the testicle, and to compress it. MUSCLES IN THE PERINEUM. 7. erector penis. Or. The tuberosity of the os ischium ; running op- wards, it embraces the crus ofthe penis. In. The sheath ofthe crus penis. 8. EJACULATOR SEMINI3. Ox. The crura penis and body of the penis; the in- ferior fibres run mo. e transversely, and the si* peior descend in an oblique direction. 109 In. In the middle of the bulb and spongy body of the urethra, and here the fibres of both sides uniting, the bulb is completely enclosed. It is connected behind with the fibres of the sphincter ani and transversalis muscles ; these ac- cordingly co-operatein their action. 9. TRANSVERSUS PERINEI. Or. The tuberosity of the os ischium ; it runs transversely. In. The ejaculator seminis and fore part of the sphincter ani. ' There is often another muscle, named TRANSVERSUS PERINEI ALTER. Or. From the tuberosity ofthe ischium behind the former ; it runs more obliquely forwards. In. The side of the ejaculator seminis. (See farther Vol. I. page 227.) Vol. 11. K 110 MUSCLES OF THE ANUS. 10. STJIINCTER AM. This muscle consists of fibres which encircle the verge of the anus, and properly it has neither origin or insertion. We, however, remark its connexion forward with the ejaculator, and backwards with the os coccy^is. L'sk. Shuts the anus ; and, by resisting, gives effect to the levator ani and other muscles. The sphincter ani internus is little more than part ofthe circular fibres ofthe muscular coat ofthe reotum, wiiich is strengthened towards its extremity 11. levator ani. Or. 1. The os pubis within the pelvis, and the upper edge of the foramen thyroideum. 2. From the thin tendinous membrane that covers the ob- turator internus and coceygeu- muscles. 3. Ill From the body and spinous process of the os ischium ; its fibre* tun down converging. In. The sphincter ani, and verge ofthe anus, and anterior part ofthe two last bones of the coc- cyx. It surrounds the extremity of the rec- tum, neck of the bladder, prostate gland, and part ofthe vesiculae seminales. Use. To sustain the contents of foe pelvis, and to help in ejecting the semen and contents ofthe rectum. To restrain the protrusion of the anus in evacuation of the fceces. See what is said of the action of these muscles of the perineum in the text, p. 23^. MUSCLES ©F THE FEMALE ORGANS OF GENERATION. 12. ERECTOR CLITORIDI*. Or. The ramus of the os ischium ; it covers the crus of l he cniuris. I sv The crus and body ofthe clitoris. 112 13. SPHINCTER VAGIN.E.' 0U. (Connected with the sphincter ani) the back part of the vagina, near the perineum. In. The crus and body, or union ofthe crura cti- toridis. 14. TRANSVERSUS PERINEI. Or. (As in the male) from the tuberosity oftheos ischium. In. The upper part of the sphincter ani, and into a white tough substance in the perineum, be- tween the lower part of the pudendum and anus. Use. To sustain the perineum. 113 DISSECTION III. MUSCLES TO BE DISSECTED AFTER OPENING THE ABDOMEN. The diaphragm is a broad thin muscle, which, with its tendon, makes a complete transverse septum or partition betwixt the thorax and abdomen ; it is con- cave downward and convex upward ; the middle of it on each side reaches as high within the thorax as the level of the fourth rib. The diaphragm is generally described as consisting of two muscles and a/i intermediate tendon. 15. THE SUPERIOR OR GREATER MUSCLE OF THE DIAPHRAGM. Or. By distinct fleshy fibres. I. From the cartilago ensiformis. 2. From the cartilages ofthe K2 114 seventh, and of all the inferior ribs on both sides. From these origins, the fibres run radiated from the circumference to the centre ofthe septum, and terminate in a cordiform tendon, which forms the middle of the diaphragm, and in ' which the fibres from opposite sides are insert- ed and interlaced. To the right of this ten- dinous centre there is perforation for trans- mitting the vena cava. THE INFERIOR OR LESSER MUSCLE OF THE DIAPHRAGM. The second, third, and fourth lumbar vertebra, by several tendinous heads, of which the cen- tral and longest arc called the crura. (Between the crura, the aorta and thoracic duct pass ; and, on the outside of these, the great sym- pathetic neives and branches of the vena azy- gos perforate the shorter heads.) The fibres run upwards, and form in the middHe two fleshy columns, which decussate and leave an oval space between them /or the passage of the oesophagus and eighth pan of nerves, then ex- pand. 115 In. The back part ofthe central tendon of the dia- phragm. Use. The diaphragm is the principal muscle of res. piration ; when it is in action, the fibres bring the septum towards a plane, by which the ca- vity of the thorax is enlarged. When relaxed, it is pressed by the abdominal muscles, which, acting through the viscera, thrust it up, and compress the lungs. See further ofthe anatomy and action ofthe dia- phragm Vol. I. page 195. 17. ftUADRATUS LUMBORUM. Or. The posterior part ofthe spine of the os ilium. In. 1. The transverse processes of all the vertebrae of the loins. 2. The last rib near the spine. 3. The side of the last vertebra of the back. Use. To move the trunk, and pull down the last rib. 116 *8. PSOAS PARVWJ, Or. The sides of the two upper vertebra; ofthe loins; sends off a small long tendon, which ends thin and flat, and is In. Into the iliac fascia and Paupart tendon. Use. To strengthen the insertion of the abdominal muscles, and prevent their yielding in the straining ofthe muscles ofthe trunk. 19. PSOAS MAGNUS." Or. 1. The body, and transverse process of the last vertebra of the back. 2. From all those of the loins. In. The trochanter minor of the thigh bone, and into that bone a little below the trochanter. Use. To bend the thigh forwards, or, when the in- ferior extremity is fixed, to assist in bringing the body forward. U7 20. ILIACUS INTERNUS. OR. 1. The transverse process of the last vertebra of the loins. 2. All the inner lip of the spine of the ilium. 3. The edge of that bone between its anterior superior spinous process and the acetabulum. 4. From most of the hollow part of the ilium. It joins with the psoas magnus, where it begins to become tendin- ous, and is In. Into the lesser trochanter. Use. To assist the psoas magnus. 118 DISSECTION IV. MUSCLES SITUATED ON TIIE FORE PART OF THE CHEST. 21. PECTORALIS MAJOR. Or. 1. The cartilages of the fifth, sixth, and seventh ribs, where it intermixes with the external oblique muscle of the abdomen. 2. Almost the whole length of the sternum. 3. The anterior half ofthe clavicle. In. Outside of the groove for lodging the tendon of the long head of the biceps. The tendon is twisted before it is inserted. Use. To move the arm forwards, or to draw itdown, or to draw it towards the side. 22. SUBCLAVIUS. Or. The cartilage that joins the first rib to the sternum. 119 In. Extensively into the lower part of the clavicle. Use. To pull the clavicle downwards. 23. PECTORALIS MINOR. Or. The upper edge ofthe second, third, and fourth ; or the third, fourth,and fifth ribs, near their cartilages. J n. The coracoid process of the scapula. Use. To bring the scapula forwards and downwards, or to raise the ribs when the shoulder is fixed. 21. SERRATUS MAGNUS. Or. The nine superior ribs, by digitations, which resembling the teeth of a saw, the anatomist calls them serrated origins. In. The whole base of the scapula internally, be- tween the insertion of the" rhomboid and the origin of the subscapularis muscles ; it is in a manner folded about the two angles of the scapula. Use. To roll the scapula and raise the arm. 120 MUSCLES OF THE CHEST CONTINUED. INTERCOSTALES. 25. intercostales externi. Or. The inferior edge of the rib, the whole length from the spine to near the joining of the rib9 with their cartilages. (From this to the stern- um, there is only a thin membrane covering the internal intercostal muscle.) In. The upper obtuse edge of the rib below, as far back as the spine, into which the posterior portion is fixed. 26. intercostales intErni. Or. Like the external muscle ; the fibres run down and obliquely backwards. In. Into the margin ofthe rib below. From the 121 angle of the rib to the spine, the internal in- tercostal muscle is deficient. Use. By means of these muscles, the ribs are raised upwards during inspiration. Their direction being oblique, they have a greater power of bringing the ribs near each other, than could be performed if they were straight. 27. TRIANGULARIS, OR STERNO-COSTALIS. It lies on the incide of the sternum. Or. 1. Allthelength of the cartilago ensiformis la- terally. 2. From the edge ofthe lower half of the middle bone of the sternum, from whence the fibers ascend obliquely. In. (By three triangular terminations,) into the low- er edge of the cartilages of the third, fourth, and fifth ribs, near their joining with the ribs. Use. To depress these cartilages and the extremi- ties ofthe ribs, and, consequently, to assist in contracting the cavity ofthe thorax. "Vol. JI. L 122 DISSECTION Y. OF THE MUSCLES LYING ON THE CRANIUM. 28. OCCIPITO-FRONTALIS. Or. The superior transverse ridge of the occipital bone, and part of the temporal bone; a tendin- ous web covers the cranium, which terminates forward in a fleshy belly (the frontal portion ;) this muscular portion covers the frontal bone. In. 1. Into the orbicularis palpebrarum. 2. Into the skin ofthe eye-brows. It sends down a fleshy slip upon the nose. Use. It draws up the skin ofthe forehead and raises the eye-brows. 123 29. CORRUGATOR SUPERCILH. Or. The internal angular process of the os frontis. k In. The skin under the eye-brows near the middle of the arch. Use. We have no power over tne individual muscle. The corrugators knit the eye-brows, and are antagonists ofthe last muscle. MUSCLES OF THE EXTERNAL EAR. 30. ATTOLLENS AUREM. A thin and almost tendinous sheet. Or. The tendon of the occipito-frontalis, where it covers the aponeurosis of the temporal muscle. i In. The upper part of the ear, opposite to the antihelix. 31. ANTERIOR AURU. A membranous muscle also, Or. Back part of the zygomatic process qf the#n^ pdral bone. In. The back ofthe helix, near the concha. 32. RETRAHENTES AURIS. Two delicate membranous muscles. Or. The mastoid process, above the insertion of the sterno-cleido-mastoideus. ' In. That part of the back of the ear which is opposite to the septum that divides the scapha and concha. These muscles in a state of nature are designed to give"tension to the ear, to make it more capable of receiving sounds, and especially to bring us ac- quainted with the irection of sounds ; but their rise is almost entirely lost. 125 THE MUSCLES OF THE EAR, LYING ON THE EX- TERNAL EAR, OR IN THE CAVITY or THE TYM- FANUM. 33. HELICIS MAJOR. Or. The upper and acute part ofthe helix anteriorly. In. Into its cartilage a little above the tragus. 34. HELICIS MINOR. Or. The inferior and anterior part ofthe helix. In. The crus ofthe helix, near the fissure in the cartilage opposite to the concha. 35. TRAGICUS. Ob. The middle and outer parts ofthe concha, at the root of the tragus. In. The point ofthe tragus. L2 lSfi 36\ ANTITRAGICUS. Or- The internal part ofthe cartilage that supports the antitiagus. In. The tip ofthe antitragus, as far as the inferioc part ofthe antihelix, where there is a fissure in the cartilage. 37. TRANSVERSUS AURIS. Or. The prominent part ofthe concha on thedorenn of the ear. In. Opposite to the outer side ofthe antihelix. These muscles are for the most part scarcely dis- cernible : they are no doubt for emitting or giving rigidity to the ear, the better to enable it to collect the sound. 127 DISSECTION VI. MUSCLES OF THE FACE AND JAWS. ' THE MUSCLES OF THE EYE-LIDS 38. ORBICULARIS PALPEBRARUM. Or. 1. By many fibres, from the edge of the or- bitary process of the superior maxillary bone. 2. From a tendon near the inner angle of the eye ; these run a little downwards, then out- wards, over the upper part of the cheek, co- vering the under eye-lid, and surround the external angle, being loosely connected only to the skin and fat, they run over the superciliary ridge of the os frontis, towards the inner can- thus, where they intermix with those of the occipitc-frontalis and corrugator supercilii ; 128 then covering the upper eye-lid, descend to the inner angle opposite to the inferior origin of this muscle, firmly adhering to the internal angular process of the os frontis, and to the short round tendon which serves to fix the palpebne and muscular fibres arising from it Jn. The nasal process ofthe superior maxillary bone covering a part of the lachrymal sac. Use. This muscle should be divided into the external and internal muscles. Seethe Text. The ciliaris is a part of this muscle which covers the cartilages of the eye-lids, called cilia or tarsi. 39. LEVATOR PALPEBRJE SUPERIORIS. Or. The upper part jof the foramen opticum of sphenoid bone. In. By a thin tendon into the cartilage that supports the upper eye-lid. Use. To open the eye, by drawing th« eye-lid up- wards. 12? OF THE MUSCLES OF THE EYE-BALL. The muscles of the globe of the eye are six, viz. Wmr straight and two oblique. The four straight muscles very much resemble each other; having their. Or. From the bottom of the orbit around the fora- men opticum of the sphenoid bone, and of course surrounding the optic nerve as it enters • the orbit. They may be taken out, adhering to the nerve. They have neat small fleshy bellies. In. The sclerotic coat on the fore part ofthe globe of 130 the eye. Their tendons form the tunica ablu ginea. The recti muscles of the eye, being four in num- ber, and inserted at four opposite points into the eye- ball are competent to perform (as they act individu- ally or in combination) all the motions of the eye- hall. They are distinguished by these names: 40. LEVATOR OCULI, OR RECTUS SUPERIOR. 41. DEPRESSOR OCULI, OR RECTUS INFERIOE. 42. ADDUCTOR OCULI, OR RECTUS INTERNUS. 43. ABDUCTOR OCULI, OR RECTUS EXTERNU*. There are two obliqui. 44. DBLiqUUS SUPERIOR, SEIi TROC [I LE ARIS. Or. The edge ofthe foramen opticum at the bottom of the orbit, between the levator and adductor oculi; from thence it takes its .course along 131 the os planum ; its tendon passes through the cartilaginous loop, attached to the inside of the internal angular process of the os frontis. It then runs backwards and outwards, over the eye-ball. In.' The tunica sclerotica, about half way betwee- the insertion of the attollens oculi and the optic nerve. Use. In co-operation with the next muscle to sus. pend the eye-ball and prevent its being re- tracted by the recti muscles. 45. OBLICIUUS INFERIOR. Cr. The outer edge ofthe orbitary process of th'e su> perior maxillary bone, near its union with the os unguis ; it runs backward and outward. tt. The sclerotica, betwixt the insertion of the ab- ductor and optic nerve. • Use. To co-operate with the former muscle-. & 1*2 $ 1. MUSCLES OF THE NOSE AND LIPS. 46. COMPRESSOR NARIS. It consists of a few fibres which run along the car- tilage of the nose in an oblique direction, towards the dorsum of the nose. On. The anterior extremity of the os nasi and nasal process of the superior maxillary bone, wher* it meets with some of the fibres descending from the occipito-frontalis muscle. In. The root of the ala nasi. Use. I conceive this muscle to expand the nostril As its name implies, it is supposed to com. press the nose. 47. LEVATOR LABII SUPERIOR1S ALJEO.UE NASI. Or. The nasal process of the superior maxillary bone where it joins the os frontis. 133 In. 1. The upper lip. 2. The ala nasi. UsE. To raise the upper lip and dilate the nostril. 48. LEVATOR ANGULI ORIS OR LEVATOR LABI- ORUM COMMUNIS. Or. The hollow on the face of thesuperior maxillary bone, between the root ofthe socket ofcthefirst dens molaris and the foramen infra orbitale. Tn. The angle of the mouth. Use. To draw the corner of the mouth upwards. 49. LEVATOR LABII SUPERIORIS PROPRIUS. Or. The superior jaw bone, above the foramen infra orbitale. Is. The upper lip and orbicularis muscle. Vol. II. M 134 50. DEPRESSOR LABII SUPERIORIS ALJEO.UE NASI, Or. The superior maxillary bone, immediately above the joining of the gums with the two denies incisivi and the dens caninus. In. The upper lip and root of the ala nasi. Use. To draw the upper lip and ala nasi downwards, an? to compress the nostril. 51. ZYGOMATICUS MAJOR. Or. The zygomatic process of the qs malae. In. The angle of the mouth. Use. To draw the corner of the mouth obliquely upwards. 52. ZYGOMATICUS MINOR. (Often wanting.) Or. The upper prominent part ofthe os malx above the origin of the former muscle. 135 In. The upper lip, near the corner ofthe mouth, along with the levator anguli oris. Use. To draw the corner of the mouth upwards. 53. DEPRESSOR ANGULI ORIS. Or. The base ofthe maxillary bone near the chin. In. The angle ofthe mouth, uniting with the zygo- maticus major and levator anguli oris. Use. To pull down the corner of the, mouth. 54. DEPRESSOR LABII INFERIORIS. Dr. Broad and fleshy, intermixed with fat, from the inferior part of the lower jaw next the chin, runs obliquely upwards, and is In. Into the edge ofthe under lip, extends along one half of the lip, and is lost in its red part. Use. To pull the under lip and the skin ofthe side of the chin downwards, and a little outwards. 130 55. LEVATOR LABII INFERIORI?. Or. The lower jaw, at the roots ofthe aveoli oftwo dentcs incisivi, and of the caninus. In. Thc.skin of the chin. Use.To pull up the chin, and.c onsequently, to rai>c and protrude the lip 56. buccinat or. (Membranous muscle in the cheek.) Or. 1. The elveolar part of the lower jaw. 2. The fore part of the root of the coronoid process. 3. The upper jaw. 4. The peterygoid process ofthe sphenoid bone. In. The angle of the mouth, within the orbicularis oris. Use. To draw the angle of the mouth, and to turn the morsel in the mouth, and to place it undci the action of the grinding teeth. 137 57. ORBICULARIS ORIS. This is a muscle, consisting of circular fibres, which surround the mouth, and constitutes a great part of the thickness of the lips. Use. To shut the mouth, and to oppose the mus- cles which converge to be inserted into the lips. 58. NASALIS LABII SUPERIORIS. Or. The fibres of the orbicularis muscle. In. The lower part ofthe septum nasi. Use. To drawdown the point ofthe nose, by ope- rating on the elastic septum. $ MUSCLES .OF THE LOWER JAW. The jaw of the carnivorus animal has no lateral mo- tion, but only muscles, which close the jaw. The M2 138 gramenivorus animals have powerful muscles for the lateral or grinding motions. Man, also, possesses" a double set. First, for closing the jaw, these : 59. TEMPORALIS. Or. 1. The semicircular ridge ofthe lower and late- ral part of the parietal bone. 2. The pars squamosa of the temporal bone. 3. The exter- nal angular process of the os frontis. 4. The temporal process ofthe sphenoid bone. 5. It is covered by an aponeurosis, from which also it takes an origin. The muscle passing under the jugum has for its In. The coronoid process of the lower jaw which it grasps with a strong tendon. Use. To raise the lower jaw. 60- MASSETER. Or. 1. The superior maxillary bone, where it joins the os mala. 2. The inferior part of the f.\ goma, in Us whole length. 139 In. The outside of the angle of the upright part of the lower jaw. U»e. To pull up the lower jaw, 'or performing the grinding or lateral motions there. 61. pterygoideus internus. Or. 1, The inner and upper part ofthe internal plate of the pterygoid process of the sphenoid bone. 2. The palatine bone. It fills the space between the two plates of the pterygoid process. In. The inside of the angle of the lower jaw. Use. To move the jaw latterally. 62. PTERYGOIDEUS externus. Or. 1. The outside of the external plate of the ptery- goid process of the sphenoid bone. 2. Part of the upper maxillary bone adjoining. 3. The 140 root of the temporal process of the sphenoid bone. In. The neck of the condyloid process of the lower jaw. Use. To assist the former muscle. MUSELES OF THE INTERNAL EAR. There are three muscles of the internal ear. 63. LAXATOR TYMPANI. Or. The extremity of the spinous process of the sphenoid bone, behind tne entry of the artery of the dura mater ; runs backwards, along with the chorda tympani, in a fissure of the temporal bone, until it reaches the tym- panum. In . The long process of the malleus. ltt Use. To relax the membrane of the tympanum. 64. TENSOR TYMPANI. On. The cartilaginous extremity ofthe Eustachian tube just where it begins to be covered y the pars petrosi, and spinous process ofthe sphenoid bone, from thence running backwards near the osseous part of the Eustachian tube, it forms a very distinct fleshy belly, the tendon turns into the tympanum along with the nerve called chorda tympani. In. The posterior part ofthe handle ofthe malleus, a little lower than the root of its long process.*' Use. To pull tense the membrane of the tympanum. 65. stapedius. * Ob. A hollow in the pars petrosa, near the cells of the mastoid process ; its tendon passes straight through a small round hole in the >one, eniers the fore part of the tympanam, and has its, 142 In. Into the head of the stapes Use. Perhaps to steady the stapes, and to prevent} the communication of too strong a sensation to the seat of the sense. 143 DISSECTION VII. MUSCLES OF THE NECK AND THROAT. 66. LATISSIMUS COLLI, OR PLATYSMA MYOIDES. Or. By many delicate fleshy fibres, from the cellular substance which covers the upper parts of the deltoid and pectoral muscles. They pass over the clavicle adhering to it. They ascend ob- liquely, to form a thin muscle, which covers all the side of the neck. In. The outside of the base of the lower jaw. 2. The depressor anguli oris, terminating in the risorius sanctorini. Use. It is said to assist the depressor anguli oris in drawing the skin ofthe cheek downwards ; 144 and, when the mouth is shut, it draws all that part ofthe skin to which it is connected, 1 clow the lower jaw, upwards. The true use of the muscle, 1 think I have explained in the Uxi, at piopeily belonging to the respiration and circulation. 67. STEKNO-CLEIDO MASTOID! CS. Or. 1. The top of the sternum near its junction with ihc clavicle. 2. Tlie upper and anterior part of the cliiv icle. In. The mastoid process of the temporal bone and mastoidean angle. Use. To turn the head to one side, and bend it for wardt. MUSCLES LYING BETWEEN TIIE LOWER JAW AND OS HYOIDES. 68. DIGASTRICUS, OR BIVENTER MAXILL/F, INFE- RIORIS. Or. The groove in the mastoid process of the tem- poral uonc. It runs downward and forward; 145 the tendon passes through the stylo-hyoideus muscle, and is fixed by a ligament to the os hyoides; then the tendon is reflected forward and upward, and becoming again muscular, it has an In. Into a rough part ofthe lower jaw behind the chin. Use. To open the mouth, by pulling the lower jaw downwards ; when the jaws are shut to raise the larynx, and, consequently, the pharynx, in deglutition. 69. MYLO-HYOIDEUS. Or. All the inside ofthe base ofthe lower jaw. In. 1. The lower edge ofthe basis ofthe os hyoides, 2. Into its fellow ofthe opposite side, Use. To pull the os hyoides upwards. Vol. II. N ,v: 146 70. GENIO-HY.OIDEt>t). Ok. A rough protuberance within the arch ofthe lower jaw, which forms the chin. In. The basis ofthe os hyoides. . Use. To raise the chin. 71. HYO-GLOSSUS. Or.. The base, cornu, and appendix of fcthe os hy- oides. In. The side ofthe tongue. Use. To pull the tongue intothe mouth, or draw it downwards. 72. GENIO-HYO-GLOSSUS. Ob. The rough protuberance on the inside of the lower jaw. J& 147 In. The tip, middle, and root of tthe tongue, and base oftheos hyoides, near its comu. U>B. According to the direction of its fibres, to move the tongue, to draw its root and the os hyoides forwards, and to thrust the tongue out of the mouth. 73. LINSUALIS. (Seated in the substance of the tongae.) Or. The root ofthe tongue laterally; runs forward between the hyo-glossus and genio-gloasus. In. The tip of the tongue, along with part of tha stylo-glossus. Use. To contract the substance of the tongue, and move the tip of it, MUSCLES ON THE FORE PART OF THE THROAT. 74. STERNO-HYOIDBUS. Or. 1. The cartilaginous extremity ofthe first rjb, 148 The upper and inner part of the sternum. 3. The clavicle, where it joins with the stern- um. In. The base ofthe os hyoides- Use. To pull the os hyoides downwards 75. OMO-HVOIDEUS, OR BIVENTER INFERIOR. Or. The superior costa of the scapula, near the se. milunar notch, and the ligament that runs across it; ascending obliquely, it becomes ten- dinous below the stei no-cleido mastoid mus- cle, it grows fleshy again towards its In. Into the base ofthe os hyoides. Use. To assist in pulling down the os hyoides, 76. STERNO-THYROIDEUS. Or, The edge ofthe trianglar portion ofthe stern- um internally, and from the cartilage of the fiist rib. U9 In. The inferior edge'of the thyroid cartilage. Use. To draw the larynx downwards.—See »»'• cles ofthe larynx. 77. THYRO-HYOIDEUS. Or. The lower part of the thyroid cartilage. I n. Part of the basis and the cornu of the os hyoides, UsB. To bring the bone and cartilage together. 78. CRICO-THYROIDEUS. Or. The side and fore part ofthe cricoid cartilage. In. The lower part of the thyroid cartilage and its inferior cornu. Use. To draw thecal tilages or to affect their *'bra. tion and influence the voice. N2 150 MUSCLES OF THE THROAT AND P1IA RYNX CONTINUED. 79. STYLO-GLOSSLS. Or. The styloid process, and from a ligament that connects that process to the angle of the lower jaw. In. The root ofthe tongue, being insensibly lost on % the side and tip of the tongue. Use. To draw the tongue laterly or backwards. 80. STYLO-HYOIDEUS. Or. The middle and inferior part of the styloid pro- cess. In. The os hyoides at the junction of the base and cornu. Use. To pull the os hyojdcs upwards. 151 Its fleshy belly is sometimes perforated by the ten- don of the diagascric muscle. There may be found another accompanying it, the stylo-hyoideus alter. 81. STYLO-PHARYNGEUS. Or. The root ofthe styloid process. In. The side ofthe pharynx and^back part ofthe thy- roid cartilage. Use. Supposed to dilate and raise the pharynx and thyroid cartilage upwards ; perhaps rather, in combination with others, to grasp the morsel, and to assist in swallowing. 82. TENSOR SEU CIRCUMFLEXUS PALATI. Or. 1. The spiniousr process ofthe sphenoid bone, behind the foramen ovale. 2. The Eustachian tube. It then runs down -along the pterygoi- deus internus muscle, passes over the hook of the internal plate of the pterygoid process, and spreads into a broad membrane. I.vl fet. The velum pendulum palati. Some of its poste- rior fibres join with the constrictor pharyngis superior, and palato-pharyngeus. Use. To stretch and draw down the velum palati. 83. LEVATOR-PALA'JI. Or. The extremity of the pars petrosa of the tem- poral bone, near the Eustachian tube, and from the membranous part of the same tube. In. The velum pendulum palati, and the root of the uvula. It unites with its fellow. Use. To draw the velum upwards, so as to shut the posterior nares. 84. CONSTRICTOR ISTHMI FAUCIUM. <0b. The side of the tongue, near its root; from thence running upwards, within the anterior arch ofthe uvula. In. The middle of the velum pendulum palati, at the root ofthe uvula. It is connected with it* fellow. \ 153 Use. Draws the velum towards the root of the tongue, which it raises at the same time. 85. PALATO-PHARYNGEUS. Or. The middle ofthe velum pendulum palati, and from the tendinous expansion ofthe circuni- flexus palati. The fibres are collected within the posterior arch behind the amygdala, sand run backwards to the top and lateral part of the pharynx, where the fibres aie scattered, and mix with those of the stylo-pharyngeus. In. The edge of the upper, and back part of the thyroid cartilage, some of its fibres being lost between the membrane of the pharynx and the two inferior constrictors. Use. Draws the uvula and velum downwards, and backwards ; and, at the same time, pulls the thyroid cartilage and pharynx upwards. In swallowing, it thrusts the food from the fauces into the pharynx. N. B. A few ofthe fibres of this muscle have been called 86. SALPINGO-PHARYNGEUS, And supposed to operate on the mouthof the Eu- stac hian tube. 154 87. AZYGOS UVUL.K. Or. The extremity of the suture which joins the palate bones. In. The tip of the uvula. Use. Raises the uvula and shortens it. MUSCLES ON THE BACK PART OF THK PHARYNX. 88. CONSTRICTOR PHARYNGIS INFERIOR. Or. 1. The side ofthe thyroid cartilage. 2. The cricoid cartilage. This muscle is the largest ofthe three constrictors. In. It joins with its fellow on the back ofthe pha- rynx, the superior fibres run upwards, and cover part of the middle constrictor, the info- 155 rlor fibres run more transversely, and sur- round the oesophagus. Use. To compress the pharynx. 89. CONSTRICTOR PHARYNGIS MEDIUS. Or. The appendix and cornu ofthe os hyoides, and the ligament which connects the os hyoides, and the thyroid cartilage, the fibres of the superior part run upwards, and cover a con- siderable part ofthe superior constrictor. In. The middle of the cuneiform process of the o$ occipitis, and it is joined to its fellow at the back of the pharynx. Use. To compress the pharynx, and draw it up- wards. 90. CONSTRICTOR PHARYNGIS SUPERIOR. On. 1. The cuneiform process oftheos occipitis, near the condyloid foramina. 2. The ptery- 15C goid process ofthe sphenoid bone. > Alve- olar process ofthe upper jaw. 4. The ]<>wu jaw. In. A white line, in the middle of the ph.irvnx, where it joins with its fellow, and is covered by the constrictor medius. Use. To compress the upper part of the pharynx, and draw it upwards. MUSCLES 'OF THE GLOTTIS. They consist generally of four pair ~of small mu*« cles and asingleone. 91. CRICO-ARYTJEN0IDEUS POSTICUS. Or. Fleshy, from the back pa t or the cricoid <*» tilage. 157 Iv The posterior part ofthe base of the arytaenoid cartilage. Use. To open the rima glottidis a little, and, by pulling back the arytaenoid cartilage, to. stretch the ligament so as to make it tense. 92. CRYCO-ARYTJENOIDEUS lateralis. Or. From the crycoid cartilage, laterally, where it is covered by part of the thyroid. In. The side of the base of the arytenoid cartilage near the former. Use. To open the rima glottidis, by pulling the liga^ ments from each other. 93. thyreo- arytjenoideus. Ok. The under and back part of the thyroid cartilage. Vol. II. O 158 Ik. The arytaenoid cartilage, higher up and farther forwards than the cryco-arytaenoideus lateralis. Use. To pull the arytaenoid cartilage forwards and to shorten and to relax the ligament of thf larynx or glottis vera. 94. ARYTJENOIDEUS OBLIRUUS. Or. The base of one arytaenoid cartilage, crosses it* fellow. In. Near the tip of the other arytanoid cartilage. Use. When both act, they pull the arytaenoid car* tilages towards each other. Very often ona of these is wanting. 159 95. ARYTJENOIDEUS TRANSVERSUS. Passes from the side of one arytaenoid cartilage, (its origin extending from near its articulation, with the cricoid, to near its tip,) towards the other arytae- noid cartilage. Use. To shut the rima glottidis, by bringing these two cartilages with their ligaments, nearer one another. There are a few pale disgregated muscular fibres on each side, which from their general direction aro named, 96. THYREO-EPIGLOTTIDEWS. Or. The thyroid cartilage. Jn. The side of tiie epiglottis. Usb. To expand the epiglottis. 160 97. arytjeno-epiglottideus. Consisting of a few fibres. Qr. From the side ofthe arytaenoid cartilage. In. The epiglottis. Use. To pull down the epiglottis on the glottis. 161 DISSECTION VIII. MUSCLES SITUATED ON THE FORE PART AND SIDE OF THE VERTEBRAE OF THE NECK. 98. LONGUS COLLI. Or. I. The bodies of the three superior vertebrae ofthe back and lowest ofthe neck. 2. From the transverse processes of the third, fourth, fifth, and sixth vertebrae of the neck. In. The fore part ofthe bodies of all the vertebrae ofthe neck. Use. To bend the neck forwards or to one side, 99. RECTUS CAPITIS INTENUS MAJOR. Or. The points ofthe transverse processes ofthe third, fourth, fifth, and sixth vetebrae of the neck. O t 162 In. The cuneiform process ofthe os occipitis a little before the condyloid process. Use. To bend the head forwards. 100. RBCTUS*CAPITIS INTERNUS MINOR. Or. The fore part ofthe body ofthe first vertebra ol the neck. I n. The root ofthe condyloid process of the os occi- pitis. Use. To nod the head forwards. 101. rectus capitis lateralis. Or. The point of the transverse process ofthe first vertebra ofthe neck. In. The os occipitis, opposite to the foramen style- mastoideum ofthe temporal bone. Use. To move the head a little to one side. 163 102. SCALENUS ANTICUS. Or. Thefourth, fifth, and sixth transverse processes of the vertebrae of the neck. In. The upper side of the first rib, near its cartilage. 103. scalenus mboius. f Or. The transverse processes of the vertebrae of the neck. r I (The nerves to the superior extremity pass between 1 this muscle and the former.) \ t Ik. The upper and outer part ofthe first rib,, extend- ing from its root to within the distance of an L 4 inch from its cartilage. 104. scalenus posTicus. u ' Or. The fifth and sixth transverse processes ofthe vertebrae ofthe neck. s In. The upper edge of the second rib near the spine. 161 The three muscles bend the neck to one side. When, the neck is fixed, they elevate the ribs, and dilate the chest. There are a number of 6mall muscles situated b«- tween the spinous and transverse processes of con- tiguous vertebrae, which are accordingly named, I!' 1 ER9PINALES COLLI AND INT ERT R AN8V ER- &ALES COLLI. 165 DISSECTION IX. MUSCLES OF THE BACK The first layer consists of two muscles, which cover almost the whole posterior part of the trunk 105. TRAPEZIUS OR CUCULARIS. Or. 1. The protuberance in the middle of the os occipitis, by a thin membranous tendon, which covers part of the splenius and complexus muscles. &. From the transverse edge of the occiput which extends from the protuber- ance towards the mastoid process of thefcempo- ral bone. 3. From the ligamentum nuchae, where it seems to arise from its fellow. 4. From the spinous processes of the two in- ferior vertebrae of the neck, and from the spinous processes of all the vertebrae of th« back, (adhering to its fellow.) 166 In. The outer half of the clavicle. 2. The aero. moin. 3. The spine ofthe scapula. Use. Moves the scapula according to she thret different directions of its fibres ; for the upper descending fibres may draw ii obliquely up, wards, the middle being transverse fibres di- rectly backwards, and the inferior ascending fibres obliquely downwards and backwards. 106. LATISSIMUS DORSI. Or. 1. The posterior part ofthe .spine ofthe o» illium. 2. All the spinous processes ofthe os 6acrum and vertebrae ofthe loins. 3. The seven inferior spines of the verteb. ae o the back. 4. The extremities of the three or four inferior ribs. The inferior nbiec ascend oUiquely, and the superior run transversely over the inferior angle ofthe scapuh, towards the axilla, where they are all collected and twist. In. By a strong thin tendon into the inner edge of the groove for lodging the tendon of the long head of the biceps : (sometimes into the ttu- don ofthe triceps.) 167 V*r.. To pull the'arm backwards, and downwards ; and to roll the os humeri. 107. SERRATUS POSTICUS INFERIOR. (Lying under the latissimus dorsi.) Or. In common with that of the latissimus dorsi, from the spinous processes ofthe two inferior vertebrae of the back, and from the three su- perior of the loins. In. The lower edges ofthe four inferior ribs, by dis- tinct fleshy slips- Use. To depress the ribs. 108. RHOMBOIDEUS. Thi- muscle is divided into two portions, rhonr boideus major and minor. 168 liliomboideus major. Or. The spinous processes of the five superior rcr- tebrac of the back. In: The basis of the scapula below its spine. Use. To draw the scapula obliquely upwards, and backwards. Rhomboideus minor. Or. The.spinous processes of the three inferior ver- tebrae ofthe neck, and from the ligamentum nuc/ue. In. The base of the scapulae opposite to its spine. Use. To assist the former. 109. SPLENIUS. This is the muscle of the back of the neck. Or. 1. The four superior spinous processes of the vertebrae of the back. 2. The five inferior of the neck, (adheres to the ligamentum nuchae 169 * At the third vertebra ofthe neck, the splenii recede from each other, so that part of the complexus muscle is seen. In. 1. The five superior transverse processes of the vertebrae of the neck. 2. The posterior part of the mastoid process. 3. The os occipitis. Use. To bring the head, and upper vertebra ofthe neck backwards and laterally, and, when both act, to pull the head directly backwards. That portion which arises from the five inferior spinous processes of the neck; and is insertedinto the mastoid process and os occipitis, is called splenius capitis : and that portion which arises from the third and fourth of the back, and is inserted into the five superior transverse processes of the neck, is called splenius colli. 110. serratus superior tosticus. . - (Under the Rhomboidei.j Vols II. P 170 0a. The spinous process of the three last ver- tebra of the neck, and the two uppermost of the back. In. The second, third, fourth,, and fifth ribs. Use. To elevate the ribs, and dilate the thorax. 111. SPINALIS DORSI. (Lying betwixt the spine, and longissimus dorsi.) Or. |The spinous processes of the two upper- most vertebras of the loins, and the three inferior of the back. In. The spinous processes of the vertebra of the back, from the second to the ninth. Use. To erect and fix the verteb-ae, and to as- sist in raising the spine 171 112. LONGISSIMUS DORSI. Or. Tendinous ^superficially, and fleshy within : 1. From the side, and spines ofthe os sacrum. 2. From the posterior spine of the os illii. 3. From all the spinous processes of the loins. 4. The transverse processes of the vertebrae of the loins. In. 1. All the transverse processes of the vertebrae of the back, chiefly by small double tendons. 2. By a tendinous and fleshy slip, into the lower edge of all the ribs, except the two in- ferior, at a little distance from their tubercles. Use. To raise, and keep the trunk ofthe body erect. . From the upper part of this muscle, there runs up a round fleshy portion which joins with the cervicalis descendens. 113. SACRO LUMBALIS. Or. In common with the longissimus dorsi. 172 I'N. All the ribs, where they begin to be curved forwards, by long thin tendons. From the upper part ofthe six or eight lower ribs arise bundles of thin fleshy fibres, which soon termi- nate in the inner side of this^muscle, and are named Ml'SCULI AD SACRO-LUMBALEM ACCESSORIl. T: r To pull the ribs down, and assist to erect the trunk of the body. 114. CERVICALIS DESCENDENS. Or. From the upper part of the last muscle. In. Thefourth, fith, and sixth transverse processes of the vertebrae of the neck, by distinct tendons. Use. To turn the neck obliquely backwards, and to one side. We turn again to the dissection of the back of the neck. 173 I 15. COMPLEXUS. Or. 1. The transverse processes ofthe seven superior vertebrae of the back/and four inferior of the neck. 2. By a fleshy slip from the spinous process ofthe first vertebrae ofthe back : from these different origins it runs upwards, and is every where intermixed with tendinous fibres. In. The protuberance of the os occipitis, and trans- verse lines Use. To draw the head backwards, and to one side, when acting as an individual muscle ; and, when both act, to draw the head directly backwards. N. B. The long portion of this muscle that is situ- ated next the spinous processes, lies more loose, and has a roundish tendon in the middle of it; for which reason Albinus calls it biventer cerricis, but if this portion should be called biventer, the term complex- us is quite misapplied to the other portion. P 3 174 116. trachelo-mastoidbUs. Or. The transverse processes of the three upper. most vertebrae of the back, and from the five lowermost of the neck by thin tendons. In. The posterior part of the mastoid process. Use. To assist the complexus ; but it pulls the head more to the side. 117. LEVATOR SCAPUL*. Ok. The transverse processes of the five superior vcrtebrx of the neck, the slips unite to form a muscle that runs downwards. In. Near the superior angle of the scapula. Use. To pull the scapula upwards. We turn once more to the back, 118. semi-spinalis dorsi. Or. I'he transverse processes ofthe seventh, eighth, ninth, and tenth vertebrae of the back. 175 Ik. Into the spinous processes ofthe vertebrae of tiie back aibove the eighth, and into the two lowei- most ofthe neck. Use. To poise the spine and support the trunk. 119. MULTIFIDU4 SPINA. Ok- 1. The spines of the os sacrum. 2. The part of the os ilium, where it joins with the sacrum. 3. All the oblique and transverse processes of the vertebrae ofthe loins. 4. all the transverse processes of the vertebrae of the back, and those of the neck, except the three first, by dis- tinct tendons, which soon grow fleshy, run in an oblique direction, and are In. Into all the spinous processes ofthe vertebrae of the loins, back, and neck, except the first. !.'*e. To support the spine and trunk. 176 On the back part of the neck these. 120. SEMISPINALS COLLI. Or. The transverse processes of the six uppermost vertebrae ofthe back, (it ascends obliquely un- der the complexus.) In. The spinous processes of all the vertebrae of the neck, except the fast and last. Use. To move the neck backwards. 121. TRANSVERSALIS COLLI. Or. The transverse processes of the five upper- most vertebrae of the back. In. The transverse processes of the cervical verte- brae, from the second to the sixth. 177 12£. RECTUS CAPITIS POSTICUS MAJOR Or. Tlie spinous process of the second vertebra of the neck. <* In. The os occipitis, (near the rectus capitis latera- lis, and the insertion of the obliquus capitis superior.) Use. To rull the head backwards, and to assist a little in its rotation. 123. RECTUS CAPITIS POSTICUS MINOR,. Or. The knob in the back part ofthe first vertebra of the neck. In. The os occ'Pitis, near its foramen magnum. Use. To assist 'the rectus major in moving the head backwards. 178 124. OBLIQUUS CAPITIS SUPBRIO*. Or. The transverse process of the first vertebra of the neck. In. The os occipitis, near the mastoid process of the temporal bone, and under the insertion of the complexus muscle. Use. To draw the head backwards. 125. OBLiqUUS CAPITIS INFERIOR. Or. The spinous process of the second vertebra of the neck. In. The transverse process of the first vertebra of, the neck. Use. To turn the head, by moving the atlas on the dentatus. 126. INTERSPINALES DORSI ET LUMBORUM J AND THE INTERTRANSVERSALES DORSI, Are rather small tendons than muscles, serving to connect the pinal, and transverse processes. 179 127- INTERTRANSVPRSA'LES LUMBORUM. Are four distinct small bundels of flesh, which fill up the spaces between the transverse processes of thfe vertebrae ofthe loins, and serve to draw them towards each other. IV DISSECTION X. MUSCLES OF THE SHOULDER LVING ON THE SCAPULA. 128. SUBSCAPULARS. Or. 1. All the base and hollow of the scapula in- ternally. 2. Its superior and inferior costje. In. The upper part of the internal protu' erance on the head ofthe humerus. 181 129. SUPRA SPINATUS. Oft. 1 • From all that part ofthe base of the scapula which is above its spine. 2. From the spine and superior costa. 3. From the fascia of the scapula. In. The part ofthe larger protuberance on the head of the os lumerithat is next the groove. \ 130. INFRASPINATUS. Or. 1. All that part of the base ofthe scapula which is between its spine and inferior angle. 2. The spine, as far as the cervix ofthe scapula. 3. The fascia of the scapula. In. The upper and middle part of the large protuber- ance on the he.id ortiie os hu.neii. .Vol II. ^ KS-' 131. TERES MIKOK. Or. All the lower edge, or, the inferior costa of the scapula. In. The back part of the large protuberance on the head of the os humeri. 132. TERES MAJOR. Or. 1. The .inferior angle. 2. Inferior costa of the scapula. In. Theiidge at the inner side of the groove, for lodging the tendon of the long head of the bi- ceps, (along with the tendon of the latis&imws dorsi.) 183 133- DELTOIDES. Or. 1. From the outer part ofthe clavicle. 2. From the acromion. 3. From the lower margin of almost the whole spine of the scapula oppo- site to the insertion of the cucullaris muscle. In. A rough protuberance in the outer side of the os humeri, near its middle. I'se. .Its centre raises the humerus, the lateral portions sustain the shoulder joint. 134. CORACO-BRACHIALI9. Or. The coracoid process of the scapula, adhrimg in its descent to the short bead of the biceps Ix. The middle of the internal part of the os humeri near the origin of the third headof the ti \v\> 181 Use. To raise the aim upwards and forward-. N. B There passes a nerve through this muscle, the external cutaneous 185 DISSECTION XI. MUSCLES LYING ON THE OS HUMERI, AND MOVING THE FORE ARM. These are two before and two behind. FLEXORS. 135.'BICEPS FLEXOR KUBITI. Or. By two heads: 1. tendinous, from the uppei edge of the glenoid cavity of the scapula. This tendon passes over the head ofthe os humeri within the capsule; and, in ts descent 0,2 186 without thejoint, runs in a groove on the head of the os humeri, and covereii by a membran- ous ligament that piocieds Irom the cap ule and aujar ent tendons. 2. The second, and shorter head, arises from the coracoid process oi -lie scapula, in common with tlie coraco-brachiahs muscle. In. 1. By a strong round tendon, into the tubercle near the up, n end or the radius; 2. and by a lateral sbp of fascia into the sheath of the fore arm. 136. BRACIIIALIS INTERNUS. Or. The middle of the os humeri, at each side of the insertion of the deltoid muscle, covering all the inferior, and fore part of this bone adheres to the ligament of thejoint. In. The coronoid process of the ulna. . 187 EXTENSORS. 137. TRICEPS EXTENSOR CUBITI. Or. By three heads ; the first and longest, from the inferior costa ofthe scapula, near its cervix. The second head from the back part ofthe os hu.i'cri, under the great tuber. The third arises by an acute beginning from the back and inner part ofthe humerus, and continues its origia all down the bone. These three heads unue lower than the insertion of the teres major, and cover the whole posterior part of the humerus, from which they receive additional origins in their descent. In. The olecranon, and partly into the condyles of the os humeri, adhering to the ligament. 138. ANCONEUS. Or. From the back part of the external condyle of the os humeri ; it soon grows fleshy. 1SS In. A ridge on the outer and posterior edge of tha ul 1a, being continued some way below the olecranon. It i< covered with a strong fascia. 189 DISSECTION XII. MUSCLES LYING ON THE FORE ARM FLEXORS OF THE WRIST. 139. FLEXOR CARPI RADIALIS. Or. The internal condyle ofthe os humeri, and , from the fore and upper part ofthe ul.ia. In. The fore and upper part of the metacarpal bone that sustains the fore finger, (runs over the . ..J* os trapezium.) ? * I9if 140. rLEXOR CARPI ULNARIS. Or. The internal con lyle ofthe os humeri and bid* ofthe olecranon, and from the fascia. In. The os pisiforme,and ligament ofthe wrist. 141. FLEXOR CARPI MEDICS, OR PALMARIS LONtil J. Or. The internal condyle ofthe os humeri, it forms a neat small belly, and oy a long slender ten- don has, In Into the annular ligament of the wrist, and pal mar aponeurosis. EXTENSORS OF THE WRIST 142. EXTENSOR CAEII RADIALIS I.ONGIOK. Or% From the lower part of the external ridge of the os humeri, above i~ external condyle, and AC below the supinator radii longm. 191 In. The back and upper part of the metacarpal bone that sustains the fore-finger. 143. EXTENSOR CARPI RADIALIS BREVIOR. Or. 1. The external condyle of the os humeri. 2. the ligament that connects the radius to it. Ix. The upper and back part of the metacarpal bone that sustains the middle finger. 144. EXTENSOR CARn ULNARIS. Or. 1. The external condyle of the os humeri. 2. The ulna. In. The posterior and upper pint ofthe metacarpal bone that sustains the little finger. MUSCLES Or THE SUPINATION AND PRONATION. These consist of six muscles, viz. two supinators, and two pronators, properly so calle.l ; and flex«r inuicles, as accessary to the acti jn . 192 Proper supinators, That is which turn tin palm ofthe hand upward, and have no other office. 145. SUPINATOR RADII LONGT S. Or. The external ridge of the os humeri, nearly as far up as the middle of that bone. 1 n . The lower end of the radius. 146. SUPINATOR RADII BREVIS. Or. 1. From theexternal condyle oftheos humeri. 2. From the externaland upper part of the ul- na. 3. The ligament which joins these two bones. In. The neck and tubercle ofthe radius and ridge running downwards from the tubercle. Pronators, that is, which throw the palm ofthe hand prone to the ground. 147. PRONATOR RADII TERES. Or. 1. The internal condyle of the humerus. 193 t. Tendinous from the coronpid process of the ulna. # In. The outside of the radius about th& middle of the bone. 148. PRONATOR RADII qVADRATUS. Or. The lower part of the ulna ; the belly of the muscle runs transversely. In. The lower and outer part ofthe radius. MUSCLES MOVINGTHE FINGERS, LY- ING ON THE FORE ARM. FLEXORS. 1.49. fLEXOR SUBLIMIS PERFORATUS. Or. 1. The internal condyle of the os humeri, 2. Tiie coronoid process ofthe ulna. 3. Tire tubercle ofthe radius. 4. The middle of the forepart ofthe radius, where the flexor polli'.i- Vol. 11. R 194 •ii u- arises. Tin tendons p.iv under the h> giinent of tiie wrist. In. The second bone of each finger being near tils extremity divided for the passage of the ten- doiis of tire pcrforans, or profundus. l.'jQ. FLEXOR PROFUNDUS PERKO !'. AN*. On. 1. The side, and upper part of the ulna. fl. l';\)in a large share of the interosseous liga- ment, and re.nolely through the fascire from the inner condyle; its tendons passunsur the ..mi liar ligament ofthe wrist, ,m,l then pasi throu; lithe slits ugthe tendons ofthe flcxoi iu ,!imis. In. Last Lcui'sof :t.r fo-e finders. 1",! . li r VOR I.ONC'iS 1 01 MCIS ..! A XL'S. Or. I- The si ie of ;*.•' coronoid prices* of ihc ulti.r. 2. The i tdliH, imniedhtely below it- »'t.it.i r■'•It; i: it continrtcd down lor some *pao- uii the • •»• wardly. I 155. EXTENSOR SECUNDI LNTERNODII. Or. 1. The back part of the ulna near the former muscle. 2. The interosseous ligament In. The posterior part of the first bone of the thumb, part of it may be traced as far as the second bone» Use. To extend and draw the second bone ofthe thumb outwards. 156. EXTENSOR TERTII INTERNODII. Or. 1. The middle and back part of the ulna, 2. From the interosseous ligament, its tendon runs througn a small groove at the inner and back part ofthe lower end of the radius. R2 198 In The last bone of the thumb. Use. To extend the last joint ofthe thumb. i 157. EXTENSOR MlNIMI DlGlTI. Or. 1. Outer condyle of the humerus. 2. The fas- cia : adhere to the common flexor. J n. The last bone of the little finger. 199 dissection xiii. THE MUSCLES OF THE HAND 158. PALMARlS BREVIS. Or. The ligamentum carpi annulare, and tendin- ous membrane that is expanded on the palm ofthe hand. Jji. Into the skin and fat that covers the abductor minimi digiti, and into the os pisiforme. Use. To assist in contracting the palm of the hand : to sustain the grasp ol the hand. 4 Muscles which form the the ball ofthe thumb. 159. ADDUCTOR POLLICIS. Or. The os trapezium and ligament ofthe carpus 200 In. Root ofthe second bone of the thumb. Use. To separate the thumb from the fingers. 160. OPPONENS POLLICIS. (Under the last.) Or, Os trapezium and ligament ofthe carpus. In. First bone of the thumb, or metacarpal ofthe thumb, as it is Sometimes called. Usr.. To bring the thumb towards the palm and fingers. 1GI. FLEXOR BREVIS POLLICIS. (Divided by the tendon ofthe long flexor.) .Or. 1. Os trapezoides : 2. os magnum : 3. os uncl- forme. - In. Ossa sesamoidea and second bone ofthe thumb. Use. To bend the thumb MUSCLES OF THE LITTLE FINGER 162. ABUCTOR MINIMI DIGITI. Or. Os pisiforme and ligament of the carpus. ' In. The side of the first bone ofthe little finger. 163. FLEXOR PARVUS MINIMI DIGI TI. Or. The ulnar side of the os uneiforme and liga- ment ofthe wrist. In. Frst bone of the little finger. Use. It is an assisting flexor ofthe little finger. 164. ABDUCTOR MINIMI DIGITI. Or. Edge ofthe os uneiforme and bgament ofthe wrist. 202 In. The side of the metacarpal bone of the little finger. Use. To draw the little finger towards the others. 165. LUMBRICALE.% These are four muscles lying in the palm of the hand, thin and fleshy, so as to resemble earth worms. Each of these muscles may be thus described. Or. One ofthe tendons of the flexor profundus ■■'•' digitorum. J? In. The sheath on the back ofthe fingers alq,ng>?i with the mterossei. Use. To move the finger on the metacarpal bon». 166. ABDUCTOR 1NDICIS. Or. Os trapezium and metacarpal bone of thr thumb. 10;j In, The first bone ofthe fore finger. Use. To bring the fore finger towards the thumb. 167. interossei interni. These are muscles lying deep betwixt the meta- carpal bones, each having its origin thus. • Ok. By one head from a metacarpal bone. In. Into the sheath of the extensor muscles on the back of the first phalanx. 16S. INTEROSSEI EXTERN!. These are bicipetes and lie on the back of the hand, but betwixt the metacarpal bones. Or. The roots ofthe metacarpal bones. 204 Ix. The tendinous expansion ofthe extensor com* munis. The priorindicis 19 a muscle of the same charac- ter with the former, only that lying on the radial edge of the metacarpal ofthe fore finger ; it cannot be so properly called an interosseous, as those which arc seated betwixt the metacarpal bones. Use or the interossii. While there seems much reason in the supposition that the lumbricales being small muscles are better calculated for the quick movements ofthe fingers (whence they have been called findicinaks) the interosseiinterni and ex terni are for the lateral movements ofthe fingers, or the adduction, and abduction of the fingers, and are oi the same class with the adductors and abduct. ors ofthe ti:^n,L, and little fin#n 205 MUSCLES LYING ON THE FORE, AND INSIDE OF THE HIP. first layer. 169. GLUTEUS MAXIMUS. Or. 1. The posterior part ofthe spine of the os ilium, near the sacrum. 2. From the convexity of the os sacrum. 3. From the sacro-ischiatic ligament- 4. From the os coccygis. In. By a strong broad tendon, into the upper and outer part of the linea aspera. Use. To carry forward the trunk upon the thigh. Vol. II. S :<)6 bECOND LAYER 170. GLUTEUS MEDIVS- Or 1. The anterior superior spinous process ofthe os ilium. 2. The edge of the spine of the ilium. 3. From the back part of the dorsum of the ilium. This muscle is covered by a strong fascia from which many of its flehy fibres arise. In. By a broad tendon into the trochanter major. into the inner side of the tibia, near the inferior part of its tu- bercle. U*e. To draw the leg inward, and to bend the knee joint. 179. PECTINALIS. Or. Broad and fleshy, from the upper and forepart of the os pubis, (or pectinis,) immediately above the foramen thyroideum. In. The anterior and upper part x>( the linea aspera of the femur, near the trochanter minor, by a flat tendon. Use. To move the thigh f >rwa ds and inwards, and to point the toes outwards. Under the name of the triceps adductor fe- moris, are comprehended three distinct muscles. •12 180- ADDUCTOR LONGUS FEMOItlJ. Or. The os pubis, near the -y.nphysis, and lower thou the last muscle. In. The inner and upper pnit or the line aspera, frooi a little below the tr'.ciin;.ter minor, to the beginning of the insertion of the adduct- or longus. 181. ADDUCTOR BREVIS FEMORIS. Or. On thein-iide ofthe pectinalis, from the upper and tore part of the os pubis, and ligament of the symphysis. In. The middle part ofthe linea aspera, being conti- nued lor some way down. 182. ADDUCTOR MAGNUS FEMORIS. Or. 1. From the os pubis and the former. 2. F:om the ramus and the tuberosity of she os ischium. In. 1. The whole length ofthe linea aspera. 2. Into a ridj,e above the inte rial condyle of the os femoris. 3. By a long round tendon (which is united to the vastus internus) into the up- per part of the condyle. 213 e. Of these three muscles, or triceps. To bring the thigh inwards, and forwards, as in clinging to the saddle, and, in some degree, to roll the toe outwards.- 183. GRACILIS. Or. The os pubis near the symphysis, and from the ramus ; it forms the outline of the thigh on the inside. In. Fore part ofthe ;tibia under the sheath ofthe sartorius. Use. It is an adductor. 184. OBTURATOR EXTERNUS. Or. 1. The os pubis. 2. Crus of the ischium. 3. The membrane which fills up the foramen thyroideum. In. The cavity at the back part ofthe root ofthe tro- chanter major ; it .adheres to rthe capsular ligament. Ill r To roll the thigh bone, and to point the toe. QUADRICEPS EXTENSOR CRURIS. 185. RECTUS Ot 1. The lower, and anterior spinous process of the os ilium. 2. Tendinous from the dorsum of the ilium. If\. The upper part ofthe patella, and throngh the medium of the patella ;.nd its ligament, int» the arrter ior tubercle ofthe tibia. t'?e. To extend the leg, or raise the body. 186. VASTUS EXTERNUS- Or. I. The root of the trochanter major. 2. The wiiole length of the linea aspera, by fleshy fi- bres whicir run obliquely forwards to a middle tendon, where they terminate. \ 215 1*. The patella ; part ofthe muscle ends in an epo- neurosis, which is continued down on the leg and is firmly fixed to the head ofthe tibia. Use.' To extend the leg, or raise the body from tht seat. 187- VASTUS IHTERNDS. Or 1. The fore part of the o3 femoris. 2. Root ol the trochanter minor. 3. Almost all the in- side ofthe linea aspera, the fibres run oblique- ly forwards and downwards, and it is fleshy considerably lower than the hist. In. The patella ; part of this also ends in an aponeu- rosis, which is continued down the leg. Use. To extend the leg, or raise the body. 188. CRUKALlS. Or. 1- The two trochanters of the os femori•. 21G 2. It adheres firmly to the fore part of the os femoris and joins the vasti muscles. In. The patella, (behind the rectus.) Use. To assist the three last muscle. MUSCLES LYING ON THE BACk OF TH! THIGH. H.EXORS OF THE LEO. 189. SEMITENDINOSUS. Oil. The posterior part ofthe tuberosity of the os ischium, in common with the long head of kbe, biceps. In. The ridge ,'and inside of the tibia, a little below its tubercle. 227 Use. To bend the leg. 190. SEMIMEMBRANOSUS. Or. The upper and backmost part ofthe tuberosity of the os ischium. In. The inner and back part of the head of the tibia. Use. To bend the leg. N. B. The two last form the inner ham-string. 191. biceps flexor cruris. Or. (Two distinct heads,) the first, longus, in com- mon with the semitendinosus, from the back part of the tuberosity of the ischium. The second, brevis, from the linea aspera, begin- nin<>- a little below the insertion ofthe gluteus, maximus, it continues to take its attachment, till within a hand breadth ofthe condyle. 218 IN. Head of the fibula and ligaments. Usb. To bend the leg. 192. POPLITEUS. Or The lower and back part of the external con- dyle ofthe os femoris, on the back of the joint. In. The ridge on the inside of the tibia, a little be- low its head. Use. To assist in bending the leg. MUSCLES LYING ON THE BACK OF THE LEG. Fist class are, extensors ofthe foot. The second, flexors ofthe toes, 219 FIRST DISSECTION. 193. GASTROCNEMIUS EXTERNUS, OR GEMELLUS, Or. 1. The upper and back part of the internal con- dyle ofthe femur, and from that bone, a little above its condyle. 2. Tht second head arises tendinous from the upper and back part ofthe external condyle of the femur. After forming two beautiful bellies, which are united bj a middle tendon, the muscle terminates in the tendo Achillis. |194» SOLEUS, OR GASTROCNEMIUS INTERNUS. On. (Two origins.) 1. The upper and back j>art of the head of the fijula, continuing to receive many of its fleshy fibres from the posteiior part of that bone, for some space below its head. 2. From the back part ofthe tibia, lower down than the insertion ot the popliteus. Tue flesh of this muscle, covered by the tendon of the gemellus, runs down, nearly to the lower end •f the tibia, by the tendo Achillis. 220 In. Into the backmost part ofthe os calcis, by the projection of which these muscles gain a con- siderable lever power. Use. T0 extend the foot. 195. FLANTARIJ. Or. The upper and back part of the external con- dyle ofthe femur ; it adheres to the ligament of t.i joint. It passes under the gastrocene- mius, and forming a long slender tendon, then runs down by the inside of the tendo Achillis, In. The inside ofthe os calcis. Use. From its delicacy, and insufficiency to assist the last muscles, it is supposed to have a use in pulling the capsular ligament ofthe knee from between the bones. FLEXORS. These consist of four, two that belong to the tibia, and two to the fibula. 221 Second disse ction, viz. tibiales and peronel, mus- cles ofthe foot. 196. TIBIALIS ANTICUS. Or. 1. The process ofthe tibia, to which the fibula is connected above. 2. The outside of the tibia. 3. Theupper part of the interosseous ligament. In. The inside oftheos cuneiforme internum, and nearer extremity of the metatarsal bone that sustains the great toe. Use. To bring the foot to right angles with the leg. 197. TIBIALIS POSTICUS. Or. 1. The fore and upper part ofthe tibia, just un- der the process which joins it to the fibula. 2. Then passing thro-gh a perforation in the T i 222 upper part ofthe interosseous ligament, it con- tinues its origin from the back part of the fibula next the tibia. 3. From near one half ofuie upper and back part of the tibia. 4. From the interosseous ligament, the tendon passes behind the malleolus internus. In. Spreads wide in the bottom of the foot, and os cuneiforme internum and medium; and also to the os calcis os cuboides, and to the iootof the metatarsal bone that sustains the middle toe. Use. To extend the foot, and to turn the toes in- ward. 198. peroneus longus. Or. From the head and whole length of the fibula, as far down as to within a Hand breadth ofthe ancle. The tendon passes through a channel atthc outer ancle,at the back ofthe lower head of the fibula • it then runs along a groove, 223 jn the os cuboides, above the muscles of the sole of the foot. In. The root ofthe metatarsal bone that sustains the great toe, and the os cuneiforme internum. Usl. To move the foot outwaads, and to press down the ball of the great toe. 199. PERONEUS BREYIS. Or. From the middle and lower part of the fibula ; from the fibula above the middle ; from the outer side ofthe anterior, spine of this bone ; as also from its round edge externally, the fibres running obliquely outwards, towards a tendon on its external side; it sends off a round tendon which passes through the groove at the outer ancle, being there includ- ed under the same ligament with that of the precedipg muscle; and a little further, it runs through an appropriate sheath. In. The root and external part ofthe metatarsal bone that sustains the little toe. 221 U*e. To direct the foot outwards, and by pressing the ball ofthe grert toe to the ground, to as- sist in carrying forwards the whole body. 200. PERONEUS TERTIUS. 0r. The middle ofthe fibula, down to near its infe- rior extremity ; the tendon passes under the annular ligament. In. The root ofthe metatarsal bone that sustains the little toe. Use. To assist the other peronei muscles. N. B. The belly of this muscle is united to the extensor digitorum. DISSECTION OF THE EXTENSORS OF THE TOES. These consist of two : 201. EXTENSOR LONGUS DIGITORUM PEDIS. Or. 1. The outside ofthe head of the tibia. 2 The 225 head of the fibula where it joins with the tibia, and spine of the fibula. 3. From the in- terosseous ligament. 4. From the tendinous fascia, which covers the outside of the leg. In. The root ofthe first bone of each of the four small toes, and is expanded over the upper side of the toes, as far as the root ofthe last bone. Use. To extend the four lesser toes. 202. EXTENSOR PROPRIUS POLICIS PEDIS. Or. Beginning some way below the head and an terior part of the fibula, along which it runs to near its lower extremity, connected to it by a number of fleshy fibies, which descend obliquely towards a tendon. In. The first and last joint of the great toe. Use. To extend the great toe. 226 203. FLEXOR LONGUS DIGITORUM PEDIS, PERFORANS. Or. The back part ofthe tibia, someway below its head, and near the entry of the medullary artery ;from this, it is continued down the inner edge of the bone ; also by tendinous and fleshy fibres, from the outer edge of the tibia, and between this double order of fibres the tibialis posticus muscle lies enclosed. Ha- ving passed under two annular ligaments, then it passes through a sinuosity at the inside of the os calcis, and, about the middle ofthe sole of the foot divides into four tendons, which pass through the slits ofthe prforatus, and, just before its division, it receives a con- siderable tendon from that of the flexor pol- licis longus. In. Into the extremity of the last joint of the four lesser toes. Usf.. To bend the last joint ofthetoes: 227 This muscle is assisted by the accessorius. See dissection ofthe sole ofthe foot. 204. FLEXOR LONGUS POLLICIS PEDIS. Or. By an acute, tendinous, and fleshy beginning, from the posterior part ofthe fibula someway below its head, being tontinued down the same bone, almost to its inferior extremity, by a double order of oblique fleshy fibres ; its ten- don passes under an annular ligament at the inner ancle. In. Into the last joint ofthe great toe, and it gen- erally sends a small tendon to the os calcis. Use. To bend the last joint of this toe. 228 MUSCLES SITUATED ON THE FORE PART OF THE FOOT. 205. EXTENSOR BREVIS DIGITORUM PEDIS. Or. The fore and upper part of the os calcis ; and it divides into four portions, which send ten- dons that pass over the upper part of the foot, under the tendons of the former. In. The tendinous expansion, which covers the toes, except the little one. Use. To assist in extending the toes, and some- what change the direction of the force ofthe long extensor. 229 MUSCLES OF THE SOLE OF THE FOOT, AFTER DISSECTING THE PLANTAR APONEUROSIS. 206. FLEXOR BREVIS DIGITORUM PEDIS, PERFORATUS. Or. The inferior and back part of a protuberance of the os calcis, (between the abductor of the great and little toes.) It sends off four tendons, which split for the transmission of the ten- dons ofthe flexorlongus. In. The >econd phalanx of the four lesser toes. (The tendon ofthe little toe is often wanting.) Use. To bend the second joint of the toes. Vol. U. u •i3G B07. FLEXOR DIGITORUM ACCESSORIUS, SEW MASSA CARNEA JACOBI SYLV II. Or. The sinuosity at the inside of the os calcis, tha fore part of the bone. In. The tendon of the flexor longus, just at its di- vision into four tendons. Use. To assist the flexor longus, and to change the direction of its operation. 228. LUMBRICALES PEDIS. Are four in number. Each has its origin thus : Or. The tendon ofthe flexor profundus, just before i*» division, and near the insertion of the massa carnea. In. The inside ofthe first joint ofthe t»e. It is lost 231 in the tendinous expansion that is sent from the extensor tendon to cover the upper part of the t oe. Use. To assist the other lesser muscles in support- ing the arch, and adding to the elasticity of the foot. SHORT MUSCLES OF THE GREAT TOE. 209. FLEXOR BREVIS POLLICIS PEDIS. Or. 1. The under and fore part of the os calcis where it joins with the os cuboides. 2. From the os cuneiforme externum, and it is inse- parably united with the abductor and adduct- or pollicis. In. The external sesamoid bone, and root of the first bone ofthe great toe. 232 Use. To bend the first join/ofthe great toe. 210. ABDUCTOR POLUCIS PEDIS. Or. The inside ofthe protuberance ofthe os calcis, where it forms the heel, and from the ?»me bone where it joins with the os naviculare. In. The internal os seamoideum, and root of the first joint of the great toe. L si;. To pull the great toe from the rest, but its power is lost by the use of shoes, 211. ADDUTOR POLLICIS PEDIS. Or. 1. The os cal i . 2. The os cuboides. 3. The os cuneiforme externum, from the root ofthe metatarsal bone of the second toe. 233 In. Tlie external os scsamoideum, and root of the metatarsal bone of the great toe. Use. To bring this toe nearer the rest, but by the pressure of the shoe reduced to move a flexor of the great toe. MUSCLES OF THE LITTLE TOE. 212. ABDUCTOR MINIMI DIGITI PEDIS. Or. Side ofthe protuberance ofthe os calcis, and from the root of the metatarsal bone of the little toe. In. The root ofthe first bone ofthe little toe. Use. To draw the little toe outwards from the rest, but, for the reason assigned, to bend the toe. U 2 234 213. FLEXOR BREVIS MINIMI DIGITI PEDIS. Or. 1. The os cuboidcs, near the furrow for the tendon ofthe peroneus longus. 2. The out- side of the uicatarsal bone that sustains this toe. In. The first bone of this toe. Use. To bend the toe, 214. INl'EROSSEI PEDIS EXTERNI BICIPITE3. These are similar to the iuteressci of the hand. The following names have been bestowed upon them. 215. ABDUCTOR INDICIS PEDIS. <216. ADDUCTOR INDICIS PEDIS. 217. ADDUCTOR MEDII DIGITI PEDIS. 218. ADDUCTOR TERTII DIGITI PEDIS. 233 IMTEROSSEI PEDIS INTERNA These are also like internal intcrossei ofthe hand, and have been called, 219. ABDUCTOR MEDII DIGITI PEDIS. 220. ABDUCTOR TERTII DIGITI PEDIS. 221. ADDUCTOR MINIMI DIGITI PEDIS. 222. TRANSVERSALIS PEDIS, OR. The extremity of the metatarsal bone of the "reat toe ; the internal os scsamoideum of the first joint (adheres to the adductor pollicis.) % In. The anterior extremity ofthe metatarsal bone of the little toe, and ligament of the next toe. 236 Lse. To contract the foot by bringing the great toe and the two outermost toes nerver each other; to support the lateral arch of the foot. The numerous muscles about the toes, the free motion of the toes of childern, and the power re- sumed by those who have lost their hands, prove the intention of nature to have bestowed as free a mo- tion on the toes as on the fingers. Why such variety of action has been given we know not, but of this we may be sure, that they are by habit reduced merely to the support of the arches of the foot. c\ ^ SECOND PART OF APPENDIX TO THE SYSTEM OF L>ISSECTIONS. CLASSIFICATION AND ORDER OF THE ARTERIES. efb 239 ARTERIES TO BE DISSECTED IN THE TAORAX. AORTA. IN THE THORAX. anterior to the arch, f Aa Corinaria dextra*. viz. 2 branches. £--------sinistraf. From the arch, r\. Aa Innominata. riz. 3 branches. \ Carotis dextra. /■ 1. Aa Inn \ Cai J Subcb J 2. Aa Cai (.3. AaSul Subclavia dextra. aroiis sinistra. Subclavia sinistra. * The right is the larger and inferior, it passes under the projecting auricle : distributed to the aorta, pulmonary artery, right auricle and inu: venae cavae ; but chiefly to the inferior plane surface ofthe heart and the right lateral convexity. f The left passes betwixt the pulmonic artery, and right auricle ; distrib.ited to t/ie aorta and pulmonary artery, to the convex surfaces, and septum of t/te heart, in two, principal branc/ies. 240 From the Thoracic aorta postc. ior to the arch, viz. 4 classes of small' arteries. *Aa Pericardiac:! posterior, -----------inferior. ' Aa Bronchialis dextra+ ------sinistra i nferior. Aa; GEsophageseJ ,Aae Intercostales aorticae. ARTERIES OFTHE LOWER PART OF THE NECK, CHEST, &c. SUBCLAVIAN ARTERY. Aa MAMMARIA INTERNA, 1. Thymicoe. 2. Comes nervi phrenici. 3. Pericardiaca, 4. Mediastinae. 5. Mammarise. 6. Epigastrica anastamotica s t There are. cJdefly two branches, the right and left, by on'- trunk from the fore part of the aorta. Thefe arc m i»'i ••■trielie>. ■} Ik' oesophageal arteries are very irregular ; some com: from the bronchial arteries. 241 Aa THYROIDEA INFERIOR. { 1. Transversalis humerif. Supra scapularis. 2. Transversalis colli. 3. Thyroidea ascendens, 4. Thyroidea propri. Aa INTERCOSTALIS§. Aa VERTEBRALIS||. Aa CERVICALIS PROFUNDA. To the muscles scaleni and longus colli, viz. ■< deep on the side of the I neck. Aa CERVICALIS SUPERFICIALIS. f To the brachial plex- < us, the scaleni, the {trapezius, skin, &c. N. B. The branches of the subclavian artery have more variety than any other in the system. t This is an artery of great size and qf considerable importance when it is prolonged into the supra scapular artery. The supra scapular artery is often an independent branch of the subclavian. §This artery supplies the two superior intercostal spaces ; it sends branches to t/ie scaleni and the muscles on the fore part of the vertebra, to the asophagus. Branches pierce also to the muscles of the back. || See Arteries of tlie Brain. Vol. II. X 242 ARTERIES ABOUT THE SHOULDER AND OUTSIDE OF THE CHEST. AXILLARIS. thoracica Superioirj -----------Longior. ------.-----Humeraria. -----------Alaris. ARTERIES OF THE ABDOMEN. ABDOMINAL AORTA. lve Branches.' I. PHRENICA DEXTRAf,? To the diaphragm, in- II-----------SINISTRA,^ osculating with the mamariae, irregular branches to the pan- creas, to the mem- branes of the liver and spleen. f These arteries are very irregular in their origin ; they sometimes come off in one trunk, sometimes in two, or'from t/ie cceliac artery. 243 111. CCELIACA. 2dary Branches. 1. A"f. CORONARIA VENTRICULI SUPERIOR. 3nary Branches. Super ior division. 1. To the stomach. 2. Ascending on the .^Esophagus. 3.Diaphr agm and omentum minus. Inferior division. On the lesser curvature of the stomach, viz. 4. Pylorica superior. 2. Aa HEPATICA, 3nary» Aa H« dextraa^. ■----cysticae. .----sinistra. (Sometimes)' a coronara dextra. Duodeno gastiica. 4 ternary. a Pylorica inferior. b Pancreadca duvdenahs. c Gastro epiploica dextra. d Pancreatica and epiploica. f N. B. When this artery gives off the left hepatic ar- tery, it is termed gastro hepatica sinistra. 1 It rises rarely from the superior mesenteric artery. 244 3. Aa SPLENICA. i Snary. 1. Pancreaticae. 2. Oasti o-epiloica sinistra. 3. Vassa brevia. IV. MESENTERIOA SUPERIOR. Distributed to the whole of the small intestines, and in these branches of the great intestines, viz. i 2ilary. 1. lleo-colica. 2. Colica dextra. 3. Colica mediaf. V. MESENTERICA INFERIOR. 2dar>. < Colica siiii^tra. £ Ilaemorrhoidalis interna'. VI. CAPSULARES. To the renal capsule. VII. RENALIS DEXTRA, „ 7 „, .. ... ________SINISTRA,1' J Tot»ekidney. fThe enumeration of the lesser branches of this artery can serve no useful purpose. J The ex'reme branch inosculating with tlie haemorrhoi- dea media, and vesicalis ima. || 'Tlte arteries to the renal capsule come from various sources, viz. Capsulares p/nenicoe. —--------aoi li<-u!. ------.—renales. 245 The lesser branches are 1. Capsulares. 2. Phremcae. 3. Adipose and mesocolicx. 4. Spermatica. 5. To the ureter. VIII. SPERMATICA SINISTRA} -----------DEXTRA. Besides its proper destination, the testicle, the speimatic artejy gives to the duodeum, mesocolon, pe- ritoneum and lumbar glands. In the female it has two divisions of branches, 1. to the ovaiium, 2d. to ihefalopian tube to the uterus and round ligament. IX UNDERTHIS ENUMERATION WE HAVE A NUMEROUS CLASS OF LESSER AR- TERIES TO THE FAT, URETERS, &.c. X. LUMBALES. To the vertebrae and nerves spinales ; to the mus- cles, posteriores.and an- teriores ; iriegularly to the diaphragm ; to the abdominal muscles, pe- ritoneum, &-C $ Very often from the renal, sometimes from the capsularis. 24o ARTERIES OF THE NECK AND HEAD. COMMON CAROTID ARTERY DIVIDES INTO THE EXTERNAL CAROTID AND INTERNAL CAROTID. EXTERNAL CAROTID. BRANCHES OF THE FIRST ORDER. 1. THYROIDEA SUPERIOR. 1. Thyroidea propria. 2. Laryngea, to the epiglottis, and ■muscles of the arytenoid cartilagef. Superficialcs, musculares, viz. to the sternocleido mastoideus, to the sternohyoideus and thyroi- deus, to the thyro-hyoideus. II- LINGUALIS. 1. Sublingualis. 2. Dorsalis linguae. 3. Ranina. 4. Irregularly to the muscles of the tongue aud pharynx. f This branch generally goes betwixt the thyroid and cru co'td cartilage accompanying the nerve here over the thy- roid cartilage- 247 III. FACIALIS. * 1. Palatina ascendcns. 2. To. the glands and muscles of the tongue. 3. Tonsilaris. 4. Submentalis. 5. i'o the masseter. 6. Coronaria labii. inferioris -superioris a Nasalis lateralis. b Annularis. IV. PHARYNGEA INFERIOR. - 1. Three internal pharyn^eae. 2.------posterior to the muscles, to the sympathetic nerve, mid jug-. ulur vein, to the glands ; enters the foramen lacerum posterius. V. OCCIPITALIS. 1. Meningeal 2. Ceivicaiis descendens]]; 3. Auricularrs. 4. Occipitalis ascendens-j-. VI. AURICULARIS POSTERIOR. 1. Branches to the parotid gland, biventer, and mastoid muscles. 2. To the meatus externus and mem- brane of the tympanum. 3. Stylomastoidea, entering the tym- panum, supplying the parts there and the mastoid cells. 4. Ascending behind the ear to its muscles and cartilage. 5. Ascending on the temple. $ J'iz. with the jugular vein through the foramen. || An internal branch inosculates with the vertebra/is. t The foram'n mastoideum posterius receives a brane to the dura mater. 248 VII. TEMPORALIS. 1. A small deep branch, and branch to the masscter. 2. Transversalis faciei, comes ductus salivae. 3. Temporalis media profunda. 4. Auriculares. 5. Temporalis anterior. 6.5------------posterior. VIII. MAXILLAR1S INTERNA, (Being in the order ofthe branching.) 1. Auricular is. 2. Meniirgea media. 3.-----•----parva, viz. to the pte- rygoid muscles, and finally piercing the foramen ovale. 4. Maxillaris inferior. 5. Temporales profunda; maxil- laris. 6. Alveolaris. 7. Infra orbitalis. & . Palatina maxillaris. 9. Pbaiyngea.------.---- 10. Nasalis, enters the foramen spficno palatitum. INTERNAL CAROTID. 1. Whilst in its transit through the bones, these blanches To the pterygoid canal and cavity of the tympanum. To the cavernous sinus and pi- tuitary canal. To the fourth, fifth, and sixth pairs of nerves. To the dura mater. (Within the cranium, and having emerged from the duia mater.) 249 II. OPHTHALMICA CEREBRALIS. Passing into tne orbit by the foramen opticuingives tnese branches. 1. To tuedura mater and sinus. 2. Lacrymalis, which goes to the gla.id after- giving many branches to ihe periosteum, optic.lerve, ^c. . Ciliares. Three or four arteries dig- nified with the distinction of wferiorcs, anteriores, breves, longioics. 4. Supra oriritalis. 5. Centralis retina:. 6. iEthmoidales. 7. Palpebrals. 8. Nasalis. 9. frontalis. III. SEVERAL LESSER BRANCHES TO THE PITUITARY GLAND, OPTIC NERVE, INFUNDBULUM AND PLEXUS CHOR- OlDES. IV. Aa COMMUNTCANS. Constituting part of the circle of Willis. V. Aa CEREBRALIS ANTERIOR. 1. Irregular branches to the first and second pair of nerves. 2. Lesser irregular branches to the anterior lobe. 3. Anterior communicans ('com- pleting the ciixlc of Willi, an- tcrioi iv.) 4. Arteria corporis callosi. VI- A» CEREBRALIS .MEDIA. Entering the frj ,sa silvii, it is minutely distribut ed to the sabstance of the middle lobe. 230 VERTEBRAL ARTERY. 1 '1. A class of small blanche to the muscles attached to the cervical vertebrae. 2. To the theca and spinal marrow. 3. Given oft as it turns under the occiput to the mus- cles ofthe neck. 4. Within the skull to the du- ra mater, viz. meningeal posterior es. Before the union of the vertebral arteries to form the basilar, these, viz. JI. POSTERIOR CEREBELLI. Viz. to the medulla oblongata, to the spine, the first and se- cond spinal nerves, to the in- ferior and posterior surface of the cerebellum. From the basilar artery. III. Lesser and irregular branches to the tuber annulare. The lower suiface ofthe cerebel- lum, and the nerves. IV. ANTERIOR CEREBELLI.f It encircles the crus cerebri. V. POSTERIOR CEREBRI.il VI. A» COMMUN1CANS. Uniting with internal carotid, (p. 11. v. iii.) and forming the circle of Willis. f Profunda cerebelS. || Profunda cerebri. 251 ARTERIES OF THE ARM. AXILLARY ARTERY. I. THORACICA SUPERIOR^. BRANCHES TO THE CHEST. Place, the second rib, and be- twixt the serratus magnus and * pectoralis minor. II. THORACICA LONGIOR. Viz. Mammaria externa. To be known from its greater length. III. THORACICA HUMERARIA. Passes off by the upper edge of the pectoralis minor, lies be- twixt ;he pectoralis minor and deltoides. IV. THORACICA ALARIS. To the glands, scaleni muscles, tne subscapular is, &.c. V. SUBSCAPULARS. 1. To the axilla and glands. 2. To the subscapular muscles. 3. Infra scapular branch, viz. to the muscles of the back. 4. To the dorsum scapulx, viz* circumfiexa scapulaiis. $ Even before this first thoracic artery, the a (Mary gives (iff a branch to tlte scaleni muscles. 2.">2 VI. CIRCUMFLEXA POSTERIOR. Passes off betwixt the subscapular and the great teres muscles : round the neck ofthe humerus, and supplies the heads of the triceps, the coiaco biachialis, the subscapulaiis, lower surface of the deltoides, and the capsule. VII. CIRCUMFLEXA ANTERIOR. A much smaller artery from nearly the same point with V I. or a branch of it. To the periostium and capsule chief BRACHIAL OR HUMERAL ARTERY. Viz. That portion of the trunk extend- ing from the edge ofthe teres major to the division below the elbow joint. A class of lesser branches to the musc;es, cellular mem- brane, nerves, ike. These are given ofi irregularly at intervals down the v\hole arm, and one of them is the nulrilia humeri. 253 III. PROFUNDA HUMERI SUPERIOR. Passes off opposite the lower edge of the teres major,|| branches to the neighbour- ing muscles in ascending and descending branches ; the radialis communicant to the external condyle ; bran- ches to the back of the el- bow joint, inosculating with the recurrens interossea, and radialis. IV. PROFUNDA HUMERI INFERIOR. Branches to the brachials intemu s and the biceps muscles : to the external condyle and supinator, to the ulnar nerve and back of the elbow joint. V. aANASTAMOTICA. The principal branch of this artery passes round the inner condyle ; but sends a branch anterior to it, then branches to the muscles arising from the inner condyle and inosculates with the ulnaris and interossea. ||; Called also collateral magna : it is sometimes « branch ofthe s ubcapular artery. fOL. II. V 25* DIVISION OF TIIE BRACHIAL ARTERY AT THE ELBOW JOINT, OR LESSER BRANCHES WHICH PLAY AROUND THE JOINT. A» HUMERALIS*.«< To tire pronator terei, i Intrmssrn. Ulnaris. < Hi'rurrann interofsecr):. ' Recurrens Vtiiinis an. _ terior\.-------posteriori. / Recurrent radiatia ahteri. J o»'$. Afit-r wht-li there '?. "S a it no bran dies of note L Uli it reaches Ike w risf- Radialis f Inosculating with the anterior branch of the anasta. motica. t----------;--------the posterior branch ofthe unasta- mutica and with the profunda injeri,,*. II—■------;---------the posterior branch ofthe anasto- micu awl with the communicans radialis of the profun- da tuperior. $-;-----—---------the radialis communicans of t/ie pro- funda sr.perior. 255 ARTERIES OF THE FOREv ARM AND HAND. ULNAR ARTERY. 1. To thepronator teres and'ori- gin ofthe flexors. 2. A branch which perforates be- twixt the bones and goes to the back ofthe joint. <> p i • ? Anterior., 3. Wecurrensulnans. s. 0 , . ^ Posterior. 4. Interossea. 5. Irregular branches to the flex- or muscles. v 6. Aa Doisalis manus comes off at the head ofthe ulna. 7. To the muscles of the little fin- S.^Palmans ptqfun laf. 9. May be said to terminate in the superficial palmar arck. N. B. The palmar arch gives these. In the palm, while Ulnaris minim i digiti, lying under the "i digrtales 1. 2. 3. > luarea. aponeurosis and £ Rs Anastamoticus. '^w above the tendons. J Aa INTEROSSEA COMMUNIS. 1. To the muscles, ligaments of thejoint, 6tc. f Which, inosculating with a branch ofthe radiaf, crms the deep arch. 25b 2. Perforans superior, a Ramus descendens. I> liecuircns interossea. 3. Branches to the flexor pro- fundus, and llexor pol- icis, and sometimes to all tlie flexors 4. I'erjo.ans inferior passes by the edge of the prona- tor qi/adratus, and divides into branches on the back of the wrist. 5. Anterior articular artery of the wristj|. RADIAL ARTERY. 1. To the supinator muscle. 2. Recurrens radialis. 3. In succession, branches to the supinator, the pronator, the flexor muscles. 4. Superficiali volttQ.) Before turning from the fore part ofthe wrist.) 5. Irregular small branches to the wrist) 6 Dorsal is Pollicis. There are often two. 7. J'orsaiis carpi. f^orsalis metacarpi, Is. 2*. 3.f. || Viz. Interrossea volarh ut. a larger artery : tr.dceaUa. ruaialis indicis sometimes takes a course (owat ds uie interstue cj the metacarpal bone of tlie fore and midate fingers, and supplies both fore and middle J^r.&ers, and ^as i.j) a considerable unastamoung branch. 258 (In the thigh,) branches to the obturator pecti- nalis, and triceps. V. GLUTEA. Passes out of the 'pelvis over the edge of the pyriformis, and betwixt two of thfc roots of the great ischiadic nerve. 1. Muscular branches within the pelvis a^ at its exit. 2. Rs. Superflcialis: viz. under the gluteus maximus. 3. R». Ascendens : viz. under the gluteus medius. 4. R*. Transversus : viz. under the gluteus medius, and forward. VI. ISCHIADIC A. Within the pelvis and in its pas- sage out branches to the bladder, rectum, and neighbouring mus- cles : on the back of tlie pelvis, to the glutei, to the great nerve, to the lesser muscles ofthe thigh bone, in many profuse branch- es. VII. PUDENDA COMMUNIS. 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