REVIEW OF RECENT ADVANCES IN OUR KNOWLEDGE OF 
THE ANATOMY AND PHYSIOLOGY OF THE 
NERVOUS SYSTEM. 
BY 
JOHN PUNTON, M. D., 
KANSAS CITY, MO. 
Professor of Nervous and Mental Diseases in the University Medical College, Neurologist to All 
Saints, and Kansas City, Fort Scott and Memphis Railroad Hospitals, etc. 
Being the Substance of an Introductory Lecture on Nervous and Mental Diseases deliv- 
livered at the University Medical College of Kansas City, Mo. 
REPRINTED FROM KANSAS CITY MEDICAL INDEX, JANUARY, 1894. 
KANSAS CITY, MO. REVIEW OF RECENT ADVANCES IN OUR KNOWLEDGE OF 
THE ANATOMY AND PHYSIOLOGY OF THE 
NERVOUS SYSTEM. 
Professor of Nervous and Mental Diseases in the University Medical College, Neurologist to All 
Saints, and Kansas City, Fort Scott and Memphis Railroad Hospitals, etc. 
BY JOHN PUNTON, M. D., KANSAS CITY, MO. 
Gentlemen:—The department of medicine which I shall teach is that of 
neurology, or that branch of medical science which especially relates to the 
mind and nervous system ; my lectures will, therefore, embrace all the various 
morbid conditions of the brain, spinal cord and peripheral nerves as well as 
insanity. 
In presenting this subject I shall bear in mind that we are studying the 
most difficult branch of medicine, so in order to render it plain and practical, 
as well as easy of comprehension, I shall purposely rob it of its many techni- 
calities and present it in as simple and common-place phraseology as possible, 
believing this to be of far more practical importance to you at this time than 
an extensive and intricate discussion of the questions under consideration. 
It seems impossible for some professors and teachers to leave the maze 
of hypothetical medical lore and descend to the more essential elementary 
plane of facts which come within the comprehension of every thoughtful 
student, and which indeed are the necessary equipment of every person seeking 
the degree of Doctor of Medicine. I shall try to avoid this error by presenting 
to you primarily only the more essential elementary principles of our subject 
with a degree of plainness which will enable you to receive them with benefit, 
for after all it is not so much what you hear as what you absorb and store away 
for future use that profits you the most. 
For a proper understanding of neurological subjects a general knowledge 
of the anatomy and physiology of the nervous system is absolutely essential; 
I shall, therefore, take occasion at the outset to review in detail some of the 
more important anatomical and physiological facts connected with the nerv- 
ous system. 
In alluding to this I am aware that there is a prevalent opinion among 
students and even practitioners of medicine that the anatomy and physiology 
of the nervous system is far too complex a study for them to master and is only 
of interest and importance to those who are willing to devote their sole time 
and attention to it. This is not so. A thorough mastery of the subject makes 
clinical neurology comparatively easy and in fact reduces much of it simply to 
a matter of logical deduction. 
Our study of the nervous system and its diseases naturally divides itself 
into a consideration of its normal anatomy, physiology, symptomatology, 
etiology, pathology, diagnosis, prognosis, treatment and prophylaxis. 
We commence, therefore, by a brief review of the more salient facts con- 
cerning its anatomy and physiology. 
Definition.-—A good working definition of the nervous system and one 
which has the advantage of being both brief and practical is that furnished by 
Dalton ; it is this : 
“The nervous system is an apparatus of inter-communicating fibres and 
cells disseminated throughout the body and standing in anatomical connection 
with the various organs of the animal system.” 4 
Anatomy and Physiology of the Nervous System—Punton. 
If we consider it as a unit we may say that it is that organ of the body 
by which the conditions of the outer world are perceived, by which its re- 
lations are appreciated and by which the actions of the individual towards it 
are regulated, while it also takes cognizance of the various conditions of the 
several parts of the body itself, in some respects controlling ihem, in others 
being in turn by them controlled. 
General Function.—Its general function is to associate the different 
parts of the body in such a manner that a stimulus applied to one organ ex- 
cites to action that of another. 
As an illustration of this we find that when food is introduced into the 
mouth it excites the flow of saliva from the parotid gland and after being 
mixed with this it is forced into the stomach where it again excites to action 
the various glands which pour out their secretion, and from thence it passes 
to the intestines where it gives rise to that wonderful mechanism we term the 
peristaltic action of the bowel. 
From this we learn that every organ of the body is subservient in the 
manifestation of its functional activity to influences from other parts of a 
structure different from its own. Hence, the normal physiological stimulus 
which calls into action the various organs of the body is not direct but indirect 
in its operation and this communication is established through the medium of 
the nervous system. 
It is evident, therefore, that the the nervous system is not, as some erroneous- 
ly suppose, simply an appendage to the rest of the body, but it is an integral 
portion of every part of it, not only having special organs of its own, but also 
entering deeply into the formation of every other organ ; indeed the perfection 
of the animal organization depends largely upon the general development of 
the nervous system and by virtue of the immense preponderance of gray cerebral 
nerve tissue man stands immeasurably above all other created beings. 
Its Composition.—The nervous system is composed of two classes of 
elements : (1) nervous tissue elements proper ; (2) non-nervous tissue elements. 
The former consists of the fibres, cells, and neuroglia, which together form 
the nerves. The latter comprise the connective tissue, blood vessels, lymphat- 
ics and epithelium. These various elements when united form two great sys- 
tems, viz: (1) A central nervous system; (2) a peripheral system. 
Both of these, however, when taken collectively constitute a series of or- 
gans consisting of (1) the cerebro spinal center or axis, (2) ganglia, (3) nerves, 
(4) and certain modifications of the peripheral terminations of nerves, technic- 
ally known as end organs. These latter constitute the organs of the external 
senses. 
Of these various organs, (a) the central nervous system includes the cerebro- 
spinal center or axis which consists of the brain and spinal cord, the nerve 
centers of which are made up of white and gray matter inclosed in membranes 
termed meninges. 
(b) The peripheral nervous system embraces the remainder, viz : the 
ganglia, nerves and end organs. It is usually described as consisting of two 
parts, (I) the cerebro-spinal system of nerves, and (II) the sympathetic sys- 
tem of nerves. The former being distributed mainly to the muscles and skin, 
the latter to the viscera and blood vessels. Both portions, however, are alike 
made up of nerve fibres derived from and dependent on the brain and spinal 
cord and both connected in their course with peripheral ganglia and end 
organs. 
Structure.—In. its structure the nervous system presents the most strik- 
ing example of simplicity and wisdom combined. 
It consists of three kinds of tissues each of which differs in appearance, 
structure and physiological endowment, (a) One of these is represented Anatomy and Physiology of the Nervous System—Punton. 
5 
by the white substance which may be disposed in layers, masses or tracts and 
is composed of nerve fibres alone. (b) Another constitutes the gray sub- 
stance or vesicular matter which contains in addition to fibres, cells and inter- 
stitial matter, (c) The remaining one is known as the gelatinous tissue and 
is sometimes termed the fibres of Remak. It differs essentially from the other 
two, but as its histological elements are still held in dispute it may be regarded 
as a supporting structure. Each of these elements may now with profit be 
reviewed in detail, and first of all the nervous tissue elements proper, viz: 
the fibres, cells and neuroglia, after which the non-nervous elements will occupy 
our attention. 
Nerve Fibres.—The nerve fibres constituting the white matter are 
cylindrical tubes or filaments arranged in bundles or tracts which for the most 
part run in a direction parallel to each other. Their size and diameter varies 
considerably in different situations from 2~sW t° ttW an according to 
Flint. The largest of them are found in the peripheral trunks and branches 
of nerves. 
Varieties.—They are divided into two principal varieties, viz: (1) 
Medullated and (2) non-medullated. The former in their most complete form 
consist of three elements, viz: (1) an external tubular sheath, (2) medul- 
lary layer or white substance of Schwann, (3) axis cylinder. The first is the 
insulating envelope of a nerve fibre, the second consists of an oleaginous sub- 
stance known as myelin, and the third the conducting element. These medul- 
lated nerve fibres make up the great bulk of the white substance of the cere- 
bro-spinal system. In their external sheath nuclei are found between it and 
the myelin. While the white substance of Schwann presents at regular in- 
tervals along its course small imperfect constrictions termed Nodes of Ranvier, 
besides these are other imperfect divisions or constrictions of the white sub- 
stance, and these are more numerous than the nodes and are called incisions of 
Schmidt or lines of Frohmann. The interval between any two nodes is term- 
ed an internode. The functions of these anatomical elements are important, as 
by the nodes the almost liquid myelin is kept evenly distributed along the 
course of a nerve fibre, while the incisions of Schmidt permits nutrient material 
to reach the axis cylinder. 
Non-Medullated Nerve Fibres.—The non-medullated fibres, or fibres of 
Remak, are composed of gelatinous tissue. These fibres are destitute of the 
white substance of Schwann. They constitute chiefly the sympathetic system 
of nerves. They are absent in all the nerves of special sense except the 
olfactory, which nerve appears to contain no other fibres. They are said to be 
grayish and faintly striated. Flint seems to make a distinction between the 
non-medullary fibres and the gelatinous, but Dana regards them as modifica- 
tions of the same. 
It is well to remember, however, that anatomists differ in their opinions 
regarding these fibres, as many think they are elements of connective tissue and 
consequently not endowed with the characteristic properties of nerves, while 
others think they have all the essential properties of nerve fibres but possess 
distinct functions of their own. 
Nerve. Cells.—In studying the nerve cells we must first understand 
thoroughly the character of the 
Gray Substance.—The characteristic anatomical element of the gray sub- 
stance is the nerve cells of which there are several varieties, but for all prac- 
tical purposes the (1) bipolar and the (2) multipolar are the most important 
for you to study. 
The bipolar cells are found in the ganglia and posterior roots of spinal 
nerves. They are characterized by sending out two prolongations. Anatomy and Physiology of the Nervous System—Punton. 
6 
Multipolar cells are irregular in shape and size and are marked by 
numerous prolongations. These prolongations are simply extensions of cellu- 
lar substance pushed out, as it were, from their centers. They serve as connect- 
ing links between the fibre and cell. 
The nerve cells act as centers in which nervous impressions are received 
through the afferent nerve fibres and from which a stimulus is given off* and 
transferred by the efferent nerve fibres to the various organs of the body. The 
general function of nerve cells may, therefore, be said to be the conversion of 
impressions into impulses. The nature of this change or its wonderful mechan- 
ism is still unknown to us but it constitutes the reflex function of the nervous 
system. . _ 
General Uses of Fibres and Cells.—From this then we learn that 
the fibres and cells make up the great bulk of the nervous appartus and their 
harmonious correllation is essential for all vital processes. To illustrate their 
several uses we may liken the nerve fibres to telegraph wires stretched between 
the brain, spinal cord, muscles, skin and all the organs of the body. While 
the nerve cells would represent the various offices of a complex telegraph sys- 
tem with the brain as the chief or central office where messages were being con- 
stantly recieved and dispatched, every message sent out would be more or less 
directly the result of some message received. So it is with the nerve cells or 
centers. We are constantly in receipt of messages from the organs of sight, 
hearing, touch, taste, smell and other organs, which are conveyed to and from 
these by means of the various nerve fibres distributed to them. Any injury 
to any of these fibres in any part of their course would necessarily cause a cor- 
responding impairment at headquarters. The practical application of these 
facts enable us to understand much concerning the effects of pathological 
lesions. 
Termination of Nerves.—For a long time the termination of nerves of 
voluntary muscles was a question of great uncertainty, but within the last few 
years the elaborate researches of French and German anatomists have been so 
accurately described that the question of the mode of* connection between the 
anatomical elements conducting stimulus to the muscles and the contractile 
elements of the muscles themselves may be considered as definitely settled. 
Rouget’s investigations published in 1862, prove that the motor nerve 
fibres terminate by a blending of the external tubular sheath with the sarco- 
lemma. The medullary layer ending abruptly at the point where the axis 
cylinder blends with the primitive muscular fibrilla. In the cutaneous surface 
the motor nerves terminate by forming plexuses. 
The sensory fibres, on the other hand, terminate in one of three ways by 
means of corpuscles named in different situations as follows : 
(1) The Pacinian bodies found in the subcutaneous layers of hands and 
feet and therefore not connected with tactile sensation. 
(2) The tactile corpuscles which implies that they subserve the tactile 
sensation. 
(3) The end bulbs of Krause found in the eye, mouth, etc. 
As a general statement then, we may say that the sensory nerve fibres end 
peripherally as plexuses in these end organs, while their central terminations 
are not as yet well understood. While the motor fibres end centrally in either 
the gray substance of the spinal cord or cortex of brain. 
"Neuroglia.—The cells and fibres are supported in their respective posi- 
tions by a connective tissue matrix known as the neuroglia. It is made up of 
cells termed deiter or spider cells. They differ in shape and size but not gen- 
eral characteristics. It also contains finely ramified fibrils which are connect- 
ed with the bloodvessels. In inflammatory processes these cells multiply? Anatomy and Physiology of the Nervous System—Punt-on. 
7 
swell up and assist in carrying off the irritating products and for this worthy 
function they have received the name of scavenger cells. 
We have reviewed in detail the essential points concerniug the ner- 
vous tissue elements proper, we now turn our attention to a very brief notice of 
the non-nervous tissue elements. 
Non-Nervous Tissue Elements.—The accessory anatomical elements 
of the nervous system constitute the non-nervous element. They consist of 
the blood vessels, lymphatics, epithelium and connective tisspe. All of these 
are found in the neuroglia. 
The arteries serve to bring fresh oxygenated blood ; the veins remove 
the exhausted, impure blood ; the lymphatics carry off the surplus fluids and 
other matters formed during the act of nutrition, while the connective tissue 
supports each of the various elements in their respective positions. 
We have already seen that the nerves are channels or organs of commu- 
nication and serve as connecting links between the brain, spinal cord, muscles, 
glands, skin, mucous membranes and other organs in which they terminate. 
Any excitation at either end of them produces an impulse corresponding 
to the sensation received. These differences in effects produced by the various 
stimuli or irritants to nerves has Jed to their division into two great classes, 
viz: (I) Afferent nerves and (II) Efferent nerves. Those which transmit im- 
pulses from the peripheral organs to the central ones are termed afferent nerves 
and the stimulus which they convey is termed its centripetal force. While 
those which transmit impulses from the central organs to the periphery are 
termed efferent nerves and the stimulus which they convey is termed its cen- 
trifugal force. The old division of nerves into motor and sensory is not 
sufficiently correct, for we know that there are many outgoing nerves that are 
not motor'in function. A much better division is that of afferent and efferent. 
As a rule both kinds of fibres are associated in the same nervous bundle, but their 
effects are entirely different. iNo essential distinction, however, has so far been 
discoverable in their anatomical structures but to all intents and purposes they 
seem completely identical. 
The immediate effect of division or injury to a nerve fibre causes a sus- 
pension or loss of its physiological function. If it be separated from the cell 
of its central connection degeneration or atrophy ensues. Nerves may regen- 
erate after injury but the time required for this varies considerably. 
Spinal Cord.—The nerves of the trunk and limbs are connected with 
a long rod of nervous matter termed the spinal cord, which again unites them 
to the brain. The cord is made up of white and gray matter, the former being 
the most external and is imperfectly divided in the median line into two 
lateral halves by the anterior and posterior fissures. Each half is composed 
of white and gray matter, the former being the most external and may be 
divided into three primary divisions, viz : (1) anterior, (2) lateral and (3) 
posterior columns. Each of these are again subdivided into several tracts, 
the study of which together with their special functions constitute one of the 
most difficult problems in neurological science. One of them is said to be the 
tract which conveys the sensations of pain, another varying degrees of temper- 
ature, a third that of muscular sense, a fourth that of tactile sensation, while 
still others represent the tracts of voluntary motion. Now it is not my inten- 
tion to enlarge on these more fully at the present time, but will do so at the 
proper time, suffice it to say that the anterior column is motor in character, 
the posterior sensory, and the lateral has a mixed function. 
The gray matter of the cord is composed of cells and minute fibres. The 
cells in the anterior portion are much larger than those found in the posterior. 
These large cells are connected with the motor nerves which supply the muscular 
system and seem to possess a trophic function, while the smaller ones are as- 8 
Anatomy and Pyhsiology of the Nervous System—Punton. 
sociated with the sensory nerves. The cells are arranged in groups, which in size 
and number differ in different situations. From either side of the spinal cord 
in successive pairs may be seen the spinal nerves which are distributed to the 
muscles and which have their central connections in the spinal cord and again 
are continued upwards by the motor tracts of fibres in the spinal cord to 
different parts of the brain. The vital activities of the nervous system may 
thus be seen in the phenomena of mind in muscular action, in the various sen- 
satipns, in the secretions of glands, in the control of blood vessels, in varying 
degrees of temperature, in visceral action as well as modifications of nutrition. 
The correllation of all these various activities therefore may be said to 
constitute the functions of the nervous system, and the principal agents which 
are instrumental in operating their special forces are three, viz: (1) the nerve 
fibre, (2) the nerve cell and (3) the end organs. 
The various mechanisms are therefore subject to classification as follows : 
The motor mechanism or functions. 
The sensory “ “ “ 
The reflex “ “ “ 
The trophic “ “ “ 
The secretory “ “ “ 
The visceral “ • “ “ 
The mental or psychical “ 
In the working of all of these the cell is the agent which generates the 
nerve force, while the fibre distributes it, at the same time the end organs serve 
as a receptacles for external stimuli. 
Now the disorder of any one of these functions produces a train of symp- 
toms which receives a name according to its character and class. Indeed it 
may he said that symptoms are the expression of some derangement of function, 
consequently we may classify symptoms of the morbid conditions pertaining 
to the nervous system under the same headings. Your ability to detect dis- 
eased conditions of the nervous system depends entirely on your knowledge of 
its functions and the character of the symptoms which their derangement 
produces, for it may be said in a general way that symptoms indicate to you 
the seat of disease, while its nature and character is determined by their mode 
of onset and other points connected with the history of the case in question, 
and these constitute two of the chief points in diagnosis. 
In conclusion, then I trust that you will understand that the sympathetic 
system governs the functions of nutrition, growth, reproduction, and all move- 
ments which are purely involuntary in character. While the cerebro spinal 
system governs all movements of animal life, which includes motion, sensa- 
tion, intellection, special senses, and indeed all acts which are purely voluntary 
in character. 
In health we find the correllation of both these forces in harmony, and 
when from any cause they are interfered with, disease lesults. 
The acts which are under control of the sympathetic system are the in- 
voluntary, and these specific functions are performed by us unconsciously, 
receiving their source of inervation principally from the spinal cord while the 
voluntary acts of life are governed and controlled by the cerebro-spinal sys- 
tem which receives its source of inervation chiefly from the cells of the cere- 
bral cortex and as this is the seat of all conscious mental action, all conscious 
acts are referred and find a residence here. 
We have thus surveyed in a general way the principal, anatomical and 
physiological facts concerning the cerebro-spinal architecture of the nervous 
system, and in my next lecture I hope to review more in detail some of the 
most important points connected with the brain and spinal cord in health and 
disease.