Elements of the anatomy, physiology and hygiene of the human system

Front matter

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Contents

= PAGE Introduction .. ee ’ . e - ‘ * ° . . 7

' PART L—THE MECHANICAL SYSTEM.

CHAPTER I.—Of the Bones 5 ‘ or SecTion 1.—General hoamueeinn, on the bons ‘ ll Sucrion 2.—Bones of the Head 4 i a

CHAPTER I.—Of the Brain, Spinal Marrow, and Nerves . . 74

SECTION 1 —The Brain i - ! . 74 The Membranes of the Brain R ‘ oe The Structure of the Brain . ; é 76 The Functions of the Brain . eo ae Section 2.—The Spinal Marrow. . +» «© « 87 Section 3.—The Nerves . P é r P eee | The Cranial Nerves . - ° ‘ 92 The Spinal Nerves r = ° « . 94

The Great Sympathetic hare ° ea 97 The Functions of the Nerves gormneR «2 «98

4 CONTENTS.

CHAPTER IJ.—Of the Organs of the Senses. : ; 5 106 Section 1.—The Sense of Sight . . 2 O—@ Sa Section 2.—The Sense of Hearing . ; ; 119 Section 3.—The Sense of Smelling . . . . » aa

*Section 4.—The Sense of Tasting : ‘ - : 130 . Section 5.—The Sense of Feeling . ; . : - 182

~ PART III.—THE REPAIRING SYSTEM.

CHAPTER I.—Of Digestion . 5 142 Section 1.—The Organs of Mastication ae Deglutition ‘148 SEcTION 2.—Thé Stomach : ; - : ; Pie) (5 |

Structure of the Stomach. ; 4 ; 152

' Thé Gastric Juice hearer

The Laws of Diet . ; 156

Section 3.+-The Duodenum and Organs sania with it 165 Section 4.—The Intestines . : : ; : ‘ 170 CHAPTER Il. —or thé Clicdlatiad ; . ; z Sa it: | The Organs of the Gitealasoms ; : 3 176

The Forces of-the Circulation . ‘ Hees bal The Object of the Circulation . + HOLM 184

CHAPTER HI.—Of Respiration . a . 187 The Organs of Réspiraiton: : pe . 187 The Object of Respiration . ; Sena The Changes in the Blood by Respiration ° 198 The Vital Force . : noe: : . 199 Animal Heat. 201

The Elements of Seotbeeilivn and of Nutrition . 202

CHAPTER IV.—Of Aboorpiion wii? oe : pote ‘ 205

' The Kinds of deere 5 4 See = 208 The Organs of Secretion . 209

' The Relation of the Secreting Ouase % nck other. .. : 5 ; : Seer’: . 215 CHAPTER Vi.—Hygione. eR es

APPENDIX. . bdceion 2.—The Muscles Individually. . . . 229

PREHFACH..

A KNOWLEDGE of human Anatomy and Physiology is not confined ; to the medical profession, nor to professed scholars.- It has become a part of general education, and is always attainable in our advanced schools, beth public ana private. The study becomes professional when it is pursued to minute details, but the general structure of the body, the uses of the several parts, the conditions upon which their healthy action depends, and the circumstances. by which such action may be interfered with, should be understood by all. The physical well-being of ourselves and of those with whom we stand connected, depends in a great measure upon our acquaintance with these laws of our orgahization.

It is the design of the following work to Loe B these principles ‘in a form adapted to class instruction.

The first object has been a suitable arrangement. Such an analysis of the objects and wants of the system is given as leads to an ‘obvious classification of the organs of the body. This enables the learner to see at once what subjects are to be investigated, and in what order they naturally present themselves, and to know when his work is done. Until the facts of a science are thus arranged, upon some principle of relation, they do not constitute a science, and can serve no purpose either of practical application or of furnishing enjoyment or mental discipline.

The Physiology and Hygiene of the several classes of organs are so obviously associated with their structure, that it was thought better to introduce them in immediate connection with the anatomical descriptions. The repetition which would be almost necessary if they were treated in separate sections is thus avoided.

Many subjects of collateral interest have been presented in the form of notes. This has been done in order that the consecutive ness of arrangement in the text might not be interfered with.

The second object has been compression. It is one of the serious difficulties met with by teachers, that their text-books are not too

6 PREFACE.

comprehensive, but too large. In most of the branches of study, they should be of such size that they can be completed in a single term. And in addition to this, time enough should be allowed for thorough review. A subject that is worth studying is worth reviewing. The principles should not only be understood, but they should be repeated ‘so many times that they cannot be forgotten. Every scholar should become so familiar with the subjects of his study as to be able to take up any of the parts, and give a ready’ and intelligible account of it. . ‘

Whenever conclusions rest upon reasoning which is complex and ‘difficult, special effort has been made to render the expression of the reasoning as clear and little involved as possible. But to simplify and popularize it in any other way has not been attempted, nor would such a course be likely to secure for it additional favor. Hence, technical terms have not been discarded. In entering upon ‘a new subject of study, the learner will necessarily meet with new terms, and it is best to employ those which express the ideas that are peculiar to the study with the greatest precision, and the least circumlocution. Science has a language in some respects peculiar to itself, and so has the counting-room and the farm. Each claims its own language, its technical terms, because the ideas to be expressed are peculiar and require such terms.

A glossary of technical terms has been combined with the index, and, as a matter of convenience to pupils, the pronunciation has also been marked.

The several] subjects are so fully illustrated by figures, that teachers, it is believed, will not find it necessary to avail themselves of anatomical plates to facilitate instruction.

The author has endeavored to bring the important principles of extended treatises on these subjects into a sufficiently narrow compass, to divest them somewhat of the professional cast which they there assume, and put them into a form in which they will be intelligible to pupils, and to give them an arrangement that will show their connection with each other, as parts of a single branch of science. In attempting to do this he has been guided by his experience as a teacher for many years. He now offers the work to the public in the hope that it will meet the approval of those to whom the instruction of youth is committed.

New York, Jan. 1, 1853,

ANATOMY, PHYSIOLOGY, AND HYGIENE.

Introduction

1. Ir is the object of Anatomy to describe the human body, the structure, form, and position of its several organs. Itis the object of Physiology to describe the uses and relations of these organs. It is the object of Hygiene to develop the principles upon which the healthy action of these organs depends. The three may be kept distinct as departments of professional study; but, as branches of general education, they are more conveniently studied together.

2. In order to arrive at a convenient classification of these organs, it is necessary to consider the object for which the body is furnished. We, that is our minds, can exert no direct control’ over the material objects around

? This statement can scarcely need illustration. We cannot, for in. stance, by a mere exertion of the will, cause a book which lies before us to change its place. Such change can be made only by the application of physical force. Perhaps we might have been so constituted that we could have controlled directly other matter, as we do our bodies ; but such power has not been given us, and those who pretend to possess it either deceive, in reference to the effect itself, or the effect is produced by the application of ordinary physical force, exerted in such a way as to elude our observation. The most successful efforts of jugglery are of this last kind. The skill consists mainly in the power which performers acquire of moving the

1. What is the object of Anatomy ? Of Physiology? Of Hygiene ? %. Why is a physical system necessary ?

8 INTRODUCTION.

us. We do, more or less, control these objects; but it is by the body as an intermediate agent. How the mind is brought into relation with this portion of matter, the body, so that it acts in obedience to our wills, is unexplained and inexplicable. All that we can say of it is, that it has pleased .our Creator thus to constitute us; and. all the knowledge which we have of the external world comes to us by this connection of mind and body.

3. Bearing in mind; then, that the body is furnished us as the means by which we may become acquainted with, and operate upon, external objects, we may inquire what kind of organization will secure this end. ‘

In the first place, there must be a suitable mechanical structure. It must be sufficiently firm to support the weight and transmit the power which the purposes of life require; and this firmness is secured by the framework of. bones which the body contains. This framework must not be a rigid structure, but capable of various motions. The joints are provided, to render these motions possible ; and the muscles are the system of connections by which the several parts of the frame are acted upon i in the performance of these functions.

As a system of mechanism, the body i is no more capable of moving itself than any other piece of machinery is. In the second place, then, the mind, regarded as the repository of voluntary power, must have the means of applying .

hands with wonder ul accuracy, and yet with a rapidity so great that the eye cannot follow them. Thus, changes take place before the observer for which he can assign no cause; but they are effected by the hand of the performer with a motion which is invisible only because of its rapidity.

3. What are the three systems of organs by which the body is fitted to perform its functions? Ofwhat classes of organs does the mechanical system consist ? Why must there be a nervous system ? Of what classes of organs does it consist ? Why isa third system of organs necessary? What objects are ‘effected by the repairing system ?

INTRODUCTION. ; 9 its power. The. nervous system, consisting of the brain, the spinal cord, the nerves, and the organs of the external senses, are the means of applying this power to the mechanical system, as well as the means by which the mind acquires a knowledge of the properties of matter.

It would seem that when these two systems are formed, and so long as they remain perfect, no others are necessary to effect the purposes for which the body is designed. But a long process of growth is necessary to perfect the body ; and, like all material structures, it is liable to become injured, and is subject to ultimate decay. It therefore becomes necessary that there should be a third system of organs, which we may call the repairing system, designed to secure the growth which is required in the earlier periods of life, and to furnish the repairs which are required at every period.

4. Our investigation of this subject will, therefore, be limited to an examination of these three systems, of which the body is mainly composed: namely, the Mechanical System, the Nervous System, and the Repairing System.

4 . To what will our study of this subject be limited? ~%

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PART L

THE MECHANICAL SYSTEM.

THIS SYSTEM CONSISTS OF THE BONES, JOINTS, AND MUSCLES.

CHAPTER IL—OF THE BONES.

Section I—General Considerations on the Bones

_ §. The principal object of the bones is to constitute the framework of the body. Its firmness, height, and general form depend upon them. They, however, serve other important purposes, particularly that of protection to some of the more delicate organs. Thus, the cranium is designed to render the brain secure from external injury, and the ribs are employed to form and protect the cavity in which the heart and lungs are lodged. :

6. It is interesting to trace the process by which the bones are developed. ‘There is a period very early in our existence, but after the body has acquired its general form, when the skeleton contains no bone, but consists entirely of cartilage (gristle). These pieces of cartilage, which constitute the first draft of the osseous structure, are traversed by minute blood-vessels, and particles of bone, conveyed by the blood, are deposited at points

Section X,—5. What is the principal object of the bones? What other purposes do they serve? :

&. Of what is the first skeleton composed? State the process by which thia is changed to one of bone, Low long time is required to make this change?

called centres of ossification, near the middle of each piece of cartilage, the corresponding cartilaginous particles being at. the same time taken up by the circulating fluid, and carried away.

Thus, by a very slow process, the original skeleton is taken down, and one of bone is built up.’. Though ossification commences sometime before birth, it is not completed till about the twentieth year of life. In certain parts the change‘ is delayed much longer. Thus, the lowest portion of the breast bone is generally cartilaginous till extreme old age, and the cartilages which connect the ribs with the breast bone, in healthy persons, never become ossified.*

7. At the most vigorous period of life, when the bones have attained their full development, they contain about three-fifths of their weight of earthy matter, of which phosphate of lime is the principal part, and the remaining twofifths is animal matter, mostly in the form of gelatine.‘

2 When children have but little exercise, breathe impure air, or are confined to food containing but little nourishment, the process of ossification is often arrested ; and as the body, which continues to increase in size, becomes too heavy to be supported by-the cartilages, they yield, and permanent deformity. results.

_® When a bone has been broken, it does not unite by a sudden deposition of bone. There is a partial cure effected by a rapid deposition of cartilage between the broken surfaces, by which they are temporarily, though not very firmly, united. The complete ossification of this cartilage may require several months.

* These two parts may easily be exhibited separately. When a bone is thrown into the fire, the animal matter which is distributed through it becomes charred (converted into charcoal) by the heat, and it becomes black. The animal matter, however, soon burns out, and a white brittle substance, the mineral matter of the bone, is left. The bones would,

7. What is the composition of the bones? How does ‘their composition differ from this in early life? Why is a flexible state of the bones better adapted to the conditions of early life? What change in the composition of the bones takes place in old age ?

But their composition varies with a person’s age. Early in life, the animal matter predominates, and. the bones are tough and flexible, though possessing less of firmness. This is the reason why there are so few permanent injuries from the accidents of childhood and youth. In advanced life, the earthy matter predominates, and the bones become brittle, and, when broken, less disposed to unite firmly.

8. The form of the bones is so various, that it can scarcely be employed in the classification.of them. Yet it is convenient to speak of long bones, as those of the leg; of flat bones, of which the cranium mostly consists; and of square bones, such as are found in the wrist and ankle.

9. The structure of the bones is by no means as simple as it at first appears. When bone begins to be formed, the osseous particles are so deposited as to form fine, stiff threads of bone, and 1. hence the long bones are always \\ iss and,for the same reason,

at Wines have a radiated aa (Fig. 1.

The outside of the ‘ody of the long bones is very dense and compact; but, at. a: very little distance, the.structure becomes’. vs porous, and the pores increase in ?*"Piting the radiation of the size as they are situated further from the surface. Finally,

Ja probably, become equally brittle during life if, by any vital process, they were as fully deprived of animal matter.

If a bone be placed in dilute muriatic acid, the acid will, in a few days, combine with and dissolve the earthy part of the bone, and leave the animal part, which will have the exact form and size of the bone, but will be flexible like India-rubber. :

8. What classification of the bones is made depending upon their forms ? 9. How are the fibrous and radiated structures produced? Whereis the structure the centre is hollow. The hollows of the bones are filled with marrow, and the cavities of the porous portions are also filled with a fatty substance resembling marrow.

By this arrangement, nearly as great strength is secured as would be if the whole were a mass of compact bone, while the weight is not more than half that of solid bone.

The extremities of the long bones, also, have the porous structure, and, are much larger than the middle portions, in order to give strength to the joints by presenting large articular surfaces.

The substance of the bones is everywhere (except in the teeth) traversed by blood-vessels, absorbents, and nerves, so that these solid parts are still living parts, and Section of the thigh are continually undergoing the processes of

bone. aa The ex- °

ag ns _fhow- removal and renewal, like the other parts texture. D5 The of the body.’ It is by means of these traexterior of the body, of very dense Versing organs that the bones are able to bone. ¢ The hol- F low of the bone, unite when they have been fractured, or to owe ee repaired when they have been injured by disease.

It follows, that children should not, before the bones have acquired their strength, be subjected to the severer kinds of labor, such as require great firmness of frame. ‘They should not be required to lift great weights, nor carry heavy burdens ; nor should they be confined, for a long time, to any one position. The restlessness of children is natural, and is designed to prevent the distortions of body which would be likely to result from a child’s maintaining habitually the same position, when the bones are so most compact? What is the structure of the central portion of the bones: Of the extremities? Why are the extremities of the bones enlarged? With what are the cavities of the bones filled, and for what purpose? What other organs are found penetrating the bones, and for what purpose? i

*.

- 10. The blood always contains, in solution, a small amount of osseous matter, and both the formation and growth of bones take place by the deposition of these particles of bone. The bones increase in diameter by the

- yielding as to allow of their readily taking any form which a constrained position would tend to give.

Children atschool often rest the elbows upon the table, and allow the

head gand chest to fall forward; they thus become round-shouldered Others acquire the habit of lounging, or of resting one elbow in such a way as to give a lateral curvature to the spine. The feeling of lassitude and weariness, which rapid growth is likely to induce, may encourage these and other objectionable positions which are liable to result in permanent deformity. The upright erect position may be recommended as preferable, so far as it can be practised ; and yet this effort should not be carried, too far, for, in the first place, to carry the head and shoulders too far back is as unnatural and as much a deformity as the opposite error; and, secondly, the most natural erect position will become injurious if persisted in to weariness. A large amount of exercise, and the frequent changes of position thus secured, are the best safeguards against all the deformities which are likely to be contracted in childhood. _.° It will hereafter be shown that, by the processes of life, the soft parts are constantly undergoing removal and renewal. Portions of every muscle, for instance, are every moment undergoing chemical change, losing their vitality, and requiring removal from the system. At the same time, there is a renewal, by the deposition of new muscular fibre from the blood. These changes are essential to the continuance of life. It was discovered accidentally that the same changes take place in the bones. A dyer threw to some domestic animals madder from which most of the coloring matter had been extracted. Some of the coloring matter, however, remained, and upon killing the animals which had fed upon it, the bones were found to be tinged with-it. . Hence, there must have been a deposition of the coloring matter in the substance of the bone. By varying the experiment, feed. ing with madder, and then, for some time before killing, withholding it, the bones were found of the ordinary color ; thus proving that the coloring matter which was at first deposited had been absorbed and removed.

10. How is the osseous matter for the growth of the bones supplied? How do they increase in diameter ? Why can they not increase in length in the same way? How do they increase in length? How long do the body and extremities of a bone contiuue unsolidified ?

deposition of layers of bone upon the outside. similar to the successive rings of growth in a tree :* but their increase in length is by a Gifferent process.

The ends of a bone are so much larger than the middle, and so different in shape, that the bone would be deformed if its elongation took place by deposition upon the ends. There is therefore a special provision for growth in this direction. A long bone has, at least, three centres of ossification: one for the formation of each extremity, and one for the formation of the body of the bone. So long as the bones are capable of elongating, the extremities of the bone are always separated from the body of it by sections of cartilage, as at aa, Fig. 3, and the bone increases in length by the deposition of bone at the ends of the body, thus pushing the extremities farther from each other. As soon as the body has fully acquired its growth, this section of cartilage becomes ossified.’ eet nody atthe 11. A dense, tough membrane, called the penttomnttiss periosteum (bone envelope), surrounds the

Fig. 3.

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(pipers. of bones, except at their extremities. It serves cartilage, ue to protect the bone, to supply it with its dy and epiphy- yoyves and blood-vessels, and is the means by egw which the ligaments, tendons, and muscles are attached.®

¢ The experiment in’ the preceding note was varied by feeding an animal that was growing rapidly with madder, for a few days, and then withholding it. The bone which was formed while the blood was charged with the coloring substance, would be more highly tinged than the bone previously at Se 31. What is the periosteum What purposes does it serve? Into what four classes are the bones divided ? ; .

BONES OF THE HEAD. : Ty

The bones are divided into four classes: those of the — head, those of the trunk, and those of the upper and of the lower extremities.

Section II.— Bones of the Head

THE bones of the head include those of the cranium and those of the face.

I. Bones of the cranium.

12. The bones of the cranium are composed of external and internal plates, and an intervening porous portion, answering to the hollow and the porous structure in the long bones, called the diploé. The external plate has the formed would become by deposition of coloring matter into the interstices. The bones of the animal were found, upon examination, to consist of concontric lamine of more highly and less highly colored. bone, showing that the bone was formed by successive depositions upon the outside.

‘If too much or too severe labor be required of an individual while these cartilages remain, and the body is forming, nature attempts to secure the system against injury by a more rapid ossification of them than would otherwise take place. Thus they may become bone before the body has acquired its full development. But it is impossible that any further growth of body should take place, and a dwarfed stature is the result. There are, however, other causes of such a stature. It may result from too little exercise in early life, or from disease, or it may be hereditary.

* This membrane; though ordinarily possessing but little sensibility, is sometimes subject to inflammation, when it becomes intensely painful The felon and fever sore are diseases originating in this membrane. Disease seldom attacks the bones directly; but it may be communicated to them either from the periosteum, or from the investing cartilage where this membrane is wanting, as in the joints.

Section 12,—What do the bones of the head include? Name the bones of the cranium. ; 12. Of what three parts do the cranial bones consist? Describe each part.

FRONT VIEW OF THE SKELETON,

Fig.

The Skeleton consists of 201 bones. In this enumeration the teeth, the hyoid bone, and the bones of the ear are not included.

Certain bones in the sutures of the head, and in some of the joints, which, though generally present, are not regarded as essential parts of the framework, are also omitted.

NAMES AND CLASSIFICATION OF THE BONES.

1. The frontal bone, . .

2. The parietal bones, .

8. The occipital bone, .

4, The temporal bones, .

The sphenoid bone, .

The ethmoid bone, .

- we © =m wD — Bones of the Cranium 8,

5. The nasal bones, . . 2 The lachrymal bones, 2

6. The upper maxillary DODOB, oo <esrcisiz-eiiie

%. The malar bones, . .

The palatine bones, . 2

The lower spongy BORGES sal as Oe

The yomer, Sl Sar es | a Bones of the Face 14,

8. The lower maxillary DONG, 25, se. %8 sk

. The vertebree, . 24 . Thesternum, . 3 . Theribs, . . . 24

7} | | . The ossa inno- t . The sacrum, . |

. The coccyx, . .

. The scapula,. . . The clavicle,. . . The humerus, . . The ulntire te « . The radius, . . . The carpal bones, 16 j

. The metacarpal

. The femur, . . 2 . The tibigggs < «..2 . The fibula, . . 2 i The patella, . . 2 . The tarsal ones, 14 . The metatarsal :

. The phalanges, . 28

BACK VIEW OF THE SKELETON. 19

Fig. 5.

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The phalanges, . 28 bones: ss

SF a Bones of the Lower Extremities 60, re | a j a= ALT a ~N YA Ww ie E' SSH ays unl ‘ae if Ui Ht eae i \\ PRS rrr

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= ye toughness and hardness of ordinary bone; the internal, called. the vitreous plate, is much harder. The bones of the cranium are eight in number. :

13. The frontal bone (1, Fig. 6; 1,1, Fig. 7%) occupies the region of the forehead, and extends from the top of the head forward to the eyes and nose, and laterally about half-way to the ears.. On the forehead, the two plates of the bone are considerably separated from each other, leaving the cavities above the eyes called the frontal sinuses. The external plate terminates at the ridge upon which the eyebrows are situated, while the internal plate

Fig. 6.

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Bones of the Cranium, separated. 1 The Frontal bone. 2 The Parietal bone. 4 Occipital bone. 4 The Temporal bone. 5 The Nasalbone. 6 The Malar bone,

13. What is the situation of the frontal bone? How are the frontal sinuses formed? Of what does the orbital plate consist, and how is it situated ?

turns backward, forming the upper part of the orbit of the eye. This is the orbital plate of the frontal bone, and becomes the floor upon which the front lobe of the brain rests.

14. The parietal bones (2, Fig. 6) are two square, smooth bones, situated directly hack: of the frontal bone, united together at. the top of the head, and forming the highest andl the lateral portions of the cranium.

15. The occipital bone (Fig.8; also 3, Fig. 6) forms, as the name indicates, the back part of the cranium, as well as the floor on which the posterior lobe of the brain rests. In the base of the bone is a large aperture, the magnum foramen, through which the spinal cord is connected with the brain.. On the under margin of this foramen are two prominences, called condyles (button-shaped, elevations), which contribute to form the joint between the head and spine.