The human body. A text-book of anatomy, physiology and hygiene

Front matter

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Preface

iv

We both desire to express our obligations to Miss Frances F. Bauman, who placed freely at our disposal the results of her long and eminently successful experience in teaching Physiology to children.

As appendices to certain of the chapters there are practical directions for the illustration of various facts in Anatomy and Physiology, which can be shown to pu¬ pils without any special apparatus, or any material not easily obtained.

Particular attention has been given to the action on the body of the more commonly abused stimulants and narcotics, especially alcohol.

H. Newell Martin.

This edition has been revised in accordance with the wishes of the Committee of the Women’s Christian Union of Maryland, who now. endorse and recommend the book.

Contents

CHAPTER PAGE

I. The General Plan on which the Human Body is Built... i

II. The Skeleton . 12

Chapter I. The General Plan On Which The Human Body Is

BUILT.

1. Why we should Learn about our Bodies.—Suppose you had given to you a delicate instrument, such as a watch: you would desire to be told something of the way it was made, how it was to be used, and what was apt to harm it. Even a little knowledge of these things would help you to take better care of the watch.

Now every one of us is responsible for the care of a body made up of many more parts than we find in a watch, and any of them liable to be injured in number¬ less different ways. If all the parts work well we are in health, able to enjoy our lives, do our work, and aid those who are less fortunate. If we lose our health we not only can do less and enjoy less ourselves, but are likely to become a burden upon others. It is therefore one of

I. If you have a watch, what ought you to know of it, and why * What is the nature of the machine given to every human being to take care of? If it is kept in good order, what is the result? If not ? What then is our duty with regard to it?

our first duties to learn enough about our bodies to be able to avoi#> doing things likely to harm them, or nejg- ; lecting to do that which is for their welfare.

2 . What Anatomy is.—We could not look at the watch without seeing that it was made up of different pieces, as i case, and face, and hands; and a glance at the works, in¬ side would show us that dozens of parts, such as wheels, and pivots, and springs, and screws, without which the portions we see on the outside would be useless, were fixed together in a special way to make the watch.

Likewise, on looking at the outside of the body you easily perceive head, and neck, and trunk, and arms, and legs; and if you could see into the inside you would find hundreds of other parts, which move the parts you see and make them useful. The science which teaches us the shape and size of all the parts of the body, where they are placed in it, and how they are joined together, is named Human Anatomy .

3 . What Physiology is.—On examining the parts of which a watch is made we find that each has its use: the case to protect the works, the glass to let us see the face and yet keep out dust, the hands to show the hour, the spring to keep it going, and so forth.

In like way it is found that the various*parts of the body have their uses: as the eyes to see, the mouth to eat, the legs to walk with. The science which teaches the uses of all the parts of the body, more particularly of its inner parts, is named Human Physiology .

2. What do we easily find out on examining a watch? In this re¬ spect how may the body be compared to a watch? What is Human Anatomy ?

3. Why are there many parts in a watch ? In the body? What h Human Physiology ?

tTYGlEKE.

4 . What Hygiene is.—Lastly, when you had learned something of how the watch was made and wfcat each part of it had to do,you would know that certain things must injure it; that it should be kept dry lest the steel springs rust, and that the case must be kept closed to prevent dust and grit from getting into the works. You might also be told some things which it would take you a longer time to find out for yourself; as, for example, that if the watch is to be a good time-keeper it must be regu¬ larly wound up, and not at one time one day and at another the next, or perhaps quite forgotten a third.

So, without learning much Anatomy and Physiology you will readily see that certain things must be bad for your body: such as getting wounds that will cause great loss of blood, or going without food. The harm¬ fulness of other things it might take you a long time to find out by yourself; as, for example, that by breathing foul air or taking too little sleep, eating imprudently or drinking what is called “ spirits,” you might very easily injure your body.beyond cure. Unless you were warned you would probably not discover the danger until too late to avert it.

Just as a watchmaker could save you a great deal of time and risk by giving the results of his experience as to the best way to manage a watch, physicians and others who have made a study of what is good and what bad for the human body can save us much labor and danger by telling what they have found out. The science which

4. Having examined a watch, what would at once occur to you about its preservation ? What studies teach you that certain things would be bad for your body? Name some injurious habits that the experience of others warns you to avoid. What is meant by Hygiene?

ORGANS ANb TISSUES.

teaches what is good and what hurtful to our bodies—in other words, how we may best preserve our health—is known as Hygiene.

5. Organs and Functions.—The separate parts of which the body is made up are called organs: thus the eye is the organ of sight, the teeth are organs of chewing, the stom¬ ach is an organ of digestion. The use of any organ is spoken of as its function: thus the function of the eye is seeing, of the ear hearing, of the hand grasping.

6. The Structure of Organs.—The human body, like a watch, not only has numerous parts, but these parts are made of different materials. Taking the hand, for ex¬ ample, we observe on the outside, skin, nails, and hairs. If the skin were removed we should see below it sorpe fat, just like that in beef and mutton. Under the fat, in the ball of the thumb you would find some red flesh, called muscle , which answers to the lean of meat. Be¬ neath all the rest would be white hard bones. At the finger-joints where the ends of separate bones come near together you would see covering each a thin layer of gristle or cartilage. And binding together the skin and fat and muscles and bones would be found a stringy sub¬ stance which, as it unites all the rest, is called the con - nective material.

7. Tissues. — Each kind of material used in constructing the body is called a tissue: and each tissue has its own peculiar properties. Connective tissue is tough and suited

5. What is an organ ? Give examples. What is a function ? Il¬ lustrate.

6. What is meant by the structure of an organ ? Describe the structure of the hand.

7. What is a tissue? Name and describe some tissues. Name Some liquids of the body.

THE TLAIV ON WHICH MAN'S BODY IS BUILT. $ to bind parts together. Bony tissue is stiff and useful to sup¬ port softer parts. Cartilage tis¬ sue is elastic and forms admir¬ able springy cushions between the hard bones. Muscle tissue has power to move parts to which it is joined; and so on.

In addition to the solid tissues, liquids form part of the body: as the blood which we see flow from a cut finger, and the saliva which moistens the mouth.

8. The General Plan on which the Body is Built.—If a man’s body were sawed in two down the middle, so as to separate it into right and left halves, we should see something like Fig. i, if we looked at the cut surface of the right half. On examining the figure you see that there are two chief cavities or chambers in the body, having between them the row of bones e e; these bones together form the back-bone or spine. The chamber, B, C, in front of the back-bone is much the larger; it is named the ven¬ tral cavity. The other chamber, a, a f ’, is the dorsal cavity.

Fig. i.—A section along the mid¬ dle of head, neck, and trunk, b , the chest, and c, the abdominal division of the ventral cavity separated by the diaphragm, d. a\ the enlarged upper end of the dor¬ sal cavity, containing the brain, N'. < 7 , the lower narrower part

of the dorsal cavity containing the spinal cord, N. e . e , the partition formed by the back-bone between the ventral and dorsal cavities, i, the nose, o , the mouth. /, the lungs; the tube leading down to them is the windpipe. A, the heart, f. the stomach; the tube leading down to it is the gullet; the tube passing from the stomach to the lower end of the trunk is the intestine, k, a kidney. s , the sympathetic nervous system.

8. I low does the plan on which a watch is made compare with that on which the body is constructed? In a human body cut down the middle what chief divisions would you find?

THORAX AND ABDOMEN.

9 . The Ventral Cavity, as you perceive in the fig¬ ure, does not reach up into the neck or head. It exists only in the trunk of the body, and is divided into an upper story, B, the chest or thorax , and a lower story, C, the abdomen, by a partition, d, which forms the floor of the thorax and the ceiling of the ab¬ domen. Tliis partition is the diaphragm. How far in vour own body the chest-cavity extends you can find out pretty accurately by beginning at the bottom of the neck and feeling down along the middle of the front of your trunk till you feel no more bones through the skin: that level marks the bottom of the thorax.

10 . Contents of the Thorax --On Fig. i you will also see that the mouth, o , and the nose, i, join behind, and that from the place of meeting two tubes run down the neck. The front one of these tubes is the windpipe or trachea; after entering the thorax it ends in the lungs, l In the thorax is also placed the heart, h.

11. Contents of the Abdomen.—The second of .the tubos above referred to is the gullet or oesophagus. It runs right on through the chest and diaphragm into the abdomen, and there opens into the stomach,/.

The air we take in when breathing goes along the windpipe to the lungs, but no further the food and drink which we swallow take a longer road along the gullet to the stomach.

In addition to the stomach, the liver, the intestines or bowels, and the kidneys , k, lie in the abdomen.

9. Where is the ventral cavity? Name its divisions. The partiturn. How can you trace the chest or thorax in your own bodv ?

10. Name contents of thorax. J

11. What is the course of the gullet ? Its use ? Use of the windpipe? Name the organs which lie in the abdomen.

CONTENTS OF THORAX AND ABDOMEN. 7

12. What would be seen if the front of the Thorax and Abdomen were cut away. —This is represented in Fig. 2 . Stretching across from side to side is seen the diaphragm,

Fig. 2.— The trunk of the body opened from the front to expose the contents of the ventral cavity, zz, the diaphragm ; lu, lu the lungs ; h , the heart; ma. the stomach; mi, the spleen; ne’ ne , the membrane (gnat omentum) which hes in front of the intestines and kidneys.

12. Name the parts which would be exposed if the front wall of chest and abdomen were cut away. State their positions.

VERTEBRATE ANIMALS zz. Above the diaphragm, in the thorax, are the lungs, lu,lu. Between the lungs is the heart , h , partly covered by fat and other things. Below the diaphragm is the liver , le, le’, the stomach , ma, and the spleen, mi. Hanging down from the stomach is a sort of apron, ne , ne; if it were lifted up we should find behind it the intestines and the kidneys.

13. The Dorsal Cavity (<7, a ', Fig 1 ) is found in the head and neck as well as in the trunk of the body. If the back or top of a man’s head were cut away the upper end of the dorsal cavity would be opened and we should find it to be a large chamber having the brain , N\ in it. In the neck and trunk the dorsal cavity is a narrow tube con¬ taining in its upper two-thirds*the spinal cord, N.

14 . Man is a Vertebrate Animal. —The presence of the ventral and dorsal cavities with a hard partition between them is a chief fact in the anatomy of the human body: it shows that man is a vertebrate animal , that is to say, is a back-boned animal, and belongs to the same great group as fishes, reptiles, birds, and beasts. Worms, clams, and insects are invertebrate animals , that is, have no back-bone

15 . Man’s Place among Vertebrates. —We have seen that man is a vertebrate, or back-boned animal. Though all vertebrates are alike in the general plan of their structure, there are such differences that zoologists di¬ vide them into classes. The most important of these

13. Where does the dorsal cavity lie ? Name its contents and give their position.

14. Why is man a vertebrate animal? Name some other verte¬ brates. How are vertebrates distinguished from invertebrates ? Give examples of invertebrate animals.

15. Why are vertebrates divided into classes? To which class does man belong? Name some other mammalia. How do mamma¬ lia differ from other vertebrates ?

CHEMISTRY OF HUMAN BODY.

classes is the mammalia , to which man belongs. Ordinary four-footed beasts, and monkeys, are also mammalia. The mammalia differ from all fishes, reptiles, and birds, first, in the possession of organs, the mammary glands •, which provide milk for the young; second, in possessing hair; third, in having the chest separated from the ab¬ domen by a diaphragm.

16. The Intellect of Man makes him superior to any other animal and supreme in the world.

H is power to form conceptions of right and wrong and his knoialedge of moral responsibility give him yet greater supe¬ riority. But as a material object only, do anatomists study man’s body, and they therefore classify it among the bodies of other animals according as it differs from or resembles them in the arrangement of its parts.

17. Chemistry of the Body. —Suppose you put a green stick into the fire: what happens? At first it hisses and gives off steam; then it begins to burn; if you draw it out When half burned you find it a black mass of charcoal; if you put it back you find most of the charcoal will burn away, but some ashes will be left which you cannot make burn. If, instead of a green piece of wood, a man’s body be burned, we find the same results. From this we learn (i) that the body contains water; ( 2 ) that it contains solid things which will burn; ( 3 ) that it con¬ tains solid matters, the ash, which will not burn.

16. What makes man superior to all other animals? What gives him yet greater superiority? From what standpoint is man studied by anatomists? How classified ?

17. What would be the action of fire on green wood? On man’s body? Hence what do we learn? What name is given the materials which burn up? What those which will not burn? Of what is every tissue composed ? In which do we find most water? Mineral matter? Animal matter?

id

StJMMAR Y.

The things going to make up the body and capable of being burned are known as animal matters ; the ashes are mineral matters . In every tissue of the body there are water, animal matter and mineral matter. In some a great deal of water, as in the blood; in others a great deal of mineral matter, as in the bones and teeth, which owe their hardness to lime; in still others a great deal of animal matter, as in fat and muscle: but everywhere some of all three.

18. Summary. — Anatomy is concerned with the form and structure of the parts of the body.

Physiology with the uses of the parts and the ways in which they work.

Hygiene with the conditions of life which promote the health of the body.

The materials of the body are hard or soft, solid or liquid, and are fitted for different purposes.

Tissue is the name given to each of the materials, whether blood, bone, muscle, fat, or any other.

The organs are formed of tissues combined in various ways. Each organ has its own particular duty, or func¬ tion, which in health it performs in harmony with all the others.

Vertebrates are animals having back-bones—such as man, beasts, birds, reptiles, and fishes. Their bodies contain two main cavities, dorsal and ventral. In the dorsal cavity are the brain and spinal cord. The ventral cavity contains lungs, heart, stomach, liver, intestines, and kidneys.

18. What does anatomy deal with? Physiology? Hygiene? What have we learned of the materials of the body ? Of tissue ? Of the organs? Of vertebrates? Of invertebrates? Of mammalia? Of the chemical constituents of the bodv ?

SUMMAR Y.

Invertebrates are animals having no back-bones—such as worms, clams, and insects.

Mammalia is the highest of the several classes of verte¬ brates and includes man, monkeys, and four-footed beasts. It is characterized by the presence of mammary glands; by the fact that the ventral cavity is separated into chest and abdomen by the diaphragm; and by having more or less of the surface covered with hair.

Water , animal matters and mineral matters compose the body. If it be burned the animal matters are consumed; the mineral matters remain in the form of ashes.

Chapter II. The Skeleton

1. The Skeleton. —By the skeleton of any animal we usually mean those hard parts which remain behind when the softer parts have decayed; as the shell of a clam or crab, or the bones of a bird or beast. In our own bodies, bones form the chief part of the skeleton; but other things help. A very young infant has a skeleton, but this skeleton is mad,e for the most part of cartilage , or gristle, and not of bone. As the child grows, more and more bone takes the place of the cartilage; but even in old age some cartilage remains. Moreover, a skeleton consists not merely of all the bones of a body, but of all the bones united together in their proper places. In our bodies they are bound together by tough stringy connec¬ tive tissue. The skeleton of the living body, as distin¬ guished from a dead skeleton made of dry bones joined together by wires, is therefore made up of three different things; namely, bones, cartilages, and connective tissue.

2. The Bones, two hundred and six in number (see table, p. 22), form the hardest, and stiffest, and heaviest

1. What is a skeleton? What change takes place in the skeleton of a child as it grows ? How are the bones of a skeleton put together ? What are the materials of the living human skeleton ?

2. Number of bones in the skeleton ? What part of it do they make? How do they provide support? Protection? How con¬ cerned in movement ?

EXPLANATION OF PLATE I.

A front view of a human skeleton with the ligaments and some of the cartilages in place.

For the names of the bones see the description of figure 3.

a Ligaments of the Elbow-Joint.

b The Ligament which is connected to the ventral surfaces of the bodies of the Vertebrae.

e Ligament connecting the Innominate Bone to the Spine.

/ Ligament connecting the Innominate Bone to the Sacrum. g The Ligaments of the Wrist-Joint.

h The connective-tissue Membrane which fills up the incerval between the two bones of the Forearm.

I A similar Membrane between the two bones of the Leg, and, lower down, l, ligaments of the Ankle-Joint.

1: A connective-tissue Membrane which fills up a hole in the Innominate Bone. n Ligaments of the Knee-Joint. o o Ligaments of the Toes and Fingers. p Capsular (bag like) Ligament of the Hip Joint. q Capsular Ligament of the Shoulder-Joint.

CAR TILA GE — CONNECTIVE TISSUE.

part of the skeleton. United in various ways, they pro¬ vide a stVong framework which supports the softer organs, and in some places, as the skull (Fig. 6 ) and thorax (Fig. 5 ), make strong boxes or cages in which delicate organs, such as the brain or lungs, lie safe. The bones are also concerned in the movements of the body; nearly all muscles pull first on some bone or other, and when the bone is made to move, it of course carries with it the surrounding soft parts.

3. Cartilage is what we know in meat as gristle: it is stiff enough to keep its shape, but can be bent with tol¬ erable ease; it is also elastic, so that it springs back to its proper shape, like a piece of whalebone, as soon as the force which has bent it ceases to act. You can easily feel on your nose the difference between bone and car¬ tilage. The skeleton of that part of it near the forehead is made of bone, and that of the lower part of cartilage. We can push the tip of the nose to either side, or up and down, but when we stop pressing, it returns to its place. The skeleton of that part of the ear which projects from the side of the head is also made of cartilage.

Cartilage is used in parts of the skeleton which have to be moderately stiff, but at the same time pliable and elastic.

4. Connective Tissue is used for several different pur¬ poses in the-body. To understand this, let us imagine a quantity of very fine strands of silk, some twisted into

3. What is cartilage ? Its properties ? How used in the nose ? In the ear ? Throughout the skeleton ?

4. To what may connective tissue be compared? Name and char¬ acter of its threads ? How are the cords made? The membranes? The loose portion ? Where do we find networks of connective tis¬ sue? Give an example.

14 A CTION OF ALCOHOL ON CONNECT IVE TISSUE.

strong cord or rope, ^ome woven into firm bands, some left in loose masses, and some made up into fine net¬ work. Connective tissue consists of threads, called fibres , which are much tougher and finer than any strand of silk. In some parts of the body these threads are united to form cords named ligaments , which bind bones together. Elsewhere the fibres are woven into bands or membranes which surround and support various parts. Lying in the crevices between different organs, forming a soft packing for them, we find loose fluffy bundles of connective tissue. Finally, very fine networks of this tissue run all through most of the organs, like the veins or ribs through the leaf of a plant, and support and unite their parts. If you watch the cook cut up a piece of suet, you will see the stringy connective tissue which penetrates it in all directions, and which must be re¬ moved from the fat because it will not melt in cooking.

5 . Action of Alcohol upon Connective Tissue.—All intoxi¬ cating liquors, such as wine, brandy, whiskey, beer, etc., contain alcohol and are known as alcoholic drinks. One very serious change in the body frequently produced by drinking such, is an excessive growth of the connective-tissue networks, especially in the liver and the kidneys. The tissue becoming too abundant crushes and slowly destroys the chief liver and kidney substance which it was meant to protect and support. The results are in¬ curable diseases. (See pp. 132, 189.)

6 . The Bony Skeleton (Fig. 3), like' the body itself, may be described as consisting of head, neck, trunk, and

5. What are alcoholic drinks ? How do they affect connective tissue?

o. Of what parts does the bony skeleton consist ?

THE SKELETON a

Fig. bone; bones; r, the tarsal n,—The bony skeleton, «, b , the skull; <r, <?, the back-bone; the breastu, the collar-bone; t , the humerus; y, the ulna; g, the radius; h, the carpal r, the metacarpal bones; k , the phalanges of the fingers; s, the hip-bone; thigh-bone; q y the knee-pan; /, the shin-bone or tibia; m, the fibula; «, the bones; 0, the metatarsal bones; /, the phalanges of the toes.

i6

THE BACK-BONE .

Fig. 4. — The spinal column viewed from the left side. C1-7, the ver¬ tebrae of the neck; D1-12 , the vertebrae behind the thorax. L 1-5, the verte¬ brae of the loins; .Si to Cox, the sacrum; CV1-4, the coccyx.

limbs. Its central part, which bears all the rest, is a stout, bony pillar, the back-bone , c , <?, on the top of which is the skull.

7. The Back-Bone, Vertebral Column, or Spine, is represented in side view in Fig. 4. Its upper part is made of twenty-four short thick bones piled one upon another, and each called a vertebra. Between each pair of verte¬ brae there is placed during life an elas¬ tic cartilaginous cushion. The lower part of the spine consists of two bones; a large one, the sacrum , extend¬ ing from Si to Co 1; and a much small ¬ er, the coccyx , reaching from Co i to the end.

Projecting from the back of each vertebra (to the right in the figure) is a bony bar, called its spinous process. Through the skin along the middle of the back we can feel the tips of these processes, and it is their presence which has given the name spinal column to the whole.

-A canal runs through the whole back¬ bone except the coccyx, and opens into the skull-chamber above. It is the lower part of the dorsal cavity ( a , Fig. i), and, as we have already learned, con* tains the spinal cord.

7. What other names has the back-bone? Divisions of its upper part? Lower part? What is the spinous process ? The dorsal cavity I

USES OF BaCJC-EOXE.

8. Uses of the Mode of Structure of the Spinal Column.—

The elastic cushions between the vertebrae make the whole column springy and prevent the transmission of sudden jars along it. By this means the soft brain, car¬ ried in the skull on its top, and the spinal cord lying in p IG 5 —The skeleton of the thorax, with some of the vertebra; of the neck and loins a lower neck vertebrae; 6 , the first rib; c, the collar-bone; d , third rib; c, seventh rib; g, last loin-vertebra; /<, the breast-bone; i, the shoulder-blade.

it, are protected from injury in running and jumping. These cushions also allow of a little bending between each pair of vertebrae, so that the spine as a whole may be bent a good deal. But no sharp bend, such as would nip the spinal cord, which lies inside it, can take place at any one point.

8 . Of what use is the cartilage between the vertebra in running- cr jumping? In bending?

18 RIBS AND STERNUM.—SKULL.—SUTURES.

9. The Ribs and Breast-Bone (Fig. 5).— The ribs are twenty-four slender curved bones, twelve on each, side of the chest. Every rib is attached behind to a vertebra, the top one to the first vertebra below the neck. In front, each rib ends in two or three inches of cartilage. The breast-bone or sternum , //, lies in front of the chest. Attached to its sides are the cartilages of most of the ribs. The two lowest ribs are not joined to the breast¬ bone and are sometimes called the free or floating ribs.

10. The Skull (Fig. 6 ) is made up of twenty-nine bones (see table, p. 22); those behind and above arranged to form the brain-box; and those in front, to support the face.

The organs of four of our senses, viz., those of hear¬ ing, sight, smell, and taste, are also protected by the skull-bones.

11. The Sutures, —Except the'lower jaw-bone, which is attached to the rest of the skull by a joint, to let us open and close our mouths, nearly all the skull-bones are very firmly united. In most cases the union is by a dovetail¬ ing, like that used by cabinet-makers. Each bone has its edge notched and fits accurately to the edge of the next. This sort of junction between bones is called a suture. It is well seen in Fig. 6 between the bone Pr and those in front of, behind, and below it.