Physiology and hygiene

Front matter

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Introduction

The dominant aim of this volume, aa of Boos One of Hygiene AND Health, is to make the instruction carry immediately over into practise. Many important facts and principles are presented, but never as an end in themselves. At every point the plans are laid and lessons organized to make it easy for pupils to live the hygienic truths learned and for teachers to help them secure this result- It follows from this statement that emphasis on hygiene is strong in the present text, as it was in Book One. In this volume, however, the hygienic element is more definitely related to physiological function and to anatomical structure in order that the pupil may more fully understand the laws and prindples which govern right physical living.

An attempt has been made to approach each topic on the plane of the pupil's interests and physical needs. Sdentific truths are stated in simple language without technicalities. The exercises and problems assigned are adapted to the age and understanding. The experiments suggested and investigations asked for are such as can be carried out in any school or home. The applications made are definite and practical and have a direct bearing on health and growth. The whole treatment seeks to stimulate interest and pride in clean, well-formed, healthy bodies, trained to skilful uses.

Teachers will appredate the effort to make the text teachable as well as leamable. Point? of major importance are set out by numbered and indented paragraphs, or by other devices which make clear assignment easy and careful testing of results possible. Besides the thought problems and simple experiments found in connection with nearly every lesson, questions are appended to each chapter on the facts contained in the text of the chapter.

This volume will have accomplished its purpose if it in some degree helps advance the effort to make our schools an effective instrument for raising the general level of health and increasing the physical efficiency of our people.

The material in Chapter XLIV, Exercises for Health and

Skill, is to be used throughout the term.

The Authors.

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ACKNOWLEDGMENTS

Acknowledgments are due and gratefully rendered the following organizations and persons for permission to use photographs supplied by them: Boston Y, M. C. A,, for pictures appearing on pages 2, 5, IS, 60, 85, 241, 309; Boy Scouts of America, for pictures appearing on pages 19, 57, 74, 118, 172, 178, 264. 265, 323 ; Boston public schools, for pictures appearing on pages 3, 9; National Girl Scouts for pictures appearing on pages 41, 148; United States Department of Agriculture, for pictures appearing on pages 150, 232; National Tuberculosis Association, for the picture appearing on page 80 ; A. B. Saunders Company, for pictures appearing on pages 212, 215; and O. A. Morris for pictures appearing on pages_319, 325. The Michigan Bulletin furnished most of the pictures in the chapter on Calisthenics, O. H. Benson furnished several out door scenes and the Los Angeles Y, M. C. A. two swimming pictures.

The Auth<h[s.

Contents

CHAPTER PAGE

I The Bodv in AcnoM 1

II The Muscles at Work 11

Index

. . 352

;,t7cdVGOOgIC

DAILY HEALTH GUIDE

Fruit, ceieals and plenty of milk, e^s, bread and butter.

No coffee or tea at any meals.

Eat dawly, walk to school, iflon't run.)

Going and Coming

Take ten deep breaths slowly, shoulders straight and head up.

Don't sneete near another person.

Use your handkerchief. Don't spU.

Haaa

Wash your handi and face; use soap. Glast of water before eating.

Bcsidea meat and potatoes, or rice, eat plenty of vegetables and only plain puddings or fruits. Chew each mouthful thoroi^hly.

Mtmmaa

Walk slowly after eating. Keep cheerful.

Play out-of-doors after schotd.

Ennttng

Wash face and hands. Glass of water.

Plenty of milk and fruits and fti>h or ^gs instead of meat. Fried foods are hard to digest.

Top and bottom.

SLEEP OUT-OF-DOORS WHEN YOU CAN.

Chapter I

Did you ever time yourself for a sixty-yard dash? Or test how many times you can chin on the bar? Or how far you can jump from a standing start?

These are important questions for boys in the schools of many towns and cities which have school athletic leagues; for those who can make a certain record, providing their school work is satisfactory and their physical posture good, are given a badge from the Athletic League.

School athletic records. — ^This is the record for seventh and eighth grade boys that will win a bronze badge in some of the leagues:

6o-yard dash 8 3/5 seconds

Chinning on the bar 4 times

Standing broad jump 5 feet 9 inches

The boy who can make a still better record wins a bronze silver badge. For the bronze silver badge, this is the record that he must make: I

B .Vj •.4'I^ySfpLDGY-AND HYGIENE

6o-yard dash indoors 8 seconds

lOO-yard dEish outdoors 14 seconds

Chinning on the bar 6 times

Standing broad jump 6 feet 6 inches

Girls also have contests in walking, swimming, basketball, relay races and folk-dancing. Girls may

Start of one-hundred-yard dash

win honors in these lines the same as the boys in their contests.

Of course it is a high honor to win a badge for physical strength and skill. Every sensible person desires a strong, well-built body, and we also want our bodies to show skill in action.

Success depends on skill. — All the world's work and achievement, as well as its play, depend on some form of action. I recently watched a girl writing in a typewriter speed contest. The record showed that she was able to make about fifteen separate movements each second with all of the fingers of both hands. She received a- valuable prize in the contest, and she also earns a fine salary. No matter whether we work in factory, mine, shop or office, our bodies must be

Leamii^ muscular control and grace of carriage and

capable of moving quickly, skilfully, and easily, to perform whatever tasks we require of them.

The "master- tissues." — All the body's movements of every kind are brought about by the muscles. Muscles and nerves have been called the master-tissues. This is because of the important work they perform, and also because most of the other tissues of the body work to support the muscles and nerves.

Each of us has more than five hundred different muscles in his body. Some are large and some are small, but scientists have studied every one, and given each its own separate name. We may be glad that it is not important that we should commit all of these names to memory.

The muscles taken together make up what we call the flesh of the body. When we buy beef-steak or any lean meat at the market we are buying muscles. If you weigh eighty pounds you have altogether about forty pounds of muscle in your body; for your muscles make up about one-half of your entire weight.

The part of the tendons.

■ — Muscles are attached to bones by means of tendons.

A tendon is a very strong, whitish, inelastic cord. You can easily see the tendons underi^eath the skin in the back of the hand, and feel them as they work.

The tendons are smaller than the muscles to which they are attached. This makes them better able to work over joints and at other places, as the hand or the foot, where muscles would be too large and clumsy.

How muscles produce movement.— The muscles

are elastic; they can contract and expand like a piece

of rubber. When the muscle at the front of your

upper arm (called the biceps) contracts it bends the

The high jump

elbow joint and draws the hand up toward the shoulder. The bones serve as levers for the muscles to act upon. Grasp the biceps of your right arm with the other hand while you bend your arm as sharply as you can. Feel the muscle swell up and become larger around as it grows shorter. Have some one measure the girth of your arm when it is extended and again when you have it tightly bent. The difference in circumference represents the increased thickness of your biceps when it is shortened by contraction.

Pairs of muscles. — An interesting thing about the muscles is that most of them work in pairs. When you bend the forearm up toward the shoulder you find the biceps in the front of the arm growing large because it is'shortened. When you straighten the arm out again, if you feel the muscles at the back of the arm you will find them growing larger as they pull the arm straight. Muscles which flex (or bend) our joints are called flexors. Those which straighten the joint out are called extensors.

Muscles which we can control. — Most of our muscles are under the control of our wills. That is, we can make them act or be still as we please. We can move the arm or keep it quiet. We can say to the muscles of our legs, "Now make me walk," and they carry out our orders; we can say to the muscles of our arm, "Now strike," and the blow comes. Muscles that we can control in this way are called voluntary muscles.

Other muscles which we can not control. —

There is another class of muscles, however, that we can not control by our wills. Such a muscle is the heart. Suppose you try to make your heart stop beating by thinking about it. Suppose you say, "I will make my heart beat faster just by choosing that it shall." You loon find that you are unable to control the beating of your heart. Your heart goes on in the same fashion no matter whether you will that it shall beat faster or slower; its muscle is involuntary.

The muscle which makes up the greater part of the stomach and food canal is also involuntary. It will not obey our commands. In the same way the muscles in our arteries and veins take care of themselves and go on doing their work day and night no matter whether we are thinking about them or not.

We may say in general that the muscles that cause movements which are always about the same, as the beating of the heart, or the action of the stomach, are involuntary; they go on acting without any attention or direction. On the other hand, muscles which cause movements that must be done quite differently at different times, such as the movements of the arms, legs, or many other parts of the body, are voluntary; these muscles move as we direct them to move, or remain still when we choose.

The structure of a voluntary muscle. — You can

easily understand the structure of a: muscle, or how it is made, if you will take a piece of lean beef that has been boiled until it begins to fall apart. You will notice that the muscle separates into small strands, and that there seems to be a very thin, almost transparent tissue wrapping around these various little strands.

Now if you will take a needle or some other sharp pointed instrument, you can still further separate these little bundles into smaller fibers. This picking them to pieces is called "teasing" them. If you are careful and use a microscope you can keep on teasing the bundles out until you have found very small fibers indeed. In fact these fibers are so small that it would take five hundred of them laid down side by side close together to make one inch.

We may think, therefore, of the. voluntary muscle

as made up of bundles of very small fibers wrapped

around by thin tissue and then more bundles laid side

by side with these until the entire muscle is finally

formed in this way. The heart muscle is made up of

shorter fibers wrapped up in bundles, while the muscle

of the arteries, veins, stomach and food canal consists

of tiny short fibers arranged, not in bundles, but in

sheets.

Interssting experiments. — i. Show how muscles

work in pairs, one bending a joint and the other

straightening it again. You can illustrate by

using the muscles of the arms, legs, neck, hips,

etc. How many pairs of antagonistic muscles

can you locate? Remember that a muscle which

bends a joint is called a flexor muscle and one

that extends a joint, or straightens it out, is

called an extensor muscle.

2. Boil a piece of muscle until it begins to separate into bundles. Then take two needles and fasten them in round pieces of wood somewhat larger than matches. Use these instruments to tease the separate strands apart to show the smallest

Chinning the bar placed in a Bchool-room door

fibers you can discover. Show also the thin

wrapping tissues that cover the bundles of

fibers.

Notice the diflference in the movements of a

skilful piano player and one who is just leamlo PHYSIOLOGY AND HYGIENE

ing; of a baseball piayer throwing a ball, and a girl throwing it; of a soldier or other person of good carriage walking, and a slouchy, "loosejointed" person walking. What other illustra- - tions can you suggest? Explain how one gets skill in the use of his muscles.

Questions to answer. — What are the usual school Athletic League's requirements for a bronze badge, or a bronze silver badge? Why should one develop muscular skill? What are the "master-tissues" of the body? Why are they so called? What are the tendons for, and where are they found? How do muscles act to produce movements? What do we call the muscles we control? What do we call the muscles we can not control? Of what is a muscle composed? How may we go about it to examine the muscle fibers in a piece of lean meat?

1. Would you rather be in the winner or the loser group in the contests pictured in this lesson? What factors will do most to determine which group you must join?

2. Do you know persons who seem to have headache or toothache or earache or something else the matter with them a good deal of the time? How may one escape these ills?

3. Thousands of dollars are spent by cities and schools upon playgrounds for children. Why is this done? What should the children do in return?

Chapter II

. THE MUSCLES AT WORK

When you have chicken for dinner, which piece do you prefer, a part of the breast, a leg or a wing? No matter which piece you take, you eat muscles. Yet the taste is very different, and while the muscle of the breast or wing is tender, that of the leg may be rather tough.

You have had beef-steak that was tender and easily chewed. Another time you may have had a piece so tough that it took all the strength of your jaws and all of your patience to masticate it.

What is it that makes one piece of muscle tender and another tough when we come to eat it?

How muscles grow firm and strong. — In order to answer this question, we shall need to refer again to the muscle fibers and the way they are wrapped together in bundles. Each of these tiny fibers is wrapped in its own little sheath, called by the hard name sarcolemma (sar c6 16m' ma), and each of the bundles of fibers is also enclosed in its own separate wrapper, while several of these bundles are bound up

XI into still larger bundles by still coarser wrappers. These wrappers which enclose the bundles of fibers are not like the sarcolemma, — the sheath of one single fiber, but consist of another kind of tissue called con- . nective tissue. It is found in all parts of the body, binding all the various parts of organs together and strengthening and protecting them. It threads in and out among all of the bundles of muscle fibers, binding them together and helping to give them their rigidity and shape.

Now there are two things that will make these tissues grow hard and tough. One is age. The young chicken or turkey is tender because its connective tissue has not yet thickened and hardened. The old fowl is tough because this tissue has grown dense and hard.

The other thing that will cause muscle to grow hard and tough is exercise. The breast or wing of the chicken is more tender than the leg because the muscles of the chicken's breast and wing have but little exercise, while those of the legs are constantly used. The law therefore is that muscles grow hard and tough with age and with use.

When muscles are not used. — ^You can eaaly

test this difference by feeling of the muscles of a child's arm and then testing the muscles of ^e arm of a blacksmith or some other person who labors with his arms.

THE MUSCLES AT WORK 13

Nobody wants muscles that are flabby and weak from lack of exse. We want our icies hard, firm tough. And we J depend upon it t our muscles will possess strength endurance unthey are conitly used and dened to their k.

'raining tlie iscies of tlie

;e. — An import fact about mus-

is the ease with ich they are ned. Suppose

now stop and ik of some person

The way the muscles would look without whose face USUally their covering of aidn a,»d fat ,^j^g ^^^^^^ ^^^^

and unpleasant. Of course he may smile now and then, but the habit of his expression is to be glum. On the other hand, think also of some friend whose face is cheerful, happy, and bright, and who instead of a frown, usually has a smile hovering about his mouth and eyes.

The expression of our faces is caused by the muscles which He just underneath the skin of the face. If these muscles have been trained to pull the face into a sour expression, if they are accustomed to turn the comers of the mouth down, and make a frown between the eyes, then they soon keep this form of expression. We then have the habit of a sour expression. If, on the other hand, the facial muscles have been trained to smile, if they have been made to turn the comers of the mouth up in place of down, then they easily take this position and give us a bright and cheerful expression. It is all a matter of habit. The muscles easily settle into the form in which they are commonly used.

Muscles that keep the body straight. — This same law is seen in the way men carry their shoulders. If you look out upon the street as men are going to their work, you will see that some have stooped, bent shoulders, and that others carry themselves upright, with shoulders straight and head up. Some stoop because of illness, but the most of these men with bent shoulders are the ones who have got into the habit of stooping as they work, and their muscles have settled into the shape in which they are con-

THE MUSCLES AT WORK 15

stantly used. The men who carry themselves erect are the ones who have trained their back and shoulder muscles to hold the body erect as they work; and their muscles have come to take the form which keeps the body straight and in good posture. Have you not been surprised at the great difference a few weeks of e where the winning athletes and strong healthy training in the army have made in some of your friends? When they went to camp they slouched along as they walked, but now they stand erect, and with what a beautiful gait they walk!

It is important to remember that muscles finally come to fake the form in which they are most commonly ■used.

With this law in mind see whether you can answer the following questions:

1. Are any of the pupils in your school room training their muscles in such a way that they will come to have stooped shoulders and hollow chests?

2. Are there any who, because they generally have an unpleasant expression of the face, are training their face muscles into undesirable habits?

3. Do you know people outside of the school who, through wrong postures when at their work, have so trained their muscles that their bodies are no longer well shaped? Do you know other people who have so trained their muscles that their bodies are as straight and erect as when they were young?

4. Are you allowing any of your muscles to develop undesirable habits?

Good muscle habits to form. — i. Make the muscles of the back and shoulders keep the body erect, the shoulders back, and the head up. This will not only give you a good carriage, but will keep you from becoming stoop-shouldered, hollow in the chest and of bad form in general.

2. Train the muscles used in walking to give you a firm, even step, such as shows decision of character, rather than to allow a careless, shambling gait, which is always unattractive.

THE MUSCLES AT WORK 17

3. Train the muscles of the face to smile instead of to frown. Do not allo'v them to twitch, grimace, or to acquire any other mannerism which is undesirable.

4. Train the muscles of speech to bring out each sound clearly and distinctly, not mumbling words nor cutting off

sounds at the ends of words as people often do when they say atC ioT aTid or goitC for going.

Questions to answer. — ^What is the tissue called which is found wrapped around bundles of muscle fibers? What is connective tissue and where is it found? What is it that makes some lean meat tough while other meat is tender? How can we make our muscles firm and strong? Explain how the muscles of the face act to give us different expressions. How Miudesof may we train our face muscles so that the leg we may have a pleasant look rather than a sour one? Why do some persons have stooped shoulders while others are straight and erect? What are some muscle habits good to form?

Chapter III Training The Muscles

Suppose the boys who read this lesson would like to increase the size of their biceps. Suppose the girls would like to cure themselves of drooping shoulders and hollow chests. What can be done about it? Can we change the size and habit of our muscles? Can we make them do the work we demand of them? Can we change awkward and unskilful muscles into muscles that are well controlled?

We can. It is comforting to know that muscles which so easily allow our shoulders and back to take wrong shapes and positions can just as easily be trained to make them take right ones; and that acts and movements which are awkward and bungling can be changed into well controlled, skilful ones.

Developing muscles through use. — ^Just to show how muscles will respond to training: Among my friends is a blacksmith, who is large of build and very strong. He works with both arms, of course, but he works most with his right arm. All day long he keeps his right biceps busy as he hammers the iron on his anvil. I recently asked him to let me measure the 18

TRAINING THE MUSCLES 19

girth of each of his arms with the biceps drawn up to full size. His left arm showed a circumference of sixteen inches, but his right arm measured nineteen inches.

This difference in size in the blacksmith's arms had

Everybody works at the Boy Scouts' camp

been caused by years of labor in which the right arm had been called upon for more work than the left arm. Whatever muscle is exercised, that muscle demands a larger supply of blood. The blood brings to the muscle additional food material. The muscle uses this food supply to increase its size, and so grows larger and stronger.

It has been proved many times by actual experiment that through proper exercise of the muscles a man of average size can increase the girth of his arm around the biceps as much as three-quarters of an inch in four or five weeks.

Muscle training and good posture. — ^The muscles of the chest and shoulders can be trained in the same way. There is no great trouble in increasing the girth of the chest by an inch or two in a few months' practise. It is all a question of proper exercise of the muscles. With careful attention given to full, deep breathing, and with erect carriage of the chest and shoulders the muscles will increase in size and strength.

In similar fashion we can develop the lai^e muscles of the back, which carry the shoulders and hold them in position. If we allow the muscles to become slack and the shoulders to sag, the muscles grow weak and flabby. On the other hand, if we make the muscles of the back do their work, if we give them exercise by requiring them to hold the shoulders straight and the body erect, then these muscles develop in size and strength so that they naturally and easily hold the body in good posture.

Muscles quickly respond to training, both in size and strength. A muscle soon comes to take the shape or form in which it does its work. It develops whatever of strength is demanded by the work it has to perform.

TRAINING THE MUSCLES ai

Training our muscles to skill. — Muscles must also be trained in skill. No one want^ to be awkward or clumsy in his movements. No one wants to be a slow or bungling workman.

I have a schoolboy friend who has practised until he can toss a number of small balls, keeping two in the air at one time. He is now working to see whether he can not keep three balls in the air. I have another friend who is working hard to gain skill on the typewriter keyboard, so that he may become an expert typist and so secure a good position. He also desires . to enter a typewriting contest soon to be held to see "whether he can not win a prize. They are both seeking muscular skill through careful practise and training of their muscles.

All of us are, of course, seeking to train our muscles to skill in many directions. We wish to learn to write a good, legible hand with fair speed. We would like to play the piano or violin ; or we are seeking to perfect ourselves in the handling of a tennis racket or a baseball bat. If not any of these things, then we are surely at work in a score of other directions trying to win skill for ourselves in our play or in our work.

The value of skill. — ^And this is all as it should be. No one likes the bungler. Every one should be ashamed of awkwardness which could be overcome by greater care and practise. The workman who does not attain both skill and speed never secures the higher salary, and never is certain of his job. The highest pay arid the highest hondrs, whether in work or in play, always go to the person who has learned to control his muscles, and who has made them the most serviceable in carrying out his will.

The boy who is learning to toss the balls has been working hard at it for a number of months. Season after season boys and girls play at different games, perfecting their skill in them. Year after year men work at their trades, developing both skill and speed, and finally become expert workmen. Through intelligent practise is the only way we can train our muscles to high skill.

D,g,t7cdb/COOglC

TRAINING THE MUSCLES 23

This, then, is the law of our muscle training: Skill comes only through well directed, faithful and continued practise. We must not aim simply at improving a little. We should never be satisfied with the skill we have already reached, but must always be aiming at something better. We should never say. Oh, that is good enough! We must rather say. No piece of work or act of skill is good enough until it is the best that we can make it!

Facts worth remembering. — i . Our muscles must be trained. Strength and skill do not come by chance; we must work for them. Harry Houdini, one of the world's greatest m^icians, tells how he is able to perform feats no other man can do. He says:

"No one except myself can appreciate how I have to work at this job every single day, never letting up for a moment. In each town where I play I hire an empty stable, or loft, or room, and here I put in hours upon hours of study and experiment." Even this great master of his art must practise daily to keep up his skill.

2. Nothing worth while is easy. If we would stand well, walk well, write well, play well, or .work skilfully we must give the time and effort necessary to train our muscles to their work. We can not stand awkwardly, slouch as we walk, write carelessly, play poorly, or work below our best without having our muscles form bad habits. We should strive to work, play, or do whatever we do always <a our best.