Our bodies and how we live; an elementary text-book of physiology and hygiene for use in schools with special reference to the effects of alcoholic drinks, tobacco and other narcotics on the bodily life

Front matter

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PRESEXTCD BY

BY ALBERT F. BLAISDELL, M. D.

Preface

REVISED EDITION

It has been the aim of the author in making this text-book, for the use of common schools, to present clearly and tersely the most important and interesting facts concerning our bodily life. To keep any machine in good running-order, we must know something of the structure and use of its various parts. So when we come to the study of this wonderful and complex machine, the human body, we must master such facts of its anatomy and physiology as are essential to a proper understanding of the simple laws of health.

The real object of studying physiology in schools is to teach young folks how to keep well and strong, and to avoid evil habits that destroy character as well as health. Hence, special emphasis has been laid upon such points as have a bearing upon our personal health.

It is now generally admitted that actual observation and actual experiment are as necessary in the study of elementary physiology as in any other branch of science. We must handle the skeleton itself if we wish

IV PREFACE

to get a fair idea of its bones. We must examine a drop of blood under the microscope if we would know how blood looks. Hence, as supplementary to the text itself, we have added a series of practical experiments. Most of them are simple, and require only a little painstaking and an inexpensive apparatus to do successfully. These experiments should be actually performed, and not merely read as a part of the text.

This book has been thoroughly revised. New sections and new chapters have been added, while others have been rewritten and rearranged. The new chapter on Physical Exercise, supplemented by a series of gymnastic exercises, will prove an attractive feature to those who realize the importance of physical culture to our young folks.

The author has aimed to make everything plain by using a simple and homely style of writing.

In the preparation of this revised and enlarged edition, the author and publishers are under deep obligations to Mrs. Mary H. Hunt, the Superintendent of the Department of Scientific Instruction of the National Woman's Christian Temperance Union, who has carefully revised the book.

Albert F. Blaisdell.

Introduction

i. Animal Life. — We need not be told that we have bodies made of flesh and bone, whose substance we see and handle every day of our life. Even a child knows that certain parts of his body, as the walls of his chest, and his heart that he feels beating within it, are always moving of themselves.

We can move of our own free will from one place to another. The wind may rustle the leaves, and a breeze may sway a strong oak ; but the leaves and the oak have no power to move of themselves. We need not wait, like the trees of the forest, for the wind to blow us to and fro, or, like the pebbles by the roadside, for some one to stir us. Like the horse, dog, bird, or any other animal that has life, we can move from place to place.

Every living animal, from ourselves down to the tiniest creature that lives its brief life in a single day, and that cannot be seen without the aid of the microscope, has the power to move of itself.

Again, every child must see for himself that he is warm. Even in the coldest day of midwinter, let the stones and trees be as cold as the winter wind, our bodies, except perhaps the tips of the fingers and toes, are always warm. The horse, dog, and even the birds and the bees, are warm. All animals, in fact, are more or less warm as long as they are alive.

2. The Body compared to a Locomotive. — Our bodies are in some rc5:e;:s very much like the locomotive. The bones and muscles answer to the machinery of the engine, and the motive-power is produced by the food we eat. We put fuel into the furnace. The water in the boiler is heated and expands into steam. Then the piston begins to work to and fro ; this moves the wheels, joints, and levers : and so the whole engine is set going by the fuel which is put into the furnace.

Now, just the same thing occurs in our bodies. We take food, and that food passes into the stomach. By reason of that food, we are kept warm, muscular force is developed, and the levers and joints within us are set working, as we see in the locomotive.

There is, however, an important difference between the two. The locomotive is all the time wearing:

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itself out. It must be stopped, taken to pieces, and repaired by the machinist. So our bodies are all the time wearing out, but they are constantly repairing themselves. We take food, not only to warm us, but also for the building-up and repairing of our bodies. Remember, then, that the body far surpasses the engine in the perfection of its mechanism, inasmuch as it is self-repairing.

3. The Body and its Nervous System. — If we exert our will, or " make up our mind " as we call it, to cross the room, to write with a pen, to pick a flower, to

INTRODUCTION 3

eat an apple, or to repeat some familiar maxim, we can do it. The mind, or brain, wills to do this or that thing. It sends out its order by the tiny, white, thread-like cords called nerves ; and the muscles are put in motion to do whatever the brain has willed them to do.

Every child must have noticed, that when he pricks his fingers with a needle, touches a hot stove, or has eaten some unwholesome food, like an unripe apple, pain is produced. These same silvery-white cords, like telegraph-wires, carry special despatches to the central station ; that is, the brain : and the feeling of pain is there made known.

This is the way every part of our bodies is watched over and protected. If it were not so, we should be continually hurting ourselves. This mind, which feels, and thinks, but which we cannot see, forms the essential part of our being. It is the power to feel, to know, to think, to reason, and to will, that makes us what we are. Our bodies are ever busy. We eat, drink, and sleep. We move about, and are warm. We feel, hear, see, talk, breathe, and think. We do not wonder about it, simply because it is so common.

When we do stop to think about it, how wonderful it is simply to be alive ! What study could be more important, interesting, and even fascinating, than that which has to do with the working of our own bodies ! We gaze with wonder and admiration at the marvellous work of some intricate machine made by man. Well we may, for it seems endowed with life. But, in the human body, we find, the more we study and think about it, not simply a most perfect and delicate machine, but one endowed with life, — a mind, — a soul.

Indeed, the more we study, and the longer we live, and reflect upon it, the more we shall realize the great fact that the All-wise Creator, in his goodness and wisdom, has made for us bodies, which, in the words of the Psalmist, are "fearfully and wonderfully made."

4. Anatomy, Physiology, and Hygiene. — Before we can tell how plants and animals live, we must know what animals and plants are. A watchmaker would be unable to describe the working of a watch or clock unless he first made himself acquainted with the various parts of which watches and clocks are made. So it is with the study of human beings. We must know the structure of their bodies before we can understand the manner in which these bodies act and move, or, in one word, live.

The science which tells us about the structure, form, and position of the different parts of the body, is called anatomy. 1 It tells us what they are, where they are, and how they look.

The science which explains the uses or functions of the different parts of the body is called physiology, meaning "a story about nature."

Now, after we have learned something about the structure and uses of different parts of the body, we should learn how to take care of these parts, and how to keep them in health. We do this by the study of hygiene, 2 or the science which tells us about health.

1 The word " anatomy " comes from the Greek, meaning " a cutting through," or dissection ; that is, the act of cutting an animal in pieces for the purpose of study.

2 The word " hygiene " is derived from the name of the Greek goddess Hygeia, who is said to have watched over the health of the people.

INTRODUCTION 5

Take the stomach for an illustration. If we learn what it is, where it is, how it looks, its shape, size, and general appearance, its coats, etc., this would be its anatomy.

If we learn for what special purpose it is made, just what these different parts do, and how they do it, this would be its physiology.

Finally, if we learn what might interfere with the proper working of each part, and how it is kept in good order, — what will injure its health, and what will do it good, — this would be its hygiene.

5. Some Technical Words Explained. — A child soon learns by experience many things about such parts of his body as the eye, the ear, the nose, the hands and feet, the tongue, and so on. Now, you must already know that there are other distinct parts inside of our bodies, although we cannot see them. You have doubtless heard of some of these parts, such as the heart, the brain, the stomach, the liver, and the lungs. It is usual to speak of these as the organs of the body.

An organ is a special part of the body which performs a special work. Thus the eye is the organ of sight, the nose of smell, the ear of hearing, the stomach of digestion, the lungs of breathing, and so on.

A number of organs, similar in structure, of different size and shape, extending throughout the body, is called a system. Thus we speak of the nervous system, the arterial system, etc.

Several organs, different in structure, but so arranged as to work together for some special end are called an apparatus. Thus the stomach and liver make up a part of the digestive apparatus.

The special work which an organ has to do is said to be the function or use of that organ : thus it is the function of the eye to see, and of the liver to secrete bile.

We speak of the body as being an organized structure because it consists of a number of organs, each performing some function necessary to the whole. One important fact must be borne in mind. Although each of these organs is placed in a distinct part of the body, and has its own special work to do, yet no one exists and works for itself alone. The special work

which eachperforms is necessary for the general well-being of the body as a whole, and cannot be carried on by another organ.

Some of the organs are more intimately connected with the life of the body than others. We often speak of them as the Tital fig. i. -Portion of a lining tis- Organs. If any one of these be

sue showing its bundles and filaments , . . .

of fibrous tissue, crossing in every diseased or injured, so that it

direction. The rounded bodies cannot carry Qn its prop er WOrk, represent a few fat-cells. Highly J - 1 *■

magnified. the rest of the organs sooner

or later suffer too, cease to perform their functions, and death ensues.

The organs and other parts of the body are composed of a variety of substances or materials. These we shall call the tissues of the body. They may be compared to the timber, stone, bricks, mortar, iron, lead, glass, and other materials, which, properly arranged, make up a dwelling-house. The principal tissues

INTRODUCTION 7

which make up the body are bone, or osseous tissue ; muscle ', or muscular tissue ; cartilage y or gristle ; fat and nerve tissue.

6. Minute Structure of the Body. — When we examine any part of the body with the microscope, we find it made up mainly of fibres, fluids, and cells. The original element out of which every other element of the body is formed is the cell. The fibres serve to give firmness to the tissues or organs and to bind the most minute parts of the body together. Fibres FlG . 2 ._ W ith biood-ceiis are properly whitish or yellowish in ra P id motion, as seen

under the microscope.

threads, slender as one can imagine.

Some are elastic ; others are not, but very tough and

strong.

The cells are so small that we must use a powerful microscope to see them at all. In a general way we may compare them to the tiniest bags filled with a semi-fluid mass, in which another still smaller bag floats, and is called the nucleus of the larger one. Cells are of all shapes and sizes, round, flat, thick, and long. Thus, we shall learn in a succeeding chapter of the rounded cells, or corpuscles, which float in the blood, and of the flattened cells which can be scraped from the outer or scarf skin.

The life of a cell is one of ceaseless change. It is ever changing its form. If we watch the cells under a microscope, we find them dividing themselves into parts with the greatest rapidity. In their never-ending changes, they are doing a remarkable work in our bodies.

Some change their forms, and become muscle : others become fluids, which help digest our food. The livercells manufacture or secrete the bile, and the bone-cells help make the bones. Milfig. 3. — showing how a ceil divides lions of blood-cells do their

into two new cells, each with its nucleus, as k d ^ ,

seen under the microscope. r J j >

.while the brain-cells act in some mysterious way to help us think. In short, our very life exists in the cell.

7. Chemical Elements found in the Body. — If we put aside the microscope, and call upon the chemist to help us, he will tell us that there are about seventy different elements known to chemistry. Of these, only sixteen exist in our bodies. The most important are carbon, hydrogen, nitrogen, oxygen, sulphur, iron, phosphorus, soda, potash, lime, and magnesium. Thus, there is iron in the blood, lime in the bones, soda in the bile, and potash in the muscles.

Very few of these elements exist as such in the body. They are mainly found as chemical compounds. Thus, water, a combination of oxygen and hydrogen, forms about two-thirds of the weight of the body ; and i the average human body contains about six ounces of I common salt, which is a form of soda.

8. General Build of the Body. — If we look at the | human body, we cannot help noticing that it is made | up of a middle, nearly round portion, which is called the trunk. On the top of this is placed a kind of round ball, called the head; while two pairs of branches, called the extremities, are attached to the upper and lower corners of the trunk.

INTRODUCTION

Again, we notice that the whole body has an outer covering, which is called the skin. Underneath the skin lie soft masses of red flesh, called the muscles. These muscles are mostly fastened to the hard parts, or bones. These bones make up the framework of our bodies. There are about two hundred separate bones in the body, which they serve to support. Taken together, they form the skeleton.

The limbs are solid ; but the head holds an important organ called the brain, which is the centre of the nervous system.

A delicate, silvery-white cord, called the spinal cord, runs from the brain down the middle of the backbone, and sends its thread-like branches, called nerves, all over the body. It is through the nervous system that we are able to think or feel, or, in fact, to know anything.

The trunk is divided into an upper and a lower room by means of a movable partition called the diaphragm.

The upper room is called the chest, and holds the heart and the lungs.

The lower room is called the abdomen, and holds the stomach, liver, intestines, and other vital organs.

Fig. 4. — Side view, showing the

Diaphragm separating the

Chest and Abdomen.

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9. General Plan of Study. — We shall now proceed to study some of the most simple facts about the human body, together with the laws of Hygiene that must be obeyed to insure its health.

iiG. 5. — Contents of the Chest and Abdomen.

Special emphasis will be laid upon the nature and the effects of alcoholic drinks, tobacco, and other narcotics.

Reference will be made to the value and importance of physical culture.

For convenience the whole subject will be considered under the following general topics : —

INTRODUCTION 1 1

GENERAL TOPICS.

1. The Skeleton, or bony framework.

2. Muscles, or the fleshy parts.

3. Physical Exercise in Schools.

6. The Digestion of Food.

8. The Respiration, or Breathing.

9. The Skin, or Outer Covering.

10. The Nervous System and the Brain.

12. Excretion, or getting rid of waste matter.

13. The Throat and the Voice.

1. The skeleton, or bony framework, consists of about two hundred bones of various shapes and sizes. It forms the main support of our bodies, ar.d serves to protect the vital organs within.

2. The muscles are the fleshy or lean parts of the body ; and they, together with the fat, give to the body its general form and proportion.

3. Physical exercise in Schools. Its practical importance and value in promoting the health of young people.

4. Food and drink are the materials necessary to keep up the warmth and growth of the body, and enable it to make its movements.

5. Origin and Nature of Fermented Drinks. Alcoholic liquors described, and their injurious effects upon the bodily life fully discussed.

6. Digestion is the process of changing the food into a condition suitable for absorption into the blood.

7. The blood is the vital fluid of the body. The course of the blood through the body is called its circulation.

8. Respiration is the act of breathing. It is carried on mainly by the lungs.

9. The skin, or the outer covering of the body.

10. The nervous system enables us to move, see, feel, taste, and so on. The brain and the spinal cord are its central organs.

11. The special senses enable us to touch, taste, smell, hear, and see. We often speak of them as the five senses, or the five gateways of knowledge.

12. Excretion is the process by which the body gets rid of its waste matters, mainly through the lungs, skin, and kidneys.

13. The throat and voice described.

Chapter II

10. The Skeleton. — Most animals must have some kind of a framework or support to give the body form or shape. This framework in many animals is a support made up of a number of firm and hard substances called bones.

The bones may be on the outside, like a coat of mail, as seen in the lobster and turtle; or there may be a framework of those inside of the body, moved by muscles outside, as seen in the codfish and shad. In fact, all animals that belong to the great backbone family have an inside framework.

This bony support is called the skeleton, meaning a "dried up body." It is to the body what the ribs are to a vessel, or what the frame is to a house. Every one is familiar with the picture of the human skeleton. It shows us how the dead bones of the human body look when taken out, cleaned, and held by wires in their proper places. The human skeleton is made up of about two hundred separate bones, 1 of various sizes and shapes.

1 To be more exact, 28 bones are counted in the head, including the three bones in each ear, 54 in the trunk, and 124 in the limbs. This number depends upon the time and how the bones are counted.

The 32 teeth are not usually reckoned as bones. Several bones, which in youth are made up of separate pieces, unite in old age, and make one bone. The breast-bone, for instance, in the child, consists of eight pieces ; but in adult life it is made up of only three.

H

The bones of the body thus arranged give firmness, strength, and protection to the soft tissues and vital organs, and form, as it were, the foundation upon which our bodies are securely built.

ii. How Bone is made up. — Bone is a hard and strong substance, made up of animal matter united with certain mineral earths, as lime and potash. The earthy part of bone makes up about two-thirds of its weight, and the animal portion the other third.

Put a slender chicken bone in a mixture of two ounces of muriatic acid and one pint of water, and let it soak for two or three days, and the earthy part will be dissolved, leaving only the animal matter. The form of the bone is kept ; but it can be easily bent, cut, torn, or even tied into a knot.

Again, put a soup-bone into a hot fire, and let it burn for two or three hours. Take it out carefully, and, while the shape is still kept, the bone is brittle, and will readily crumble when pinched between the fingers. The animal part has been burned out, and only the white bone-earth is left.

The lime gives hardness and firmness to the bones ; while the animal substance makes them elastic, tough, and flexible. The proportion varies with age. In childhood the bones have more animal matter than earthy: hence a child's bones do not break easilv, and, when broken, soon

Fig. 6. — The outer bone of the leg, tied into a knot, after the hard mineral matter has been dissolved out by acid.

knit together. In old age, there is more lime in the bones than animal matter : hence they are brittle, and easily broken. They unite slowly, and sometimes not at all.

12. General Structure of the Bones. — If we take a long bone, like that from a sheep's leg, or even a part of a beef shin-bone, and saw it lengthwise, we see that

Fig. 7. — A thin slice of bone, cut crosswise, as seen under the microscope.

the ends are soft and spongy, while the shaft is hard and compact. It is hollow, and the central cavity runs almost the whole length of the bone. It is filled, in life, with a soft substance called marrow.

If the bones were solid, they would be much too heavy for ordinary use. A bone may be hard as a rock on the outside, on account of its thin, dense layer of compact bony tissue, and yet be light because of its cavity and the trellis-work of loose, spongy texture at the ends.

Bones are of many different shapes, according to the uses to which they are put. Some are long, with hollow shafts, as the bones of the arm and leg; others are short, to give strength, as the bones of the fingers and toes ; some are flat, for protection, and to cover cavities, like the bones of the skull and shoulder-blades ; while others are of various odd shapes, and hence called irregular, as the bones of the backbone and ankle.

13. Minute Structure of Bones. — When bones are alive or fresh, they have a pinkish-white color, caused by the blood which flows through every part of them. Take a long, slender bone, like a rib or a sheep's leg, and we find that it is elastic, and will bend.

Now, if we scrape down on the bone with a sharp knife, we find that it is wrapped round with a tough but very thin covering, called the periosteum, meaning

Power of Bone to resist Decay. — " The power of bone to resist decay is remarkable. Fossil bones deposited in the ground long before the appearance of man upon the earth have been found to exhibit a considerable portion of cartilage. The jaw of the Cambridge Mastodon contained over forty per cent of animal matter — enough to make a good glue — and others about the same. From this we see that a nutritious soup might be made from the bones of animals that lived before the creation of man. The teeth resemble bone in their structure, but resist decay longer ; they are brought up by deep-sea dredging, when all other parts of the animal have wasted away. The bones differ at different ages, and under different social conditions. In the disease called ' rickets,' quite common among the ill-fed children of the poor in Europe, but somewhat rare in America, there is an inadequate deposit of the mineral substance, rendering the bones so flexible that they may be bent almost like wax. Exercise is as necessary to the strength of bone as to the strength of muscle ; if a limb be disused, from paralysis or long sickness, the bones lose in weight and strength as well as the soft parts. Bone is said to be twice as strong as oak, and, to crush a cubic inch of it, a pressure equal to 5,000 pounds is requisite."

"about a bone." All bones are covered with periosteum except where they go to form a joint. They would die if this covering were for any cause removed.

Bones have a great number of blood-vessels, which, becoming very small and hair-like, pass through tiny holes, or tubes, in the bones, and bring materials for their nourishment and growth. The tiny tubes called "canals," through which the blood-vessels of the bones travel, can be seen only with a microscope.

Round these tubes the bony matter is arranged in layers, and between these layers are small cavities.

These cavities are joined to each other, and to the canal which they surround, by other extremely fine tubes.

As seen under the microscope, the appearance is not unlike a small animal with a great many legs.

Thus the bones are tunnelled, like honey-comb, with passages through which the blood — " the river of life " — flows in every direction. (Fig. 7.)

Fig. 8. — Cross Section of Bone, highly magnified; the Canals are left white.

THE HEAD.

14. The Head. — The skeleton, or bony framework of the "house we live in," consists of the bones of the head, the trunk, and the extremities.

The bones of the head include those of the cranium and those of the face. Together they form the strong box of bone commonly called the skull.

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JBOHBA*

VEBTESE^

The general shape of the head is that of an arch. The arch is the strongest shape in which the skull could be made, just as the arched bridge is the strongest-shaped bridge which can be made to bear the heavy loads that have to pass over it.

15. The Cranium. — The Cranium, or brain-case, is a kind of oval, bony shell, which holds and protects the

Fig.

■The Skul brain. It is made up of eight bones closely locked together by seams or sutures, somewhat like the dovetailing used by carpenters. Let us arrange and describe these eight bones thus : —

One Frontal (forehead).

Two Parietal (side of head).

Two Temporal (temples).

One Occipital (back of head).

One Sphenoid (wedge-shaped).

One Ethmoid (sieve-like).

The frontal bone forms the forehead. It is this bone which gives a beauty of form and a dignity of person seen in no other animal in creation.

Two bones make the sides, or walls, of the head. They are called the parietal bones, from a Latin word meaning a wall. They join the two temporal bones, which lie round each ear, and form the " temples."

The occipital bone forms the lower and back part of the skull. This broad, flat bone rests on the topmost bone of the backbone, and is pierced by a large hole through which a long cord of whitish marrow, called the spinal cord, passes from the brain-case into the spinal canal, and runs down the whole length of the backbone.

The sphenoid, or wedge bone, is wedged in between the bones of the cranium and those of the face, and serves to lock together fourteen of these bones.

The ethmoid, or sieve-like bone, so called because it is full of holes, like a sieve, lies between the eye-cavities just at the root of tfte nose. The nerves of smell pass through the holes in this bone into the cavities of the nose.

1 6. The Face. — All the bones of the face, except the lower jaw-bone, are firmly fixed to each other, and to the bones of the cranium. By their union, these bones form five cavities ; namely, the two large cup-like cavities called the orbits, the two nostrils, and the mouth. The orbits are hollow, bony sockets in which the eyes are placed. In the back part of each cavity is a crevice through which the nerve of sight (optic nerve) passes from the brain to the eye.