Healthful living : based on the essentials of physiology for high school pupils

Front matter

Bot arenes ytttgeesemen?

Soha

VO.

Introduction

In writing this book, I have been guided by two considerations: first, to present the essentials of physiology for the high school pupil in a form that would provide motives and material that would enable him to interpret intelligently conditions underlying the problem of effective living, and second, to limit the technical discussion without making the subject matter worthless as a scientific text, incapable of providing the background necessary to secure the first consideration.

As regards the limiting of material, it is evident that the selection of what to give and what to omit is a matter of judgment on the part of the author. If that judgment is to be approved by the edueational world interested, then the anatomy should have a definite relation to the physiology, and the physiology, although it may give incidentally a scientific basis for more advanced study, should be determined by the larger question of usefulness in understanding essential life processes.

The material and the method of presentation have been tried out for several years with many students and there is reason for feeling that a proper and satisfactory selection of physiologic facts and principles has been made.

It is interesting to note that at one time physiology in the schools was merely the teaching of anatomy. “How many bones in the skeleton?” was a typical question. As the texts improved and the method changed, function was emphasized, and in most texts to-day, the presentation of

Vv vi Introduction function is the goal of endeavor. It should be remembered, however, that knowledge of the structure and function of the body is of value in proportion as it helps the boy or girl to live a finer and more vigorous life, or as it lays the foundation. for further study in this field. As regards these values, it : may serve effectively to teach not only hygiene, but also social science and ethics.

The study. of physiology should arouse interest in health in the student and provide guidance for intelligent care of the body. One effect of civilization on the race is that health is increasingly harder to maintain. The gradual but pronounced change in the character of our food, the increasing emphasis laid upon studies, the prevalence of bad housing conditions, the increase in sedentary occupations, and the enforced use of the transportation facilities are a few of the forces arrayed against the maintenance of health. The school does not stand alone and unrelated to these problems, and physiology to be of most service must help to educate the child in the nature of the human body and the dangers that confront its growth, development, and efficiency.

With this object in mind, distinct emphasis is given the application of the physiological fact to the life of the reader. Therefore, relatively little space is devoted to the study of the mechanism of the eye and ear; but the physiology of exercise is stated prominently, both in text and in illustration. The wisdom of such a course will be clear to every one whether he judges by the standards of ‘“‘pure science’’ or by those of ‘‘applied science.”

Spirited questions, which should suggest many others of similar character, are placed at the end of chapters. There are numerous laboratory experiments ; most of these require only the simplest apparatus or none at all. The text is not impaired if the experiments are not performed, but its value is increased by the demonstration of both structure and function. At the close of each chapter is a glossary of technical

Introduction vii terms used in that chapter. There is no thought of doing away with the need for consultation or reference books ; they are always necessary, and the brief glossary should stimulate to greater use of dictionary and encyclopedia.

To acknowledge the service of those who have contributed in the preparation of this book, gives me especial pleasure. The organization is based partly on the plan of Coleman’s Elements of Physiology. All rights in that work have been purchased by the publishers and this new book is offered to the school public without apology for similarities or identities, which are many. The task was to remodel a structure that had been very valuable but .was now in need of repairs. The repairs have been made but it would ill become me to deny the old in my enthusiasm for the new.

To Miss Marguerite Smith for the picture of girls’ athletics, to Miss Mary Gross for excellent illustrations of posture, to Dr. Frank 8. Matthews for the splendid pictures of adenoid deformity, to Dr. Thomas D. Wood for numerous health essentials which he has proposed, I desire to express my thanks.

Students, instructors and friends who have gone over this subject with me share with me whatever merit the book may have, but I desire especially to acknowledge the inspiration and help of Professor Henry Carr Pearson, principal of the Horace Mann School.

The criticism and suggestions of Professor Edward Lawrence Hall-Quest, of the University of Cincinnati, have been valuable indeed. Professor Hall-Quest has read the entire manuscript, correcting mistakes and revising statements. Numerous conferences with Professor William Paxton Burris, Dean of Teachers College of the University of Cincinnati have resulted in substantial aid in preparing the manuscript.

Credit should be given to the Harvard Apparatus Co., The Metropolitan Life Insurance Co., The American Posture viii Introduction

League; and The Scientific Temperance Federation for the privilege of reproducing illustrations that have appeared in other publications.

With such an indebtedness, I hesitate to call the book my own. However, I am glad to owe something to all of these. | J. F. W.

CHAPTER I. Il

IIT.

zy,

Part I How The Body Is Constructed

PAGE THE CEeLLs oF THE Bopy . : ; : j . 1-11 The cell, the unit of structure. The origin of cells. The properties of cells. Tissues formed from cell groups. Organs formed from tissues. Similarity between living organisms and social groups. Similarity between the human body and a city.

Tissups i i > ‘ ’ ‘ : . 12-37 Kinds of tissues. Epithelial tissues. Indications of good health.

TissugEs (continued) . ; . F ; ; . 388-59 Connective tissues. Muscular tissues. Nervous tissues. Building good tissues.

OrGANS FoRMED FROM TISSUES ‘ . ‘ . 60-71 The different systems in the body. Organs of the muscular system. Organs of the skeletal system. Organs of the digestive system. Organs of the respiratory system. Organs of the circulatory system. Organs of the nervous system. Organs of the excretory system. Organs of the reproductive system. PART II HOW THE BODY IS MOVED . Tae SKELETON FRAMEWORK OF THE Bopy ; . 72-94

The use of the skeleton. Parts of the skeleton. The structure of a long bone. The composition of bone. Joints.

ix x

CHAPTER

VI.

VII.

VIII.

XI.

Contents

PAGE HyGImne OF THE SKELETON . , ® , . 95-108 The nourishment of bones. Broken bones. Dislocations and sprains. Weak feet. Deformities of the spinal column. Posture. Essential facts in the growth and development of bones.

Tuer MuscLes aS THE Motor MACHINERY OF THE Bopy - : l ; ; ; . 109-121

What the Seicialias do. Muscles and nerves. Kinds of muscles. Voluntary and involuntary muscles compared. The attachment of muscles. How muscles and bones codperate. Names and positions of muscles.

Tore Muscies 1N ACTION AND THE HYGIENE OF EXERCISE ; “ : : r : . 122-145

The neuro-muscular mechanism. Muscular energy. Muscular tone. Muscular activity and fatigue. The effects of stimulants and narcotics on muscular action. The effect of exercise on growth. The relation of exercise to health. Forms of exercise. Over-development of the muscles.

PART III HOW THE BODY IS NOURISHED . Foop anp Its ELEMENTS . : a ; . 146-157

Nutritive and non-nutritive elements in food. Composition of foods. Sources of food elements. Uses of food in the body. Proportion of food elements in a normal diet. Calculation of food values. The diet of different peoples. The body’s method of regulating the food supply. The work of enzymes in digestion.

. Tue Dicestion or Foop : : . 158-188

The structure and functions of the ii itaie canal. The liver. Diagram of digestive mechanism. The waste products from food elements.

Tue Hyaiene or DIGESTION , . 189-210

Digestion and health. Digestion ot environment. Hobbies about nutrition. Man’s original food ‘re-

CHAPTER

XII.

XII.

XIV.

XV.

XVI.

XVII.

Contents : xi

PAGE sources and how they have been enlarged. Present day sources of food. Patent medicines. Eating and drinking at meals. General rules modified by individual needs. Cooking. The fireless cooker. Times for eating.

THe CIRCULATION OF THE BLoop . : P . 211-234 How the circulation of blood serves the body. The

nature of circulation. The composition of the blood.

The heart as a pump. The blood vessels as tubes.

Blood pressure. The heart rate.

Tuer CIRCULATION OF THE BLOop (continued) . 2385-255

How the heart is aided in its work. The lymphatic circulation. Hygiene of the circulation.

Why breathing organs are needed. The respiratory organs. The breathing process. The air we breathe. The hygiene of respiration.

PART IV HOW THE BODY IS CONTROLLED Tue Nervous System . ; E ; F . 286-315

The functions of the nervous system. The nerve cell the unit of the nervous system. Nerve action. Sensations. Injury to nerves. General arrangement of the nervous system.

Connection between body and mind. The effect of activity of the nervous system. The effect of sleep. The effect of fatigue. The effect of alcohol. Improper functioning of the nervous system. Ten Golden Rules of Health.

SENSATIONS AND THE SPECIAL SENSES . ; . 332-356 Classification of the senses. The sense of taste. The

sense of smell. The sense of sight. The sense of hearing.

The sense of touch. The muscular sense, General

sensations of the body.

xii - Contents

CHAPTER PAGE XVIII. Some Spectat RecGuLative PRocEssEs . ; . 857-367 The regulation of the temperature of the body. The regulation of body activity and growth. The control of the voice.

Part V How The Body Is Injured

XIX. Bacteria AND DISEASE . ? - ’ ; - 368-399

Injury to the body by forces in its environment. Microscopic forms of life. The effects of bacterial growth in the body. The germ theory of disease. Anti-toxins and immunity. Injury of the body by poisons in food. Injury of the body by physical agents. Injury of the body by chemical agents. Diseases caused by mosquitoes. Tuberculosis. Prevention of communicable diseases. Table of ways and means of communication of the important infections of man. How bacteria are destroyed within the body. How bacteria are destroyed outside the body. A curious theory of disease. Health rules for school children.

XX. Tue Errect or ALCOHOL AND ToRACCcO : . 400-416

The body as a storehouse of energy. The meaning of fatigue. The effect of stimulants on energy and nerves. Alcohol. Tobacco.

APPENDIX. First Amp IN EMERGENCIES - : . 417-426

CHAPTER I

I. The Cell, the Unit of Structure.

Protoplasm Nucleus One-celled animals II. The Origin of Cells.

III. The Properties of Cells.

IV. Tissues Formed from Cell Groups.

V. Organs Formed from Tissues. “ ; VI. Similarity between Living Organisms and Social Groups. One-celled animals and primitive society The developed body and modern society VII. Similarity between the Human Body and a City.

The cell, the unit of structure.— A brick wall is constructed from bricks. Assembled in a certain order, they are the parts which compose the wall. It makes no difference whether the brick is round, square, or irregular, whether it is painted red, green, or blue; it remains, in all cases, the unit out of which the wall is built. Consequently we speak of the brick as being the unit of structure of the wall (Fig. 1, A). In similar fashion, all forms of life are composed of cells. Plants and animals are both constructed from cells. They may vary in shape, size, color, and activity, but, nevertheless, they are to be considered as the units of structure. These units are so small that they can be seen only by means of the microscope, but when we look B I at them through this instrument, we notice that they are as definite in shape as the bricks in a brick wall (Fig. 1, C). The cells of plant and animal are not hard and solid as_ bricks are. On the contrary, they are soft and liquid.

It is quite com- Fie. 1.— A, brick wall; B, segment of orange; arenes to think of C, cells from stomach. The cell is the unit of strue- an orange as a ture. Relative size is not shown. The cells in C ° are much smaller than the cells in B. solid substance, and yet the orange is composed of cells which are filled with a liquid, the juice. If we break open the segment of an orange, we can see the cells with the unaided eye, and if we prick one of them the juice will run out (Fig. 1, B).

Protoplasm.* — The liquid substance of which the body cell is made is called protoplasm, and this name is applied to the cell substance of both animals and plants. Workers with the microscope, many years ago, found that plant and animal tissues are composed of cells, and that the liquid in the cells is of more importance than the walls ite Me y NH ye Pe je

- % Fic. 2.— Diagram of a cell. which the protoplasm builds Showing that protoplasm has an around itself intricate structure; in this case it appears somewhat like honeycomb.

We should not think be- ‘cause we use the same name, protoplasm, for the substance forming the cellular material of both plants and animals,

* Words marked with a star * are defined in the glossary at the end of each chapter.

that its chemical composition is always the same (Fig. 2). It is best to think of it as a substance that makes possible the life and activity of the cell rather than as a substance that has definite and fixed chemical properties. Furthermore, it is important to remember that the composition of protoplasm ‘varies in the same cell according to many factors. Exercise, food, fresh air, alcohol, and disease cause changes in the protoplasm. Some of these changes are favorable. Can you name, from the above, the factors which cause unfavorable changes? Physiology is the study of the way this protoplasm acts in the cells of the body. ; Nucleus. — A living cell has two essential parts. One is a small mass or globule* of protoplasm, and the other is a small body within the mass of protoplasm, called the nucleus * (Fig. 2). There are two other parts of less importance. Within the nucleus there may be a small body, called the nucleolus,* and usually the protoplasm has a membrane surrounding it, called the wall. The nucleus is the vital part of the cell. If a cell is divided, that portion containing the nucleus alone survives. After they lose their nucleus, the red cells of the blood live only a few days. : One-celled animals. — The cells of the body, ' poh of i owing to the fact that they have a wall, soft food (as seen contents, and a nucleus, resemble minute one- U4e" 2, high 7 power of the celled animals sometimes found in stagnant microscope). water. Figure 3 shows the appearance under the microscope of the amoeba, one of these small animals. The amoeba seems to be hardly more than a minute drop of jelly, yet it lives and does in a simple way many of the things that the human body can do. It moves by pushing out a part of its body; it takes in food by rolling a process of its body around the food to be eaten; and after digesting the part it wants, it discards the indigestible portion of the food. If the ameeba is struck or jarred, it reacts by moving its body. It absorbs oxygen * from the air and it gives off carbon dioxide.* When it attains a certain size, it divides into two parts. It does not divide, however, and produce new individuals until it has reached its full growth.*

The origin of cells. — For many years it was believed that life originated spontaneously. This view is called the theory of spontaneous generation. We know now, however, that all cells are derived from cells (Fig. 4) and that the vast number of different cells which compose a living body are all derived from two single cells, the ovwm* (Fig. 5) and the spermatozoén.* The health and strength of these two cells are dependent upon the health,

Fie. 4.— A cell undergoing division. A, cell before division; B, thread-like formation of the vital parts of the nucleus; C, equal division of the nuclear thread ; D, separation of the nuclear structure for the new cells and commencing constriction of cell body; £, nuclei beginning return to resting states; F', complete division of cell body into daughter cells whose nuclei have returned to the resting states.

strength, and vigor of the whole body. In this respect, the strength and vigor of the race are dependent upon the strength and vigor of each member of the race. This is an important responsibility because each person, by being strong and vigorous, makes it possible for coming generations to have health and strength.

In this way, health is a duty that no one may neglect.

The properties of cells. — If we say that a stone is hard, that it sinks when thrown into the water, that it will break when hit with sufficient force, we are speaking of the properties * that belong to the stone. - Cells also have properties —

B

Fie. 5. — Different stages in the development of the frog’s egg (A) to form the body of the frog. In D the egg (ovum) has divided many times, and presently these cells will begin to ‘change into bone, nerve, and muscle cells, and other types of body cells.

the characteristics which distinguish them from other structures.

In the first stages of the formation of the body, the cells which later on develop into muscle cells, or nerve cells, or skin cells, look very much alike and have identical properties. They can divide and reproduce themselves (the property of reproduction*) ; they can take up food and build it into tissue * and remove the waste (the property of metabolism *) ; they can receive an impulse and conduct it to all parts of the cell (the property of irritability * and conductivity *) ; they can respond to a stimulus and contract the cell body (the property of contractility *).

They also change in their properties. Certain cells become unable to contract, but are very proficient in sending nerve impulses; others cannot secrete digestive juices, but they are able to reproduce the individual. We say, therefore, that the sex cells develop the property of reproduction, the nerve cells the properties of irritability and conductivity ; the digestive and excretory cells develop the property of metabolism, and the muscle cells the property of contractility.

Tissues formed from cell groups. — Cells of one kind group themselves together to perform a particular function and are called a tissue. We speak of muscle tissue, and we understand that there is this grouping of many muscle cells for the purpose of contraction. Therefore, a group of cells of a particular kind to perform a particular function is known as a tissue (Figs. 6, 7, 8).

Organs formed from tissues. — Tissues combine to perform more effectively a highly complex act. The resulting structure is an organ. Tissues grouped in a definite way to coéperate their tissue functions in some special task are known as an organ. The stomach, for example, is an organ composed of muscle, nerve, and connective tissues, and each tissue codperates in the digestion of food in the stomach. The muscle contracts the stomach and moves the food at the proper time into the intestine; the nerve tissue tells the muscles when to contract, and the epithelial cells when to secrete digestive juice; and the connective tissue binds the other tissues together to produce the whole organ.

Similarity between living organisms and social groups. — It has been learned that the body is composed of cells with special properties grouped into tissues; that the tissues are arranged to form organs. An individual constructed to carry on the activity of life by means of parts or organs which are separate and yet dependent upon each other is called an organism.* Man is, therefore, frequently referred to as an organism. The term is sometimes used with reference to society. The relation of the parts of the body to the whole body and of the individual man to the organism of society is very important. We have learned that there are organisms composed of only one cell and that such organisms may show all the properties of living matter. As soon as an organism becomes multicellular,* an arrangement is necessary for groups of cells to take up certain special tasks. This arrangement and organization permits greater achievement in the group because certain cells are free to accomplish results which would have been impossible in an unicellular * type of organism.

This division of labor among cells may be likened to a> similar division of labor that occurs in human society. A city with its million inhabitants is a superior social group for the performing of greater tasks than are possible for the people in a pioneer settlement. In this respect, the organism, man, is superior to the amceba. Both man and a city are superior as types because they have greater opportunities and can make better use of abilities in acts that enrich the life of the world. The city is more complex, more alive, more sensitive than the pioneer settlement, but in order to maintain this highly specialized state it must be exceedingly watchful against disease * and degeneration.* In this same way, man, a highly specialized organism, superior to the unicellular animals, needs to be careful of the laws of life and health, the observance of which makes such high specialization* possible. In each case then, in animal life and in human society, specialization produces a superior life, but it also produces the need for intelligent care of the basis of life. The castle needs a better foundation than the kennel.

One-celled animals and primitive society. — The basis of life for the complex organism is the same as that for the simple organism. The ameeba in its self-dependence is like the savage living alone. Modern man with his highly developed body is like the organization of a great city. In each case, however, the simple organism and the complex organism resemble each other by requiring food, air, and water, by needing activity of the proper kind and the removal of body waste. In a complex society, it is necessary that all groups of men do their special tasks well. In a similar fashion, man must look for his strength and security to the proper functioning of all his cells, and in no instance may he with impunity sacrifice the removal of waste to the development of the nerve cell. All must be cared for.

The developed body and modern society. — The more complex an organism becomes the greater is the necessity for coéperation. In human groups there is this important relation between men and women and their fellow members in society, which illustrates the codperation required in the developed body. Members of the human family are dependent upon each other. The chemist has to rely upon the integrity of the manufacturer of chemical apparatus ; the farmer is dependent upon the chemist for a complete and accurate analysis of his soil; the child in school is dependent upon the teacher for guidance and instruction; and every man must rely upon other men to do their work honestly and efficiently. Therefore, just as man is dependent upon his fellow men, just as eight players on a baseball team are dependent upon how the ninth player plays the game, just as the work of a class is dependent upon the codperation of the individual members, so in the body, cells in one place are dependent upon the action of other cells forming some other part of the body and doing a different sort of work. The muscle cells cannot act unless the nerve cells do the work of sending nerve impulses; the nerve cells cannot send and receive impulses unless the heart and lung cells do the work that is expected of them. This interdependence of cells upon other cells and of men upon other men is very important.

Similarity between the human body and a city. — In comparing the city with an animal such as man, it will be noted that the construction of the city and the way its work is carried on resemble the body and the activities of its cells. The city proper is composed of buildings that serve definite purposes ; the body is made up of a great number of distinct cells which perform special tasks. The stores on the outskirts of the city obtain their supplies from the wholesale district by the established channels of trade and commerce ; the body cells receive their nutritive supply through the blood channels which run past the great digestive tract and respiratory tract. The blood with its millions of red blood cells transporting life-giving oxygen, and with its plasma, carrying life-giving food, resembles a continuous chain of auto trucks transporting the necessities of life to the outlying population. The waste products are carried by the blood to the kidneys, skin, and lungs — organs which serve to remove this waste material. So in a city the ‘ white wings ” gather the ashes, rubbish, and garbage and, carrying it to the disposal plant or scows in the river, perform for the city the function of excretion.

The city is controlled and directed by officers elected by the people. These officers must provide for the life and development * of the people, not only with reference to what they need in the way of food, protection, and recreation, but also with reference to what other cities are doing in providing for man the best opportunities for life. In similar fashion, the body is controlled and directed by the nervous system, which constantly receives messages from all the cells of the body. To these messages it responds and provides the necessities of life. It also responds to messages from other men. In this way, man and city, both, in cooperation with other groups and led by high ideals, achieve the best development.

Carbon Dioxide. — A gas having the composition of two molecules of oxygen in combination with one of carbon. It is heavy, colorless, and incombustible. It is produced in the decay of animal and vegetable matter and in the bodies of animals during activity.

Conductivity. — Ability to carry heat or electricity. In nerves, it is the ability to transmit stimuli from one part of the body to another.

Contractility. — Power to change the shape, to shorten, in the case of a muscle. In single cells, the shortening in one direction produces an increase in diameter in the opposite direction.

Degeneration. — The change in the chemical constitution of the cells from a complex to a simpler chemical form.

Development. — A series of changes by which the body progresses from a lower to a higher type of being. Growth may best be thought of as an increase in substance; development refers to the organization of that substance.

Disease. — The general term for any deviation from health. It may be caused by destruction of essential body cells, or by poisoning so that the cells are unable to function properly.

Globule. — A small spherical structure.

Growth. — The process of increasing in size. It is to be distinguished from development, which refers to organization of the mass.

Irritability. — The responsiveness that living matter shows to more or less rapid changes in external conditions, manifested by motion, change of form, and in other ways.

Metabolism. — The act or process by which on the one hand food is built up into living material, and by which on the other hand the living matter in protoplasm is broken down into simple, waste elements for removal from the body. Sometimes the building up of food into protoplasm is called anabolism; the breaking down into simple waste products, katabolism.

Multicellular. — Many-celled.

Nucleolus. — A small, well-defined particle found within the nucleus of the cell. It is easily stained with staining fluids, and because it absorbs stain more readily than the nucleus, it is distinguished without difficulty.

Nucleus. — A round or oval body within the protoplasm; it is surrounded by a delicate membrane. The nucleus is responsible for the vital functions of the cell.

Organism. — A body composed of different organs or parts, performing functions that are mutually dependent and essential to life. A single cell may be considered an organism although the different parts are not readily distinguished.

Ovum. — A cell produced by the generative organs, the ovaries, of the female. It is capable of producing a new individual.

Oxygen. — In chemical terms, oxygen is represented by the letter O. It is a colorless, tasteless, odorless gas, very abundant in nature. It was first discovered by Priestley in England. It combines with other chemical elements, and all mechanical power obtained from combustion, whether through the medium of steam, electricity, or reece! action, depends upon oxidation.

The Cells of the Body II

Properties. — Distinguishing characteristics. Qualities that make the object what it is.

Protoplasm. — The semiliquid, more or less granular substance that forms the principal portion of an animal or vegetable cell. It is present in all organized bodies and so Huxley called it ‘‘ the physical basis of life.’’