Brief lessons on the human body

Preface

This book is the result of several years' practical work in the class-room. It has been the practice of the author to teach the subject of Physiology topically, objectively, and with such simple experiments as can be performed with inexpensive apparatus. The notes prepared for the use of pupils have been revised and extended from time to time, until they have grown into the substance of this little book.

In its preparation a logical order has been observed in the arrangement of subjects and in the sequence of topics, so that each lesson may be presented to the class orally and objectively before being assigned from the text. The subject of each topic has been placed in the form of a question. Each question is a useful and interesting question, and deals with some important fact in regard to the structure or function of some of the organs of the body.

In answering these questions it has been assumed that every teacher who uses this book will supplement each lesson with interesting conversation, and, as far as possible, with object-teaching and experiments. Consequently all matter which should be introduced orally by the teacher, or which should be brought out by observation, questions or experiments before the class, has been purposely omitted. An effort has been made to have the answers clear and con-

4 PREFACE.

cise, within the understanding of children, and as free as possible from scientific terms.

Special care has been taken to present the leading facts of Anatomy and Physiology in such a way as to show clearly the reasons why the health of the body requires us to follow or avoid certain courses of conduct. In this way the general laws of health will be fixed in the minds of pupils as guiding principles, from which they can draw their own conclusions regarding special cases.

In preparing this work the author has examined a great many text-books and other authorities upon the subject, and has used what he considered the best material, wherever found. A list of the text-books consulted, with the names and addresses of the publishers, is given on the following page. L. S.

September 1, 1889.

TEXT-BOOKS CONSULTED.

Walker's Anatomy, Physiology and Hygiene ; published by Bacon & Allyn, Boston, Mass. Hitchcock's Anatomy and Physiology, and Smith's Elementary Physiology and Hygiene'; published by Ivison, Blakeman, Taylor & Co., New York. Cutter's Analytic Anatomy, Physiology and Hygiene; published by J. B. Lippincott & Co., Philadelphia. The Human Body, by H. Newell Martin ; published by Henry Holt & Co., New York. Steele's Hygienic Physiology ; published by A. S. Barnes & Co., New York. Hutchinson's Physiology and Hygiene ; published by Clark & Maynard, New York. Dunglison's Physiology ; published by Porter & Coates, Philadelphia. Kellogg's First Lessons in Physiology and Hygiene ; published by Harper & Brothers, New York. Brands' Lessons on the Human Body ^published by Leach, She well & Sanborn, New York. Blaisdell's Young Folks' Physiology ; published by Cowperthwait & Co., Philadelphia. Huxley and Youmans' Physiology and Hygiene ; published by D. Appleton & Co., New York. Stowell's Syllabus of Lectures ; published by C. W. Bardeen, Syracuse, N. Y.

Contents

CHAPTER PAGE

I. A Talk to Pupils about our Bodies and the Object of this

Book 9

Chapter I

A TALK TO PUPILS ABOUT OUR BODIES AND THE OBJECT OF THIS BOOK.

The great world about us has in it many curious and interesting things. If we stop to look, we find them everywhere. Many of them are so close to us, and have become so familiar, that unless w T e stop to study them, they fail to excite our wonder or admiration. Among plants, animals, or anything else in all nature, there is nothing more wonderful than our own bodies. No study is more pleasing, no knowledge is more valuable, than that so closely connected with ourselves.

Boys and girls find themselves taller and larger this year than they were last! How did they become so ? " They grew." Yes, they ate and grew; but how did the food which they ate find its way to the very extremities of the body, and become flesh and bone ? As you have been out in the fields alone on a cold winter's day, did you never ask yourself why it was that while everything about you was cold, your body was warm ? Our homes, the horse-cars, and the schoolroom must have fires in them to keep them warm ; but w T hat is the source of the heat which keeps our bodies warm ? It would be of interest to know. Again, we notice that unless somebody moves them, the trees live and spend their lives in the places where they began to grow ; while we and other animals move about where we will. Both, we say, are alive ; but how is it that we have a power which the tree has not ? A clock ticks, and its wheels move. I ask you why, and you say that it has a spring in it which, when wound up, gives to the wheels the power of motion. When it runs down the wheels stop, and somebody must wind it again. Our hands move, but they do not wait like the boughs of the tree for a breath of wind to stir them. Our bodies move, but they do not have to be wound up like the clock. Why is it ? Where do we get the power ? Why must we eat and drink ? Why must we breathe ? How do we see and hear ? Why must we sleep ? Why is it that improper food or exposure will make us sick ? By and by, on account of sickness, an accident, or old age, we become as cold and as motionless as the stones themselves. What has happened ?

These are only a few of the great many interesting questions which we can ask about our bodies. Some of them neither you, nor I, nor any one else, can answer fully ; but many of them can be answered, and perhaps all of them in part.

To answer some of these questions is the object of this little book. We hope that some of the boys and girls who use it will become so much interested in this study that they will be eager to study other books and to make investigations for themselves. Many things can be best learned by handling and examining them instead of reading about them. We cannot see how things are arranged, or what takes place within our own bodies ; but, if we will, we can find out much by carefully examining the dead bodies of animals. A dead rabbit, the heart of a sheep, or the bones of an ox,, will afford a more interesting lesson than any book.

OUR BODIES AND THE OBJECT OF THIS BOOK. 11

As we study, we shall find that in some respects our bodies are like houses ; they afford a home and protection to what is within them. In other respects they are like machines, each part of which has some particular work to do. If we wish to know all about a machine, a pump, a watch, or a sewing-machine, we study all its parts, how they are put together, and what each part does. In order that the machine shall work well and last long, we must know how to use it and how to take care of it. It is just so with the machine which we call our body. You know it sometimes gets out of order, and we say we are sick, and we send for the physician in order that he may advise us what to do to remove the difficulty, and to put the machine in good working order again.

To avoid sickness and pain, and to prolong life and strength as long as possible, is a matter of great importance to each one of us. In order to do this, we must understand the human machine, our body. We must learn all its parts, know how they are put together, w T hat they are for, and how they work. We also must learn how to take care of the body, so that it will be strong and last as many years as possible, and give us the least amount of pain.

Each part of the body which does some work is called an organ. The eye, the ear, the hands, the heart, the stomach, etc., are all organs. The study of the organs of the body, how they are made and put together, is called Anatomy. The study of the office of each one of these organs, or what it does, is called Physiology. The study by which we learn to take care of the organs of the body is called Hygiene. This book is intended to teach you something of Anatomy, Physiology, and Hygiene.

CHAPTEE II.

A GENERAL VIEW OF THE PARTS AND ORGANS OF THE

BODY.

What are the principal parts of the body?

The principal parts of the body are the trunk ; the head ; the upper extremities, or arms ; and the lower extremities, or legs.

What are the chief parts of the trunk ?

The chief parts of the trunk are the chest, the abdomen (ab-do'-men), and the backbone.

What are the chief parts of the head?

The chief parts of the head are the skull and face. The forehead, temples, cheeks, eyes, ears, nose, mouth, etc., may be called parts of the face.

What are the chief parts of the upper extremities ?

The chief parts of the upper extremities are in each arm a shoulder, an upper-arm, a fore-arm, a wrist, and a hand. The fingers are parts of the hand.

What are the chief parts of the lower extremities ?

The chief parts of the lower extremities are in each leg a hip, a thigh, a lower-leg, an ankle, and afoot. The toes are a part of the foot.

With what is the entire body covered?

The entire body is covered with the skin, to which belong the hair of the head, and the nails which grow at the ends of the fingers and toes.

PARTS AKD ORGANS OF THE BODY. 13

What is an organ of the body ?

An organ is any part of the body which has some special work to do.

Name the principal sets of organs in the body.

The principal sets of organs are the bones, which give form and support to the body ; the organs by which we digest our food, called the organs of digestion ; the organs which pump and carry the blood through the body, called the organs of circulation ; the organs used in breathing and talking, called the organs of breathing ; the organs by which we know, see, hear, feel, etc., called the organs of the nervous system ; the organs which enable us to move any part of the body, called the muscles, or the organs of motion.

What is the bony frameiuork of the body called ?

The bony framework of the body is called the skeleton.

What is the principal organ of digestion, and ivhere is it situated ?

The principal organ of digestion is the stomach. It is situated in the upper part of the abdomen.

What is the principal organ of circulation, and ivhere is it situated?

The principal organ of circulation is the heart. It is situated in the central part of the chest.

What are the principal organs of breathing, and where are they situated ?

The principal organs of breathing are the lungs. They are situated in the chest, one on each side.

What is the principal organ of the nervous system, and where is it situated?

The principal organ of the nervous system is the brain. It is situated in the cavity of the skull.

What are the muscles, and where are they situated ?

The muscles are the reddish flesh, or lean portions of the body. They are situated in all parts of the body.

What are all the solid parts of the body called?

All the solid parts of the body, such as bones, muscles, fat, etc., are called tissues.

Chapter III. The Bo^es, Or The Framework Of The Body

What are the uses of the bones ?

The uses of the bones are, to protect the delicate organs which are enclosed by them ; to support the body and to give it form ; and to act as levers by which the muscles attached to them may move the body.

Name some important organs which are protected by the bones.

The brain is protected by the bones of the skull. The heart and lungs are protected by the bones which enclose the chest. The spinal cord is protected by the bones of the spinal column, or backbone. The eye is protected by the bones of the face.

Wliat can be said about the form of the bones f

The bones vary greatly in form. Some are long, some are short, some are flat, and others are irregular in form.

Mention some bones of the body which may be called long bones.

The bones of the upper-arm, fore-arm, thigh, andjowerleg, may be called long bones

Mention some bones ivhich may be called short bones.

Examples of short bones are found in the wrist, ankle, and spinal column.

Mention some examples of flat bones.

BRIEF LESSONS ON THE HUMAN BODY.

THE FRAMEWORK OF THE BODY.

THE SKELETON.

The Head, 28 Bones.

Occipital (base of skull) Parietal (sides of skull) Temporal (temples) . .

Frontal (forehead) . .

Sphenoid (behind the face) Ethmoid (behind the face) Nasal (bridge of nose) .

Vomer (between nasal fossa?) Turbinated (on walls of nasal fossce)

Palate (back part of roof of

Lachrymal (in orbit) ... 2

Malar (cheek-bones) .... 2

Superior Maxillary {upper

jaw) 2

Inferior Maxillary (loicer

jaw) 1

Malleus (in the ear) ~) ^_j ( 2

Incus (in the ear) > & 3 ■< 2

Stapes (in the ear) ) M ( 2

Vertebrae

Sacrum

Coccyx

The Trunk, 52 Bones.

(backbone)

. 24 . 1 . 1

Hyoid (in the neck) .... 1 Ribs 24

SternUxM (breast-bone) . . ' . 1

The Upper Limbs, 64 Bones.

Scapula (shoulder-blade) . . 2

Clavicle (collar-bone) ... 2

Humerus (arm-bone) .... 2

Radius (fore-arm) .... 2

Ulna (fore-arm) .

Carpus (wrist) . .

Metacarpus (hand) Phalanges (fingers)

16 10

The Lower Limbs, 62 Bones.

Innominate (hip-bone) ... 2

Femur (thigh-bone) .... 2

Patella (knee-pan) .... 2

Tibia (leg) 2

Fibula (leg) 2

Tarsus (ankle, heel, instep) . 14 Metatarsus (flat of foot) . . 10 Phalanges (toes) . . . . . 28

Examples of flat bones are the bones of the skull, the ribs, the breast-bone, and the shoulder-blades.

Why are some bones hollotv ?

If the bones of the limbs were solid, they would have to be much heavier. Their hollow form gives them greater strength than the same amount of bone would have in a solid form.

Describe the structure of a bone.

The outside part of a bone is hard, but within it is somewhat softer and hollow. The hollow portions are filled with a spongy substance called the marrow.

Of ivhat materials are bones composed ?

Bones are composed of animal matter, a jelly-like substance, and of mineral matter, mostly lime.

What is the use of the animal matter ?

The use of the animal matter is to give toughness and elasticity to the bones.

What is the use of the mineral matter ?

The use of the mineral matter is to give hardness and stiffness to the bones.

How do the bones of an infant differ from those of an old person ?

The bones of an infant are merely cartilage ; they contain an abundance of animal matter, but less mineral matter ; they are tough and not easily broken. The bones of an old person contain more mineral matter, which makes them hard and brittle, and more easily broken.

How do bones groiv ?

The materials of which bones are composed are continually being worn out and replaced by new material. Bones grow, chiefly, by additions to their free ends and surfaces. The blood circulates freely through the bones, and supplies

THE FRAMEWORK OF THE BODY. 19

them with the materials which are required for their growth and nourishment.

How is a broken bone repaired?

The blood carries and leaves at the broken place a watery fluid which contains the materials of which gristle is formed. This hardens and cements the broken ends together until the blood in the same way gradually adds the mineral matter and completes the union.

How are the bones held together ?

The bones are held together by strong bands of tissue, called ligaments. The muscles also help to hold them in place.

What is a joint ?

A joint is the place where two bones unite.

How are joints classified ?

Joints are classified as movable, immovable, and mixed.

Give examples of each hind.

The joints of the bones of the arms and legs are movable. The joints of the bones of the skull are immovable. The joints of the bones of the spinal column (backbone) are mixed.

Hotv many hinds of movable joints are there ?

There are three kinds of movable joints. They are called hinge joints, ball-and-socket joints, and irregular joints.

Give examples of each kind.

The joints of the elbows, knees, and fingers are hinge joints. The joints of the shoulders and hips are ball-andsocket joints. The joints of the w T rists, ankles and neck are irregular joints.

How do these joints differ from each other ?

The hinge joint permits motion in only two directions, as

20 BRIEE LESSON'S ON THE HUMAN BODY.

backward and forward, like the hinges of a door. The ball-and-socket joint allows motion in every direction, forward, backward, and in a circular manner ; it consists of a ball at the end of one bone, which fits into a socket in the end of another. The irregular joint is one in which the surface of one bone moves only a little on the surface of another ; such joints are useful where little motion but great strength is required.

How does nature provide for the oiling of the joints ?

In the cavity of each joint there is a thin lining, or membrane, which gives out a fluid called joint-water. This serves as oil to the joint.

Chapter IV. Classes Of Boxes. — Bones Of The Head And Trunk

How many bones in the human skeleton ?

The number of bones in the human skeleton is 206. The number varies somewhat at different periods of life. That which is merely gristle, or cartilage, in infancy, becomes bone later in life.

How may the bones of the skeleton be divided ?

The bones of the skeleton may be divided into four classes, viz. : bones of the head, bones of the trunk, bones of the upper extremities, and bones of the lower extremities.

Hoiv many bones in the head ?

In the head there are twenty-eight bones. Eight of them form the skull, fourteen are in the face, and six in the ears. (For the names of the bones of the head see table on page 17.)

Describe the construction of the skull.

The bones of the skull form a cavity in which the brain is situated. These bones are united by peculiar notched joints, called sutures. The cavity has an opening at the bottom through which the spinal cord enters. There are no other openings except very small ones through which nerves and blood-vessels enter or pass out. The upper bones of the skull consist of two hard plates, with a spongy layer between them.

Describe the uses of the bones of the head.

The bones of the skull and face protect the brain and the organs of sense— smell, taste, hearing, and sight — from injury. The bones of the ear are an aid in hearing. The jaws contain the teeth, and are used in masticating food.

What is the only movable bone in the head ?

The only movable bone in the head is the lower jaw. It can be moved in five different directions. Its joints are very liable to dislocation.

How many teeth appear in infancy ? In later life ?

The temporary, or milk teeth, which appear during infancy, are twenty in number, ten in each jaw. The permanent teeth, which appear later, are thirty-two in number, sixteen in each jaw.

What names are given to the permanent teeth, and hozv many of each hind ?

The names and number of the permanent teeth on each jaw, beginning at the back part of the mouth, are : two wisdom, four molars, four bicuspids, two canine, and four incisors.

Are the teeth regarded as bones ? Why ?

The teeth are not regarded as bones. They differ from bones in several respects. They are covered with an enamel, which bones have not ; when broken a tooth decays, a bone will repair itself ; teeth differ from bones in manner and time of growth ; teeth do not appear in the infant at birth, bones do ; the first set of teeth drop out and are replaced by others, no such thing takes place with the bones.

Hoiv many bones are found in the trunk ?

In the trunk there are fifty-two bones. They are located as follows : in the spine, twenty-four bones ; ribs, twenty-four bones ; breast-bone, one ; sacrum, one ; coccyx, one ; at base of the tongue, one. (For the names of the bones of the trunk, see table, page 17.).

BONES OF THE HEAD AND TRUNK. 23

What cavities are formed by the bones of the trunk ?

Two cavities are formed by the bones of the trunk. The upper one, called the chest, is enclosed by the spine, ribs, and sternum ; the lower one, called the abdomen, is enclosed by the spine at the back, the bones of the pelvis below, and by muscles in front.

What organs are found in the chest?

The lungs and heart are found in the chest.

What organs are found in the abdomen ?

The abdomen contains the stomach, intestines, liver, kidneys, and other organs. It is the largest cavity of the body.

Describe the spinal column.

The spinal column extends from the head to the bones of the pelvis. It consists of twenty-four bones so put together that the body can turn on them readily. These bones are called the vertebrce. Through the spinal column there extends a tube-like canal, called the spinal canal, which contains the spinal cord.

What is the use of the spinal column ?

The spinal column protects the spinal cord ; it holds the body in an upright position, yet allows it to bend when we will ; it supports the weight of the head, arms, chest, etc.

Describe the ribs.

The ribs are slender, curved bones, which help to enclose the cavity of the chest. They are arranged in pairs, twelve on each side.

What is the Use of the ribs ?

The use of the ribs is to afford protection to the lungs, heart, and great blood-vessels. They also furnish an attachment for the muscles which move the walls of the chest when we breathe.

Chapter V. Bones Of The Upper And Lower Extremities

How many hones in the upper limbs, or arms ?

In the upper limbs, or arms, there are sixty-four bones. (For their names see table, page 17.)

Describe the scapula, or shoulder-blade.

The scapula, or shoulder-blade, is a broad, thin, flat, triangular bone situated at the top and back of the chest. It is not directly attached to the trunk, but is held in place by muscles. It is connected with the collar-bone, and contains the socket of the shoulder-joint.

What is the use of the scapula?

The use of the scapula is to make an attachment for the muscles of the shoulder, and to connect the arm with the trunk of the body.

Describe the clavicle, or collar-bone.

The clavicle, or collar-bone, is a long, slender bone which extends from the breast-bone and first rib to the shoulder-blade.

What is the use of the clavicle ?

The use of the clavicle, or collar-bone, is to brace the shoulders back and to hold them out from the chest.

Describe the bones of the arm.

That part of the arm between the shoulder and elbow consists of a single bone, called the humerus. That part between the elbow and wrist consists of two bones, called

BONES OF THE UPPER AND LOWER EXTREMITIES. 25

the ulna and the radius. To these bones are attached a large number of muscles which move the hand and fingers. The radius is on the thumb side of the arm, the ulna is on the side of the little finger.

What advantage comes from having two tones in the forearm?

It permits an arrangement of joints which allows the fore-arm and hand to take a rolling motion which turns the palm of the hand up or down.

Describe the wrist, or carpus.

The wrist is situated between the fore-arm and the hand. It contains eight bones, irregular in shape, arranged in two rows. The bones are held together by strong ligaments, and form an irregular joint.

Describe the bones of the hand.

The bones of the palm of the hand are fi^e in number in each hand. They are joined at one end with the bones of the wrist, at the other with the bones of the fingers or the thumb. There are three bones in each finger, but only two in each thumb ; they are called the phalanges.

Bow many bones in the lower extremities, or legs?

In the lower extremities, or legs, there are sixty-two bones. (For the names of these bones, see table, page 17.)

What is the pelvis, and what is its use?

The pelvis is the bony structure at the base of the trunk. Its use is to make a foundation for the support of the spinal column and for the weight of the body above it. The hipbones, which form a part of the pelvis, contain the sockets for the attachment of the thigh-bones, and thus connect the trunk of the body with the lower extremities.

Describe the hip-joint.

The hip-joint is a ball-and-socket joint. At the upper end of the thigh-bone, or femur, there is a ball which fits snugly into a deep socket in the side of the pelvis. The hip-joint is similar to the shoulder-joint, and permits motion in eyery direction.

Describe the knee-joint.

The knee-joint is a hinge joint. It is formed by the joining of the thigh-bone with one of the bones of the lower leg, the tibia. Over the joint in front is a little heart-shaped bone, called the knee-pan, or patella. It protects and strengthens the joint.

Describe the bones of the lower leg.

The lower leg has two bones, the tibia and fibula. The tibia is a strong bone. It has a sharp ridge in front, called the shin. The fibula is the outer bone of the lower leg. It is fastened at both ends to the tibia. It serves as a brace to the tibia, protects the ankle-joint, and affords an attachment for muscles.

Describe the ankle.

The joint at the ankle is similar to that of the wrist. The bones here are seven in number, and form the ankle, heel, and instep.

Describe the bones of the foot.

The bony structure of the foot is quite similar to that of the hand. Besides the seven bones of the ankle and instep, which have just been mentioned, there are in each foot nineteen other bones, — in the "flat "of the foot, five bones, called the metatarsals; in the toes, fourteen bones, called the phalanges, — making twenty-six bones in all.

Chapter VI. Hygiene Of The Bones And Teeth

From what sources does the body derive the materials for making bones %

The materials for making bones are derived from the food we eat and the water we drink.

In order that the bones may be strong and healthy, tohat must our food contain ?

Our food must contain a proper amount of bone-making material, otherwise our bones will become weak and unhealthy.

What disease of the bones is sometimes caused by ivant of proper food ?

The disease called rickets is caused by a deficiency of mineral matter in the bones. The bones become soft, and are drawn out of shape by the muscles, producing deformity.

Mention some articles of food tvhich are rich in bone-making material:

Milk, eggs, oatmeal, and bread made from coarse flour or whole grain, are foods which are rich in bone-making material. In making fine white flour the miller takes out the part that is most useful for making strong and healthy bones.

Name some foods which are deficient in bone-making material.

Sugar, candy, fat meats, and bread and cakes made from fine flour, are deficient in bone-making material.

What is the cause of " boiv-legs " in infants ?

The bones of infants are soft and easily bent. If young children are allowed to stand on their feet too much, the weight of the body bends the legs outward. As the bones gradually harden they retain their curved shape and become permanently deformed.

What effect has exercise upon the hones ?

As is the case w 7 ith all other organs of the body, a proper amount of exercise helps to keep the bones in a strong and healthy condition. The exercise should not be too severe or too long continued.

Wliat deformities are caused by improper positions in sitting, standing, or tvorking ?

The bones of young persons, being soft and flexible, are easily bent out of shape by improper positions in sitting, standing, or working. In this way hollow chests, round shoulders, curved spines, and other deformities are formed.