Good health, how to get it and how to keep it

Front matter

Class

Book

^ iS^VT*

Preface

Years ago it was believed that matters relating to the preservation of health and the prevention of disease should be left in the hands of physicians, and little effort was made by the public in aid of this important work. Now we know that the health of a community depends chiefly upon the exertion of its individual members in maintaining not only their own well-being, but also that of their neighbor. This newer conception has recently led to a stimulation of interest in this subject, and societies are being organized to bring about personal cooperation in carrying out the laws of hygiene and sanitation. It is essential that the public should become familiar with recent advances which have been made along these lines, for many of the older theories regarding the care and protection of the body, and the means by which diseases are transmitted, have been proved to be erroneous.

It is an extremely difficult task for the medical profession, as well as health departments and other public agencies, to attempt to combat physical inefficiency, ill health, and disease without the cooperation of those for whom their efforts are so generously expended. There should be not a mere passive acquiescence in following the teaching of sanitarians or in complying with health ordinances, but an intelligent appreciation of the fundamental principles which animate them and a definite sense of responsibility in maintaining bodily health for both individual and social ends.

The terms ''hygiene^' and ' ^sanitation' ^ are very much alike in their meaning and are commonly used interchangeably. By

Viii PREFACE

way of clearer definition, it may be said that hygiene refers more particularly to the care of the body, while sanitation relates rather to the methods of maintaining healthful conditions in the environment and covers matters of a more general and extended character; for instance, school sanitation, sanitation of the workshop, and municipal sanitation. It is sufficient to know that both refer to the preservation of health and the prevention of disease.

It has been the aim of the author to include in this book the essential and salient points in the construction of the body and function of its various parts; also to discuss public health problems, the maintenance of individual physical well-being, the means by which infectious diseases are transmitted and how they may be prevented, the importance of pure air, good water and nourishing food, as well as other matters connected with the subject of hygiene. The author has endeavored to present these in a clear and simple manner, and in a way that will make the application of the information practicable in everyday life and conduct.

Chapter I Page

THE STRUCTURE OF THE BODY i

The Skeleton — Articulation — ^Joints — Muscles — Blood.

CHAPTER II THE VITAL PROCESSES: CIRCULATION, RES- PIRATION, DIGESTION, NERVOUS SYSTEM AND LYMPHATIC SYSTEM 23

Circulation — Blood-vessels — Heart — Respiration — Digestion — Kidneys — Skin — Spleen — Nervous System — Lymphatic System.

Chapter X Hygiene Of The Home, School And Work- Shop 176

Hygiene of the Home — Hygiene of the School — Hygiene of the Workshop.

CHAPTER XI BACTERIA, INFECTIOUS DISEASES AND THE MEANS BY WHICH THEY ARE TRANSMITTED 192 Bacteria — Infectious Diseases and the Means by Which They are Transmitted.

Chapter XV Page

Hemorrhage — Shock — Collapse — Electric Shock — Instructions for Resuscitation — Syncope — Fainting ^Apoplexy or Stroke of Paralysis — Epilepsy — Hysteria — Heat-Stroke, Sun-Stroke, Insolation, Sun Fever, Fever Heat — Asphyxiation — Suffocation — Drowning — Burns and Scalds — Frost-Bite — Wounds — Fractures — Dislocations — Sprains.

INDEX 280

LIST OF ILLUSTRATIONS

I. — The skeleton ....

2. — Biceps at rest ....

3. — Biceps contracted

4. — Human red blood corpuscles and two white corpuscles ....

5. — The heart and large blood-vessels

6. — Diagram showing course of the blood through the heart ....

7. — Showing the relative position of heart and lungs in the cavity of the chest .

8. — The jaws and the teeth ....

9. — Salivary glands

10. — The stomach

II. — Position of abdominal contents .

12. — Under surface of the liver, showing the gall

bladder and a section of blood-vessels . 13. — The pancreas .... 14. — Vertical section of a kidney 15. — Section of skin greatly magnified 16. — The cerebrospinal system of nerves 17. — Side view of the brain 18. — Under surface of brain 19. — The mosquito: female 20. — Manner in which the eggs of the Culex pipiens

or common house mosquito, are deposited 21. — Eggs of the anopheles .... 22. — The mosquito larva .

16 16

19 29

33 37 38 41 43

45 46 48

207 208 209 xiv LIST OF ILLUSTRATIONS

riGURE PAGE

2^. — Position of larva of common mosquito in obtaining air 2IO

24. — Position of anopheles larva in obtaining air • 210

26, — Culex pipiens, or common house mosquito,

female 212

2y, — Anopheles, or malarial mosquito, female . . 213

28. — Stegomyia, or yellov^ fever mosquito, female . 215 29. — Culex sollicitans. Salt water sv^amp, or

striped-legged mosquito 219

30. — Diagram showing the position of the important

arteries 244

31. — Artificial respiration: inspiration. Pressure off 255

^2, — Artificial respiration: expiration. Pressure on 255

Chapter I

The owner and master of a human body cannot hope to manage it properly, secure and maintain its usefulness and enjoyment, safeguard it in the diverse struggles of life and occupation, and protect it against sickness and disease without some precise knowledge of its construction and the various things which its organs are made to do.

Some glimpses in brief of the strvicture and function of the body will therefore fittingly introduce a book designed to foster in direct and practical fashion the welfare of its readers.

THE SKELETON

In the study of this subject it is proper that we should begin with an examination of the skeleton, for this constitutes the framework of the body and supports and protects the various organs which are found within the several cavities formed by the structures. In order to perform these functions, the skeleton must be composed of a hard and unyielding material which retains its shape, but it must have at the same time a certain desrrcc of elasticitv. For these reasons the skeleton is constructed of bone, and it will be of interest to learn something of the composition and peculiarities of this substance.

Bone consists of animal and earthy matter. The former is chiefly a substance which is converted by boiling into gelatin. It also contains fat and blood-vessels. The animal tissue in bone makes it tough and elastic, while the earthy matter, known as ''bone earth," consisting principally of phosphate of lime, furnishes the required hardness.

In very early life the animal matter forms about one-third and the earthy matter two-thirds of bone; later in life, the proportion of lime is somewhat increased in amount, and the bone becomes denser. This explains why the bones of children are more elastic than those of adults. When considerable force is used a child's bone is apt to bend like a green stick, rather than break through, as in the case of adult bone.

Rickets is a disease of childhood, and is due chiefly to an insufficient amount of earthy matter. In this condition the bones, for want of hardness, become bent and distorted, the deformity being particularly marked in the bones of the lower extremity which, for the time being at least, are unable to support the weight of the body properly.

Bone is composed of compact and cancellated tissue. The former consists largely of earthy matter and is exceedingly dense and hard like ivory. The latter is a network of thin plates or columns and is sponge-like in appearance. The compact tissue forms the outer portions of bone and is increased in amount where great strength is required, as in the shaft of the femur or thigh bone. The cancellated tissue is particularly abundant, where bones become enlarged in order to form joints, as in the ends of the long bones. Although cancellated tissue is very light, it is also very strong ; a portion corresponding in size and shape to a piece of loaf or lump sugar will support a weight of three or four hundred pounds. A piece of compact tissue an inch square and half an inch in thickness will support a weight of five thousand pounds. In formation of the skull, where great strength is necessary to protect the brain, the bone is composed of two layers of compact tissue with a small amount of cancellated tissue between.

The long bones are hollow for the same reason that tubular columns are used in constructing a building — to secure strength with the minimum weight. The hollow part or canal in the shaft of long bones, as well as cancellated tissue, contains a substance called marrow or oil of bone. In the canals this substance is known as yellozv marrozv, and is composed almost entirely of fat. That found in the cancellated or spongy tissue of bone and known as red niarrozi' is three-fourths composed of water and contains but a small amount of fat. In very early life all the marrow of bone is of the red kind. It is now known that all of the red corpuscles and some of the white corpuscles, or leukocytes, of the blood, which will be referred to again later, are formed in the red marrow of bone. In addition, the yellow marrow has something to do with the nourishment of the tissues, particularly in emergencies.

The canals in the bones of birds communicate with the lungs, and contain air instead of marrow, thus rendering them very light and properly adapted to flight.

Bone is supplied with nutrition from two sources : the periosteum and the nutrient arteries.

The periosteum is a firm and resisting fibrous membrane, pinkish in color and closely adherent to the bone. It covers it at all points except at the ends where joints are formed and where cartilage exists. In the substance of periosteum are found blood-vessels which divide and subdivide and pass into minute openings in the compact tissue of bone to supply its outer surface with nutrition. When the periosteum is detached from- a bone, either by accident or otherwise, the compact tissue is deprived of its principal means of nutrition, and death or ''necrosis'' — corresponding to '"gangrene" in the soft tissues — follows. The nutrient arteries supply the interior of the bone with nourishment.

Bones are also supplied with nerves and absorbents or lymphatics. The power of absorption possessed by the latter is so great that ivory pegs employed to hold in place the broken ends of bone unable to unite by natural processes, have been absorbed.

The shape of a bone depends largely upon its use. The long bones, of which the femur or thigh bone is a type, are not only used for support, but act as levers to lift or move the various parts of the body through muscular attachment. They are composed of a shaft and two extremities. The short bones are found where a number of joints are required for Hmited motion combined with strength — for instance, the carpus or wrist. Flat bones aid in the construction of cavities, help to protect their contents, and provide for muscular attachment, as the bones of the skull and shoulder blades. Examples of irregular bones are the superior and inferior maxillary bones, or the upper and lower jaw, and the vertebrae or bones forming the spine.

The skeleton, which is composed of two hundred bones, not including some small ones in the ear, is the framework of the body; it supports the soft tissues, protects the internal organs, and serves for the attachment of muscles. It consists of a central column or spine, four extremities — two upper and two lower — and three bony cavities, namely, the cranium or skull, containing the brain, the thorax or chest, enclosing the heart and lungs, and the pelvis or basin, holding the pelvic and some of the abdominal organs. The arrangement of the bones is as follows :

Spine 26

Skull 22

Hyoid bone I

Sternum i

Ribs" 24

Upper extremities 64

Lower extremities 62

The spine or backbone, which is about one-third the length of the body, is an articulated column composed of a number of bones (vertebrae) joined together and forming three slight curves which aid in the formation of cavities for the protection of internal organs. These curves also add strength to the column and go far to diminish shocks to the spinal cord and brain which might occur if the column were straight. The spine supports the skull and its contents and protects the spinal cord, which is contained in a canal formed by the union of the vertebrae. The spinal column rests upon the posterior and upper portions of the pelvis.

The freest movement of the spine is found in the neck or cervical region, and the least in the back between the shoulders where the ribs are connected with the spine. The weakest part of the spine is at its lowest part where the column is very movable.

The skull is for the lodgment and protection of the brain and its membranes, blood-vessels and nerves. In very early life bone is not hard but is somewhat similar in consistence to cartilage. The fontanelles, or ^'soft spots,'' on an infant's head represent bones which have not become hardened or ossified, or brought closely and firmly together by this process. This condition usually disappears after the child is a year or so old. At birth and for some time afterwards even the long bones are not sufficiently hard or dense to be capable of supporting the body; and for this reason infants should not be placed on their feet too early.

Fig.

-The skeleton. 7

A large opening exists at the base of the skull called the foramen magnum, through which the spinal cord passes from the brain to the canal in the vertebral column. Other and smaller openings are found in the skull for the passage of blood-vessels and nerves.

The hyoid hone is a small and somewhat horseshoe shaped bone found above the ^'Adam's apple.'^ It helps to support the tongue and also furnishes attachment for muscles.

The sternum or breast bone is flat and narrow, about seven inches long, and may be easily felt under the skin in the front and upper part of the chest. It supports the clavicles, or collar bones, and the front end of the ribs with the exception of the last two.

There are twenty-four ribs, twelve on each side, being numbered from above downwards. All of them articulate or join in the back with the vertebrae or spinal column, and in the front the upper ten connect through the medium of cartilage with the sternum. The two lower ribs, the eleventh and the twelfth, are connected only with the spinal column behind, and are known as ^'floating ribs.'' These are rarely broken, for when struck or rested upon, they sink inwards because they have but one attachment, and usually escape injury.

The peculiar arrangement of the ribs renders them very important agents of respiration, for when they are elevated by muscular action during inspiration, the chest becomes enlarged and the air passes readily into the lungs. In expiration the ribs are depressed, the chest cavity is diminished in size, and the air in the lungs is expelled. The diaphragm, which will be referred to again later on, plays an even more important part than the ribs in connection with respiration.

Each upper extremity is composed of thirty-two bones, named as follows : scapula or shoulder blade; clavicle or collar bone ; humerus or arm bone ; ulna and radius, the bones of the forearm; eight carpal bones, composing the wrist; five metacarpal bones, forming the framework of the palm and back of the hand, and fourteen phalanges or bones composing the fingers and thumbs.

The scapula is a thin, flat, triangular bone, situated at the upper part of the back. It joins the clavicle and humerus at its outer end or border. It helps to protect the contents of the chest and forms a broad surface for the attachment of muscles.

The clavicle is shaped somewhat like the italic letter s, and may be easily felt as the upper and most superficial bone at the base of the neck in front. It extends from the sternum to a process on the outer portion of the shoulder blade; it holds the latter upward, backward and outward.

The humerus is the longest and strongest bone of the upper extremity. It has a shaft and two extremities, the upper one being received in a cup-like depression in the outer part of the shoulder blade. The humerus has a greater range of motion than any other bone in the body, and is most often removed from its position and dislocated.

The ulna and radius compose the forearm ; the ulna with the humerus forms the elbow-joint. The upjx^r end of the radius does not take part in this joint or articulation. It is attached by ligaments to the outer side of the ulna, over which it freely glides or rotates, allowing the hand to move inwards and outwards. Its lower end, which is comparatively broad, takes part in the formation of the wrist- joint. The ulna takes no part in this articulation.

The carpus or wrist is composed of eight small irregular bones arranged in two rows. This arrangement insures strength, motion and elasticity.

The metacarpus consists of five long bones connecting the wrist with the bones of the fingers and thumb, and forms the framework of the palm and back of the hand, where they may be easily identified.

The phalanges, which are miniature long bones, are fourteen in number : three for each finger and two for the thumb. ' Their position may be easily demonstrated by bending or flexing the fingers. This arrangement is such that when the hand is opened, the fingers do not correspond in length; but when closed, as in grasping an object, there is no apparent difference. This is necessary, for if the fingers when closed were uneven, the grasping power of the hand would be diminished.

Each lower extremity consists of thirty-one bones, one less than in the upper extremities. They are as follows : the haunch or pelvic bone ; the femur or thigh bone ; the tibia, leg or shin bone ; and the fibula or splint bone; the tarsal bones (seven) or instep; the metatarsal bones (five) or ankle; the phalanges or toes, and the patella or knee cap.

THE STRUCTURE OF THE BODY ii

The pelvis is composed of the haunch bones and two smaller ones which join them behind, the sacrum and coccyx, constituting the lower portions of the vertebral column. The pelvis supports the trunk of the body and protects the pelvic and some of the abdominal organs.

The femur is the strongest and longest bone in the body. Its length is characteristic of the human skeleton. In the erect position of man, the tips of the fingers reach to about the middle of the thigh, while in the orang-outang, the fingers reach to the ankle. This difference is also due to the comparative shortness of the arms in the human skeleton. The upper end of the femur is composed of a spherical head which connects obliquely with the shaft of the bone by a long neck. The function of the latter is to keep the thigh bone a proper distance from the pelvis and to prevent interference with locomotion. This round head rests in a depression or socket in the pelvis. The lower end of the femur is very large and broad, and articulates with the upper extremity of the tibia and, with the patella, or knee cap, forms the joint.

The tibia or shin bone and fibula or splint bone form the leg. The tibia, which is very superficial, having only the skin as a cover, is the larger of these two bones, and is constructed mainly for strength and support, although some muscles are attached to it. The fibula, companion bone of the tibia, is external to it and very slim. It aids in supporting the tibia, takes part in the formation of the ankle-joint, and furnishes attachment for a number of muscles.

The tarsus, or instep, corresponds to the carpus, or wrist, in the upper extremities ; it consists of seven bones, while eight bones form the wrist. The tarsal bones, which form the arch of the foot, possess great strength; this is necessary to support the weight of the body. If the ligaments and other tissues which hold the bones of the tarsus together, particularly underneath, become relaxed, tofn, or otherwise disabled, the instep sinks, the arch of the foot is more or less destroyed, and what is known as ''flat foot'' or "broken arch" occurs. This not infrequently follows certain diseases of the bone. Some people are naturally flat-footed.

The metatarsal bones of the foot correspond to the metacarpal bones of the hand and are the same in number. They form the framework of the foot.

The phalanges are fourteen in number and correspond to the phalanges of the hand.

The patella, or knee cap, is situated in front of the knee-joint. It lies in the tendon of a large muscle, and assists in the formation and protection of this joint. When the leg is extended and the muscle relaxed, the patella will be found to be freely movable. Sometimes the little closed sack over the patella, the interior of which is moistened with a fluid to prevent friction, becomes injured and inflamed and very much increased in size, due to the presence of the fluid. This is known as ''house-maid's knee," for it is sometimes produced by resting on the knees, as in the act of scrubbing. There are, however, other and probably more frequent causes for this affection.

ARTICULATION— JOINTS

Bones are connected at different points in the skeleton; such a connection is called an articulation or joint. Some are immovable — those in the skull, for instance; others slightly movable, as the joints of the spine; while the greater number are freely movable, as the knee and shoulder joints and joints of the fingers and toes.

Some joints have a gliding movement, as the wrist and instep. A ball and socket joint, where a globular head is received in a cup-like cavity, permits movement in several directions, as in the shoulder and hip. In a hinge joint the motion is limited to a forward and backward movement, as at the elbow and knee.

The structures entering into the formation of joints are as follows : bone, cartilage, ligaments, tendons, synovial membranes, blood-vessels, and nerves. Bone has already been described.

Cartilage, or ''gristle," covers the ends of bones which form joints. It acts as a buffer, protecting the adjacent bony surfaces from friction and preventing shock which would occur if these surfaces were directly applied to each other. This is particularly noticeable in the vertebrae of the spinal column.

The continual pressure brought to bear on cartilage would cause pain, inflammation and disease if it were supplied with blood-vessels and nerves ; consequently it is destitute of these structures, and is known as non-vascular tissue. It absorbs its nourishment from the surrounding parts by the process known as imbibition. Cartilage is also found lining tubes, such as the air passages, ears and nose, where it is necessary that channels be kept permanently open.

Continued pressure on cartilage diminishes its thickness, and during the day we may lose half an inch or so in height. However, rest and the recumbent position at night restore the cartilage to its proper thickness. Leaning too much on one side may cause a permanent change in the cartilage, and consequent deformity.

Ligaments are composed of two kinds of tissue : white -fibrous and yellow elastic. The former are more common and connect the extremities of bones forming the joints. White fibrous tissue is very strong and flexible but it does not stretch; and while it permits the necessary movements of the joints, it does not allow the articular ends of the bone forming the joint to become displaced. When a bone is dislocated, the ligaments, as a rule, are either ruptured or torn from their attachment.

The ligaments composed of yellow elastic tissue are very elastic, and are found in parts where considerable range of motion is required, as in the cervical region of the spinal column. This elasticity aids in returning the parts to their proper place after movement.

Synovial membranes are delicate structures connected with the movable joints lining the inner side of ligaments ; but they do not extend between the articular surfaces of the bone. They secrete a thick, glairy fluid, resembling the white of egg, and known as synovia or "joint oil," the function of which is to lubricate the surfaces of the joint, and thus prevent friction. These membranes often become inflamed ; this condition is called ''synovitis."

MUSCLES

Muscles are bundles of reddish-brown fibers, having the power of contraction. There are two kinds : voluntary or striped . muscles, and involuntary or unstriped muscles. The terms ''striped" and "unstriped" refer to the microscopical appearance of the individual fibers composing the muscles.

The voluntary muscles are under the control of the will, and comprise the bulk of the muscular system. They are attached to the different parts of the skeleton and act on the bones as levers ; they are agents of locomotion. They also protect the various structures beneath them, and give grace and symmetry to the form. When the muscles are poorly developed or become diminished in size, a person becomes angular and bony. The lean meat of animals used for food is voluntary or striped muscular tissue.

The voluntary muscles differ in length and shape, and are designated as long, short, broad, etc. They are arranged in pairs, for as a rule there are corresponding muscles on each side of the body.

There are over four hundred muscles attached to the human frame. At many points their outlines are apparent to the eye, and are used by physicians as guides to the location of important vessels and nerves.

Muscles are surrounded by thin wob-like tissue i6 known as fascia, which serves as a support and lessens friction while the muscles are in action.

Fig. 2. — Biceps at rest.

Voluntary muscles are composed of a belly and two extremities. The more fixed extremity is called the

Fig. 3. — Biceps contracted.

origin, and the movable one the insertion, though in some muscles the origin and insertion are equally movable. During contraction the origin and insertion draw closer together, the muscle in action thereby becoming shorter and thicker. This can be easily demonstrated by raising a heavy weight with the hand, when the ''biceps/' the large muscle on the front of the upper arm, will be seen to thicken and bulge forward.

Muscles gradually diminish in size towards their extremities. The fibers at this point are replaced by a firm and resisting substance composed of white fibrous tissue known as ''tendon." This is directly and intimately connected with the periosteum, and sometimes directly with the bone. Tendons differ in appearance from the muscular tissue in being white and glistening. An ''aponeurosis'' is simply an expanded tendon and is found where the muscle has a broad attachment.

Muscles are abundantly provided with blood-vessels, nerves and lymphatics in order that there may be a constant supply of nourishment, that there may be a prompt response to stimulus from the nerv^e centers, and also that waste matter may be absorbed. Tendons have but few blood-vessels, and only those of larger size have nerves.

In the disease known as tetanus or "lock jaw,'' the nerve stimulus is so strong and the contraction of the muscles so powerful that fibers are sometimes ruptured. The stiffness of the body which ensues after death, known as "rigor mortis," is due to the solidification of some of the fluid portions of the muscles : this again is followed within a few hours by the relaxation of the body. It is believed that this rigidity is not so apt to occur in persons killed by lightning.

If muscles are not sufficiently used they become diminished in size and atrophy takes place. From continued non-use they may undergo degeneration, from which there is no recovery, for nature is not favorable to tissue which is of no use. Thus the value of exercise is apparent. Hypertrophy represents the opposite condition to atrophy, and the muscles become increased in size. This is due to unusual and continued exercise and activity. The heart muscle becomes hypertrophied when it is necessary that this organ make up for the partial loss of function due to diseased valves.

The involuntary or unstriped muscles, which are not under the control of the will, are not connected with bones, but form the muscular covering of some of the internal organs, as the stomach and intestines, and also the muscular coat of the blood-vessels. The contraction of this form of muscular fiber is not abrupt and rapid as in voluntary muscles, but slow, worm-like and unequal, and does not affect all portions of the muscles at the same time. The value of this during digestion will be referred to later. The involuntary muscles have no tendons, the muscular fibers simply interlacing with each other. Although the heart is an involuntary muscle and not under the control of the will, the fibers are striped in a manner somewhat similar to voluntary muscular fibers. This is the only instance of the kind.