Physiology and hygiene for girls' schools and colleges

Preface

It has for some time been recognised that the education of girls must include a comprehensive training in what will fit them to be efficient in the home sphere. This book aims at supplying a knowledge of home hygiene, dietetics, cooking, and personal hygiene, which will be of service to girls in after-life. The subject of elementary physiology is given in sufficient detail to make the book suitable for examination purposes, and I have included sick-nursing, first aid, and child management, in order to conform to the Collegiate Syllabus of the Institute of Hygiene.

Whilst many of the illustrations have been specially prepared by my husband, Mr. Stennett Chesser, I have to thank Dr. Strickland Goodall for the original drawing illustrating the psychic factor in appetite. I am indebted to many people for valuable suggestions and helpful criticism, more especially Dr. Murray Leslie, Miss I. M. Oakden, M.A., and Mr. Grant Ramsay.

ELIZABETH SLOAN CHESSER.

150, Harley Street, W.

V

Contents

CHAPTER

I. CONSTRUCTION AND BUILD OF THE BODY

II. THE BODY CAVITIES AND BODY SYSTEMS

Chapter I

The meaning of hygiene, anatomy, physiology — The skeleton — Skull — -Vertebral column — Thorax — Upper limb — Lower limb — J oints — -Muscles .

In order to ensure an intelligent study of hygiene, the science which deals with the preservation of health, it is necessary to know something about the body itself — of how it is built up, and the work that each part has to do. Work, either mental or muscular, is the chief object of our daily lives; this has to be carried on by one part of the body, called the “ nervous system,” or another part, called the “ muscular system.”

These systems, having to perform work for us, must be properly fed. The food, being prepared and supplied by the digestive and absorptive system, is carried to all parts of the body by the circulatory system, which in its turn is supplied with oxygen by the respiratory system, the waste matters produced being got rid of by the excretory system.

To understand the various organs of the body we must, study a little anatomy, which concerns the structure of the various organs, and physiology, which is a study of their functions. If we examine any organ of the body under the microscope, we shall find it to consist of parts that differ from each other; these parts are known as various kinds of tissues.

On further examination of tissue, we find that it is built up of cells.

A human being commences life as a single cell, consisting of protoplasm, which contains a nucleus. When fertilised, this rapidly divides into numberless cells, which gradually arrange themselves into definite shapes and positions to form the organs of the body — one kind of cell for the brain, one for muscle, another for skin. All these parts of the body have to be supported, and for this purpose we have connective-tissue cells, and bone cells, with which to form the skeleton, that gives to man his distinguishing shape or form.

Before considering the organs, an outline of the general build or arrangement of the body must be given. As far as possible, the special organs forming the various systems will be studied along with those sections of hygiene which are concerned with the health of the different parts or systems of the body. For example, the anatomy of the respiratory system and the circulatory or blood system will be described in association with ventilation; the skin and other excretory organs in connection with personal hygiene. But the student must first have a fair idea of the general build of the body.

THE SKELETON.

The human body contains over two hundred bones, which are united to form a flexible skeleton, which gives definite structure to the body, allows free locomotion, and supports or protects the soft parts. The skeleton consists of the head or skull ; the vertebral or spinal column and the ribs; the upper and lower limbs, which are attached to the rest of the skeleton by the pectoral and pelvic girdles respectively. The living bones consist of a hard material, composed chiefly of lime, and various soft parts — -bloodvessels, nerves, fatty material, etc. In the centre of the long bones, for instance, we find the marrow, whilst the bone is covered on the surface by a membrane ( periosteum ), which is rich in bloodvessels, in order to ensure nourishment to the bone. Certain bones in the body, such as the ribs and vertebrae, contain no cavities, but consist simply of bony material, hard or compact on the surface, and honeycombed or cancellous in the centre.

THE SKULL OR BONES OF THE HEAD.

The bones of the head may be described under two headings — (i) The cranium, or brain-box; and (2) the bones of the face. All these bones are united firmly, except the iower jaw, which is movable.

The Cranium is composed of eight bones — one frontal, two parietal, two temporal, one occipital, one sphenoid, one ethmoid. The frontal bone forms the forehead and

Parietal Temporal --Inferior Maxilla

Vertebral Column (cervical region)

Clavicle

ijT Scapula

Sternum

Humeru3

[ Vertebral Column ~ \ (lumbar region)

- Radius Dina

— Pelvis

- Carpus Metacarpus

Phalauge3

Tarsus

Metatarsus Phalanges

The Skeleton (Front View).

the roof of the eye sockets. Ihe parietal bones are two large bones on either side of the head, which meet each other above. The occipital bone lies at the back of the head, and is pierced at its lower part by a large hole, the foramen magnum, through which the spinal cord is continuous with the brain. The temporal bodies are situated at the sides of the head between the parietals above and the occipital bone behind. These bones contain the bony parts of the ear. The sphenoid and the ethmoid bones form the base of the cranium, and take part in the formation of the roof of the nose and the inner sides of the eye sockets. These eight bones provide a box in which the soft, easily injured brain lies protected. The edges of the bones of the cranium are serrated, like the teeth of a saw. In infancy these do not meet, thus allowing the bones to grow at their edges until the brain has attained its full size, when these edges come together, leaving a “ suture ” or seam between the different bones.

The Face consists of the following bones : 2 small nasal bones; 2 inferior turbinate bones in the nasal cavities; 2 upper jaw bones (superior maxilla) ; 2 lachrymal bones, small flat bones lying on the inner side of each orbit; 2 malar or cheek bones, which bound the orbits below and on the outer side; 2 palate bones, which lie behind each upper jaw bone, and take part in forming the hard palate; 1 vomer bone, placed vertically between the nasal cavities; and 1 lower jaw bone (inferior maxilla), a single bone which articulates with the temporal bone in front of the ear.

The Eye Sockets, or Orbits, are conical cavities, formed by various bones of the cranium and face. An opening can be seen at the apex of the cone behind where the optic nerve from the brain enters the eye socket.

The Nose Cavity is divided into two by a bony septum, the vomer. On the outer side of each passage the little turbinate bones can be seen.

The Mouth shows the hard palate above and the sockets, containing the teeth.

SPINAL OR VERTEBRAL COLUMN.

The spine, or backbone, consists of a series of small bones, the vertebrae, thirty-three in number — seven cervical, twelve dorsal, five lumbar, five sacral, four coccygeal.

The Cervical vertebrae constitute the neck. The first supports the skull, and it is called the “ atlas.’ At this joint the nodding movements of the head take place. The side-to-side movements take place between the atlas and the second cervical vertebra, the axis.

The Vertebral Column (Side View).

The bodies of the 10th, nth, nth dorsal, and 1st lumbar vertebrae have been cut away to show the vertebral canal.

The Dorsal, or back region of the spinal column, contains twelve vertebrae, which support the ribs.

Lumbar vertebrae.

Cervical vertebrm.

Dorsal vertebra;.

Coccyx.

Sacrum.

- Intervertebral disc.

Intervertebral disc.

Intervertebral disc.

Intervertebral disc.

The Lumbar, or loin vertebrae, five in number, are larger, because they have to support a greater weight.

The Sacrum consists of five vertebrae, which become fused in the adult to form one bone.

The Coccyx, or tail, consists of four small vertebrae, which become fused in the adult.

It will be seen from the diagram that the spinal column is not straight, but takes the shape of four curves. It is curved slightly forwards in the neck, backward in the dorsum, and forwards in the lumbar region; whilst in the sacral and coccygeal regions there is a double curve, forming a concavity towards the pelvis, and a convex lump behind. These curves add to its flexibility, and avoid shock and jarring to the brain.

Pedicle.

Facet for head of rib.

Body or Centrum.

Facet for head of rib.

Intervertebral notch. \ Inferior articular process.

Superior articular process.

Facet for articulation of tubercle of rib.

- Spinous process.

A Dorsal Vertebra (Side View).

Structure of a Vertebra. — Each vertebra consists of tlnee parts — (i) The body, (2) the arches, (3) the three processes. The body helps to support the weight of the trunk, f lie long arch is attached to the back of the body. It encloses a space, which forms the spinal canal, in which he- the spinal ,cord. On either side of the arch of the vertebra transverse processes are seen, and behind there is a sing e spinous process which can be felt beneath the skin at t re back. The powerful muscles for supporting the bod) are attached to these processes. The bodies of the vei tebne are united by a gristle-like material (cartilage) , wnic 1 forms a pad between each body to prevent shock and o provide flexibility. These gristle pads are called intervertebral discs.

The Spinal Canal is a channel extending the length of the column, formed, as we have seen, by the processes from the bodies of the vertebrae, and it contains the spinal cord. This cord gives off thirty-one pairs of nerves, which pass from the canal by apertures between the vertebrae.

THE THORAX.

The thorax is a bony cage, bounded at the back by the twelve dorsal vertebrae, the hinder part of the ribs, with dorsal and intercostal muscles; at the sides by ribs and intercostal muscles; at the front by the front portions of the ribs, the costal cartilages, the sternum and the muscles lying between.

Above, the thorax is narrow, and closed by the first short pair of ribs, with the muscles and vessels at the root of the nfeck. Below it is wide, and has for its floor the diaphragm, passing upwards and inwards to a central tendon, forming an arched partition, convex above and concave below.

The Ribs. — There are twelve pairs of ribs, each pair being attached to a dorsal vertebra behind. The upper seven pairs reach from the back-bone to the sternum, and are called the true ribs. The remaining five pairs do not reach the middle line of the body, and are called false ribs; but they are attached through their cartilages to the sternum, except the last two pairs, which are called floating ribs. These last ribs are easily pressed out of place by badly fitting or tight stays.

The intervals between the ribs are called intercostal spaces, and they are closed in by the intercostal muscles.

The Sternum, or breast-bone, is dagger-shaped, with its broader upper end at the root of the neck, and its pointed cartilaginous end at the upper part of the abdomen. Attached on either side to the upper end of the sternum we have the clavicles, or collar-bones, and on either side of the shaft of the sternum the cartilages of the upper seven ribs are fixed.

THE UPPER LIMB.

Each upper limb consists of the following bones:

Pectoral girdle ( Scapula, and upper-! Clavicle.

arm

Forearm

( Humerus. /Radius.

I Ulna.

f 8 carpal bones (wrist).

Wrist and hand-* 5 metacarpal bones (hand).

[14 phalanges (fingers).

The Shoulder Bones. — The upper limb is supported and attached to the body by the shoulder, or pectoral girdle, which is composed of the scapula (shoulder-blade) and the clavicle (collar-bone).

The Scapula is a flat, triangular bone, hung on the upper ribs at the back of the chest on each side. A ridge or spine can be felt beneath the skin at the back of the shoulder. This can be traced forwards over the shoulder-joint as the acromion process, which forms the “ tip of the shoulder.” At the outer angle of the scapula towards the shoulder-joint a shallow smooth surface (glenoid fossa) receives the upper end of the arm bone (humerus), and forms the shoulder-joint.

The Clavicle, or collar-bone, is curved like the italic letter /, so that it is very elastic, and able to resist strain. The collar-bone is jointed in front to the sternum, and behind to the acromion process of the scapula. By drawing the finger along the collar-bone, it can be felt that the inner curve has its convexity directed forwards, whilst the outer curve has its convexity directed backwards.

The Humerus. — The long arm-bone has a shaft, a head, which articulates with the scapula, and a lower flattened end, which articulates with the two bones of the forearm to form the elbow-joint.

The Forearm consists of the radius, or outer bone, extending to the thumb, and the ulna, or inner bone. The upper end of the ulna is enlarged to form the olecranon process, on which the bent elbow rests. The radius is small at its upper extremity, but it forms the principal part of the wrist-joint. In pronation — i.e., turning the hand palm downwards— the lower end of the radius crosses the ulna

The Hand consists of the carpus, eight small bones arranged in two rows (the upper row articulates with the radius to form the wrist-joint) ; the metacarpus, five bones reaching from the carpus to the knuckles; and the phalanges. Each finger consists of three phalanges placed end to end, the joints of the fingers being made by their articulation with each other. The thumb has only two phalanges. The metacarpal bones and phalanges of the thumb lie rather obliquely, so man is able to bring the tip of the thumb in contact with the tip of each finger. This movement of “ opposition ” distinguishes man from the lower animals.

THE LOWER LIMB.

The Hip-Bones. — The sacrum supports on either side the large hip-bone. The hip-bones curve outwards and forwards to meet each other in front, thus enclosing the pelvic

Acetabulum.

Round ligament.

Ilium.

'Pubes.

Ischium, o

Capsule. ■ • Synovial membrane.

Head of femur.

Capsule.

Neck of femur.

Greater trochanter.

Shaft of femur.

Hip-Joint (Laid Open).

cavity, and forming, with the sacrum and coccyx behind, the pelvic girdle. On the outer side of the large hip-bone can be seen a deep saucer-like cavity (acetabulum) for the head of the thigh-bone to form the hip-joint.

The bones of the leg are similar to those of the arm, consisting of —

Thigh . . The femur (thigh-bone).

f The patella (knee-cap) .

Lower leg . . -J Tibia (shin-bone) .

(Fibula (splint-bone, or brooch-bone).

Ankle and f 7 tarsal bones (ankle).

font 1 5 metatarsal bones (instep).

(14 phalanges (toes).

The femur, or thigh-bone, is the longest bone in the body. It consists of a head, which articulates with the hip-bone, a shaft, and a lower end, which forms part of the knee-joint. In front of this joint is the knee-cap, or patella. The leg below the knee has two bones — the tibia at the inner side, which supports the lower end of the femur (its sharp anterior border can be felt as the shin), and the fibula, or brooch-bone, which begins below the knee-joint, where it is attached to the tibia and passes down the outer side of the leg, to form the external malleolus, a bony prominence at the outer side of the ankle.

The Foot. — At the ankle there are seven bones, which form the tarsus, which articulate with the tibia and fibula to form the ankle-joint. The five long bones in the middle of the foot are called the “ metatarsus,” and they articulate with the phalanges or toes, which contain three bones each, except the big toe, which has only two.

THE JOINTS.

In connection with joints we find ligaments, which are tough bands or straps, which connect and bind the movable bones together, preventing them from being easily dislocated.

Ligaments, therefore, join bone to bone, while tendons join muscle to bone, and may be considered as a continuation of the muscle, being exceedingly strong, but flexible.

J oints are movable or immovable.

Immovable Joints show seams or cracks between the bones, which are dovetailed into each other in such a way that the power of movement is practically non-existent. The bones of the skull articulate in this way, whilst other bones ( i.e ., the pelvis) may be separated by cartilage or gristle, which does not allow movement, but serves rather to prevent shock or strain.

Movable Joints. — When two bones meet to form a movable joint, their surfaces are covered by cartilage, which allows of smooth and free movements. The joint is further enclosed in a capsule, which contains synovial fluid secreted by the synovial membrane lining the capsule. This fluid oils or lubricates the joint. The capsule is strengthened by strong fibrous bands, which strap the bones together.

CONSTRUCTION AND BUILD OF THE BODY n

Some joints are called “ ball-and-socket ” {e.g., the hip and shoulder joints), because they allow of more or less movement of a “ universal ” type. The hinge-joints ( e.g ., the knee, ankle, elbow, and lower jaw) permit only hinge-like movements; whilst in the carpus and tarsus the movements are of a gliding description.

The Intervertebral Discs form joints between the vertebrae, as has already been mentioned.

A Pivot Joint is found between the atlas and axis, which permits side-to-side movements of the head to take place.

THE MUSCLES.

The joints themselves are immovable, all movements being performed by means of contraction of muscles. Muscle is flesh; a piece of steak or a slice of mutton is “ muscle.” This substance is made up of fibres, and each fibre under the microscope is seen to consist of bundles of finer fibres, which show dark stripes, and so these muscles are said to be striated. Each stripe marks the separation between the cells of which the fibre is composed. When a muscle contracts, the fibres swell, and the muscle is shortened. There are two classes of muscles — (i) Voluntary muscles, the fibres of which are striated or striped; (2) involuntary muscles, which is non-striated.

The Voluntary Muscles are under the control of the will. They have to do with the locomotion of the body. A voluntary muscle is generally attached to two bones, with a joint between. It may be attached directly to the bone, or by means of a tendon. The simplest forms of movement are flexion (bending) and extension. For example, if the hand is placed on the biceps muscle of the arm (which is attached to the scapula at the shoulder-joint, and to the radius below the elbow), and the elbow is bent, it can be felt that the muscle swells into a hard lump, as it contracts to bring about this movement. Other movements of the shoulder and hip joints are more complex, but they are all brought about by contraction and relaxation of muscles.

The Involuntary Muscles are found in the walls of the intestine, stomach, heart, bladder, bloodvessels. They act independently of the will, and they differ in structure from voluntary muscle. They are not formed of fibres, but consist simply of muscle cells, spread as a coating to the tubes they enclose. The movement of these muscles are like those of a worm, and so they are called vermicular movements.

Heart Muscle, of which the heart is largely composed, differs both from striated and non-striated muscular tissue. Each fibre is a short quadrangular cell, showing faint transverse striations. The fibre cells are arranged end to end, having branches uniting with neighbouring cells, and are bound together in bundles by connective tissue.

Chapter II The Body Cavities And Body Systems

Contents of thorax — The abdomen — The systems of the body — The tissues — The cells — The chemical composition of the body.

The limbs may be described as solid structures, composed of bone, cartilage, and muscles, with their bloodvessels and nerves. The trunk, however, is hollow, and the skeleton, with its enclosing envelope, the skin, has to support the vital organs. The body is therefore divided into two cavities, the thorax or chest, above, and the abdomen below, by means of a muscular partition, the diaphragm.

CONTENTS OF THE THORAX.

The thorax contains the lungs, and the heart lying between them. Each lung is enclosed in a double sac, the pleura, a glistening membrane which envelops the lung and lines the chest wall. The two layers are in contact, and move smoothly against each other, because they are lubricated by a little fluid. In the centre of the thorax above can be seen the trachea, or windpipe, which divides into two bronchi, one going to each lung. The heart lies in a double membrane or sac, called the pericardium ; and the thorax also contains the great vessels of the heart — the aorta, the pulmonary vessels, and the large veins. Other structures in the thorax include the oesophagus, or foodpipe, lying behind the trachea, or windpipe; the thoracic duct (carrying the lymph); and the lymphatic glands. The thorax is separated from the abdomen, as we have said, by a sheet of muscle, the diaphragm, which in inspiration extends downwards to enlarge the capacity of the chest.

H

THE ABDOMEN.

This cavity is bounded above by the diaphragm, in front by the strong abdominal muscles, which pass from the ribs to the pelvis. Behind are the lumbar vertebrae, the sacrum, the coccyx, and the muscles of the back; whilst below the abdomen is bounded by the pelvic bones. Just as the thorax is lined by a glistening membrane— the pleura — so

Contents of Thorax and Abdomen.

Collar bone

Right lung

Bladder

Thyroid gland Right common carotid artery Jugular vein

Right subclavian vein

Diaphragm^ in section j

Heart

Gall bladder

Stomach

Spleen

{Transverse colon

Ascending 1 colon J

Left common carotid artery

Trachea or windpipe

Descending colon

Coils of small intestine the abdomen is lined with peritoneum, a smooth, moist membrane, which also covers the organs in the abdominal cavity. These are the stomach, intestines, pancreas, spleen, liver, kidneys, and bladder. The stomach communicates above with the oesophagus, and below with the small intestine, a coiled tube which terminates at the lower right-hand corner of the abdomen as it enters the large intestine.

THE BODY CAVITIES AND BODY SYSTEMS 15

The large intestine passes up the right side, across the abdomen just below the stomach, and down the left side to terminate in the lower bowel. The liver is a large gland on the upper right side of the abdomen. The pancreas, or sweetbread, lies in the bend of the duodenum. The spleen is a small, dark-coloured gland lying to the left of the stomach and pancreas. The kidneys are placed against the backbone in the lumbar region. The ureters are two tubes leading from the kidneys to the bladder. The bladder lies rather in the pelvic cavity, which contains also the organs of reproduction.

THE SYSTEMS OF THE BODY.

The body is composed of different systems. Each system has a special function — for example, the digestion of food — and is made up of organs specially constructed to promote the function of the system of which they form a part. The chief systems are —

1. The Alimentary or Digestive System, composed of the stomach, intestines and various glands. This system is concerned with the digestion of food, which has to be altered so that it may be absorbed into the blood.

2. The Circulatory System has to do with supplying the blood which nourishes the tissues to every part of the body. Its organs are the heart, arteries, capillaries, and veins.

3. The Respiratory System is concerned with supplying the tissues and cells with oxygen, which is essential to their vitality, by means of the lungs, the organs in which the blood is purified, aerated, or supplied with fresh oxygen.

4. The Muscular System has to do with the movements or locomotion of the body.

5. The Osseous or Bony System or skeleton supports the soft parts.

6. The Excretory System, the chief organs of which are the lungs, kidneys, and skin, eliminates or gets rid of impurities from the blood.

7. The Lymphatic System consists of glands and lymphatics, containing ?lymph, which1! also lies in spaces in the tissues. Lymph escapes through the thin walls of the i6 bloodvessels, carrying food for the nourishment of the tissues, and removes waste materials from the tissues, being conveyed by the lymphatics to the thoracic duct, thence to the large veins entering the right auricle.

8. The Nervous System controls every other system of the body, and is also the centre of “ will,” consciousness, and the higher attributes of the mind. The organs belonging to this system are the brain, spinal cord, and the nerves.

The Tissues. — Now, the organs of the different systems are in their turn composed of materials called tissues. Tissue is the name given to particular types of cells uniting to perform a definite function.

Connective Tissue. — If a piece of beef or mutton is dissected with a fine knife or needle, it can be seen that the muscular fibres are held together by a glistening white material. This is connective tissue, so called because it connects or holds together other tissues in the body. It forms a sheath round the muscles, and connects the skin with the structures underlying it. It is found round the bloodvessels, and acts as a framework for all the organs. Microscopically, it is made up of bundles of white wavy fibres, with a few yellow elastic fibres, and certain branching cells or connective-tissue corpuscles.

Epithelial Tissue consists of a layer of smooth cells. This tissue lines the various tubes of the body, the bloodvessels, the digestive tube, the respiratory passages, etc Various types of epithelial tissue are — Columnar epithelium (column cells), striated epithelium, and ciliated epithelium (where the cells have little hair-like processes).

Adipose Tissue, or fatt}' tissue, consists of cells held together by connective tissue, each cell containing a drop of liquid fat or oil globule.

Muscle Tissue, as we have said, consists of fibres (voluntary muscles), or cells with connective tissue between them (involuntary muscles).

Cartilage is the material which covers the ends of bones, where they articulate one with another. Microscopically, it shows a clear substance or matrix with cells embedded in it. This type of cartilage is called hyaline cartilage, and it forms also the rib cartilages, the rings of the trachea and bronchi, and part of the larynx, or organ of voice, and it invests the ends of bones at the joints.

THE BODY CAVITIES AND BODY SYSTEMS 17

Striated Muscle Fibre Two Cardiac Muscle Fibres.

(Highly Magnified). , •

' ' I wo nuclei are seen.

A nucleus is seen at the lower p, Processes which join other

end of the left side. fibres.

i8 PHYSIOLOGY AND HYGIENE

Cartilage forming the intervertebral discs contains fibres, and is called white fibrous cartilage.

In other cartilages— for example, the ear cartilageyellow elastic fibres are found in the matrix, and so this type of cartilage is called yellow elastic cartilage.

Bone.- — The microscopic structure of bone tissue consists of tiny channels or canals (the Haversian canals), surrounded by concentric rings, which are marked out by spaces, the lacunae. In the lacunae, bone cells can be seen which are branched. Small bloodvessels traverse the canals, which supply nourishment to the bone. Bone consists of animal matter or organic matter (about 33 per cent.) and mineral salts (about 67 per cent.), which impart rigidity to the bone.

Nerve Tissue is made up, as we shall see, of nerve cells and nerve fibres. Nerve cells have a highly specialised function. They are found, for instance, on the surface of the brain, and each nerve cell shows branching processes, one process being continued into a nerve fibre.

Most of the organs contain several kinds of tissues. The stomach, for instance, is lined with epithelial tissue. It has muscular tissue in its walls, also gland tissue, nerves, bloodvessels, etc. If a tissue is examined under the microscope, it is found to be made up of cells. The different tissues have different varieties of cells, which can quite easily be distinguished under the microscope. The human body is therefore made up of cells — millions of cells — which are constantly changing. We know that the surface cells of the skin are daily shed as scurf, and that these lost cells are made up by new cells formed in the deeper layers of the skin. Each living cell is composed of a substance called protoplasm, which Professor Huxley defined as “ the physical basis of life.” A cell is a mass of protoplasm containing a nucleus which is a more highly specialised area, and the cells may measure perhaps .i(p0l5 inch, some being smaller than this, and some larger.