Physiology and Hygiene for Secondary Schools

to the organs which remove them from the body. We are now to consider the passage of materials from outside the body to the cells and vice versa. One

or, carbon dioxide, and argon. All of the regular constituents of the atmosphere are gases, and these, as compared with liquids and solids, are very light. Nevertheless the atmosphere has weight and, on this account, exerts pressure upon everything on the earth. At the sea

e body, called the lungs, and that of expelling air from the lungs. The first process is known as inspiration; the second as expiration. We mus

ordinary breathing parts with about five per cent of itself in the form of oxygen and receives about four and one half per cent of car

mosphere the supply of o

certain materials (wastes) whic

ncerned in the work

c cavity, and occupying all the space not taken up by the heart. They are no

d the right lung, is made up of three divisions, o

ons, called lobules (Fig. 33). Each lobule receives a distinct divisi

ung shows the lobes and their divisions, the lobules. The tissu

ding in a thin-walled sac, called an infundibulum. The interior of the infund

vessels; the membranes that line their inner and outer surfaces; and the connective tissue that binds these parts together. All these tissues are more

ageway between the outside atmosphere and the different divisions of the lungs. The air

passages and other parts. 1. Left nostril. 2. Pharynx. 3. Ton

and has its surface much extended by reason of being spread over some thin, scroll-shaped bones that project into the passage. This membrane is well supplied with blood vessels and secretes a considerable quantity of liq

the organs of digestion (Chapter X). Air entering the pharynx, either by the nostrils or by the mouth, passes through it into the larynx. The larynx, being the special organ for the production of the voice, is described later (Chapter XXI). The entrance int

th their openings directed backward, are held in place by thin layers of connective and muscular tissue. At the lower end the trachea divides into two branches, called the bronchi, each of which closely resembles it in structure. Each bronchus separates into a number of smaller divisions, called the bronchial tubes, and these

kept open by special contrivances found in their walls, which, by supplying a degree of stiffness, cause the tubes to keep their form. In the trachea, bronchi, and larger bronchial tubes, the stiffness is supplied by rings of ca

ighly magnified. c. Cilia, n. Nucleus. B. Diagram

cilia (Fig. 35). They line the mucous membrane in most of the air passages, and are so placed that the cilia project into the tubes. Here they keep up an inward and outward wave-like movement, which is quicker and has greater forc

large sacs are infundibula; the sma

sue, supports a dense network of capillaries (Fig. 37), and is lined by a single layer of cells placed edge to edge. By this arrangement the air within the alveoli is brought very near a large surface of blood, and the exchange of gases between the air and the blood is made possible. It is at the alveoli t

injected with coloring matter. The small pits are alveol

gs. The blood leaves the heart by the pulmonary artery and returns by the pul

nal air sac. While the air moves into and from the space w

ight ventricle and by its branches conveys blood to the capillaries surrounding the alveoli in all parts of the lungs. The branches of the pulmonary artery lie alongside of, and divide similarly to, the bronchial tubes. At the places where the fin

already been supplied with oxygen, passing it into the capillaries in the walls of the bronchi, bronchial tubes, and large blood vessels, as well as the connective tissue between

emoved). A, A'. Places occupied by the lungs. B, B'. Slight space within the pleural sacs containing the pleural secretion, a, a'. Outer layer of pleura an

a closed sac by[pg 085] which the lung is surrounded, the arrangement being similar to that of the pericardium. Properly speaking, there are two pleur?, one for each lung, and these, besides inclosing the lungs, partition off a middle space which is occupied by

he thoracic cavity, is a variable space and the walls surrounding this space are air-tight. A framework for the thorax is supplied by the ribs which connect with the spinal column behind and with the sternum, or breast-bone, in front. They form joints with the spinal colu

of this principle in a most practical manner. The lungs are suspended from the upper portion of the thoracic cavity, and the trachea and the upper air passages provide the only opening to the outside atmosphere. Air entering the thorax must on[pg 086] this accou

inciple in breathing. A. The human bellows.

slightly greater than that of the atmosphere on the outside. The air now flows out until the equality of the pressure is again restored. Thus the thorax, by mak

air flows out. If an air-tight sack were hung in the bellows with its mouth attached to the projecting tube, the arrangement would resemble closely the general plan of the breathing organs (Fig. 41). One respect, however, in which th

is through the movements of the ribs and their resultant effect upon the walls[pg 087

end with the vertebr? of the neck and at the other with the first and sec

ed, at one end, to the back portion of a rib and, at the other, to a projection of the vertebra a few inches above. The

argin of the rib above and the outer upper margin of the rib below, and extend obliquely downward and forward. The internal intercostals are attached between the inner margins of adjacent ribs, and

art being raised or lowered by threads moving through attachments at 1 and 2. As the front is raised the space between the uprights is increased. The fro

nd from side to side. Lowering and converging the ribs has, of course, the opposite effect (Fig. 42). Except in forced

f the abdomen. The edges of the diaphragm are firmly attached to the walls of the trunk, and the center is supported by the pericardium and the pleura. The outer margin is muscular, but the central portion co

nal walls (after their having been pushed out by the lowering of the diaphragm), pressure is exerted on the organs of the abdomen and these in turn press

action of currents and eddies and by the rapid diffusion of gas particles, the air from the outside mixes with that in the alveoli and comes in contact with the membranous walls. Here the oxygen, after being dissolved by the moisture in the membrane, diffuses

m illustrating

alf full; the air which remains is called the residual air. The air which is expelled from the lungs by a forced expiration, less the tidal air, is called the reserve, or supplemental, air. These several quantities are easily estimated. (See Prac

iration and its dependence on external res

king place between the cells and the blood, similar to[pg 090] that taking place between the blood and the air. This exchange is known as internal, or cell, respiration. By internal respiration the oxygen reaches the place where it is to serve its purpose, and the carbon dioxide be

F RESPIRA

bled spot in the lungs which has lost its "power of resistance." Though consumption is not inherited, as some suppose, lung weaknesses may be transmitted from parents to children. This, together with the fact, now generally recognized, that consumption is cont

infrequently of disease germs.33 Partly through[pg 091] the small hairs in the nose, but mainly through the moist membrane that lines the passages, the nostrils serve as filters for removing the minute solid particles (Fig. 45). While it is i

s covered with moist membrane against which the air is made to strike by the narrow passag

rmth and moisture which the air receives in this way, prepare it for entering the lungs. Mouth breathing, on the othe

se it fails to keep up a healthy condition of the entire lung surface. Portions of the lungs to which air does not easily penetrate fail to get the fresh air and exercise which they need. As a consequence, they become weak and, by losing their "p

h the free movements of the ribs and are recognized causes. Clothing also may impede the respiratory movements and lead to shallow breathing. If too tight around the chest, clothing interferes with the elevation of the ribs; and if too tight around the waist, it prevents

e taking of exercise sufficiently vigorous to cause deep and[pg 093] rapid breathing should be a common practice and one should spend considerable time out of doors.

he hands on the hips, the shoulders drawn back and down, the chest pushed upward and forward, and the chin slightly depressed, draw the air slowly through the nostrils until the lungs are completely full. After hol

hest. Though such movements are best carried on by the aid of a physical director, one can do much to help himself. One may safely proceed on the principle that slight deformities of the che

umption find it easy to get a start. On this account a cold on the chest which does not disappear in a few days, but which persists, causing more or less coughing and pain in the lungs, must be given serious consideration.37 The usual home remedies failing to give relief, a physician should be consulted. It should also be noted that certain diseases o

(colder in winter, warmer in summer) from that indoors, and as a consequence differs from it slightly in weight. On account of this difference, suitable openings in the walls of buildings induce currents which pass between the rooms and the outside atmosphere even when there is no wind. In winter care must be

usted for ventilat

ting, and the condition of the weather. Specific directions cannot be given, but the following sugg

r this purpose, raise the lower sash and drop the upper one slightly for several windows, varying the widt

of the room.[pg 096] The air should, if possi

entilate principally on the

bed be so placed that strong air currents do not pass over the sleeper. In schoolhouses and halls for public gatherings the

a laboratory experiment. Expiratio

pends upon the prompt application of artificial respiration. This is accomplished by alternately compressing and enlarging the thorax by means of variable pressure on the outside, imitati

t the diaphragm, while the elastic reaction of the parts causes fresh air to enter (Figs. 47 and 48). "The operator kneels or squats by the side of, or across the patient, places his hands over the lowest ribs and swings his body backward and forward so as to allow his weight to fall

cial respirati

ual and fora long period of time without exhaustion. 2. It allows the mucus and water (in case of drowning) to run out of the mouth,

se of drowning, the patient should be wrapped in dry blankets or clothing, while bottles of hot water may be placed in contact with the body. T

delicate linings and tends to clog them up. Tobacco smoke also contains the poison nicotine, which is absorbed into the blood. For these reasons the cigarette user who inhales the smoke does himself great harm, inju

"alcoholism is perhaps the most potent predisposing cause" of pneumonia.41 A person addicted to the use of alcohol is also less likely to recover from the disease than one who has avoided its use, a result due in part to

lcoholism is a recognized cause of consumption. Some authorities claim that this disease is more frequent in heavy drinkers than in those of

on the most nourishing food, and is made to spend practically his entire time, including the sleeping hours, out of doors. Not only is this done during the pleasant months of summer, but also during the winter when the temperature is below freezing

ime as he conveniently can out of doors. He should provide the most ample ventilation at night and have a sleeping room to himself. He should practice deep breathing exercises and partake of a nouri

ts of the atmosphere. By alternately increasing and diminishing[pg 100] the thoracic space, air is made to pass between the outside atmosphere and the interior of the lungs. Finding its way into the smallest divisions of the lungs, called the alveoli, the air comes very near a large surface of blood. By

for demonstrat

in composition from air leaving the lungs? What purpo

divisions

alveoli. Trace the blood from the right ventricle

blood through the lungs with respect to (a) the direction of the motion. (b) t

ir passages kept

o what divisions does it se

d name uses of

and .05 of this is retained as oxygen, calculate the number of cubic feet o

gen, as found in the above problem, allowin

he hygienic ventilati

ages of full breathing

oulders be a cause of consumption? Ho

ctions for applying a

TICA

two lungs and their position with reference to the heart and diaphragm. Compare the side to side an

tached and the specimen kept in a moist condition until used. Demonstrate the trachea, bronchi, and the bronchial tubes, and the ge

r that has been held as long as possible in the lungs. When filled with air, remove the jar from the pan, keeping the top well covered. Slipping the cover slightly to one side, insert a burning splinter and observe that the flame i

wing changes which air un

ort and one long glass tube, the long tube extending below the limewater. Connect the short tube of one bottle and the long tube of the other bottle with a Y-tube. Now breathe slowly three or four times through the Y-tube. It will be found that the inspired air p

ld window pane. Note and accoun

eathe several times upon the bulb, noting the rise in the mercury. Wh

nd should be secured firmly in place by screws or nails. The other should be movable. With this contrivance measure the sideward and forward expansion of a boy's thora

s for measuring

possible has been expelled from the lungs. Take it again when the lungs h

s for illustrating the

one half inch in advance of it.) Place the bottle in a large glass jar filled two thirds full of water (Fig. 52). Let the space above the water represent the chest cavity and the water surface represent the diaphragm. Raise the bottle, noting that the water fa

(lung tester) during a period, say of ten respirations (Fig. 53). Note the total amount of air exhaled and

ometer) for measuring t

his amount, less the tidal air, is known as the reserve air. The air which is now left in the lungs is called the residual air

ossible into the spirometer, noting the amount expelled. This, less the tidal air and the

g