Respiration and the Voice : Part 2

Hygienic Physiology: with Special Reference to the Use of Alcoholic Drinks and Narcotics
by Joel Dorman Steele, Ph.D.

(Page 5 of 15)

How We Breathe. - Respiration consists of two acts - taking in the air, or inspiration, and expelling the air, or expiration.

1. Inspiration. - When we draw in a full breath, we straighten the spine and throw the head and shoulders back, so as to give the greatest advantage to the muscles.

At the same time, the diaphragm descends and presses the walls of the abdomen outward. Both these processes increase the size of the chest. Thereupon, the elastic lungs expand to occupy the extra space, while the air, rushing in through the windpipe, pours along the bronchial tubes and crowds into every cell.

2. Expiration. - When we forcibly expel the air from our lungs, the operation is reversed. We bend forward, draw in the walls of the abdomen, and press the diaphragm upward, while the ribs are pulled downward, - all together diminishing the size of the chest, and forcing the air outward.

Ordinary, quiet breathing is performed mainly by the diaphragm, - one breath to every four beats of the heart, or eighteen per minute.

Modifications of the Breath. - Sighing is merely a prolonged inspiration followed by an audible expiration. Coughing is a violent expiration in which the air is driven through the mouth. Sneezing differs from coughing, the air being forced through the nose. Snoring is produced by the passage of the breath through the pharynx when the tongue and soft palate are in certain positions. Laughing and crying are very much alike. The expression of the face is necessary to distinguish between them. The sounds are produced by short, rapid contractions of the diaphragm. Hiccough is confined to inspiration. It is caused by a contraction of the diaphragm and a constriction of the glottis; the current of air just entering, as it strikes the closed glottis, gives rise to the well-known sound. Yawning, or gaping, is like sighing. It is distinguished by a wide opening of the mouth and a deep, profound inspiration. Both processes furnish additional air, and therefore probably meet a demand of the system for more oxygen. Frequently, however, they are like laughing, sobbing, etc., merely a sort of contagion, which runs through an audience, and seems almost irresistible.

The Capacity of the Lungs. - If we take a deep inspiration, and then forcibly exhale all the air we can expel from the lungs, this amount, which is termed the breathing capacity, will bear a very close correspondence to our stature. For a man of medium height (five feet eight inches) it will be about two hundred and thirty cubic inches, or a gallon, and for each inch of height between five and six feet there will be an increase of eight cubic inches. In addition, it is found that the lungs contain about one hundred cubic inches which can not be expelled. Therefore making their entire contents about three hundred and thirty cubic inches, or eleven pints. The extra amount always on hand in the lungs is of great value, since thereby the action of the air goes on continuously, even during a violent expiration. In ordinary breathing, only about twenty or thirty cubic inches (less than a pint) of air pass in and out.

The Need of Air. - The body needs food, clothing, sunshine, bathing, and. drink; but none of these wants is so pressing as that for air. The other demands may be met by occasional supplies, but air must be furnished every moment or we die. Now the vital element of the atmosphere is oxygen gas. This is a stimulating, life- giving principle. No tonic will so invigorate as a few full, deep breaths of cold, pure air. Every organ will glow with the energy of the fiery oxygen.

Action of the Air In The Lungs. - In the delicate cells of the lungs, the air gives up its oxygen to the blood, and receives in turn carbonic-acid gas and water, foul with waste matter which the blood has picked up in its circulation through the body. The blood. Therefore purified and laden with the inspiring oxygen, goes bounding through the system, while the air we exhale carries off the impurities. In this process, the blood changes from purple to red. If we examine our breath, we can readily see what it has removed from the blood.

Tests of the Breath. - 1. Breathe into a jar, and on lowering into it a lighted candle, the flame will be instantly extinguished. Therefore indicating the presence of carbonic-acid gas. 2. Breathe upon a mirror, and a film of moisture will show the vapor. 3. If breath be confined in a bottle, the animal matter will decompose and give off an offensive odor.

Analysis of the Expired Air shows that it has lost about twenty-five per cent of its oxygen, and gained an equal amount of carbonic-acid gas, besides moisture, and organic impurities. Our breath, then, is air robbed of its vitality, and containing in its place a gas as fatal to life as it is to a flame, and effete matter which is disagreeable to the smell, injurious to the health, and which may contain the germs of serious disease.

The Evil Effect of Rebreathing the air can not be overestimated. We take back into our bodies that which has just been rejected. The blood thereupon leaves the lungs, bearing, not the invigorating oxygen, but refuse matter to obstruct the whole system. We soon feel the effect. The muscles become inactive. The blood stagnates. The heart acts slowly. The food is undigested. The brain is clogged. The head aches. Instances of fatal results are only too frequent. The constant breathing of even the slightly impure air of our houses can not but tend to undermine the health. The blood is not purified, and i. Therefore in a condition to receive the seeds of disease at any time. The system uninspired by the energizing oxygen is sensitive to cold. The pale cheek, the lusterless eye, the languid step, spoke but too plainly of oxygen starvation. In such a soil, catarrh, scrofula, and kindred diseases run riot.

Concerning The Need For Ventilation. - The foul air which passes off from the lungs and through the pores of the skin does not fall to the floor, but diffuses itself through the surrounding atmosphere. A single breath will to a trifling but certain extent taint the air of a whole room. A light will vitiate as much air as a dozen persons. Many breaths and lights therefore rapidly unfit the air for our use.