How do our lungs work?

Man breathes by drawing air into his lungs (inhaling) and letting it out again (exhaling). In breathing, a fresh supply of air is brought into contact in the lung with tissue very rich in blood. In the lung, gases are exchanged between blood and the air.

The lungs are large, soft organs, which fill both sides of the chest cavity. The lung tissue is like a fine sponge in some ways. The spaces, or air sacs, are the pockets where the air is received, the proper gases used, and the unwanted gases forced out.

The air sacs are separated from each other by very thin walls filled with very delicate blood vessels, the capillaries. Only a few cells separate the blood from the air, so gases can pass easily through these thin walls.

The lungs are elastic (stretchable), and fill the chest. When we breathe in, the chest enlarges and the lungs expand with it. Then air rushes in through the nose, pharynx, Larynx, trachea (the tube going down), and bronchi (two smaller tubes, one of which enter each lung), and finally into the air sacs of the lungs. When we breathe out, the space inside the chest becomes smaller, the lungs snap partly closed, and the air is forced out again through the upper tubes.

How much air can the lungs hold? To measure this, we have to consider the usual breath, plus the extra air it is possible to inhale if we try, and the amount that can be forced out. This is called the “vital capacity,” or the amount of air the lungs will hold. An adult man has a vital capacity of a little over seven pints of air; a woman’s vital capacity is about five pints.

The lung is never empty, even when the greatest effort has been made to force air out. The amount of air remaining after exhaling with great force is called “residual air,” and when we inhale we mix fresh air this residual air.

Breathing is both voluntary and involuntary. It goes on regularly even when we don’t think about it, or are asleep. But we can stop breathing for a short time if we wish-as when we hold our breath when we are under water.

What is ASTHMA?

Asthma is not a disease itself, but a symptom of some other condition. When a person has asthma, he finds it hard to breathe because there is an obstruction to the flow of air into and out of the lungs.

This barrier or obstruction may be caused by a swelling of the mucous membranes, or by a constriction of the tubes leading from the windpipe to the lungs. When a person has an attack of asthma, he develops shortness or breath, wheezing, and coughing. The attack may come on gradually or develop suddenly.

The only way to get rid or asthma is to find out the cause and eliminate it. The cause may be an allergy, an emotional disturbance, or atmospheric conditions. If a person develops asthma before he is 30 years old, it is usually the result of an allergy. He may be sensitive to pollens, dust, animals, or certain foods or medicines.

There are many dusts and pollens which cause asthma. Children, especially tend to develop asthma from food allergies which may be caused by eggs, milk, or wheat products.

Doctors have also observed that an attack of asthma may be caused by emotional disturbance. For example, if a person has family troubles or financial worries asthma may develop. In many cases the emotional disturbance consists of a feeling of being unwanted or unloved. This produces a state which sets off a chain reaction ending in an attack of asthma.

This is why in cases of asthma the diagnosis by the physician is very important. He will take a complete and careful medical history of the patient. He will ask all kinds of questions about the patient’s eating habits, health habits, and environment. If there has been even the slightest change in the person’s routine, he will investigate to see if it has anything to do with the attack of asthma. It may have come after a visit to relatives who keep certain animals, or a visit to the beach, or after eating certain new foods. People who have asthma are often put on special diets by the doctor.