Breathing is the first law of life. We can only last a few minutes without adequate intake of oxygen. To make this possible, nature has provided us with a breathing pipeline called the wind pipe or trachea which is naturally serviced and made clear by coughing. Air must be kept flowing in and out of the body constantly. This is done by the expansion and contraction of the chest and the abdomen. The process of breathing is automatic though in some cases one could take a deep breath whenever he wishes. This delicate balance of respiration is maintained by various chemical changes that occur within the blood stream.
There are at least three different centers in the brain that helps to maintain and regulate the rhythm and rate of our breathing. If any of these centers is damaged by diseases, we soon begin to breathe in short gasps and this kind of breathing is not adequate to provide the body with sufficient oxygen to keep us living. The lungs are among the most remarkable organs in the body that facilitates the process of breathing. They are light and spongy; capable of expanding and contracting into a very narrow space. They are extremely elastic and must remain so or they will be ineffective. Sometimes they become scarred and infiltrated with fibrous bands and this could lead to tuberculosis, asthma, emphysema etc; and will greatly impair normal breathing.
The windpipe that brings air into the lungs or trachea begins just below the voice-box or ‘Adam’s apple’ and extends down to the middle of the chest where it divides into two main branches called bronchi. One main bronchus goes to the right and the other to the left. These main tubes later breaks up into numerous smaller branches and these smaller branches breaks into other smaller tubes called bronchioles, which in turn carry the incoming air to myriads of the tiny chambers called air sacks or alveoli. The alveoli are a microscopic air sac compressed within the spongy tissues of the lungs to provide an enormous inner surface over which the air can pass.
Inside the walls of the alveoli are myriads of tiny capillaries, smallest of all blood vessels. The walls of the capillaries are so thin that the molecules of oxygen in the air readily pass through them and into the red blood cells where they unite with the hemoglobin. This chemical merger called oxygenation changes the blood from bluish-purple to a bright red while carbon dioxide is separated from the red blood cells and is breathed out through the windpipe.
The air we breath is mainly composed of two different types of gas namely, oxygen and nitrogen. Oxygen constitutes about one-fifth of the air mass taken in to the lungs. Without oxygen, the process of breathing cannot be completed. We must endeavour to locate ourselves to the proximity of abundant air containing oxygen if we must live healthy. There is an air conditioning system in the nose that takes charge of the filtration, moistening, and warming the air to the right temperature and humidity required by the lungs. We usually breathe in and out about fifteen times a minute and the total amount of air inhaled at a time is about one pint. Our lungs hold about six pints of air, so that approximately one-sixth of the air is exchanged every time we take a breath.