Respiration
In simple terms, respiration means exchange of oxygen and carbon dioxide between the living body and the outside air, and this exchange, effected by the breathing of fresh air, continually stands between us and the grave. Although we never think of it, each breath we take is vaporized, warmed and filtered as it enters the lungs. While these important functions are performed mostly by the nose, there is also an elaborate but simple cleansing system inside our lungs for the removal of dust particles and other impurities.
To understand the essentials of breathing, we must realize that our blood stream, the river of life, constantly flows in enormous quantities through the lung tissues. It is here that the blood drinks deeply of the fresh air and oxygen which we have inhaled and at the same time throws off the waste gases, such as, carbon dioxide, which we exhale. In short, the whole of respiration is the ability of our red blood cells to drink in oxygen and to discard carbon dioxide. Each red cell contains the chemical hemoglobin, which gives blood its red color and is the substance that actually carries the oxygen. Even in this atomic age, no one has been able to manufacture anything that can approach hemoglobin.
When the red cells have taken their fill of oxygen from the lungs, they travel throughout the blood vessel system of the body, bringing their eagerly sought parcel of oxygen to the body tissues. They then pick up the waste gas, or carbon dioxide, and return it to the lungs to be exhaled, thus completing the vital exchange.
How often do we breathe in sickness and in health? At rest, the average person may breathe in and out about sixteen to twenty-four times a minute. Exertion, excitement, or work of any sort increases the rate of breathing to bring into the body greater amounts of required oxygen. The fact that we breathe during our sleep tells us that there must be a mechanism which regulates breathing for us even when we are unconscious. We may voluntarily hold our breath for a time but we can never suffocate in this way, because as unconsciousness arrives, the brain centers again promote the regular respiration which will bring back consciousness. This governing mechanism is located within the brain and if it is damaged, breathing may be considerably changed. In disease the respiration can be greatly affected. One example is disease of the lungs, such as pneumonia, or tuberculosis. Because the body calls for more oxygen in such diseases, the remaining lung tissue must expand and contract faster to maintain adequate respiration. Like the heart, the lungs are capable of great effort when it becomes necessary for continuing life. From birth to the grave, the sweetest thing we will ever have is a deep breath of fresh air.