Our organism is a laboratory in which continuous physiochemical reactions take place, mostly oxidation. Fats, carbohydrates and proteins are burned supplying the necessary energy for continuation of life and growth. During these processes oxygen is consumed and CO2 and H20 are produced. Therefore these reactions cannot be carried on unless 02 is supplied and CO2 eliminated by a well regulated mechanism.
Respiration and circulation represent the most important factors of that rather complicated mechanism in which internal secretions, vitamins and even inorganic catalysers play an important part. Respiration insures the supply of O~ and elimination of CO2 in the lung and in the tissues. Circulation regulates through the circulating blood the distribution of 02 to the tissues, according to their action and continuously varying metabolic needs, and, on the other hand, it renders possible the elimination of CO2.
In fact, respiration and circulation can be considered as one function, the only objective of which is, as Claude Bernard put it, " to preserve constant the conditions of life in the internal environment, the blood." * Presented at a meeting held Thursday, March 28th, I935.