Blood reaction and respiration.

Abstract

Experimental and clinical observations indicate that when the respiratory mechanism is normal, increase in alkaline reserve is only partially compensated by increase in CO₂ tension, so that increase in pH also occurs. In the same way decrease in alkaline reserve is accompanied by decrease in pH. There is a decrease in CO₂ tension but not sufficient to prevent pH change. The usual percentage change in hydrion concentration is about twice that in CO₂ tension. The arterial CO₂ tension is kept normally between 35 to 45 mm., which is a much narrower range than would be necessitated for the maintenance of normal pH. The conception of the CO₂ tension as a factor physiologically important only from its relationship to blood pH is not consistent with these facts. When conditions force the organism to choose between change in CO₂ tension and change in pH it tends to compromise between the two, and acts in a manner to indicate that maintenance of normal CO₂ tension is in itself an important factor.