Acid-base physiology respiratory mechanism

The renal mechanisms come into play immediately the disturbance of acid-base physiology starts. However, it takes a relatively long period for the renal mechanisms to come to maximum efficiency and for the renal retention of bicarbonate to build up the concentration throughout the body. In respiratory acidosis, it takes around three days for the subject to settle to the compensated point. This is where the subject then stays so long as the same degree of hypoventilation persists. 

Disorders of acid-base physiology which are not of respiratory origin are called metabolic disorders. This nomenclature derives from the fact that such disorders result from abnormal metabolism. Metabolic disorders of metabolism may also be due to excessive intake of acid or alkali or to failure of renal function, when the tubular mechanisms for formation of acid or alkaline urine are impaired. 

Carbon dioxide is normally present in the atmosphere at about 0.035 percent by volume. It is also a normal end-product of human and animal metabolism. The exhaled breath contains up to 5.6 percent carbon dioxide. The greatest physiological effect of carbon dioxide is to stimulate the respiratory center, thereby controlling the volume and rate of respiration. It is able to cause dilation and constriction of blood vessels and is a vital constituent of the acid-base mechanism that controls the pH of the blood. 

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