acid-base balance

the balance between the amount of carbonic acid and bicarbonate in the blood, which must be maintained at a constant ratio of 1:20 in order to keep the hydrogen ion concentration of the plasma at a constant value (pH 7.4). Any alteration in this ratio will disturb the acid-base balance of the blood and tissues and cause either ACIDOSIS or ALKALOSIS . The lungs and the kidneys play an important role in the regulation of the acid-base balance.