Blood pH

A typical pH range for blood is 7.35 to 7.45, just slightly on the alkaline side of neutral. The pH of blood is kept within rather narrow limits by a variety of mechanisms that include contri­butions by the kidneys (see Chapter 23) and the respiratory system (see Chapter 19). Several chemical buffer systems in the plasma also con­tribute to the control of blood pH. The most important of these is the bicarbonate buffer system, and the bicarbonate ion is the base in this system. The bicarbonate ion is the second most prevalent anion in plasma (Table 15-1). in acidosis or acidemia the blood pH is abnor­mally low, and in alkalosis or alkalemia the pH is abnormally high.