Acid-base balance via systemic buffering

Acid-base balance via systemic buffering refers to the regulation of hydrogen ion concentration and maintenance of physiological pH in body fluids, primarily accomplished by the bicarbonate buffer system, phosphate buffers, protein buffers, and regulatory actions of the respiratory and renal systems. The most important extracellular buffer is the bicarbonate buffer system, composed of carbonic acid (H₂CO₃) and bicarbonate (HCO₃⁻), which interconvert with carbon dioxide (CO₂) and water via carbonic anhydrase. This open system allows rapid pH regulation by the lungs (removal of CO₂) and longer-term adjustments by the kidneys (reabsorption or excretion of bicarbonate and hydrogen ions). Disruptions in these systems are implicated in a variety of acid-base disturbances, including metabolic and respiratory acidosis and alkalosis[1][3][4][5][9].

Other names

Bicarbonate buffer systemAcid-base homeostasisSystemic acid-base regulation

Neutralization of excess H^+^ or OH^- in body fluids through chemical buffering Drugs can supplement buffers (e.g., sodium bicarbonate) or alter excretion/reabsorption of buffer components (e.g., acetazolamide inhibits carbonic anhydrase, shifting bicarbonate balance)