Question

How does the kidney regulate the pH balance of the blood? Include at least 2 pathways in your response.

Answer 1

Kidney helps in regulating the blood pH through excreting more hydrogen ions and by generating the bicarbonate (by reabsorption of carbonic acids in the nephron tubules) and maintains the acid -base balance.

The pathways which is involved in the regulating the pH by kidney are - Bicarbonate buffer system and excretion of hydrogen ions in urine.

By the bicarbonate buffer system in kidney, the antiport transport system in the apical membrane lining the renal tubules allows the sodium ions to reabsorbed from the filterate and hydrogen ions get exchanged in response to that. As a result of that bicarbonate ions are produced by the cells of renal tubules which is not allowed to pass to the perutibular capillares. When the amount of carbon dioxide in blood rises, the formation of carbonic acid occurs and that breaks down into bicarbonate and hydrogen ions. Now bicarbonate ions travels through the peritubular capillaries and goes back to the blood. The hydrogen ions which is getting secreted into the filterate and combine with the water molecules present there, reabsorbed and excreted via urineflow.