If a drop in the pH of the blood occurs, the kidneys will...?

Question

If a drop in the pH of the blood occurs, the kidneys will

A. increase the absorption of urea

B. decrease the absorption of sodium ions

C. decrease the secretion of hydrogen ions

D. increase the re-absorption of bicarbonate ions

Answer 1

D. Bicarb

The bicarb will work to buffer the pH in the blood, but most buffering of pH will occur intracellulary by proteins.  Many proteins are enzymes and can loose their functions.  Therefore buffering the pH with bicarb is a temporary fix, and not a solution.

With a respiratory acidosis, the problem can be correct by increasing ventilation to blow off excess CO2.

With a metabolic acidosis, the kidney is required to rid the body of acids by increasing the net acid excretion.

net acid excretion = ammonium + titratable acids

Answer 2

D., but it's a slow process. The major corrective factor acutely is pulmonary, with hyperventilation blowing off CO2.

You'll want to google (1) Henderson-Hasselbach and (2) carbonic anhydrase.