MICROANATOMY

Detailed explanation-1: -The renal system regulates blood pressure by altering the amount of water held in the blood (blood volume). The renal system regulates blood pH by excreting and reabsorbing hydronium ions and bicarbonate. The renal system does not play a direct role in regulating blood temperature.

Detailed explanation-2: -The kidneys regulate circulatory volume by controlling sodium and water balance, thus maintaining extracellular fluid volume (ECFV) homeostasis. Simply put, an increase in sodium and water consumption leads to an increase in ECFV, which in turn increases blood volume.

Detailed explanation-3: -The kidney regulates arterial blood pressure by maintaining sodium homeostasis and through afferent sympathetic signals to the central nervous system. Renal artery perfusion pressure directly regulates sodium excretion and the RAAS plays a central role in maintaining the pressure–natriuresis relationship.