What percentage of arterial blood do the kidneys receive?

The kidneys receive approximately 20-25% of the resting cardiac output in arterial blood. This is a significant proportion, reflecting the vital role that the kidneys play in filtering blood, regulating blood pressure, and maintaining electrolyte and fluid balance in the body. Given the total volume of blood pumped by the heart, this percentage underscores the high metabolic demands of the renal tissues and their continuous activity in excreting waste products and regulating homeostasis.

Receiving about one-fifth of the heart’s output demonstrates the kidneys' importance in overall circulation and their specialized functions, which include filtration, excretion, and reabsorption processes essential for maintaining normal physiological functions.