Which is NOT a listed function of the kidney?

• A. Production of insulin
• B. Excretion of metabolic wastes
• C. Regulation of salt and water balance
• D. Regulation of blood pressure

Answer: (A)

The kidneys are primarily involved in managing wastes, fluids, and blood pressure. They excrete metabolic wastes such as urea and creatinine, regulate salt and water balance to keep extracellular fluid and body osmolality stable, and influence blood pressure through mechanisms like the renin-angiotensin system and volume control. They also have other roles, like producing erythropoietin and activating vitamin D, but insulin production is not among their functions. Insulin is produced by pancreatic beta cells and is key for glucose regulation. So the option describing production of insulin is not a kidney function, making it the correct choice. The other listed functions align with renal physiology.