Which gland is responsible for the antidiuretic hormone that controls the kidneys?

• A. Anterior pituitary
• B. Posterior pituitary
• C. Hypothalamus
• D. Pineal gland

Answer: (B)

ADH, also known as vasopressin, controls how much water the kidneys reabsorb. It is produced in the hypothalamus but stored and released into the bloodstream by the posterior pituitary. When ADH is released, it increases the permeability of the kidney’s collecting ducts to water, so more water is reabsorbed back into the blood and less urine is produced. This helps maintain blood volume and osmolarity. The anterior pituitary releases other hormones, and the pineal gland makes melatonin, not ADH. So the gland responsible for releasing ADH that regulates the kidneys is the posterior pituitary.