Which hormones are stored in the posterior pituitary and released in response to hypothalamic stimulation?

• A. ADH and Oxytocin
• B. Insulin and Glucagon
• C. TSH and T4
• D. Cortisol and Aldosterone

Answer: (A)

Neurohormones produced in the hypothalamus are stored in the posterior pituitary and released when the hypothalamic neurons fire. The two hormones stored there are ADH (vasopressin) and oxytocin. They travel down the nerve fibers from the hypothalamus to the posterior pituitary, where they’re held in nerve terminals and released into the bloodstream in response to hypothalamic stimulation.

ADH concentrates urine by acting on the kidneys and is released in response to increased plasma osmolality or decreased blood volume. Oxytocin is involved in uterine contractions and milk ejection and is released during stimuli such as suckling or certain reflexes.

The other substances listed aren’t stored in the posterior pituitary. Insulin and glucagon come from the pancreas; TSH is secreted by the anterior pituitary and stimulates the thyroid; cortisol and aldosterone come from the adrenal cortex.