Which gland secretes the antidiuretic hormone (ADH)?

The gland responsible for secreting antidiuretic hormone (ADH), also known as vasopressin, is the posterior pituitary. ADH is produced in the hypothalamus but is stored and released from the posterior pituitary gland. This hormone plays a critical role in regulating the body's water balance by influencing the amount of water the kidneys retain while filtering blood. When the body needs to conserve water, the secretion of ADH increases, leading to a reduction in urine output.

The anterior pituitary primarily secretes different hormones that regulate various bodily functions, including growth hormone and prolactin, but it does not produce ADH. The thyroid gland is involved in regulating metabolism through hormones such as thyroxine but is not associated with the secretion of ADH. The adrenal gland produces hormones like cortisol and adrenaline, which help manage stress but do not have a direct role in water regulation like ADH does. Thus, the posterior pituitary's role in releasing ADH is essential for maintaining fluid balance in the body.