Which hormone is secreted from the posterior pituitary?

The hormone secreted from the posterior pituitary is antidiuretic hormone (ADH), also known as vasopressin. This hormone plays a crucial role in regulating water balance in the body by promoting water reabsorption in the kidneys. When the body's water levels are low, ADH is released from the posterior pituitary gland into the bloodstream, signaling the kidneys to retain more water, thus concentrating the urine and reducing the volume of water lost.

In contrast, insulin is a hormone produced by the pancreas that regulates blood glucose levels, while prolactin, which is involved in lactation and reproductive functions, is secreted by the anterior pituitary. Dopamine is a neurotransmitter that functions in the brain and is involved in several important processes, but it is not secreted by the pituitary gland. Therefore, ADH is accurately identified as the hormone secreted from the posterior pituitary gland.