Which hormone is also known as antidiuretic hormone (ADH)?

The hormone known as antidiuretic hormone (ADH) is vasopressin. Vasopressin plays a critical role in regulating the body’s water balance by promoting water reabsorption in the kidneys. When the body is dehydrated or when there is an increase in blood osmolarity, vasopressin is released from the posterior pituitary gland. This hormone acts on the renal collecting ducts, making them more permeable to water, which leads to increased water reabsorption back into the bloodstream and results in more concentrated urine.

Vasopressin’s function encompasses not just water retention but also the regulation of blood pressure through its vasoconstrictive effects. The term "antidiuretic" reflects its ability to reduce urine production, which is a significant aspect of its role in fluid homeostasis.

In considering the other hormones mentioned, while oxytocin is involved in several physiological processes, including childbirth and lactation, it does not function as an antidiuretic. Aldosterone primarily regulates sodium and potassium levels and is involved in blood pressure regulation, but it does not act directly as an antidiuretic. Cortisol is a glucocorticoid that affects metabolism and immune response, but like ald