Hormones of the Pituitary Gland

The anterior pituitary's pars distalis secretes six primary hormones: growth hormone, thyroid-stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, and prolactin. These hormones regulate growth, metabolism, reproduction, and lactation. Each is controlled by hypothalamic regulators that direct their synthesis and release.

Growth hormone controls overall growth by regulating insulin-like growth factor production from the liver, bones, and muscles. It also regulates metabolism by balancing fat and glucose usage for energy generation. This dual function makes growth hormone essential for both physical development and metabolic homeostasis throughout life.

Tropins are anterior pituitary hormones that control hormone secretion by other endocrine glands. Thyroid-stimulating hormone regulates thyroid hormones, while adrenocorticotropic hormone controls cortisol release from the adrenal glands. These regulatory hormones enable the pituitary to coordinate responses across the entire endocrine system.

Luteinizing hormone and follicle-stimulating hormone control reproductive function in both sexes but produce different outcomes. In females, these hormones regulate the menstrual cycle; in males, they regulate testosterone production. Despite their different effects, both hormones are essential for normal reproductive development and function.

The posterior pituitary does not synthesize hormones; instead, it stores and releases oxytocin and antidiuretic hormone produced by hypothalamic neurons. Oxytocin stimulates uterine contractions during labor and aids milk release. Antidiuretic hormone regulates water balance by controlling thirst and kidney function.

Prolactin is an anterior pituitary hormone that stimulates breast milk production in lactating mothers. It is one of six primary hormones secreted by the pars distalis and is controlled by hypothalamic regulators. Prolactin levels increase during pregnancy and lactation to support maternal milk supply.

Antidiuretic hormone, released by the posterior pituitary, regulates water balance through two mechanisms: controlling thirst sensation and modulating kidney function. By adjusting water reabsorption in the kidneys and signaling thirst when needed, antidiuretic hormone maintains proper hydration and osmotic balance in body fluids.