Pituitary gland (hypophysis) – an organ with a size of a peanut, positioned directly beneath the brain – is the most important endocrine gland (gland that secretes hormones) in the body. It is sometimes called the “main” gland, because it is the real management center that regulates many aspects associated with the growth, development and operation of the body.
The gland is composed of two parts:
– front (anterior) and
– rear (posterior) lobe.
The front lobe secretes six hormones. Growth hormone manages, as indicated by its name, physical growth in most parts of the body. Prolactin stimulates the secretion of milk in the breast. The other four hormones that are produced by the anterior lobe stimulate four other endocrine glands – the thyroid gland, adrenal glands, ovaries (in women) and testes (in men) – which then themselves produce “their” hormones.
Rear lobe secretes two hormones. Antidiuretic hormone (ADH) acts on the kidneys and plays an important role in regulating the amount of urine. Another hormone, oxytocin, stimulates contraction (shrinkage) of the uterus during childbirth and lactation during breast-feeding.
Disorders of the pituitary gland are rare, but every year the hospital cures about 1 person per 30, 000.