Pituitary, << pih TOO uh `tehr` ee, >> gland is one of the body’s most important glands. It secretes a number of hormones, which control a wide range of body functions. The pituitary gland, also called the hypophysis, is about the size of a pea and lies under the brain near the center of the skull. A short stalk connects the pituitary to the hypothalamus, a part of the brain.
The pituitary has two main sections–the anterior lobe (front part) and the posterior lobe (rear part). The anterior lobe secretes several hormones. Four of these hormones control the secretions of other hormone-producing glands. The four hormones and the glands they control are: adrenocorticotropic hormone (ACTH), the adrenal glands; follicle-stimulating hormone (FSH) and luteinizing hormone (LH), the sex glands; and thyroid-stimulating hormone (TSH), the thyroid gland. Secretions from these glands, in turn, signal the pituitary to decrease secretion of the hormones controling them.
The anterior lobe of the pituitary also produces growth hormone (GH), which regulates the growth of children and adolescents. Growth hormone also helps control the way food is utilized in people of all ages. Prolactin, another hormone of the anterior lobe, stimulates milk production in nursing mothers.
The hypothalamus plays an important role in regulating the anterior lobe of the pituitary. It produces releasing hormones that govern the release of secretions from the anterior lobe.
The posterior lobe of the pituitary gland stores two hormones, antidiuretic hormone (ADH, also called vasopressin) and oxytocin. The hypothalamus manufactures and triggers the release of both these hormones. Antidiuretic hormone causes the kidneys to retain sufficient water for the body. Oxytocin causes the uterus to contract during childbirth and stimulates the release of milk during nursing.
