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Pituitary Disorders

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What are pituitary disorders?

Thumbnail diagram of the pituitaryThe pituitary gland is part of the endocrine system, which produces and regulates hormones that affect processes throughout the body. Pituitary disorders are characterized by too much or too little of one or more of the hormones produced by the pituitary gland. A pituitary tumor compressing surrounding tissues can also cause symptoms of a pituitary disorder.

The pituitary is a pea-sized gland in the center of the head behind the sinus cavity, at the bottom of the brain, below the hypothalamus. Together, the hypothalamus and pituitary gland are part of the endocrine system, a group of glands that work together to produce and regulate hormones that affect tissues throughout the body. The hypothalamus communicates with other parts of the brain and nervous system to regulate the body. It sends hormones that signal the pituitary to initiate or decrease production of certain hormones.

The pituitary has two parts: the anterior (front) and the posterior (back), which target hormones to different parts of the body. In the anterior portion, growth hormone (GH), adrenocorticotrophic hormone (ACTH), thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin are produced. These hormones help regulate bone growth, muscle mass, the body's response to stress, blood sugar, the rate at which the body uses energy (metabolic rate), the development of secondary sexual characteristics, fertility, and milk production. They affect specific "target" tissues throughout the body, including the thyroid gland, adrenal glands, ovaries (women), and testes (men).

In the posterior portion of the pituitary, oxytocin and antidiuretic hormone (ADH), produced in the hypothalamus, are stored for release. ADH controls the amount of water that the kidneys excrete, which in turn helps regulate the balance of water in the body. Oxytocin stimulates the contraction of the uterus during and after childbirth and is responsible for stimulating the release of milk during breastfeeding.

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