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The pituitary gland or hypophysis is an endocrine gland in vertebrates. In humans , the pituitary gland is located at the base of the brain , protruding off the bottom of the hypothalamus . The human pituitary gland is oval shaped , about 1 cm in diameter, 0.5–1 gram (0.018–0.035 oz) in weight on average, and about the size of a kidney bean .
Hyperpituitarism is a condition due to the primary hypersecretion of pituitary hormones; [3] [medical citation needed] it typically results from a pituitary adenoma.In children with hyperpituitarism, disruption of growth regulation is rare, either because of hormone hypersecretion or because of manifestations caused by local compression of the adenoma.
The pituitary gland (or hypophysis) is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold (diaphragma sellae).
If there is an excess of growth hormone, it is usually because of over-secretion of somatotrope cells in the anterior pituitary gland. A significant amount of excess somatotrope secretion before puberty or before the end of new bone tissue growth can lead to gigantism, a disease that causes excess growth of body (e.g. being over 7 ft. tall) and unusually long limbs.
One of the most important functions of the hypothalamus—it is located in the brain adjacent to the pituitary gland—is to link the endocrine system to the nervous system via the pituitary gland.) Other organs, such as the kidneys, also have roles within the endocrine system by secreting certain hormones.
The pituitary gland is divided into three lobes: the anterior pituitary, the intermediate pituitary lobe, and the posterior pituitary. The hypothalamus controls the anterior pituitary's hormone secretion by sending releasing factors, called tropic hormones , down the hypothalamo-hypophysial portal system. [ 3 ]
There is a pituitary portal system, with which the hormones are transported. These hormones are prolactin, growth hormone, TSH, adrenocorticotropic hormone, FSH and LH. They are all released by anterior pituitary. Some have targets in glands and some with direct function. Anterior pituitary is an amalgam of hormone producing glandular cells.
The underlying mechanism generally involves problems with the pituitary gland. [2] Some cases are associated with a lack of other pituitary hormones, in which case it is known as combined pituitary hormone deficiency. [4] Diagnosis involves blood tests to measure growth hormone levels. [2]