pituitary(redirected from pituitary hypoplasia)
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The adenohypophysis originates from epithelial tissue. The adenohypophysis secretes six important hormones: growth hormone, thyroid-stimulating hormone or thyrotropin, adrenocorticotropic hormone or corticotropin, prolactin, follicle-stimulating hormone, and luteinizing hormone. Most of these hormones are tropic hormones, which regulate the growth, development, and proper functioning of other endocrine glands and are of vital importance to the growth, maturation, and reproduction of the individual. Secretion of the anterior pituitary hormones is controlled by releasing and inhibiting hormones produced by the hypothalamus. Information gathered by the nervous system about the well-being of an individual is collected in the hypothalamus and used to control the secretion of hormones by the pituitary gland. The hypothalamic releasing and inhibiting hormones are transported to the pituitary gland by way of the hypothalamic-hypophyseal portal system in which the hypothalamic venules connect with the capillaries of the anterior pituitary.
The neurohypophysis originates from neural tissue; it stores and secretes two hormones, oxytocin and vasopressin (antidiuretic hormone). These hormones are synthesized in the cell bodies of neurons located in the hypothalamus and transported along the axons to the terminals located in the neurohypophysis and are released in response to neural stimulation.
Surgical removal of part or all of the pituitary gland is called hypophysectomy and is usually done for treatment of a pituitary tumor. Because of its influence on the adrenal cortex and other endocrine glands, removal of the pituitary gland has widespread effects on the body. See hypophysectomy.
pituitaryadjective Referring to the pituitary gland, see there.
noun Pituitary gland, see there.
pituitarypea-sized expansion at terminus of the pituitary stalk, itself an extension of the hypothalamus
anterior pituitary; AP anterior lobe of pituitary; secretes a range of releasing factors and hormones, in response to secretion of hypothalamic-releasing factors into the hypophyseal portal system; AP hormones are releasing factors and include luteinizing hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), prolactin, adrenocorticotrophic hormone (ACTH); AP hormones trigger release of hormones from target endocrine glands
posterior pituitary posterior part of pituitary; stores and secretes vasopressin (antidiuretic hormone; ADH) and oxytocin