- Pituitary gland
- The main endocrine gland. It is a small structure in the head. It is called the master gland because it produces hormones that control other glands and many body functions including growth. The pituitary consists of the anterior and posterior pituitary. The anterior pituitary is the front portion of the pituitary. Hormones secreted by it influence growth, sexual development, skin pigmentation, thyroid function, and adrenocortical function. These influences are exerted through the effects of pituitary hormones on other endocrine glands except for growth hormone which acts directly on cells. The effects of underfunction of the anterior pituitary include growth retardation (dwarfism) in childhood and a decrease in all other endocrine gland functions normally under the control of the anterior pituitary (except the parathyroid glands). The results of overfunction of the anterior pituitary include overgrowth (gigantism) in children and a condition called acromegaly in adults. The posterior pituitary is the back portion of the pituitary. It secretes the hormone oxytocin which increases uterine contractions and antidiuretic hormone (ADH) which increases reabsorption of water by the tubules of the kidney. Underproduction of ADH results in a disorder called diabetes insipidus characterized by inability to concentrate the urine and, consequently, excess urination leading potentially to dehydration. The urine is "insipid" (overly dilute).
* * *pituitary gland n a small oval reddish gray very vascular endocrine organ that is attached to the infundibulum of the brain and occupies the sella turcica, that is present in all craniate vertebrates, that consists essentially of an epithelial anterior lobe derived from a diverticulum of the oral cavity and joined to a posterior lobe of nervous origin by a pars intermedia, and that has the several parts associated with various hormones which directly or indirectly affect most basic bodily functions and include substances exerting a controlling and regulating influence on other endocrine organs, controlling growth and development, or modifying the contraction of smooth muscle, renal function, and reproduction called also hypophysis, pituitary body see adenohypophysis, NEUROHYPOPHYSIS
* * *the master endocrine gland: a pea-sized body attached beneath the hypothalamus in a bony cavity at the base of the skull. It has an anterior lobe (adenohypophysis), which secretes thyroid-stimulating hormone, ACTH (adrenocorticotrophic hormone), the gonadotrophin, growth hormone, prolactin, lipotrophin, and melanocyte-stimulating hormone. The secretion of all these hormones is regulated by specific releasing hormones, which are produced in the hypothalamus (see also corticotrophin-releasing hormone, gonadotrophin-releasing hormone, thyrotrophin-releasing hormone). The posterior lobe (neurohypophysis) secretes vasopressin and oxytocin, which are synthesized in the hypothalamus and transported to the pituitary, where they are stored before release.
* * *hypophysis.
Medical dictionary. 2011.