Search results
Results From The WOW.Com Content Network
The hypophyseal portal system is a system of blood vessels in the microcirculation at the base of the brain, connecting the hypothalamus with the anterior pituitary. Its main function is to quickly transport and exchange hormones between the hypothalamus arcuate nucleus and anterior pituitary gland.
The anterior pituitary (also called the adenohypophysis or pars anterior) is a major organ of the endocrine system.The anterior pituitary is the glandular, anterior lobe that together with the (posterior pituitary, or the neurohypophysis) makes up the pituitary gland (hypophysis) which, in humans, is located at the base of the brain, protruding off the bottom of the hypothalamus.
Unlike most tropic hormones released by the anterior pituitary gland, prolactin secretion is primarily regulated by hypothalamic inhibition rather than by negative feedback from peripheral hormones. Prolactin also self-regulates through a counter-current flow in the hypophyseal pituitary portal system, which triggers the release of hypothalamic ...
The anterior pituitary is supplied by a low pressure portal venous system. [15] The anterior pituitary is more commonly affected in Sheehan's syndrome because of the structure of the portal venous system. Posterior pituitary involvement leading to central diabetes insipidus is much rarer, and typically reflects more extensive damage to the ...
Autoimmune hypophysitis can lead to deficiencies in one or more pituitary hormones, causing central diabetes insipidus if the posterior pituitary gland is affected as well as central adrenal insufficiency and central hypothyroidism if the anterior pituitary gland is affected. [1] The symptoms depend on what part of the pituitary is affected.
Most commonly, the initial symptoms are headaches and visual disturbances. Some symptoms are derived from the lesser functioning of the adenohypophyseal hormones. Of the adenohypophyseal hormones, the most frequently affected are corticotropes, lactotropes and gonadotropes, all which are found in the anterior pituitary.
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.