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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 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.
In general, the intermediate lobe tends to be well developed, and may equal the remainder of the anterior pituitary in size. The posterior lobe typically forms a sheet of tissue at the base of the pituitary stalk, and in most cases sends irregular finger-like projection into the tissue of the anterior pituitary, which lies directly beneath it.
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.
A chromophobe is a histological structure that does not stain readily, and thus appears relatively pale under the microscope. Chromophobe cells are one of three cell stain types present in the anterior and intermediate lobes of the pituitary gland, the others being basophils and acidophils. One type of chromophobe cell is known as amphophils.
Other hormone-secreting cells of the pituitary undergo rapid growth in pregnant women as well, which contribute to the gland's enlargement. [10] 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.
The pars intermedia is one of the three parts of the anterior pituitary. It is a section of tissue sometimes called a middle or intermediate lobe, between the pars distalis, and the posterior pituitary. [1] It is a small region that is largely without blood supply. [2] The cells in the pars intermedia are large and pale.
The protein Annexin A1 (ANXA1), found in high quantities in the anterior pituitary gland, is located specifically in the folliculostellate cell. [1] In addition to the anterior pituitary gland, it can also be found in the non-endocrine cells of the hypothalamus. Glucocorticoids act on the folliculostellate cells to increase synthesis of ANXA1 ...