Search results
Results From The WOW.Com Content Network
The hypothalamic–pituitary–thyroid axis (HPT axis for short, a.k.a. thyroid homeostasis or thyrotropic feedback control) is part of the neuroendocrine system responsible for the regulation of metabolism and also responds to stress. As its name suggests, it depends upon the hypothalamus, the pituitary gland, and the thyroid gland.
SimThyr is a free continuous dynamic simulation program for the pituitary-thyroid feedback control system. [1] The open-source program is based on a nonlinear model of thyroid homeostasis. [ 2 ] [ 3 ] [ 4 ] In addition to simulations in the time domain the software supports various methods of sensitivity analysis .
Thyroid gland. follicular cells of the thyroid gland produce and secrete T 3 and T 4 in response to elevated levels of TRH, produced by the hypothalamus, and subsequent elevated levels of TSH, produced by the anterior pituitary gland, which further regulates the metabolic activity and rate of all cells, including cell growth and tissue ...
The concentration of thyroid hormones (T 3 and T 4) in the blood regulates the pituitary release of TSH; when T 3 and T 4 concentrations are low, the production of TSH is increased, and, conversely, when T 3 and T 4 concentrations are high, TSH production is decreased. This is an example of a negative feedback loop. [5]
By contrast, the hormones of the anterior pituitary gland (the adenohypophysis) are secreted from endocrine cells that, in mammals, are not directly innervated, yet the secretion of these hormones (adrenocorticotrophic hormone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, prolactin, and growth hormone) remains ...
The pyramidal lobe is a remnant of the thyroglossal duct, which usually wastes away during the thyroid gland's descent. [5] Small accessory thyroid glands may in fact occur anywhere along the thyroglossal duct, from the foramen cecum of the tongue to the position of the thyroid in the adult. [4]
The thyroid gland is located in the front of the neck, in front of the thyroid cartilage, and is shaped like a butterfly, with two wings connected by a central isthmus. Thyroid tissue consists of follicles with a stored protein called colloid, containing[thyroglobulin], a precursor to other thyroid hormones, which are manufactured within the ...
This is an example of a homeostatic negative feedback loop. Breakdown of the hormone. Exocytosis and other methods of membrane transport are used to secrete hormones when the endocrine glands are signaled. The hierarchical model is an oversimplification of the hormonal signaling process.