Search results
Results from the WOW.Com Content Network
Hypothyroidism (also called underactive thyroid, low thyroid or hypothyreosis) is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormones. [3] It can cause a number of symptoms, such as poor ability to tolerate cold , extreme fatigue, muscle aches , constipation , slow heart rate , depression , and ...
If the increase in serum TSH level following TRH administration is absent or very slight, then the cause of the hypothyroidism is in the anterior pituitary gland, i.e. the pituitary is not secreting TSH. Therefore, even when TRH is given exogenously, TSH levels do not rise as the pituitary is diseased. [citation needed]
For example, insufficient production (hyposecretion) of thyroid stimulating hormone (TSH) in the pituitary gland will cause hypothyroidism, while overproduction (hypersecretion) of TSH will cause hyperthyroidism. Thyroidisms caused by the pituitary gland are less common though, accounting for less than 10% of all hypothyroidism cases and much ...
Thyroid stimulating hormone (TSH) is produced by the pituitary gland, another hormone-producing organ in the head. This in turn causes the thyroid to produce T3 and T4, which play a role in the ...
Thyroid-stimulating hormone (also known as thyrotropin, thyrotropic hormone, or abbreviated TSH) is a pituitary hormone that stimulates the thyroid gland to produce thyroxine (T 4), and then triiodothyronine (T 3) which stimulates the metabolism of almost every tissue in the body. [1]
Thyroid hormones (T 4 and T 3) are produced by the follicular cells of the thyroid gland and are regulated by TSH made by the thyrotropes of the anterior pituitary gland. The effects of T 4 in vivo are mediated via T 3 (T 4 is converted to T 3 in target tissues). T 3 is three to five times more active than T 4.
For example, thyrotropin-releasing hormone (TRH) is released from the hypothalamus in response to low levels of secretion of thyroid-stimulating hormone (TSH) from the pituitary gland. The TSH in turn is under feedback control by the thyroid hormones T4 and T3. When the level of TSH is too high, they feed back on the brain to shut down the ...
One cause of pituitary growth associated with the risk of Sheehan's syndrome is the hyperplasia of lactotrophs which produce prolactin, the hormone responsible for milk production. [5] Other hormone-secreting cells of the pituitary undergo rapid growth in pregnant women as well, which contribute to the gland's enlargement.