| hormone, thyroid | Chemical substance made by the thyroid gland which is located in the front of the neck. The thyroid gland uses iodine to make thyroid hormones. The two most important thyroid hormones are thyroxine (t4) and triiodothyronine (t3). (12 Dec 1998) |
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| hormone, thyroid stimulating | A hormone produced by the pituitary gland (at the base of the brain) that promotes the growth of the thyroid gland (in the neck) and stimulates it to produce its thyroid hormones. Normally, the rate of thyroid hormone production is controlled by the pituitary. When there are insufficient thyroid hormones in the body for normal functioning of the cells, the pituitary releases tsh. Tsh in turn stimulates the thyroid gland to produce more thyroid hormones. In contrast, when there is excessive amount of thyroid hormones, the pituitary gland stops producing tsh. The tsh level then falls and thyroid hormone production is reduced. This mechanism maintains a relatively constant level of thyroid hormones circulating in the blood. This phenomenon is analogous to a thermostat used for temperature regulation in a room: when the temperature rises, the thermostat shuts the heater off and the room temperature falls back to normal. High levels of thyroid hormones cause the tsh level to fall, resulting in no further stimulation of the thyroid gland. In hyperthyroidism, there are continuously elevated levels of the thyroid hormones. Tsh is also known as thyrotropin. (12 Dec 1998) |
| hormone, thyrotropin | A hormone produced by the pituitary gland (at the base of the brain) that promotes the growth of the thyroid gland (in the neck) and stimulates it. The suffix -tropin indicates an affinity for. Thyrotropin has an affinity for the thyroid. Thyrotropin is known also as thyroid stimulating hormone (tsh). (12 Dec 1998) |
| hormone, thyroxine | A chemical substance made by the thyroid gland the thyroid gland uses iodine to make thyroid hormones. Thyroxine (t4), one of the most important thypoid hormones, has four iodine molecules attached to its molecular structure. (12 Dec 1998) |
| hormone, triiodothyronine | A hormone made by the thyroid gland. The thyroid gland uses iodine to make thyroid hormones. Triiodothyronine (t3) has three iodine molecules attached to its molecular structure. Iodine is found in seafood, bread, seaweed, and ordinary table salt. (12 Dec 1998) |
| hormone, tsh | Stands for Thyroid Stimulating Hormone. Also known as thyrotropin. (12 Dec 1998) |
| hormone,t4 | Thyroxine, a thyroid hormone. The number 4 is usually in subscript. (12 Dec 1998) |
| hormones | Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various endocrine glands and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects. (12 Dec 1998) |
| hormones, ectopic | Hormones released from neoplasms or cells outside the usual sources of hormones. Such hormones may be useful as tumour markers. (12 Dec 1998) |
| hormones, hormone substitutes, and hormone antagonists | A collective grouping for both naturally occurring and synthetic hormones, substitutes, and antagonists. (12 Dec 1998) |
| hormones, synthetic | Synthetic chemical compounds that mimic the activity of hormones produced in the body, but differ in structure from naturally occurring hormones. (12 Dec 1998) |
| hormonogenesis | The formation of hormones. Synonym: hormonopoiesis. (05 Mar 2000) |
| hormonogenic | Pertaining to the formation of a hormone. Synonym: hormonopoietic. (05 Mar 2000) |
| hormonopoiesis | Synonym: hormonogenesis. Origin: hormone + G. Poiesis, production (05 Mar 2000) |
| hormonopoietic | Pertaining to the formation of a hormone. Synonym: hormonopoietic. (05 Mar 2000) |