noun, plural: thyroid-stimulating hormones
In animals, hormones are substances produced and secreted by an endocrine gland, the ductless gland of the endocrine system. In humans, the pituitary gland is one of the endocrine glands. The pituitary gland is located at the base of the brain and is regarded as the master gland of the endocrine system since it is responsible for the release of different hormones that regulate growth and metabolism. One of the hormones that the pituitary gland releases is the thyroid-stimulating hormone.
The thyroid-stimulating hormone is a glycoprotein hormone produced and released from the anterior pituitary gland, particularly by thyrotrope cells. It works by stimulating the thyroid to produce and release thyroid hormones, particularly thyroxine.
The thyroxine is a hormone that regulates metabolism by controlling the rate of oxidation in cells. It also serves as a precursor of the active thyroid hormone, triiodothyronine. However, when the level of thyroxine becomes high, it controls further release of thyroid-stimulating hormone. Thus, negative feedback occurs as it inhibits the secretion of thyroid-stimulating hormone when thyroxine levels in the body are high.