How do you thyroid gland work?
Thyroid hormone production is regulated by a feedback loop between the hypothalamus, pituitary gland and the thyroid gland. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates pituitary thyrotropin (TSH) synthesis and secretion.In turn, TSH stimulates production and release of T4 and T3 from the thyroid gland. When enough T4 is produced, it signals to TRH and TSH that there is enough thyroid hormone in circulation and not to produce more.
About 85% of the hormone produced by our thyroid gland is T4, which is an inactive form of the hormone. After T4 is made, a small amount of it is converted into T3, which is the active form of thyroid hormone.
To complicate matters, T3 also gets converted into either Free T3 (FT3) or Reverse T3 (RT3). It’s the Free T3 that really matters in all of this since it’s the only hormone that can attach to a receptor and cause your metabolism to rise, keep you warm, keep your bowels moving, mind working, and other hormones in check. The role of Reverse T3 is not well known, however, I do see it elevated in persons under extreme stress and those who have mercury toxicity.
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