Posted by Bobbie P. (161.184.21.38) on January 29, 2000 at 20:37:04:
In Reply to: Good answer, but to what relevance? posted by Q on January 29, 2000 at 19:47:30:
Hope you don't mind my answering Ted. In a nutshell:some of the neurons in the hypothalamus secrete hormones that strictly control secretion of hormones from the anterior pituitary. The hypothalamic hormones are referred to as releasing hormones and inhibiting hormones, reflecting their influence on anterior pituitary hormones. Thyroid releasing hormone from the hypothalamus binds to receptors on anterior pituitary cells called thyrotrophs, stimulating them tho secrete thyroid-stimulating hormone or TSH. Or put another way, the hypothalamus contains cells sensitive to amount of thyroxine in the blood. If the thyroxine levels falls below normal, the hypothalamus stimulates tha anterior pituitary to secrete thyroid stimulating hormone.(TSH) TSH is secreted into the bloodstream and reachs the thyroid gland where it stimulates thyroxine production.
Armed with this knowledge, synthetically produced thyroxine or T4 was developed(Synthoid). It is used to treat diseases of the thyroid and as a replacement hormone cases where the thyroid has been removed due to cancer. So, indirectly or directly depending on how you look at it, it relates to the question of the week.
PS: Excellent research Ted!