MICROANATOMY

Detailed explanation-1: -What is thyroid stimulating hormone? Thyroid Stimulating Hormone (TSH) is produced and released into the bloodstream by the pituitary gland. It stimulates the production of the thyroid hormones, thyroxine (T4) and triiodothyronine (T3), by the thyroid gland by binding to its receptors in the thyroid gland.

Detailed explanation-2: -When the level of thyroid hormones (T3 & T4) drops too low, the pituitary gland produces Thyroid Stimulating Hormone (TSH) which stimulates the thyroid gland to produce more hormones. Under the influence of TSH, the thyroid will manufacture and secrete T3 and T4 thereby raising their blood levels.

Detailed explanation-3: -TSH then triggers your thyroid to produce T4 and T3. Of the total amount of hormones that TSH triggers your thyroid to release, about 80% is T4 and 20% is T3. Your thyroid also needs adequate amounts of iodine, a substance you get from the food you eat, to create T4 and T3.

Detailed explanation-4: -When T4 enters the circulation, it gets converted to T3 through the process of deiodination. T4 and T3 can then exert negative feedback on TSH levels (high levels of T3/T4 decrease TSH release from the anterior pituitary, while low levels of T3/T4 increase TSH release). T3 is the predominant inhibitor of TSH secretion.