How would lack of dietary iodine affect the negative feedback mechanism that controls the level(no space)?

How would lack of dietary iodine affect the negative feedback mechanism that controls the level of the thyroid hormones?





Ty.How would lack of dietary iodine affect the negative feedback mechanism that controls the level(no space)?
The thyroid hormones T4 (thyroxine) and T3 contain iodine; high concentrations of T4 and T3 prevent their own synthesis by inhibiting the release of thyrotrophin-releasing hormone (TRH). TRH is normally released from the hypothalamus to the anterior pituitary, which in turn releases thyroid-stimulating hormone (TSH), which stimulates the thyroid to synthesize T4 and T3. Without iodine, T4 and T3 can't be produced, so TRH and TSH can't be inhibited; they continue to stimulate the thyroid gland to produce T4 and T3 even though it can't. This causes the thyroid to work constantly to try to make thyroid hormones and all this extra strain makes it grow, and without iodine supplementation, this can result in a goiter, which is a severely hypertrophied thyroid gland.