Umm that really is a lot of words there but I will try to find a explanatory answer
Answer:
Hypothalamus and anterior pituitary gland.
Explanation:
Lower levels of T3 and T4 in the blood or lower metabolic rate serve as signal and stimulate the release of thyrotropin-releasing hormone (TRH) from the hypothalamus. The TRH stimulates the anterior pituitary gland to release thyroid-stimulating hormone (TSH) which in turn makes the thyroid gland to release the thyroid hormones.
The elevated levels of thyroid hormones inhibit the release of TRH from the hypothalamus and that of TSH from the anterior pituitary gland.
Hence, the cells of hypothalamus and anterior pituitary gland would be inhibited by the binding of thyroid hormone to regulate the release of these hormones by a negative feedback mechanism.
The nutrients in some soils could be toxic to microorganisms/fish in those ponds or lakes.
