Endocrinology is defined as the study of how chemical messenger molecules, referred to as hormones, influence physiological processes. By definition, a hormone is a signaling molecule that is released into the bloodstream, where the hormone can then travel to distant target cells and tissues within the body. Along with the nervous system, the hormones of the endocrine system provide an important means by which information travels within the body. Test your basic knowledge of the endocrine system by taking this simple quiz.
(1) The following is the most physiologically active form of the thyroid hormone:
(2) The thyroid hormones travel in blood bound to the following binding progein(s):
(3) This enzyme is responsible for the conversion of T4 (tetraiodothyronine; also known as thyroxine) to T3 (triiodothyronine):
(4) Binding of thyroid stimulating hormone (TSH) to the thyroid follicular cell TSH receptor leads to the elevation of cytoplasmic cAMP levels in follicular cells.
(5) Binding of thyroid stimulating hormone (TSH) to the thyroid follicular cell TSH receptor leads to the elevation of cytoplasmic calcium (Ca2+) levels in follicular cells.