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) Which of the following thyroid hormones are physiologically active?
(2) Which of the following thyroid hormones is/are physiologically inactive?
(3) Which of the following thyroid hormones is the most physiologically active form of the thyroid hormone?
(4) This thyroid hormone is the most abundant thyroid hormone in the circulation?
(5) Thyroid binding globulin (TBG) exhibits the highest affinity for this thyroid hormone: