Physiology Quiz: Endocrinology - Part 48

Physiology Quiz -
Endocrinology - Part 48

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 is/are true?

	(A) Thyroxine binding globulin (TBG) has a higher affinity for triiodothyronine (T₃) than for tetraiodothyronine (T₄ or thyroxine).
	(B) Thyroxine binding globulin (TBG) has a higher affinity for tetraiodothyronine (T₄ or thyroxine) than for triiodothyronine (T₃).
	(C) The plasma half-life of triiodothyronine (T₃) is longer than that of tetraiodothyronine (T₄ or thyroxine).
	(D) The plasma half-life of tetraiodothyronine (T₄ or thyroxine) is longer than that of triiodothyronine (T₃).

(2) Unlike all other endocrine organs, hormone production within the thyroid gland takes place in the extracellular compartment.

	True
	False

(3) During thyroid hormone synthesis, the following protein is responsible for organification of iodide.

	(A) Na⁺/iodide symporter (NIS)
	(B) Iodide channel
	(C) Thyroid peroxidase (TPO)
	(D) Thyroglobulin
	(E) Thyroid stimulating hormone (TSH) receptor

(4) During thyroid hormone synthesis, the following protein is responsible for coupling of iodotyrosine moieties to form iodothyronines.

	(A) Na⁺/iodide symporter (NIS)
	(B) Iodide channel
	(C) Thyroid peroxidase (TPO)
	(D) Thyroglobulin
	(E) Thyroid stimulating hormone (TSH) receptor

(5) During thyroid hormone synthesis, each thyroglobulin molecule leads to the production of only one molecule of thyroid hormone (i.e., one T₃ or one T₄).

	True
	False