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) This hormone leads to a rise in plasma calcium concentration and a reduction in plasma phosphate concentration.
(2) Calcium-sensing receptor (CaSR) is a member of the G protein coupled receptor (GPCR) family and binds extracellular calcium. It is expressed in this cell type:
(3) This is the most active form of vitamin D:
(4) Considering Vitamin D and its precursor molecules, which of the following is found at the highest concentration in the plasma?
(5) Two successive hydroxylation steps are required to lead to the biosynthesis of the active form of vitamin D. These hydroxylation steps take place in the following organs: