MICROANATOMY

Detailed explanation-1: -The parathyroid glands in the throat make parathyroid hormone, which regulates the amounts of calcium, phosphorus and magnesium in the bones and blood. Problems include overactivity (hyperparathyroidism) and underactivity (hypoparathyroidism).

Detailed explanation-2: -Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. It does this through its actions on the kidneys, bones and intestine: Bones – parathyroid hormone stimulates the release of calcium from large calcium stores in the bones into the bloodstream.

Detailed explanation-3: -The parathyroid cell is unusual in that decreasing concentrations of calcium stimulate secretion of PTH, and increasing concentrations of calcium inhibit secretion of PTH. Thus, this cell, which is responsible for the critical maintenance of ionized blood calcium levels, is, in turn, regulated by calcium itself.