What are the parathyroid glands?
The parathyroid glands are two pair (four in total) of glands that secrete parathyroid hormone. The parathyroid gland, like the THYROID GLAND, is part of the endocrine (gland) system. What is parathyroid hormone? Parathyroid hormone is a substance that helps regulate the amount of calcium in the bloodstream. Calcium is needed to make strong bones and teeth. However, a normal calcium level in the bloodstream is also very important for normal function of muscles and nerves. Parathyroid hormone raises the amount of calcium in the bloodstream by removing calcium from bones, by increasing the amount of calcium taken from the diet, and by decreasing the amount of calcium excreted in the urine. Where are the parathyroid glands located? The parathyroid glands are located behind the two lobes of the THYROID GLAND in the neck. What problems can develop with the parathyroid gland?
Illustration of location of thyroid and parathyroids. The parathyroid glands are four pea-sized glands located on the thyroid gland in the neck. Occasionally, a person is born with one or more of the parathyroid glands embedded in the thyroid, in the thymus, or located elsewhere around this area. In most such cases, however, the glands function normally. Though their names are similar, the thyroid and parathyroid glands are entirely different glands, each producing distinct hormones with specific functions. The parathyroid glands secrete PTH, a substance that helps maintain the correct balance of calcium and phosphorus in the body. PTH regulates the level of calcium in the blood, release of calcium from bone, absorption of calcium in the intestine, and excretion of calcium in the urine. When the level of calcium in the blood falls too low, the parathyroid glands secrete just enough PTH to restore the blood calcium level.
