<prompt> Cells present in parathyroid glands are all exceptChief cellsParietal cellsOxyphil cellsWater-clear cells  <response>: The parathyroid glands of infants and children are composed mainly of chief cells, which produce parathyroid hormone PTH. Acidophilic, mitochondria-rich oxyphil cells are derived from chief cells, can be seen around pubey, and increase in numbers in adulthood. A third group of cells, known as water-clear cells, also are derived from chief cells, are present in small numbers, and are rich in glycogen. Although most oxyphil and water-clear cells retain the ability to secrete PTH, their functional significance is not known. 