Part of “CHAPTER 48 – MORPHOLOGY OF THE PARATHYROID GLANDS“

Electron microscopic studies of parathyroid cells have shown that the chief cells undergo morphologic change caused by the synthesis of parathyroid hormone. The Golgi apparatus increases in
size; vesicles are prominent. In active parathyroid cells, little lipid is present.11 In the involuting and resting phase, the cytoplasm of the chief cells contains glycogen and lipid. In the euparathyroid normal adult, only ˜20% of the chief cells appears to be producing hormone at any one time.4,11 Ultrastructurally, oxyphil cells contain numerous tightly packed mitochondria, some glycogen, and few free ribosomes. Evidence at the ultrastructural level for parathyroid hormone secretion is rarely observed in oxyphils.4,11