parathyroid

Introduction

One of 4 endocrine glands adjacent to the thyroid gland in the neck.

Occasionally, a parathyroid gland may undergo aberrant embryonic migration & occur in the mediastinum.

Function

• the parathyroid gland secretes parathyroid hormone (PTH).
• cell types:
  • chief cells
    • more numerous
    • 6-8 microns diameter, polygonal, round nuclei
    • secrete parathyroid hormone (PTH)
    • most sensitive to ionized calcium
  • oxyphil cells
    • minor portion of parathyroid gland
    • 12 micron diameter
    • acidophilic cytoplasm due to mitochondria
    • not known to have secretory role
  • water clear cell
    • chief cell with excessive glycogen
    • abundant clear cytoplasm

Pathology

• parathyroid adenomas are benign tumors secreting PTH, resulting in hypercalcemia
• Surgical removal of all 4 parathyroids may result in profound & refractory hypocalcemia

More general terms

• endocrine gland

Additional terms

• parathyroid disease
• parathyroid hormone; parathormone; parathyrin (PTH)

Component of

• neck