Superior parathyroid gland
Glandula parathyroidea superior
Endocrine & glandsGlandsNeckLeft and right
View left in 3D View right in 3D
- What it is
- A lentil-sized superior parathyroid gland embedded in the back of the thyroid lobe, one of four. Despite the name it has nothing to do with thyroid hormone; it is the body's calcium sensor.
- Function
- Secretes parathyroid hormone (PTH), which raises blood calcium by releasing it from bone, reducing its loss in urine and activating vitamin D.
- Size
- 6 × 4 × 2 mm, 30–50 mg each
- Clinical note
- The superior glands are the more constant in position (behind the upper-middle lobe, near where the inferior thyroid artery crosses the recurrent laryngeal nerve). Removing all four during thyroid surgery causes tetany from low calcium within a day or two.