Number of parathyroid glands in human:September 2005
High-Yield Explanation
The parathyroid glands are ovoid bodies measuring about 6 mm long in their greatest diameter.They are four in number and are closely related to the posterior border of the thyroid gland, lying within its fascial capsule.The two superior parathyroid glands are the more constant in position and lie at the level of the middle of the posterior border of the thyroid gland.The two inferior parathyroid glands usually lie close to the inferior poles of the thyroid gland. They may lie within the fascial sheath, embedded in the thyroid substance, or outside the fascial sheath