Explain the Parathyroid Glands

The parathyroid and thyroid glands are neighbours in the neck. You would realize that parathyroid glands are the small glands that lie behind the thyroid gland, arranged in two pairs - the superior and inferior parathyroids.

In fact, there are four parathyroid glands, two behind each side of the thyroid, as can be seen in Figure. The glands are surrounded by the connective tissue capsules. The cells forming the glands are spherical in shape and are arranged in columns. These are known as the principal cells.