Answer:
Parathyroid glands.
Explanation:
The parathyroid glands are small endocrine glands that are located behind the thyroid gland in the neck. Its primary function is to secrete a parathyroid hormone (PTH), responsible for controlling and maintaining the balance of calcium and phosphorus in the blood within certain limits. This helps to achieve proper functioning of the muscles and nerves, and also helps maintain strong bones.
