What is the function of the parathyroid glands?

The function of the parathyroid glands is to regulate calcium levels in the blood. These small glands are located on the back of the thyroid gland and play a critical role in maintaining homeostasis of calcium, which is vital for normal functioning of the nervous system, muscle contraction, and blood coagulation. The parathyroid glands secrete parathyroid hormone (PTH), which increases blood calcium levels by stimulating the release of calcium from bones, increasing calcium absorption in the intestines, and promoting the reabsorption of calcium in the kidneys.

The regulation of calcium levels is crucial because both hypocalcemia (low calcium levels) and hypercalcemia (high calcium levels) can lead to serious health issues, including neurological and cardiovascular problems. The actions of PTH ensure that the body maintains an adequate supply of calcium in the bloodstream, thereby preventing potential complications associated with abnormal calcium levels.