AP BIOLOGY

Detailed explanation-1: -Parathyroid hormone (PTH) levels are mainly controlled by a feedback loop of calcium levels in your blood to your parathyroid glands. In other words, low calcium levels in your blood stimulate parathyroid hormone release, whereas high calcium levels in your blood prevent your glands from releasing parathyroid hormone.

Detailed explanation-2: -PTH, also known as parathormone, is made by your parathyroid glands. These are four pea-sized glands in your neck. PTH controls the level of calcium in the blood. Calcium is a mineral that keeps your bones and teeth healthy and strong.

Detailed explanation-3: -Parathyroid hormone is directly involved in the bones, kidneys, and small intestine. In the bones, PTH stimulates the release of calcium in an indirect process through osteoclasts which ultimately leads to the resorption of the bones.

Detailed explanation-4: -Binding of PTH to the receptor increases bone resorption and bone formation (coupled bone remodeling), stimulates calcium reabsorption in the distal renal tubule, and increases calcitriol production in the proximal renal tubule.