Parathyroid Hormone Feedback Loop
Function
Increase Blood CA++Levels
Stimulating Agent
Low Blood CA++ Levels
Target
Parathyroid gland It's Embedded in Posterior surface of thyroid gland This is very vascular lots of blood stream flows through here.
Hormone Released (Chemical Nature)
Parathyroid hormone (Protein) It's produced by chief cells. It's released into general circulation. PTH is the most important hormone primary regulator in calcium homeostasis.
Target
The Parathyroid Hormone (PTH) targets 3 areas, bone, kidneys and the digestive tract. - Bone - PTH stimulates osteoblast to remove calcium from the bones; Inhibits Osteoblasts - Kidney - CA++ reasborsorbed from kidney tubules into the blood, phospate excreted in urine. - Intestine - influence CA++ absorption; activates VD (cholecalciferol). Stimulates formation of calcitriol at the kidneys.
