How well do you know the role of PTH and Calcium in the human body?

• Calcium is a vital mineral in the human body, with 1-2kg in an adult human body, mostly found in bones and teeth.
• Calcium plays a crucial role in bone growth and remodeling, blood coagulation, muscle contraction, neuronal function, enzyme action, exocytosis of hormones and neurotransmitters, and intracellular signaling.
• Calcium homeostasis is tightly regulated in the serum, interstitium, and intracellular fluids.
• Parathyroid hormone (PTH) and vitamin D increase serum calcium levels, while calcitonin fine-tunes it.
• PTH is produced by parathyroid Chief cells and acts on bones, kidneys, and the small intestine to increase plasma calcium levels.
• PTH is synthesized continuously and released from the parathyroid gland in response to reduced plasma calcium levels.
• PTH is inhibited by an increase in extracellular calcium and vitamin D.
• PTH binds to the G-protein coupled receptor PTH-R, causing increases in cAMP and release of calcium from intracellular stores.
• PTH promotes bone resorption, phosphaturia, less complexed Ca-PO4, and stimulates calcium reabsorption in the kidneys and small intestine.
• PTH stimulates renal 1α-hydroxylase, which converts 25-hydroxycholecalciferol to 1,25 dihydroxycholecalciferol, stimulating intestinal calcium absorption.

Test your knowledge of the vital mineral calcium and its role in the human body with our quiz! From bone growth to enzyme action, calcium plays a crucial role in various physiological processes. Discover more about calcium homeostasis and the role of hormones like PTH and vitamin D in regulating calcium levels. Challenge yourself and see how much you know about this essential mineral.