Parathyroid Hormone Flashcards
What are the 4 main functions of Parathyroid hormone?
Increase calcium
decrease phosphorus
Activate vitamin D
Promote bone remodeling
Decreased calcium = ______ PTH release
Increased
Increased calcium = _______ PTH release
Decreased
Vitamin D ________ PTH synthesis and secretion by ______ chief cell proliferation
Inhibits
Decreasing
______ sensing receptors ______ PTH secretion
Calcium
Inhibit
PTH in the Kidney causes 3 things:
Increased calcium reabsorption,
increased excretion of phosphorus
Increased synthesis of vitamin D
PTH function in the bone is to:
Increase bone resorption during hypocalcemia
PTH tells the kidneys:
Reabsorb calcium, excrete phosphorus
PTH tells bone:
Release calcium AND phosphorus
PTH receptor activation requires what ion?
Mg2+
PTH increases the activity of 1-alpha-hydroxylase. This enzyme is responsible for what?
Converting vitamin D into its active form (calcitriol!)
PTH in the loop of henle does 3 things:
- Makes lumen (+)
- Increases Paracellular transport of calcium and magnesium
- Increases activity of Na/K/Cl cotransporter via cAMP
In the proximal tubules, PTH:
Inhibits Na/Pi cotransporter
This inhibits reabsorption of phosphorus and promotes phosphorus excretion!
PTH binds to PTH receptors on ___________
This causes secretion of factors that activate __________
Osteoblasts
Osteoclasts
Osteoclasts have no PTH receptors but they do have _______ receptors
Calcitonin
