Control of secretion of calcitonin and parathyroid hormone

a lower than normal calcium level in the

blood stimulates chief cell to produce pth

calcitrol stimulates increased absorption of

calcium from foods in the gi tract, which helps increase the blood level of calcium

pth also stimulates the

kidneys to synthesize calcitrol , the active form of vit d

calcitonin inhibits the activity of

osteoclasts , thereby dcreasing the blood calcium level

a higher than normal level of calcium ions in the blod stimulates

parafollicular cells of the thyroid gland to release more calcitonin

pth promotes

resorption of bone extracellular matrix, which realese calcium into the blood cslows loss of calcium in the urine rasing the calcium blood level

a higher than normal level of calcium ions in the blood stimulates parafollicular cells of the thyroid gland to release more calcitonin

1 , first step!

calcitonin inhibits the activity of osteoclasts , thereby dcreasing the blood calcium level

2, second step!

a lower than normal calcium level in the blood stimulates chief cell to produce pth

3, third step!

pth promotes resorption of bone extracellular matrix , which realease calcium into the blood slows loss of calcium in the urine raising the blood calcium level

4, step four!

pth also stimulate the kidneys to synthesize calcitrol , the active form of vit D

5, step five!

calcitrol stimulates increased absortion of calcium from foods in the gi tract, which helps increase the blood level of calcium

6, step six!