Unformatted text preview: to stimulate the intestine to absorb calcium, phosphate and magnesium. Calcitriol also weakly promotes urinary reabsorption of calcium ions. Significantly, calcitriol also promotes osteoclast activity, raising blood calcium levels. Calcitonin Calcitonin is secreted by special cells of the thyroid gland when calcium blood concentration rises too high. It reduces osteoclast activity by as much as 70% in 15 minutes and increases the number and activity of osteoblasts. Parathyroid Parathyroid hormone is secreted by the parathyroid glands when calcium blood levels are too low. It stimulates osteoclast production and activity, promotes calcium resorption by the kidneys, calcitriol synthesis in the kidneys, and inhibits collagen synthesis and bone deposition by osteoblasts....
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- Fall '10
- Anatomy, 15 minutes, calcitriol