|
|
|
| Untersuchte Arbeit: Seite: 40, Zeilen: 1ff (entire page) |
Quelle: Bowen 2003 Seite(n): 1 (online source), Zeilen: - |
|---|---|
| Three organs participate in supplying calcium to blood and removing it from blood when necessary:
• The small intestine is the site where dietary calcium is absorbed. Importantly, efficient absorption of calcium in the small intestine is dependent on expression of a calcium-binding protein in epithelial cells. • Bone serves as a vast reservoir of calcium. Stimulating net resorption of bone mineral releases calcium and phosphate into blood, and suppressing this effect allows calcium to be deposited in bone. • The kidney is critically important in calcium homeostasis. Under normal blood calcium concentrations, almost all of the calcium that enters glomerular filtrate is reabsorbed from the tubular system back into blood, which preserves blood calcium levels. If tubular reabsorption of calcium decreases, calcium is lost by excretion into urine. The following table summarizes body responses to changes in calcium:
|
Three organs participate in supplying calcium to blood and removing it from blood when necessary:
• The small intestine is the site where dietary calcium is absorbed. Importantly, efficient absorption of calcium in the small intestine is dependent on expression of a calcium-binding protein in epithelial cells. • Bone serves as a vast reservoir of calcium. Stimulating net resorption of bone mineral releases calcium and phosphate into blood, and suppressing this effect allows calcium to be deposited in bone. • The kidney is critcally [sic] important in calcium homeostasis. Under normal blood calcium concentrations, almost all of the calcium that enters glomerular filtrate is reabsorbed from the tubular system back into blood, which preserves blood calcium levels. If tubular reabsorption of calcium decreases, calcium is lost by excretion into urine. [...] [...] The following table summarizes body responses to conditions that would otherwise lead to serious imbalances in calcium and phosphate levels in blood.
|
The source is not given. |
|