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9 Cards in this Set
- Front
- Back
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What 4 factors control calcium homeostasis
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1) Dietary intake
2) Intestinal absorption 3) Bone accretion and reabsorption 4) Renal excretion |
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What chemical form is most of the bodies calcium and phosphate stored as?
What is the function of this compound? |
Hydroxyapatite (Ca10(PO4)6(OH)2)
The main mineral component of bone |
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What different calcium stores are there and what proportion is held in each?
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1) 40 % is protein bound (esp albumin)
2) 10 percent is complexed with citrate, bicarbonate, sulfate, or phosphate 3) 50 percent as ionised (free) calcium |
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Which hormones mediate calcium and phosphate metabolism?
What mechanisms do they do this by? |
PTH and Vit D metabolites
Altered intestinal absorption, bone formation and resorption, and urinary excretion |
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What affect do Vitamin A and retinoids have on calcium metabolism?
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The increase serum calcium by increasing bone resorption.
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What affect do diuretics have on calcium metabolism?
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Loop diuretics reduce serum calcium by increasing urinary excretion
Thiazide diuretics increase serum calcium by reducing urinary excretion |
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What affect does PTH have on the kidney?
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It reduces urinary excretion in response to hypocalcaemia
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What differences in calcium and phosphate content exist between preterm and term breast milk?
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Term breast milk contains higher concentrations of caclium and phosphate.
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What factors increase an infants risk of osteopenia?
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1)Very low birth weight
2) only receive unsupplemented breast milk 3) delayed enteral feeding 4) prolonged use of diuretics (increased urinary losses) 5) poor vitamin D intake 6) malabsorption of calcium or vit D 7) immobolisation |
