Mineral Balance Lectures Flashcards
Calcium Reference Range
8.6-10.0 mg/dl
Calcium Functions
- Skeletal mineralization
- Nerve impulse transmission
- muscle contraction
- blood coagulation
- enzyme cofactor
- cell membrane integrity and permeability
Organs associated with Calcium balance
- Small intestine
- Bones
- Kidneys
Hydroxyapatite
components
Calcium+Phosphorus+hydroxide
Hydroxyapatite importance
99% of calcium in bones and teeth is in this form
Calcium bound to proteins (%)
-40%
most bound to albumin
Free “ionized” calcium and pH (acidosis/alkalosis)
Acidosis: more free Ca2+ (less binding)
Alkalosis: less free Ca2+ (more binding)
Free calcium (%)
50%
Calcium in salts (%)
10%
Ionized Calcium function
- Physiologically active calcium
- monitored in heart surgery
Ionized calcium reference range
4.6-5.3 mg/dl
PTH and calcium
- Secretion increases calcium levels
- glands have calcium receptors that respond to Ca levels
How PTH increases calcium
- Bone resorption and release of Ca to blood.
- Increase renal reabsorption of Ca (excretion of phosphorous)
- Intestinal reabsorption
Calcium and Phosphorous relationship
- Inverse relationship
- Reabsorption of Ca = secretion of Phosphorous
- Influenced by PTH
Vitamin D/Calcium
Increases calcium and phosphate by increasing absorption from GI tract
Vitamin D/Calcium
Increases calcium and phosphate by increasing absorption from GI tract
Vitamin D/PTH
Increases bone resorption and enhances PTH
Calcitonin
Inhibits bone resorption, promotes bone formation