P37 - Ca, P, Mg Flashcards
T/F: all Ca in the body is ionized
- true
3 fractions of ca in serum/plasma
- fCa
- Ca/Pr
- Ca/A
decrease [fCa] -> increase ____ and ___ (_____) -> has what 3 effects:
- ____ mobilization of Ca from bone
- ____ absorption of Ca by intestine
- ____ excretion of Ca by kidneys
- PTH
- Vit D (calcitriol)
- increase mobilization of Ca from bone
- increase absorption of Ca by intestine
- decrease excretion of Ca by kidneys
horses: absorption of Ca ____ tightly regulated
- ___ vit D dependent
- do not produce _____(____)
- is not
- not
- 1,24-DHCC (calcitriol)
total calcium (tCa) concentration sample
- serum (not EDTA or citrate)
free calcium (fCa) concentration sample
- serum
- heparinized plasma or blood
(not EDTA or citrate)
- primary hyperparathyroidism
- hypervitaminosis D
- decrease urinary excretion
- Addison’s disease (hypoadrenocorticism)
can all cause ___ in Ca
- increase (hypercalcemia)
how does primary hyperparathyroidism cause hypercalcemia
- increase production and release of PTH -> increase [PTH]
- > increase mobilization of Ca from bone
- > increase absorption of Ca in intestine
- > decrease renal excretion of Ca
how dose hypervitaminosis D cause hypercalcemia
- excess intake or production -> increase [1,25-DHCC] (calcitriol)
- > increase mobilization of Ca from bone
- > increase absorption of Ca in intestine
- > decrease renal excretion of Ca
how does decrease urinary excretion (failure in equine and canine) cause hypercalcemia
- equine renal failure -> decrease GFR -> decrease clearance of Ca and Ca/A
- canine renal failure (mostly acute) -> decrease GFR -> decrease clearance of A -> increase formation of Ca/A complexes in plasma and not cleared
who does Addison’s disease cause hypercalcemia
- hypoadrenocorticism -> hypovolemia -> increase activation of renin-angiotensin system -> increase angiotensin cause increase proximal tubular resorption of Na&Ca
when there is a state of hypocalcemia what should be thought of first (what disorder?)
- hypoalbuminemia (hypoproteinemia)
- protein bound is down -> decrease total
- hypoalbuminemia
- primary hypoparathyroidism
- hypovitaminosis D
- increase urinary excretion
- pregnancy, parturient, lactational
all can cause ___ in Ca
- decrease (hypocalcemia)
how does primary hypoparathyroidism cause hypocalcemia
- parathyroid gland destruction -> decrease production and release of PTH -> decrease [PTH]
- > decrease mobilization of Ca from bone
- > decrease absorption of Ca in intestine
- > increase renal excretion of Ca
how does hypovitaminosis D (chronic renal disease) cause hypocalcemia
- chronic renal disease -> secondary renal hyperparathyroidism -> decrease 1a-hydroxylase -> decrease [calcitriol] -> decrease fCa absorption from intestine and resorption from bone
how does pregnancy, parturient, and lactation cause hypocalcemia
- rapid increase of Ca loss in milk -> not mobilizing Ca from bone fast enough
what type of Ca concentration is commonly caused “ionized calcium”
- free calcium (fCa)
if sample measuring fCa is aerobic effects on pH
- decreases [H] - alkalemic
disorders of [tCa] are typically disorders of [fCa] except (2)
- decrease [tCa] due to hypoalbuminemia
- increase binding of Ca to anions
why is [Pi] inorganic phosphorus concentration higher in puppys and kittens
- GH -> increase renal resorption of Pi
Pi is measured from
- PO4
- decrease urinary PO4 excretion
- increase PO4 absorption from intestine
- shift PO4 ICF to ECF
all cause __ of [Pi]
- increase
- hyperphosphatemia
how does a decrease urinary PO4 excretion cause hyperphosphatemia
- decrease GFR -> decrease clearance of PO4
- decrease PTH activity -> increase tubular resorption of PO4
how does increase PO4 absorption from intestine cause hyperphosphatemia
- phosphate enema
- hyoervitaminosis D -> increase mobilization of PO4 from bone
