Endo 6 - Calcium Flashcards
(53 cards)
Is there more Ca in ICF or ECF
ICF
can Ca and PO4 be regulated separately
NO
Ca x PO4 = ?
constant
where does most calcium come from
our bones
what % of ca do we absorb in diet
15-35%
what type of hormone is vitamin D
steroid
what is stimulated when vitD binds receptor
calcium binding protein synthesis
what is the function of calcium binding protein
allows ca to cross intestines and enter blood
how does vitD binding affect differentiation
increases diff and maturation
how is PO4 affected by vitD active
increase intestinal absorption
how are kidneys affected by vitD
increase ca reabsorption
how are osteoclasts affected by vitD
increase # of osteoclasts
how are muscles affeted by vitD
more strength
why are younger people better at making vitD
thicker skin = more vitD precursor = more rxn
what is storage form of vitD
25-vitD
what enzyme makes vitD active
1a-hydroxylase
what are 4 ca-regulating hormones
PTH, PTHrP, calcitonin, vitD
T/F PTH is constantly made and stored in parathyroid
TRUE
what causes increase in PTH secretion
low serum Ca => activate Ca sensor in parathy => PTH secretion
what is the mechanism of PTH action
GPCR => AC => cAMP
how does PTH affect immature osteoblasts
binds to young osteob to stim and form osteocl
where are PTH receptors in the kidney
distal tubule
what happens to PO4 in response to PTH
PO4 is kicked out
T/F high PO4 can stimulate PTH
TRUE
