PTH Flashcards
1
Q
Source
A
Chief cell of para
2
Q
Function
A
1) increase bone reabsorption of Ca2+ and phos
2) increase kidney reab of ca2+ in distal convoluted
3) decrease reab of phosphate in proximal convoluted tubule
4) increase calcitriol (1,25) production by stimulating kindey 1alpha-hydroxylase.
3
Q
Overall effect
A
high PTH;
high serum Ca2, low serum phos, high urine phos
“PTH: phosphate trashing hormone”
4
Q
How does it actually regulate bone reabsorption
A
Increase production of M-CSF and RANK-L in osteoblasts, which stimulates osteoclasts.
5
Q
Regulation
A
Stimulated by
1) low serum Ca2+
2) low serum Mg2+
(but really really low Mg2+ DECREASE PTH secretion)
Common causes of low Mg2+ is diarrhea, aminoglycoside, diuretics, alcohol abuse.
