Bone Disorders Flashcards
Regulation of calcium is by?
Vitamin d 25 and PTH
Leak of calcium by?
EcaC1 TRPV5 in kidney and EcaC2, TRPV6 in intestine
And pump basolateral calcium ATPase PMCA1b
EcaC expression is activated by?
1,25 VitD
Through gene transcription and phosphorylation of channels
And insertion of EcaC rich vesicles
Activation of vit D 1 alpha hydroxylation done by?
In kidney by PTH
As Phosphate increases, PTH
INCREASES
PTh half life
4 mins
Low magnesium causes?
Inhibits PTH release
Humeral hypercalcaemia malignancy caused by?
PTHrP
Enzymes for activation of cholecaciferol?
Renal 1 alpha hydroxylase and 25 hydroxylase
Calcitonin effect?
Reduce bone resorption
FGF23?
Reduced phosphate reabsorption in the renal proximal tubule and inhibits 1 alpha hydroxyase
Phosphate is secreted by?
Osteocytes, osteoblasts and osteoclasts
FGF23 can cause?
Reduction is phosphate reabsorption in renal proximal tubule, and inhibits 1 alpha hydroxylase
How much of calcium is ionised?
50%
What can total calcium be changed by?
Changes in albumin
Range for calcium is?
2.20 and 2.60 mmol/L
Hypercalcaemia with suppressed PTH is caused by?
Malignancy of blood, lung and breast, vit D excess and sarcoidosis
Hypercalcaemia with raised PTH caused by?
1 or 3 hyperparathyroidism or defects in calcium receptors FHH
Hypocalcaemia and increased PTH?
Vitamin D deficiency, malabsorption, renal failure, PTH receptor defect and vit D receptor defect
Hypocalcaemia and low or normal PTH?
Hypoparathyroidism, congenital Digeorge
Post surgery radiotherapy
Mg deficiency