mistake in kaplan physiology qbank? - fhelou

[ArchivalUser]

http://i15.tinypic.com/62oocow.jpg

[ArchivalUser]

No B is the correct answer. The line for B shows that it is inhibiting the reabsorption of bone. Calcitonin decreases plama calcium levels by inhibitit bone reabsorption. Line A shows that it stimulates bone reabsorption that would be the line for Parathyroid hormone

[ArchivalUser]

i know B is the correct one, but what about A and A D
does Vit D really reabsorbs calcium from bone? I thought the whole function of Vit D was to mineralize bone!

[ArchivalUser]

Parathyroid hormone increases the the formation of (1,25 di-OH D3) in the proximal tubules of the kidney and that leads to increased absorption of Calcium and phosphate from the small intestine. Letter D indicates that calcium is reabsorbed from the gut and returned to the plama. Letter A indicates that bone is reasborbed resulting in an increase in calcium levels and therfore Letter A must be PTH

[ArchivalUser]

see, it's a mistake then, because they say it can be Vit D too!
I hate this qbank how am I gonna trust it now, I am OC, lol

FA 2007 says that VitD "↑ bone resorption of Ca2+ and (PO4)3-" but i am sure they mean absorption or something, resorption is breaking bone down!
I hate FA too, both FA and qbank seem to have been made hastily, I rather depend on well done books that people actually put some effort in it (like Goljan's gem)

[ArchivalUser]

at high level vit D increase resorption of Ca from bone ..... kaplan physio p 435

[ArchivalUser]

actually, you have to know 1.25 vitamin D do increase resorption of bone, the question is correct and explanation is excellent

[ArchivalUser]

take a look at this ........http://en.wikipedia.org/wiki/Reabsorption. it gives you the physiological defination of reabsorption. Hope this helps But your rite Vitamin D does stimulate reabsorption of bone only calium from the small intestine. PTH has three funcitons 1) to activate Vit D 2) to stimulate bone reabsorption and 3) increase Ca reabsorption in the proximal tubule

[ArchivalUser]

thanks for the replies guys, it is true that VitD toxicity causes increase resorption of ca from bone but the diagram is supposed to be about normal ca homeostasis, not extreme conditions

also in FA they said resorption not reabsobtion, there is a difference between the two

[ArchivalUser]

bengalbabu u should be more respectful. We are all here to learn and help each other and it is a shame that you cant refrain from obseneities