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Previous Topic | Next Topic  Tetany and hyperaldosteronism 




 
Kaplan Qbank USMLE



Author8 Posts
  #1

can you explain how hyperaldosteronism can cause tetany?

  #2

Hyper Aldo-->Hypo K-->H for K exchange-->Alkalosis-->Hypo Ca-->Tetany

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  #3

Also hyperaldosternism increase Na+ this drives Ca+ absortion by cotransport in kidney. Also higher uptake of Ca++ in the small intestine by the same mechanism. Causing in this way a hypercalcemic state.

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  #4

but tetany is caused by a HYPOcalcemic state??

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  #5

I admit I am wrong dismiss my reply. I got consfuse with the mechanisms that implies this question. Chvostek's sign made me remember. A state of severe alkalosis cause tetany by the mechanisms mdwannabe explained.

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  #6

very well replied mdwannabe! thankx to others too

  #7

thank you.

___________________
"Life not lived for others, is not worth living" Uncle Einstein
"A life is not important, except in the impact it has on other lives" -Jackie Robinson

  #8

Aldosterone at the distal tubule and collecting ducts causes Na+ retention and K+ secretion. During action potential formation in a neurone, Na+ is responsible for the depolarization phase and K+'s movement out is responsible for the repolarization phase. For a nerve that innervates a muscle, the repolarization phase of the action potential is responsible for relaxation. Due to depletion of K+, repolarization phase does not occur and hence muscle remains in a state of persistent contractility(tetany) due to firing of the Action potentials which don't die down by repolarization.







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