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blueocean
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09/06/06 - 04:57 PM

A healthy 38-year-old woman is found unconscious and severely dehydrated. Her plasma levels of antidiuretic hormone (ADH) are increased about 5-fold above normal. In which portion of her kidney tubule is most of the water being reabsorbed?

A. Cortical collecting duct
B. Distal tubules
C. Loops of Henle
D. Medullary collecting duct
E. Proximal tubule

Leopard
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09/06/06 - 05:00 PM

Proximal convoluted tubues 67%

Only 10% is ADH dependent absorption in the late DCT and CT.

Best of luck

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docsrinu
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09/06/06 - 07:43 PM

E. reason given by leopard.

blueocean
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09/06/06 - 07:46 PM

Leopard
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09/06/06 - 08:09 PM

Now queswtion extends

If patient is completely ADH deficient ,how much urine (max) he is likely to pass in 24 hrs?

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Leopard
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09/07/06 - 04:01 AM

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drpkaur
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09/07/06 - 11:59 AM

DI...

Leopard
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09/07/06 - 12:10 PM

drpkaur wrote:
DI...

Yes drpkaur this DI but

How much (max) urine pt will pass in 24hr in case of complete absence of ADH??

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aisha2
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09/07/06 - 02:58 PM

5L ??????

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Leopard
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09/07/06 - 03:13 PM

#10

Within twenty four hrs

Approximatel filtrate in both kidneys = 180 liters

Out this 179L are absorbed back and Urine is left as 1 L

ADH dependent reabsorption is only 10% so a patient with complete absence of ADH is likely to pass 18L (10% of 180) /24hrs.But in fact these patients pass upto 12-13 L /24hrs

Best of luck

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girl^interrupted
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12/06/06 - 08:53 PM

#11

can anybody tell me where ADH primary action is?
Is it cortical or medullary collecting ducts???????

P.s. I do understand the qs very well....my question is not related to this question...

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Palaniappan
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12/16/06 - 10:06 AM

#12

Medullary collecting duct

me007
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12/18/06 - 01:44 PM

#13

why medullary?

Ancylostoma
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12/18/06 - 04:55 PM

#14

The question is not which portion of the tubule is responsible for the change in water reabsorbiont, but in with portion is most of the water reabsorbed. its the proximal tubule. Leopard's explanation says its all

Edited by Ancylostoma on 12/18/06 - 06:26 PM

mjl1717
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12/18/06 - 05:14 PM

#15

Leopard wrote:

Yes drpkaur this DI but

How much (max) urine pt will pass in 24hr in case of complete absence of ADH??

In a 70 kg man about 1680ml/24 hrs using parkland formula.

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kashdoc21
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12/18/06 - 09:35 PM

#16

i would appreciate if blueocean posts the correct ans

i think it shd be collecting ducts

Leopard
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12/19/06 - 03:51 PM

#17

mjl1717 wrote:

In a 70 kg man about 1680ml/24 hrs using parkland formula.

Parkland formula for ADH deficiency fluid loss ?????????????

I always thought it is for calculation of fluid requirement in a burn patient. Would you please explain ???

Thanks

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blueocean
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12/22/06 - 05:49 AM

#18

I already did- smiling face

It is E!

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