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Old 06-06-2011
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Kidney Nephron part most permeable to water!

which part of collecting duct is most permeable to water reabsorption IN PRESENCE OF ADH and in absence of ADH..

Nephron part most permeable to water!-photo2409.jpg
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Old 06-06-2011
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In presence its E) the collecting duct.

But I think without it was PCT (not 100%)
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presence E, absence B
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In the presence ..D
In the absence ..B(concentrating segment ..Descending limb of loop of henle)
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In presence - E
In absence - B
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Old 06-06-2011
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Default Correct Answer: Presence E and Absence B

Ok, In presence of ADH ( AntiDiuretic Hormone is the Collecting DUCT ) in abscense is the Descending part of Henle.

A) most of protein/glucose/aa are reabsorve there.
B) Most permeable to water
C) Actually this is the Lower osmolarity part of the whole Kidney ( around 100)
D) Specific Site of Aldosterone Site of Action (Cortex )
E) Specific site of ADH site of action (Outer Medulla )

Note both ADH and Aldosterone works on the Collecting duct, but have to note which part of collecting duct...

Hope it helps....

Last edited by rulz; 06-06-2011 at 06:46 PM.
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Old 06-06-2011
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Quote:
Originally Posted by IKR123 View Post
which part of collecting duct is most permeable to water reabsorption IN PRESENCE OF ADH and in absence of ADH..

Attachment 1444
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PRESENCE C
absence E
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Old 06-06-2011
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Quote:
Originally Posted by IKR123 View Post
which part of collecting duct is most permeable to water reabsorption IN PRESENCE OF ADH and in absence of ADH..

Attachment 1444
click image to enlarge
i think its E in presence of ADH and
A in absence of ADH ( 2/3rd of water being absorbed in PCT)
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Old 06-06-2011
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the site of majority of water reabsorption is Proximal Convoluted Tubule (PCT) whether ADH is Present or absent because water reabsorption in PCT is almost 65%

so with presence of ADH: PCT = 65% , Collecting Duct (CD) = around 30%
in absence of ADH: PCT is also 65% of water reabsorption. CD = almost 0%
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i think in the presence it is E
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Old 06-06-2011
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in the absence of ADH there is no reabsorption in the collecting duct, but in the presence of ADH, part E will be responsible for this function
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Old 06-09-2011
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ADH full function is unknown. how exactly does it work by aquaporins etc..

however IN PRESENCE OF ADH most permeable portion is (E)

BUT STILL MOST OF WATER IS REABSORBED IN (A)..

PROF. FRANK NOTO, M.D @ Kaplan Manhattan NY
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