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  #1  
Old 08-24-2014
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Post Biochemistry Question

Which of the following substances has the lowest Afferent to Efferent Arteriole concentration ratio ??

A- Albumin
B- Chloride
C- Glucose
D- Sodium
E- Pottasium
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Old 08-24-2014
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I will go with A. Albumin is only not filtered substance. So it's relative concentration in efferent arteriole should be increased
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Old 08-24-2014
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Ill go with AA.

As Albumin is not filtered so its relative conc. would be higher in efferent.

Thanks for the question.
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Old 08-24-2014
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Quote:
Originally Posted by DrNewB View Post
Ill go with AA.

As Albumin is not filtered so its relative conc. would be higher in efferent.

Thanks for the question.
Do u really think it will be higher at the efferent end or the same?
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Old 08-24-2014
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Quote:
Originally Posted by nsesereso View Post
Do u really think it will be higher at the efferent end or the same?
It will be relatively higher.

For example, If Conc. of albumin is 1 in 100 ml in afferent and Albumin didnt get filtered.However water was filtered (most got resorbed) But some of it is made into urine.

So, now Albumin in efferent would still be 1 (amount not conc) but in 80 ml.

so concentration is relatively increased from 1 in 100 to 1 in 80. (these are hypothetical numbers)
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Old 08-27-2014
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I think its E because k is secreted in the collecting ducts by aldosterone
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Old 08-28-2014
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I think it's E as well. Lowest Afferent/Efferent ratio means low conc in afferent but high in Efferent. and only K is being secreted among the choices...
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Old 08-28-2014
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Quote:
Originally Posted by coelom View Post
I think it's E as well. Lowest Afferent/Efferent ratio means low conc in afferent but high in Efferent. and only K is being secreted among the choices...
This is why I dont think that option E is correct,

Suppose we have 100 molecules of K in 100ml of the bloodflow to kidney. I.e, Efferent has 100 molecules of K in 100 ml.

75 gets resorbed in PCT and 25 goes to the efferent. so, efferent Conc = 25 ml.

So 75/25 = 3. Conc ratio inc. Right?

Now your secretion thingy,

Do you know where the secretion takes place?? Mostly between distal tubule and peritubular capillaries, which are formed from efferent arteriole.

so there is no need to see secretion etc in this case. as we are talking about the efferent arteriole and not renal vein.

Thanks for your input too.
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Old 08-29-2014
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Quote:
Originally Posted by DrNewB View Post
This is why I dont think that option E is correct,

Suppose we have 100 molecules of K in 100ml of the bloodflow to kidney. I.e, Efferent has 100 molecules of K in 100 ml.

75 gets resorbed in PCT and 25 goes to the efferent. so, efferent Conc = 25 ml.

So 75/25 = 3. Conc ratio inc. Right?

Now your secretion thingy,

Do you know where the secretion takes place?? Mostly between distal tubule and peritubular capillaries, which are formed from efferent arteriole.

so there is no need to see secretion etc in this case. as we are talking about the efferent arteriole and not renal vein.

Thanks for your input too.

I agree with you. The answer is AAAA
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Old 09-11-2014
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Yes you are right im sorry I was thinking of the concentration in distal convoluted tubules
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Old 09-12-2014
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I think its glucose! Lowest afferent to effent concentration!! Since glucose is easily filtered!!
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