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IMG SURVIVOR
04-04-2006, 03:35 PM
FILTRATION and CXA:flag:




What will happen to the GFR and to the RPF if you have:

1-Constriction of the afferent arteriole
2-Constriction of the efferent arteriole
3-Increase plama protein?









1- your GFR will go down your RFP will go down
2-your GFR will go up your RFP will go down
3-yor GFR will go down your RFP will not change




PLEASE GIVE EXAMPLES OF CAUSES THAT CAN GIVE YOU 1,2 OR3

THANK YOU

md90
04-04-2006, 09:59 PM
decrease in GFR: renal failure, increased age, hypoperfusion of the kidneys

increase in GFR: diabetics, can be an early sign of diabetic nephropathy; also seen in normal pregnancy

How can you tell that the GFR is increased or decreased?
Creatinine Clearance.. is not reabsorbed or excreted BUT filtered in the kidneys






please correct or add to the information...

jguru2
04-05-2006, 06:44 PM
Inulin clearance is used for GFR measurement..it is filtered, but neither secreted nor re-absorbed...

md90
04-05-2006, 09:23 PM
Inulin clearance is used for GFR measurement..it is filtered, but neither secreted nor re-absorbed...


Creatinine Clearance.. is not reabsorbed or excreted BUT filtered in the kidneys

I had to look this up on the internet.. We are both right.



Glomerular filtration rate (GFR) can be calculated by measuring any chemical that has a steady level in the blood, and is freely filtered but neither reabsorbed nor secreted by the kidneys.

Creatinine fulfills these requirements to an extent; is a metabolite of creatine found in our muscles; also overestimates the GFR by 10-20% but this is acceptable because of the way it is measured; There are other methods that is more accurate.

Inulin clearance is one of them but it needs to be infused to maintain a steady state in the blood; Creatinine is already has that steady state therefore it is less work and probably cheap; Remember, on boards, being cheap is the name of the game;


please post any other information r/t the topic.. we are here to learn.. thank you.







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