Quantitative Renal Phys or Eval of Renal Fuction (Rao) Flashcards Preview

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Flashcards in Quantitative Renal Phys or Eval of Renal Fuction (Rao) Deck (28):
1

Mass flow =
(formula)

concentration x rate of flow

(expression od solute movements as a function of time)

2

For solutes that are ingested and metabolized... (i.e. glucose)
rate of output =

rate of intake + rate of production - metabolism

3

For solutes that are produced only by metabolism... (i.e uric acid, urea)
rate of output =

Rate of production

4

For solutes that are not producedin the body... (i.e NaCl)
rate of output =

rate of intake

5

T or F: Urea can be excreted in sweat and feces.

F: only in urine

6

What are the 3 routes for kidney output?

renal vein, lymphatic, urine

7

Mass flow in the kidney =

rate of flow in renal vein + lymphatics + urine x the conc in enal vein + lymphatics + urine

8

Water input to the kidney is the same as ______ into the kidney

plasma flow

9

In a healthy nephron:
Filtration + secretion =

reabsorption + excretion

*input = output

10

Filtration rate =

GFR X Px

11

Excretion rate =

UF x Ux

12

What are the 3 parameters that quantify kidney function?

GFR
plasma clearence of solutes
renal blood flow

13

Why is inulin the model for measuring kidney function?

it is not produced in the body
it is not metabolized
it is excreted only in the kidney
not secreted by tubule
not reabs by tubule

14

What is the formula for GFR?

GFR = UF x Ux/Px

15

What is the volume of plasma that is completely cleared of the substance by the kidneys per unit time?

clearance

16

What effect does increased reabs have on clearance

decreases it

17

What effect does increased secretion have on clearance

increases it

18

What does a low clearance for a solute indicate?

it is reabs

19

What does a high clearance for a solute indicate?

it is secreted

20

What is the formula for extraction ratio?

Ex ratio = (Ax -Vx)/Ax

21

What does the extraction ratio measure?

the % of substance removed from the plasma

22

WIll a substance that is reabs have a high or low extraction ratio?

low

23

WIll a substance that is secreted have a high or low extraction ratio?

high

24

T or F: If a substance X is cleared completely from the plasma the clearance will equal the venous plasma concentraton

F: Cx = total renal plasma flow (when a substance is cleared completely)

25

What is the extraction ratio of PAH (para amino hippuric acid)

~1

*90-95% clearance

26

T or F: Cx of PAH = RPF

T: bc PAH is cleared completely

27

If GFR increases, plasma creatinine will (inc, decrease, stay the same).

decreases

28

T or F: decreasing GFR by 1/2 has very little effect on plasma creatinine levels

F: there is a mechanism for compensation of dec GRF... but after 50% you will see an sharp increase in plasma creatinine bc the threshold will be reached