L8: counter current system

Question 1

What 2 components make up the CC system?

Answer 1

Multiplication in medullary interstitium
Exchange in vasa recta

Question 2

Renal Blood Flow

Answer 2

Volume of blood flowing through the kidneys per unit time 1L/min

Question 3

Renal Plasma Flow (RPF)

Answer 3

Volume of blood flowing through the kidneys per unit time (normal: ~600mL/min).
* “The plasma fraction of RBF”

Question 4

Glomerular Filtration Rate (GFR)

Answer 4

The volume of plasma entering the Bowman’s space per unit time (normal: 125mL/min).
* eGFR: Determined via inulin or creatinine clearance

Question 5

Filtration fraction (FF)

Answer 5

Percent of plasma entering the bowman’s space per unit time (normal:125mL/min)

Question 6

Filtered Load

Answer 6

Mass of substance entering the Bowman’s space from the plasma per unit time

Question 7

Excretion rate

Answer 7

mass of substance exiting the kidneys per time

Question 8

Renal clearance

Answer 8

Volume of substance exiting the kidneys per unit time

Question 9

Fractional excretion

Answer 9

Percent of a substance exiting the kidneys from amount filtered (FL)

Question 10

Urinary flow rate

Answer 10

volume of urine excreted per unit time 1mL/min

Question 11

Urinary flow rate

Answer 11

volume of urine excreted per unit time 1mL/min

Question 12

GFR

Answer 12

GFR = Kf (NFR)

Question 13

assume haematocrit of

Answer 13

0.35

Question 14

RBF =

Answer 14

P/R

Question 15

RPF

Answer 15

(1-Hct)(RBF)

Question 16

FF=

Answer 16

GFR/RPF

Question 17

Fractional excretion=

Answer 17

Excretion rate/filtered load

Question 18

What is a normal GFR?

Answer 18

120ml?min