4.1 Renal Blood Flow DSA Equations

Question 1

What is the equation for urine excretion rate?

Answer 1

Urine excretion rate = urine concentration of a given substance x urine flow rate

(Excretion = (Ux) (V))

Question 2

What equation do we use to calculate GFR for molecules that meet our criteria?

Answer 2

GFR = (concentration of the substance in urine, x urine flow rate) / concentration of the substance in plasma

Question 3

What is the equation for filtered load?

Answer 3

Filtered load = plasma concentration x GFR

Question 4

What is the equation for urinary excretion?

Answer 4

Urinary excretion = amount filtered - amount reabsorbed + amount secreted

Question 5

What is the equation for the filtration fraction?

Answer 5

FF = GFR/RPF

(Filtration fraction = glomerular filtration rate / renal blood (plasma) flow)

Question 6

What is the equation for renal clearance?

Answer 6

Question 7

What is the equation for tubular reabsorption?

Answer 7

Tubular reabsorption = filtered load - urinary excretion + amount secreted