Quantitative Renal Physiology or Evaluation of Renal Function

Question 1

Equation for Mass Flow.

Answer 1

Mass Flow = Conc. x Vol. Flow

Question 2

What 3 main factors should you consider when looking at total body content of a substance?

Answer 2

• Intake (food, drink)
• Production (from metabolism)
• Output (Urin, Feces, Respiration)

Question 3

What are 3 good indicators of the extent and progression of Renal Diseases?

Answer 3

1. GFR - Best indicators of Extent and Progression of Renal Diseases
2. Plasma Clearance of Solutes
3. Renal Blood Flow

Question 4

What is the formula for GFR?

• aka?

Answer 4

• GFR = (UF x Uin) / Pin

***AKA: Clearance

Question 5

Define Clearance.

Answer 5

**Volume of Plasma that is completely cleared of the substance by the kidneys per unit time

Question 6

What is the formula for the extraction ratio?

Answer 6

Ex. Ratio = (Ax - Vx [renal venous]) / Ax

Question 7

What is the effect of reabsorption and secretion on the extraction ratio?

Answer 7

Reabsorption = LOW Extraction ratio

Secretion = HIGH Extraction ratio

essentially how much you put in vs. how much you get out