Question

Calculate the net filtration pressure if the glomerular hydrostatic pressure measures 46 mmHg, the colloid osmotic pressure 34 mmHg, and the capsular hydrostatic pressure 10 mmHg. Does this differ from the normal value? If so, how? What effect, if any, would this have on the GFR?

Answer 1

Answer:

Net filtration pressure is 2 mmHg

Solution:

As per the question:

Glomerular Pressure, $P_{gh} = 46\ mmHg$

Colloidal Osmotic Pressure, $P_{co} = 34\ mmHg$

Capsular Hydrostatic Pressure, $P_{ch} = 10\ mmHg$

Now,

The net filtration Pressure is given by:

$P_{net} = P_{gh} - (P_{co} + P_{ch})$

$P_{net} = 46 - (34 + 10) = 2\ mmHg$

• The normal value of the net filtration pressure is 20 mmHg and the calculated value is very low as compared to the normal value.

• GFR is low for increased hydrostatic pressure.

• The lower rate of the glomerular filtration can result in lower value of the GFR