Question

Explain how net filtration pressure behind the GFR is determined. Describe the influence hydrostatic pressure has on GFR?

Answer 1

Glomerular filtration is driven by the pressure that builds in these capillaries. Several factors leading and affecting this pressure is.

• The diameter of afferent arterioles that bring blood in the glomerulus is larger than efferent arterioles that take away the blood. This difference leads to a pressure build-up called glomerular hydrostatic pressure which is 60 mm
• The hydrostatic pressure by the capsules oppose it - capsular hydrostatic pressure = - 18 mm
• The colloidal osmotic pressure due to proteins like albumin also oppose = -32 mm

Hence a sum of these pressures, resultant +10 mm is the net filtration pressure