MEDICAL PHYSIOLOGY

Detailed explanation-1: -To calculate NFP, we subtract the forces that oppose filtration from the GBHP. A normal NFP (using the figures mentioned) would be: NFP=55-(15+30)=55-45=10mm Hg. This means that a pressure of only 10mm Hg causes a normal amount of plasma (minus plasma proteins) to filter from the glomerulus into the capsular space.

Detailed explanation-2: -The blood pressure in the glomerular capillaries is called the capsular hydrostatic pressure.

Detailed explanation-3: -That is, the blood flowing into the glomerulus contains plasma proteins and blood cells that displace the water content of the blood. This creates, in effect, a counter force called oncotic pressure, as water outside the capillaries seeks to equalize with the water inside the capillaries through osmosis.

Detailed explanation-4: -Causes could include accumulation of fluid outside of the vascular space such as edema or ascites, lowered pressure and flow with congestive heart failure, peripheral vasodilation with toxic products of sepsis, or impaired renal blood flow or reduced glomerular capillary pressure from some drugs.