Flow through the system is reduced. If the constriction is the afferent arteriole, then the hydrostatic pressure in the glomerulus is decreased and blood flow is reduced. Released from endothelial cells and diffuses relax vascular smooth muscles cells and cause vasodilatation. Topic 8 . The GFR is measured by determining the renal clearance of creatinine.
Clearance is based on mass laws or everything has to be someplace.
Clearance is the volume of plasma cleared of a substance as it passes through the kidney. This can be thought of as having 1 ml of plasma cleared of a substance as plasma flows through the kidney. The GFR is equal to the amount of plasma that is cleared of creatinine or inulin as it passes through the kidney. Clinical conditions resulting from an increased permeability. The nephrotic syndrome is associated with an increased permeability.