ABSTRACT
It can be seen that clearance has the same units as blood ow (mL/min). is is because clearance is the virtual incoming blood (or plasma) ow that can be imagined to be completely cleared of the substance in a single pass. e proportion of blood ow that is cleared is the extraction fraction, which is an important concept in renal physiology. In the context of glomerular ltration, the renal extraction fraction of a ltration marker is the ratio of GFR to renal plasma ow (ltration fraction).
