Processesof urineformation1. Glomerular filtration1.1 Glomerular filtration rate (GFR)1) definition : the volume of the filtrate by two kidneys (125ml/min)2)filtration fraction (FF) : GFR/RPF =19%renal plasma flow (660ml/min)PPTPresentationbyChenQiYangzhouUniversity
1.2 Filtration mechanism1)effective filtration pressure (EFP)glomerularcapillary'spressure-PccBowman's capsule's pressure-Prccolloid osmotic pressure in glomeruli-ccEFP=PGC-(PBC+元GC)PPTPresentationbyChenQi,YangzhouUniversity
2)Permeabilityendothelialcellsofglomerularcapillary size of moleculesbasementmembraneepithelial lining of Bowman's capsule (podocytes)<4nm (filtered)> 8nm (cannot)4-8nm→ albumin, red cells2)electrical charge of molecules (sialoproteins“"+"> neutral molecule>“_"PPTPresentationbyChenQi,YangzhouUniversity