Filtration membrane -Basement membrane(lamina densa) with the mesh of 2-8 nm diameter od C: capillary F P fenestration BM- S BM: basal P BM membrane E BM P podocytes FS: filtration slit 10
Filtration Membrane –Basement membrane(lamina densa) –with the mesh of 2-8 nm diameter C: capillary F: fenestration BM: basal membrane P podocytes FS: filtration slit
Filtration membrane -One layer of cells in bowman s capsule -podocytes have foot like projections(pedicels) with filtration slits(滤过裂隙) in between 密 capillary P F fenestration BM- FS e P11 BM: basal <P E membrane BM 八A podocytes F FS: filtration slit um
Filtration Membrane –One layer of cells in Bowman’s capsule: –Podocytes have foot like projections (pedicels) with filtration slits (滤过裂隙）in between C: capillary F: fenestration BM: basal membrane P podocytes FS: filtration slit
10 08 Polycationic 0.6 dextran Neutral 右旋糖苷 04 dextran Polyanionic dextran 0.2 0 822263034384240 Effective molecular radius (a)
Stanton BA & Koeppen BM: ‘The Kidney’ in Physiology, Ed. Berne & Levy, Mosby, 1998 2934 Dextran filterability 右旋糖苷
1.0 日0.8 sc 0.6 Loss of negative charges on filtration barrier 0.4 Normal 0.2 1822263034384246 Effective mnolecular radius (A)
Protein filtration: influence of negative charge on glomerular wall
Filterablility of plasma constituents vS. water Constituent Mol Wt filteration ratio Urea 60 1.00 Glucose 180 1.00 Inulin 5.500 1.00 Myoglobin 17,000 0.75 Hemoglobin 64,00 0.03 Serum albumin 69000 0.01
Constituent Mol. Wt. Filteration ratio Urea 60 1.00 Glucose 180 1.00 Inulin 5,500 1.00 Myoglobin 17,000 0.75 Hemoglobin 64,000 0.03 Serum albumin 69,000 0.01 Filterablility of plasma constituents vs. water