Expansion
Glomerular capillaries, Bowman capsule, podocytes and mesangium
Expansion
Components
- Glomerular capillaries: fenestrated endothelium
- Podocytes (visceral epithelium): foot processes with filtration slits bridged by nephrin and podocin
- Basement membrane: shared, with type IV collagen and negatively charged heparan sulphate
- Bowman capsule (parietal epithelium): simple squamous
- Mesangium: mesangial cells and matrix, providing structural support, contractility regulating filtration surface, and phagocytosis of trapped macromolecules
Two poles: the vascular pole where afferent and efferent arterioles enter and leave, adjacent to the juxtaglomerular apparatus; and the urinary pole where the proximal tubule begins.
Disease localises to the components:
- Podocyte effacement: minimal change disease and focal segmental glomerulosclerosis
- Basement membrane thickening with subepithelial deposits: membranous nephropathy
- Mesangial proliferation with IgA deposits: IgA nephropathy
- Endothelial and mesangial proliferation: post-streptococcal glomerulonephritis
- Parietal epithelial proliferation: crescents in rapidly progressive glomerulonephritis