Renal corpuscle
Corpusculum renale
Also known as: Malpighian corpuscle, glomerulus (loosely)
The filtering unit at the start of each nephron (≈200 µm), formed by the glomerular capillary tuft invaginated into the double-walled glomerular (Bowman) capsule.
Overview
The renal corpuscle has two poles. At the vascular pole the afferent arteriole enters and the efferent arteriole leaves; the juxtaglomerular apparatus sits here. At the opposite urinary (tubular) pole the capsular (Bowman) space opens into the proximal convoluted tubule. The glomerulus is a tuft of fenestrated capillaries supported by mesangium; it is covered by the visceral layer of the capsule (podocytes), while the parietal layer (simple squamous epithelium) forms the outer wall. Plasma is filtered from the capillaries across the glomerular filtration barrier into the capsular space.
All renal corpuscles lie in the cortex, giving it a granular appearance; there are ≈1 million per kidney with a very large total filtering surface (of the order of 1–2 m²; estimates vary).
- Location
Renal cortex.
Parts & subdivisions
- Tuft of fenestrated capillaries between afferent and efferent arterioles.
- Visceral (podocyte) and parietal layers enclosing the capsular (Bowman) space.
- Mesangial cells and matrix supporting the capillary loops.
- Vascular poleEntry/exit of afferent and efferent arterioles; site of the JGA.
- Urinary poleOpening of the capsular space into the PCT.
Anatomy
- Histology
Rounded structure ≈200 µm across; capillary loops covered by podocytes; parietal epithelium simple squamous, changing abruptly to cuboidal PCT epithelium with brush border at the urinary pole.
Function
- Ultrafiltration of plasma to form glomerular filtrate (primary urine)
Compiled from standard anatomy and physiology references — see the Urinary System sources. For education only; not medical advice.