What type of epithelium lines the renal corpuscle and how does its structure relate to function?

• A. Simple squamous epithelium; thick basal lamina for filtration.
• B. Stratified squamous epithelium; keratinization to protect against abrasion.
• C. Podocytes line the visceral layer of Bowman's capsule and form filtration slits; the glomerular capillary endothelium is fenestrated to facilitate filtration.
• D. Transitional epithelium; stretch to accommodate urine.

Answer: (C)

The renal corpuscle is lined by specialized visceral epithelial cells called podocytes, which wrap around the glomerular capillaries. Podocytes have interdigitating foot processes that create narrow filtration slits, covered by slit diaphragms. This arrangement forms the selective filtration barrier, allowing water and small solutes to pass into Bowman’s space while restricting large proteins and cells. The glomerular capillaries themselves have fenestrated endothelium, which facilitates the movement of plasma out of the bloodstream. Together, the podocyte filtration slits and the fenestrated endothelium establish the functional filtration interface of the renal corpuscle.