Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Fenestrations are small pores or openings in the endothelial cells of the glomerular capillaries within the kidneys. They allow for the filtration of blood while blocking larger molecules such as proteins and blood cells.
Related terms
Glomerulus: A network of tiny blood vessels located at the beginning of a nephron where blood filtration begins.
Filtration Barrier: A three-layer structure in the kidney that filters blood, consisting of fenestrated endothelial cells, basement membrane, and podocytes.
Specialized cells in the Bowman's capsule with foot-like extensions that wrap around capillaries of the glomerulus, playing a crucial role in blood filtration