Question

Which of the following forms the filtration barrier?

1) capillary endothelial cells only
2) podocytes only
3) basement membrane only
4) both capillary endothelial cells and basement membrane
5) capillary endothelial cells, basement membrane, and podocytes

Answer 1

The filtration barrier is formed by capillary endothelial cells, basement membrane, and podocytes, which work together to regulate filtration in the glomerulus.

Step-by-step explanation:

The filtration barrier in the kidney is formed by capillary endothelial cells, basement membrane, and podocytes. The capillary endothelial cells have fenestrations that allow the passage of substances up to 8 nm in size. The basement membrane prevents filtration of medium-to-large proteins. Podocytes have finger-like extensions called pedicels that interdigitate to form filtration slits. Together, these three components regulate filtration in the glomerulus and create a filtrate that does not contain cells or large proteins.