Which Blood Vessels Have Porous Walls That Allow Water and Small

Question

Which blood vessels have porous walls that allow water and small solutes to seep through?
A) veins
B) arterioles
C) venules
D) arteries
E) capillaries

Accepted Answer

Capillaries have very thin, porous walls that allow for the exchange of fluids and small solutes between the blood and tissues. Veins have some porous areas, but not to the same extent as capillaries. Arteries and arterioles have thick, muscular walls that are not porous, and venules have slightly more porous walls than veins, but still not to the same extent as capillaries.