Question

The wall of capillaries have a layer of

• A. endothelium and smooth muscle
• B. elastic fibres only
• C. endothelium and elastic fibres
• D. endothelium only

Answer 1

The correct option is D endothelium only

Capillaries are the thinnest among the blood vessels. These vessels join the arteries with the veins. The exchange of gases and other materials between blood and organ cells takes place through the walls of capillaries.
So the wall is made up of only an endothelium layer which comprises flat and squamous cells.