Question

explain briefly: why are the capillaries thin walled?

Answer 1

The capillary walls are also very small, only one cell thick. These thin walls easily allow water, oxygen, carbon dioxide, and other nutrient and waste substances to exchange between blood cells and the surrounding tissue

Answer 2

The main job of the capillaries is gas exchange between oxygen and carbon dioxide. For easy gas exchange,it is necessary to have thin,so than gas can easily penetrate through them. I hope this helped you