Question

Exchange of nutrients between blood and tissues occurs at the ______.

Options

• veins

• capillaries

• arteries

• venule

Answer 1

Exchange of nutrients between blood and tissues occurs at the capillaries.

Explanation:

Capillaries are microscopic, thin-walled blood vessels whose walls are composed of only a single layer of endothelial cells. This exceptionally thin barrier allows gases, nutrients, and metabolic wastes to easily diffuse across the membrane between the circulating blood and the surrounding tissue cells. In contrast, arteries, veins, and venules have much thicker, multi-layered walls designed to withstand pressure or transport bulk blood, making them structurally unsuited for chemical exchange.