ANATOMY

Detailed explanation-1: -Capillaries are the smallest blood vessels in the body. How small are they? About ten of them equal the thickness of one human hair, and most are so small that only one blood cell can pass through them at a time.

Detailed explanation-2: -Why Are Capillaries Very Small in Size? Capillaries need to be small in order to facilitate oxygen and carbon dioxide gas exchange in cells. 3 They also play a role in fluid and nutrient exchange, forming the connection between the body’s smallest arteries (arterioles) and smallest veins (venules).

Detailed explanation-3: -Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins).

Detailed explanation-4: -An arteriole (är-’tir-ē-, ōl) is a very small blood vessel that branches off from your artery and carries blood away from your heart to your tissues and organs. Arterioles are small arteries that link up to capillaries, which are smaller yet.