EVERYDAY SCIENCE

Detailed explanation-1: -What are capillaries? Capillaries are delicate blood vessels that exist throughout your body. They transport blood, nutrients and oxygen to cells in your organs and body systems. Capillaries are the smallest blood vessels in your vascular system.

Detailed explanation-2: -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-3: -Endothelial Cells Line All Blood Vessels In the finest branches of the vascular tree-the capillaries and sinusoids-the walls consist of nothing but endothelial cells and a basal lamina (Figure 22-23), together with a few scattered-but functionally important-pericytes.

Detailed explanation-4: -Two types, continuous fenestrated capillaries and continuous nonfenestrated capillaries, have different purposes. Many genetic and nongenetic conditions may affect your continuous capillaries.