NEET PG DENTAL EXAM

Detailed explanation-1: -Capillaries are the smallest blood vessels in the cardiovascular system. They are so small that only one red blood cell at a time can squeeze through a capillary, and then only if the red blood cell deforms. Capillaries connect arterioles and venules, as shown in Figure 17.4.

Detailed explanation-2: -Capillaries have the smallest lumen but relative to their size the lumen is quite large. This is because capillaries are where exchange of oxygen, nutrients and waste products occur between blood and tissues so they have evolved to have the greatest surface area to volume ratio to increase efficiency of the exchange.

Detailed explanation-3: -Capillaries are very thin, approximately 5 micrometers in diameter and composed of only two layers of cells. The inner layer is made up of endothelial cells with an outer layer of epithelial cells.

Detailed explanation-4: -Capillaries are 5–10 m in diameter and contain pericytes on their abluminal side.