NEET PG DENTAL EXAM

Detailed explanation-1: -A vein is a blood vessel that conducts blood toward the heart. Compared to arteries, veins are thin-walled vessels with large and irregular lumens (see Figure 6). Figure 6. Many veins have valves to prevent back flow of blood, whereas venules do not.

Detailed explanation-2: -Capillaries are thin-walled vessels composed of a single endothelial layer. Because of the thin walls of the capillary, the exchange of nutrients and metabolites occurs primarily via diffusion. The arteriolar lumen regulates the flow of blood through the capillaries.

Detailed explanation-3: -Arteries are more muscular and have smaller, rounder lumens (internal spaces) than veins. The artery lumen has a wavy endothelium, or inner lining, due to the configuration of elastic tissue beneath it.

Detailed explanation-4: -Veins are generally larger in diameter, carry more blood volume and have thinner walls in proportion to their lumen. Arteries are smaller, have thicker walls in proportion to their lumen and carry blood under higher pressure than veins. Arteries and veins often travel in pairs using the same connective tissue pathways.