PATHOLOGY

Detailed explanation-1: -The large lumens and relatively thin walls of veins make them far more distensible than arteries; thus, they are said to be capacitance vessels.

Detailed explanation-2: -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.

Detailed explanation-3: -Veins carry unoxygenated blood towards the heart, away from tissues at low pressure so the lumen is large. Blood moves more slower and often against gravity so valves and a larger lumen ensure it is still transported efficiently. Capillaries have the smallest lumen but relative to their size the lumen is quite large.

Detailed explanation-4: -Arteries and arterioles The arteries branch into smaller and smaller vessels, eventually becoming very small vessels called arterioles. Arteries and arterioles have muscular walls that can adjust their diameter to increase or decrease blood flow to a particular part of the body.