MICROANATOMY

Detailed explanation-1: -Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction.)

Detailed explanation-2: -But arteries carry blood downwards away from the heart and into an organ, hence, have no valves in their inner lining.

Detailed explanation-3: -The blood passing through the veins is deoxygenated (except in pulmonary veins) and flows at a low pressure. It flows slow and steady against the direction of gravity. Therefore, veins have valves to prevent the backflow of blood.

Detailed explanation-4: -Background: The ophthalmic and facial veins are frequently stated to be devoid of valves, facilitating the spread of infection from the mid-face to the cavernous sinus.

Detailed explanation-5: -Why do veins have valves and what is their function? These valves are what ensure blood flows toward your heart. Vein valves work hard, against gravity, to bring the blood that flowed down via arteries back up to your heart.