PATHOLOGY

Detailed explanation-1: -Veins: Unlike arteries, veins don’t have to carry highly pressurized blood, but they do have to carry large volumes of deoxygenated blood back to your heart. Thin, less elastic walls help them handle high volumes and low pressure. Most veins have valves that open and close.

Detailed explanation-2: -Studies suggested that femoral veins contain between one and six valves, and popliteal veins contain between zero and four valves.

Detailed explanation-3: -Veins use valves to transport blood towards the heart, but capillaries don’t have valves. Capillaries diffuse blood and nutrients between veins and arteries through their thin walls.

Detailed explanation-4: -Most veins contain valves (known as the valvula venosa in the TA) to prevent backflow, i.e. ensuring that blood flow is always towards the heart 1. Recent evidence shows that veins that were previously thought to be valveless, are now known to have valves, including the facial and superior ophthalmic veins 2.