EVERYDAY SCIENCE

Detailed explanation-1: -Unlike arteries, veins contain valves that ensure blood flows in only one direction. But, Arteries don’t require valves because pressure from the heart is so strong that blood is only able to flow in one direction. Valves also help blood travel back to the heart against the force of gravity.

Detailed explanation-2: -Arteries can maintain that high blood pressure due to their strong lining and flexible walls that allow for the additional push of blood. Because of this unique design and the assistance they receive from the heart, they do not need valves to prevent backflow.

Detailed explanation-3: -Veins have valves to prevent this backflow of blood. Valves ensure that blood flows only in one direction through veins. Therefore, veins have valves, not the arteries.

Detailed explanation-4: -Medium and large veins have venous valves, similar to the semilunar valves associated with the heart, that help keep the blood flowing toward the heart. Venous valves are especially important in the arms and legs, where they prevent the backflow of blood in response to the pull of gravity.

Detailed explanation-5: -Studies suggested that femoral veins contain between one and six valves, and popliteal veins contain between zero and four valves.