NEET BIOLOGY

Detailed explanation-1: -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-2: -The deep veins play a significant role in pushing blood toward the heart. The one-way valves in deep veins prevent blood from flowing backward.

Detailed explanation-3: -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.) Valves also help blood travel back to the heart against the force of gravity.

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. Methods: Twelve superior and eight inferior ophthalmic veins together with 13 angular and facial veins were harvested from adult cadavers.

Detailed explanation-5: -So, the correct option is ‘Veins’.