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.) Valves also help blood travel back to the heart against the force of gravity.

Detailed explanation-2: -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-3: -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-4: -Typically, arteries lack valves. However, there are valves on the two arteries exiting the right and left ventricles that stop blood from flowing backward. Aortic and pulmonary valves are typically regarded as heart valves.

Detailed explanation-5: -Structures called valves are present in veins and lymph ducts but are absent in arteries. These valves mainly prevent the backflow of blood in the vessels. Due to the high pressure of blood flowing n the arteries, they do not require valves to prevent backflow of the blood.