Question

Give reasons for the following
Valves are present in veins but not in arteries

Answer 1

Arteries carry blood from the heart to the different parts of the body and therefore it needs to be in higher pressure. For this, they have a narrower lumen. This causes the blood in the arteries to have higher pressure and due to this high pressure there is less chance of backflow of blood and valves need not be present. However, the pressure of the blood flowing through the veins is not high. So, to prevent backflow of blood valves are present in the veins.