Question

Vains are thin walled and have valves . justify

Answer 1

Answer:

Veins are thin-walled and have valves that prevent the blood from flowing back in the wrong direction. Veins carry blood heading toward the heart. Blood coming from the tissues has delivered O2 and picked up CO2 from the cells.

Answer 2

Explanation:

veins are thin walled as pressure of blood is less in veins so thick layer is not required.

valves are there for prevention of backflow of deoxygenated blood.