You know arteries should be narrow so as to have enough pressure to pump oxygenated blood to all parts of the body.But veins do not need such pressure to turn deoxygenated blood to the heart.
Why Do Veins Are Wider Than The Arteries?
Because they contain valves to prevent back flow of blood.
Do arteries pulsate and have valves
Veins carry impure blood from tissue and organ while artery carry pure blood from heart.hence flow of blood through veins requires less pressure than artery also veins have valves.