Which blood vessels carry blood away from the heart?

Which blood vessels carry blood back to the heart?

What is the largest artery in the body?

How many chambers are there in the heart?

What is the average heart beat per minute?

How big is the heart?

Why is the blood in arteries bright red?

Why is the blood in veins bluish in colour?

Why are the walls of arteries thick and elastic?

Why are the walls of veins thinner than arteries?