Answer:
Arteries are thicker and stretchier to be able to handle the higher pressure of blood moving through them. Veins are thinner and less stretchy. This structure helps veins move higher amounts of blood over a longer time than arteries.
Arteries are blood vessels responsible for carrying oxygen-rich blood away from the heart to the body. Veins are blood vessels that carry blood low in oxygen from the body back to the heart for reoxygenation.