Final answer:
Arteries have both an external and internal elastic membrane, which provide structure and support while allowing the artery to stretch.
Step-by-step explanation:
In larger arteries, there is both an external and internal elastic membrane. The external elastic membrane is a thick layer of elastic fibers that separates the tunica media (middle layer) from the tunica externa (outer layer). It provides structure and support to the artery while allowing it to stretch. The internal elastic membrane is also a thick layer of elastic fibers, located at the boundary between the tunica intima (inner layer) and the tunica media. It also provides structure and allows the vessel to stretch.