7. Arteries are blood vessels which deliver oxygen rich blood from the heart to the tissues of the body. Its structure is specialized with a muscular tube lined by smooth tissue which has three layers (see images below): Artery walls contain muscle cells so that they can change blood flow and blood pressure by either contracting or relaxing. Given that fainting is caused by a sudden drop in blood pressure, explain how the structure of smooth muscle cells contributes to their action (function) when a person faints. (MS-LS1-2) (DOK3) (3 PT)