Final answer:
The three layers of arterial vasculature are the tunica intima, tunica media, and tunica externa, each providing specific structure and functions necessary for arterial performance.
Step-by-step explanation:
The walls of arteries are composed of three distinct layers known as tunics. These layers, from the innermost layer to the outermost layer, are:
- Tunica intima: This is the innermost layer adjacent to the lumen of the artery. It consists of a simple squamous epithelium layer known as endothelium and a small amount of connective tissue.
- Tunica media: This middle layer is composed primarily of smooth muscle and connective tissue. It is thicker in arteries compared to veins and is responsible for vasoconstriction and vasodilation to regulate blood pressure and flow.
- Tunica externa (also known as tunica adventitia): This is the outermost layer made of collagen and elastic fibers, providing structural support and flexibility to the artery.
Both arteries and veins have these three layers, but the arteries have a thicker tunica media to manage the higher pressure of blood flow away from the heart.