ABSTRACT
Arterial blood vessels consist of three layers: the intima, media, and adventitia (Figure 7.1). The adventitia, the outermost layer, is a connective tissue layer composed of collagen fibers with the addition of supportive cells such as fibroblasts, pericytes, and nerve fibers [1]. It serves as the first layer of connection between blood vessels and the surrounding tissue. Directly interior of the adventitia is the media, which consists chiefly of smooth muscle cells and is responsible for the contractile forces that control vessel diameter and, therefore, blood pressure. Together, the adventitia and media support the innermost layer, the intima. The intima is composed of an endothelial cell 154(EC) monolayer, called endothelium, which forms an interface between circulating blood and the blood vessel wall [2].
