Figure 52-1 Distribution of atherosclerotic lesions. Plaques occur at the origins of large vessels and at bifurcations. Distribution and relative severity depend on risk factors. (From Zwolak RM, Cronenwett JL: Pathophysiology of vascular disease. In Yeager MP, Glass DD [eds]: Anesthesiology and Vascular Surgery. East Norwalk, CT, Appleton & Lange, 1990, pp 3–29.)