Fig. 5.

Structure of the superficial femoral (SFA) and popliteal (PA) arteries in longitudinal (left) and transverse (right) directions evaluated using Movat (elastin is black, glycosaminoglycans are greenish-gray) and Masson’s Trichrome (collagen is blue, smooth muscle is red) stains. Note directional differences in elastin (longitudinal fibers) and SMCs (mostly circumferential) demonstrated by the inserts. Compare the structure of these above-knee arteries to the arteries below the knee from the same subject (Fig. 6).