Histology of a muscular artery (radial artery) and a vein (femoral vein). The artery has a well defined muscular wall (tunica media) composed mainly of many layers of smooth muscle, together with elastin fibres (irregular strands stained red). The vein has more elastin (black) for vessel dilation and elastic recoil. Weigerts elastin and alum carmine stain. From Sobotta, J. (1911) Atlas und Lehrbuch der Histologie und mikroskopischen Anatomie des Menschen. J.F.Lehmann, Munchen, Plate 10. Magnifications x120, x50 printed at 10 cm wide.