The moderator band in glass slide 16 is an excellent example of cardiomyocytes in cross section. Note that cross sections of individual myofibrils are evident in the myocyte cytoplasm. Recall the ultrastructural distribution of T-tubules and sarcoplasmic reticulum with respect to these myofibrils. Note that the Purkinje fibers also contain myofibrils in cross section, though typicaly many fewer per cell. Can you find any smooth muscle cells in the inner subendothelium?