Quick-frozen deep-etched preparation of skeletal muscle tissue shows the muscle fiber and associated extracellular components. The basement membrane (labeled basal lamina) lies adjacent to the undulating sarcolemma. Myofilaments of the muscle fiber are composed of actin and myosin filaments. Image by J. Heuser, Figure 30 from Chapter 1 (The Cell Surface) of 'The Cell, 2nd Ed.' by Don W. Fawcett M.D. A PDF copy of the accompanying chapter is available on the ASCB's BioEDUCATE website.