Ultrastructure of Cardiac Muscle and Nerve Contiguities

FIOURE 1 This electron micrograph shows a nerve process (gr) containing predominantly granular vesicles which makes intimate contact with the surface of a cardiac muscle cell (arrows). A portion of a nerve process (affr) containing only agranular vesicles is situated above the other nerve process. Serial sections would most likely show these two nerve processes lying side-by-side, g, glycogen particles; p, protrusion of cardiac muscle cell; grv, large granular vesicles. Myocardium of the apex of, the ventricle of frog heart. X 40,000.