
Myocardium
Diagnostic features of cardiac muscle fibers are central nuclei, branching fibers and intercalated discs. Intercalated discs, appearing as thick lines, are specialized junctions between fibers; each is composed of interdigitating plasma membranes, myofilaments and cell junctions. The striations and banding pattern of cardiac muscle are not very obvious in this longitudinal section. 400x

Central nuclei
Diagnostic features of cardiac muscle fibers are central nuclei, branching fibers and intercalated discs. Intercalated discs, appearing as thick lines, are specialized junctions between fibers; each is composed of interdigitating plasma membranes, myofilaments and cell junctions. The striations and banding pattern of cardiac muscle are not very obvious in this longitudinal section. 400x

Branching fibers
Diagnostic features of cardiac muscle fibers are central nuclei, branching fibers and intercalated discs. Intercalated discs, appearing as thick lines, are specialized junctions between fibers; each is composed of interdigitating plasma membranes, myofilaments and cell junctions. The striations and banding pattern of cardiac muscle are not very obvious in this longitudinal section. 400x

Intercalated discs
Diagnostic features of cardiac muscle fibers are central nuclei, branching fibers and intercalated discs. Intercalated discs, appearing as thick lines, are specialized junctions between fibers; each is composed of interdigitating plasma membranes, myofilaments and cell junctions. The striations and banding pattern of cardiac muscle are not very obvious in this longitudinal section. 400x

Striations
Diagnostic features of cardiac muscle fibers are central nuclei, branching fibers and intercalated discs. Intercalated discs, appearing as thick lines, are specialized junctions between fibers; each is composed of interdigitating plasma membranes, myofilaments and cell junctions. The striations and banding pattern of cardiac muscle are not very obvious in this longitudinal section. 400x