Video - Cardiac muscle histology

The cardiac muscle is a specialized type of involuntary muscle tissue that makes up the bulk of the heart. Cardiac muscle cells, or cardiomyocytes, are elongated and spindle-shaped, with one to two centrally located nuclei. These cell fibers are arranged in a branching network and intercalated discs, which are junctions that allow these muscle cells to contract in synchronization. The cardiac muscle is capable of self-excitation, meaning it can generate electrical impulses that coordinately contract all of the heart muscles to pump blood. The cardiac muscle has many unique properties that allow it to function effectively. For example, cardiomyocytes have a high mitochondria density, providing them adequate energy to contract repeatedly. In addition, cardiac muscle cells have a large number of myofibrils, which are specialized protein filaments that allow for efficient contraction. Finally, the intercalation between cardiac muscle cells allows for rapid and coordinated contractions of the heart.