Heart Musculature

The heart’s muscular wall, the myocardium, consists of specialized cardiac muscle cells arranged in spiral and circular bundles unique to each chamber. Atrial muscle is thinner and arranged in loops, while ventricular muscle forms complex figure-eight patterns that twist during contraction for efficient ejection. Intercalated discs with gap junctions allow rapid electrical coupling, making the myocardium function as a syncytium. Endocardium lines the interior, epicardium covers the outside, and a fibrous skeleton provides attachment points for valves and prevents electrical crossover between atria and ventricles.