The major types of cardiac muscle Atrial muscle Contractile cells Ventricular muscle (收缩细胞) Specialized excitatory and conductive muscle Autorhythmic cells (自律细胞)• The major types of cardiac muscle: – Atrial muscle – Ventricular muscle – Specialized excitatory and conductive muscle Contractile cells （收缩细胞） Autorhythmic cells （自律细胞）