Cardiac muscle: activation and contraction.
D000818:Animals; D004594:Electrophysiology; D006321:Heart / Q000502:physiology*; D006329:Heart Conduction System / Q000033:anatomy & histology; D006352:Heart Ventricles / Q000033:anatomy & histology; D009119:Muscle Contraction; D009206:Myocardium / Q000378:metabolism; D010210:Papillary Muscles