Musculature of the pulmonary veins.
D000200:Action Potentials; D000818:Animals; D004594:Electrophysiology; D051379:Mice; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology* / Q000648:ultrastructure; D009200:Myocardial Contraction; D011652:Pulmonary Circulation; D011667:Pulmonary Veins / Q000502:physiology* / Q000648:ultrastructure