Atrial FunctionHeart AtriaPressoreceptorsNeurons, EfferentBretylium TosylateDiuresisVagus NerveDogsMechanoreceptorsReflexSensory Receptor CellsEfferent PathwaysRhodniusPhysical StimulationMalpighian TubulesHeartBretylium CompoundsDenervationCold TemperatureBlood VolumeHeart RatePulmonary VeinsVena Cava, SuperiorSympathetic Nervous SystemChemoreceptor CellsAtenololCarotid SinusCardiovascular Physiological PhenomenaVasopressinsCardiac VolumeNatriuresisKidneyNerve FibersNeurons, AfferentBlood PressureFemoral ArteryCatheterizationAction PotentialsNeural ConductionPressureCatsSodium