Excitation Contraction CouplingMuscle ContractionIsometric ContractionMuscle, SmoothMusclesMuscle, SkeletalMyocardial ContractionMuscle, Smooth, VascularUterine ContractionMuscle ProteinsElectric StimulationMuscle Fibers, SkeletalCalciumMuscle FatigueMyocytes, CardiacMuscle RelaxationElectromyographyHeartGuinea PigsRabbitsTime FactorsMuscle DevelopmentVasoconstrictionRats, Sprague-DawleyTracheaMuscle Fibers, Fast-TwitchMyocardiumAction PotentialsIsotonic ContractionMotor NeuronsRats, WistarCardiac OutputMuscle SpindlesDose-Response Relationship, DrugMuscle Fibers, Slow-TwitchPotassium ChlorideAcetylcholineDogsMyocytes, Smooth MusclePapillary MusclesMyosinsMyofibrilsPeristalsisCatsBiomechanical PhenomenaMyosin Light ChainsNorepinephrineSarcomeresGastrointestinal MotilityCells, CulturedMembrane PotentialsArrhythmias, CardiacMuscle DenervationUrinary BladderVasoconstrictor AgentsCarbacholModels, BiologicalActinsElectrophysiologyPhenylephrineAtropineAdenosine TriphosphateMitochondria, MuscleMuscle, StriatedKineticsTorqueHindlimbHeart Ventricles