PeristalsisEsophagusManometryDeglutitionGastrointestinal MotilityEsophageal Motility DisordersEsophageal Sphincter, LowerUreterPressureEsophageal AchalasiaEsophagogastric JunctionIleumMuscle ContractionMuscle, SmoothCineradiographyAirGuinea PigsRespiratory System AbnormalitiesReflex, AbdominalKidney PelvisIntestine, SmallDeglutition DisordersEnteric Nervous SystemUrinary Tract Physiological PhenomenaSenna ExtractGastroesophageal RefluxMethysergideScopolamine HydrobromideAtropineCatenanesEsophageal Sphincter, UpperPharynxDigestive System Physiological PhenomenaHernia, HiatalPurinergic AntagonistsFundoplicationSubmucous PlexusApaminLaryngeal NervesEsophageal DiseasesReflexBornanesBarium SulfateOpossums