PeristalsisEsophagusManometryDeglutitionResearchGastrointestinal MotilityEsophageal Motility DisordersEsophageal Sphincter, LowerUreterPressureEsophageal AchalasiaEsophagogastric JunctionIleumMuscle ContractionResearch Support as TopicMuscle, SmoothAirCineradiographyGuinea PigsResearch DesignRespiratory System AbnormalitiesReflex, AbdominalKidney PelvisEthics, ResearchResearch PersonnelIntestine, SmallDeglutition DisordersEnteric Nervous SystemUrinary Tract Physiological PhenomenaSenna ExtractNursing ResearchGastroesophageal RefluxMethysergideScopolamine HydrobromideAtropineCatenanesEsophageal Sphincter, UpperPharynxDigestive System Physiological PhenomenaHealth Services ResearchTranslational Medical ResearchHernia, HiatalPurinergic AntagonistsFundoplicationSubmucous PlexusGenetic ResearchApaminEsophageal DiseasesReflexLaryngeal NervesBornanesBarium SulfateOpossums