Plethysmography, Whole BodyAirway ResistanceLung Volume MeasurementsThoraxFunctional Residual CapacityLungRespiratory Function TestsPlethysmographyGasesRespiratory MechanicsAirway ObstructionHeliumTidal VolumeLung CompliancePulmonary VentilationNeonBronchoconstrictionAirway RemodelingTotal Lung CapacityRespirationPulmonary Gas ExchangeBronchoconstrictor AgentsDrug ResistanceMethacholine ChlorideBronchial HyperreactivityAsthmaPulmonary Surfactant-Associated Protein CBronchiRespiratory SystemDrug Resistance, MicrobialDrug Resistance, BacterialInhalationBronchial Provocation TestsRhinomanometryDrug Resistance, NeoplasmNasal ObstructionForced Expiratory VolumeSpirometryBlood VolumeAir PressureBronchodilator AgentsHistamineRespiratory Physiological PhenomenaRhinometry, AcousticDrug Resistance, MultipleNasal DecongestantsDisease ResistanceBronchoalveolar Lavage FluidAdministration, InhalationNoseVascular ResistanceOscillometryAlbuterolIpratropiumPositive-Pressure RespirationAerosolsRespiratory HypersensitivityDrug Resistance, ViralDrug Resistance, Multiple, BacterialRespiratory MusclesNitrogenIntubation, IntratrachealNasal CavityEpiglottisNasal Provocation TestsBronchial SpasmInfant, NewbornMaximal Expiratory Flow-Volume CurvesWork of BreathingAnti-Bacterial AgentsClemastineVital CapacityPharynxMouth BreathingLung Diseases, ObstructiveTime FactorsBlood Gas AnalysisRespiratory MucosaForced Expiratory Flow RatesAirway ManagementMuscle, Smooth