Lower Body Negative PressureHypovolemiaForearmHead-Down TiltBed RestOrthostatic IntoleranceVascular CapacitanceCentral Venous PressureDizzinessBlood PressurePressoreceptorsHypotension, OrthostaticCardiovascular DeconditioningBaroreflexHeart RateGravity SuitsSympathetic Nervous SystemSupine PositionVascular ResistanceWeightlessness SimulationWeightlessness CountermeasuresSpace FlightRegional Blood FlowReflexSyncopeNegative-Pressure Wound TherapyPlethysmographyVentilators, Negative-PressureVasoconstrictionTilt-Table TestPressureHemodynamicsArterial PressureBlood VolumeNorepinephrineGravitationLegCardiac OutputWeightlessnessPostureBlood Flow VelocityStroke VolumeVasomotor SystemComplianceCold TemperatureVeinsSkin TemperatureHypotensionPelvisAutonomic Nervous SystemHand StrengthCardiovascular Physiological PhenomenaPulmonary Wedge PressureRestExerciseBrachial ArteryMuscle, SkeletalStress, PhysiologicalMiddle Cerebral ArteryCerebrovascular CirculationTime FactorsOxygen ConsumptionReference ValuesEpinephrineSkinMusclesAir PressureElectrocardiographyAnalysis of VarianceHeartSuctionAbdominal Wound Closure TechniquesSkin Care