Ophthalmic ArteryBlood Flow VelocityRegional Blood FlowUltrasonography, Doppler, TranscranialCerebrovascular CirculationRetinal ArteryCiliary ArteriesUltrasonography, Doppler, ColorCerebral ArteriesArteriesMiddle Cerebral ArteryUltrasonography, DopplerPulsatile FlowUltrasonography, Doppler, PulsedRetinal Artery OcclusionLaser-Doppler FlowmetryCarotid Artery, InternalBlood PressureVascular ResistanceHemodynamicsCoronary CirculationOrbitCircle of WillisUmbilical ArteriesPulmonary ArteryHypocapniaOphthalmodynamometryEyeCarotid ArteriesEchocardiography, DopplerVision, EntopticUltrasonographyEchoencephalographyArterial Occlusive DiseasesRenal ArteryCollateral CirculationRheologyFemoral ArteryCarotid Artery DiseasesVasodilationRetinal VeinBasilar ArteryCoronary VesselsVasodilator AgentsCeliac ArteryEthmoid SinusitisHyperventilationMicrocirculationReference ValuesCarbon DioxideSubarachnoid Hemorrhage, TraumaticIntraocular PressureCarotid StenosisDiastoleUltrasonography, PrenatalMesenteric Artery, SuperiorHyperemiaHeart RateCerebral AngiographyCarotid Artery, ExternalVertebral ArteryAnterior Cerebral ArteryVasoconstrictionAmaurosis FugaxModels, CardiovascularMesenteric ArteriesCarotid Artery, CommonPregnancyTime FactorsReproducibility of ResultsDogsEthmoid SinusRadial ArterySystoleEmbolization, TherapeuticCarotid Artery ThrombosisNitroglycerinIntracranial PressureBrachial ArteryHeart Rate, FetalProspective StudiesReceptor, Muscarinic M5HomeostasisGestational AgeAcetazolamideFundus OculiRetinal NeoplasmsCoronary AngiographyEnbucrilateOptic Neuropathy, IschemicAngiographyPlacental CirculationIliac ArteryOxygenBrainDoppler EffectFetal Growth RetardationVasomotor SystemCoronary Artery BypassRetinoblastoma