Aortic BodiesParaganglia, NonchromaffinCarotid BodyCarotid Body TumorChemoreceptor CellsParaganglioma, Extra-AdrenalCarotid ArteriesPeripheral Nervous System NeoplasmsCarotid StenosisCarotid Artery DiseasesCarotid SinusHypercapniaEndarterectomy, CarotidCarotid Artery, InternalReflexCarotid Artery, CommonAnoxiaDogsSodium Cyanide