part of part of located_in develops_from contributes to morphology of respiratory tube respiratory system thoracic cavity trachea AAO:0010140 An elongated tube which carries air to and from the lungs.[AAO] BTO:0001388 CALOHA:TS-1060 EFO:0000935 EHDAA2:0002066 EHDAA:3078 EMAPA:16853 EV:0100040 FMA:7394 GAID:361 In birds, the trachea runs from the pharynx to the syrinx, from which the primary bronchi diverge. Swans have an unusually elongated trachea, part of which is coiled beneath the sternum; this may act as a resonator to amplify sound. In some birds, the cartilagenous rings are complete, and may even be ossified. In amphibians, the trachea is normally extremely short, and leads directly into the lungs, without clear primary bronchi. A longer trachea is, however found in some long-necked salamanders, and in caecilians. While there are irregular cartilagenous nodules on the amphibian trachea, these do not form the rings found in amniotes. The only vertebrate to have lungs, but no trachea, is Polypterus, in which the lungs arise directly from the pharynx. In primitive fishes and most tetrapods, the lungs of adults are usually paired. They lie ventral to the digestive tract and are connected to the outside environment through the trachea.[well established][VHOG] MA:0000441 MAT:0000137 MESH:D014132 MIAA:0000137 OpenCyc:Mx4rvViOX5wpEbGdrcN5Y29ycA The respiratory tube between the larynx and the bronchi. [Bemis_WE, Functional_Anatomy_of_the_Vertebrates:_An_Evolutionary_Perspective, Glossary_G-29, Grande_L, Liem_KF, Third_Edition_(2001)_Orlando_Fla.:_Harcourt_College_Publishers, Walker_WF][VHOG] The trachea is the portion of the airway that attaches to the bronchi as it branches [GO:dph]. UBERON:0003126 UMLS:C0040578 VHOG:0000371 XAO:0000118 cartilaginous trachea in mouse 15-18 C-rings, 15-20 in human. tracheal tracheal tubule uberon vertebrate trachea windpipe tracheobronchial tree respiratory primordium