http://upload.wikimedia.org/wikipedia/commons/9/9f/Illu_conducting_passages.svg, http://upload.wikimedia.org/wikipedia/commons/c/c3/Illu_conducting_passages.jpg

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], An elongated tube which carries air to and from the lungs.[AAO]

uberon

tracheal tubule

tracheal

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]

UBERON:0003126

in mouse 15-18 C-rings, 15-20 in human., 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.

• lumen of trachea

• smooth muscle of trachea
• epithelium of trachea

• tracheobronchial tree

• trachea cartilage
• smooth muscle of trachea
• trachea connective tissue
• trachea blood vessel
• epithelium of trachea
• submucosal gland
• submucosa of trachea
• lumen of trachea
• mesenchyme of trachea