[[Image:TrachealWallstainedforelasticfibresCAT.jpg|right|thumb|200px|A histology section of the tracheal wall stained for elastic fibres (Cat) ©RVC 2008]] | [[Image:TrachealWallstainedforelasticfibresCAT.jpg|right|thumb|200px|A histology section of the tracheal wall stained for elastic fibres (Cat) ©RVC 2008]] |