Carina of trachea

The tracheal carina is an internal cartilaginous ridge located at the caudal end of the trachea, marking the precise point of its division into the two main bronchi.

The tracheal carina is a median sagittal ridge, formed by the last tracheal cartilaginous ring, which projects into the lumen of the trachea at the site of its bifurcation. It physically separates the openings of the right and the left main bronchus. This structure is composed of hyaline cartilage and is covered by the same respiratory mucosa as the rest of the trachea (pseudostratified ciliated columnar epithelium with goblet cells). Its position is generally at the level of the heart base, often between the 4th and 6th thoracic vertebra depending on the species.