Carina of trachea

The carina of trachea is a cartilaginous ridge within the trachea that runs antero-posteriorly between the two primary bronchi at the site of the tracheal bifurcation at the lower end of the trachea (usually at the level of the 5th thoracic vertebra, which is in line with the angle of Louis, but may raise or descend up to two vertebrae higher or lower with breathing). This ridge lies to the left of the midline.