Bifurcation of the trachea

Carina of trachea
Cartilages of larynx, trachea and bronchi. (Carina is at the point of bifurcation.)
Transverse section of the trachea, just above its bifurcation, with a bird’s-eye view of the interior. (Carina not labeled; the ridge that separates the left and right bronchus.)
Details
System	Respiratory system
Identifiers
Latin	Carina tracheae, bifurcatio tracheae
Dorlands /Elsevier	c_11/12215629
TA	A06.3.01.009
FMA	7465
Anatomical terminology []

In anatomy, the carina is a ridge of cartilage in the trachea that occurs between the division of the two main bronchi. This occurs at the lower end of the trachea (usually at the level of the 4th thoracic vertebra, which is in line with the sternal angle, but may raise or descend up to two vertebrae higher or lower with breathing). This ridge lies to the left of the midline, and runs antero-posteriorly (front to back). Foreign bodies that fall down the trachea are more likely to enter the right bronchus.

The mucous membrane of the carina is the most sensitive area of the trachea and larynx for triggering a cough reflex. Widening and distortion of the carina is a serious sign because it usually indicates carcinoma of the lymph nodes around the region where the trachea divides.

Tracheobronchial injury, an injury to the airways, occurs within 2.5 cm of the carina 60% of the time.

 This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".