Organ
Carina
Internal ridge between the main bronchial openings
High-yield
The carina is a useful internal landmark for airway examination. Its relation to vertebral levels is approximate rather than a fixed coordinate.
Overview
At the lower end of the trachea, a mucosa-covered ridge separates the entrances to the two main bronchi. Its cartilage and the angle between the bronchi vary among individuals.
Reference facts
- Location
- At the tracheal bifurcation, commonly near the transverse plane of the sternal angle
- Parts
- Mucosal ridge with an underlying cartilaginous framework of variable shape
- Blood supply
- Predominantly bronchial arterial branches
- Innervation
- Vagal sensory pathways supplying the airway mucosa
- Relations
- Right pulmonary artery anterior and inferior; subcarinal nodes below, with esophagus posteriorly
- Function
- Separates the bronchial entrances and participates in protective airway reflexes
Clinical correlation
Contact with the carinal region can provoke cough. A widened bronchial angle has several possible explanations and is not a reliable stand-alone sign of left atrial enlargement.
Frequently asked questions
Where is the carina located?
At the tracheal bifurcation, commonly near the transverse plane of the sternal angle.
What does the carina do?
Separates the bronchial entrances and participates in protective airway reflexes.
What are the parts of the carina?
The parts of the carina are the mucosal ridge with an underlying cartilaginous framework of variable shape.
What is the blood supply of the carina?
Predominantly bronchial arterial branches.