Expansion
The carina lies at the level of the sternal angle, T4 to T5
Expansion
- Trachea begins at the cricoid cartilage, at C6
- Trachea divides at the carina, at the level of the sternal angle, T4 to T5
The carina carries a particularly sensitive cough reflex, mediated by the vagus, which is why an endotracheal tube tip resting on it provokes coughing and bucking. The tube tip should sit several centimetres above it.
The normal subcarinal angle is roughly 60 to 75 degrees. Splaying beyond this is a recognised radiographic sign of an enlarged left atrium or of subcarinal nodal disease.