Organ
Left main bronchus
Main airway beneath the aortic arch
High-yield
Compared with the right, this bronchus is generally longer, narrower and more horizontal. The left pulmonary artery passes above it at the root.
Overview
The left main bronchus travels obliquely toward the left hilum. It passes under the aortic arch before dividing into airways for the superior and inferior lobes.
Reference facts
- Location
- Between the carina and left lung hilum, following a longer and more oblique course than the right main bronchus
- Parts
- Superior and inferior lobar divisions; the superior division includes the lingular airways
- Blood supply
- Left bronchial arteries, commonly from the descending thoracic aorta
- Innervation
- Vagal and sympathetic pathways within the pulmonary plexus
- Relations
- Aortic arch above; esophagus and descending thoracic aorta posteriorly; pulmonary artery above the bronchus at the root
- Function
- Carries air to and from both lobes of the left lung
Clinical correlation
The left bronchus can be displaced or compressed by neighboring disease. A widened bronchial angle alone is an insensitive and nonspecific way to identify left atrial enlargement.
Frequently asked questions
Where is the left main bronchus located?
Between the carina and left lung hilum, following a longer and more oblique course than the right main bronchus.
What does the left main bronchus do?
Carries air to and from both lobes of the left lung.
What are the parts of the left main bronchus?
Superior and inferior lobar divisions; the superior division includes the lingular airways.
What is the blood supply of the left main bronchus?
The left main bronchus is supplied by the left bronchial arteries, commonly from the descending thoracic aorta.