right main bronchus
The trachea bifurcates into the right and left main bronchi at the level of the carina, supplying air to the right and left lungs respectively. Each main or primary bronchus enters the hilum of its lung and gives rise to secondary lobar bronchi, which further divide into tertiary segmental bronchi supplying the bronchopulmonary segment.
The right main bronchus is wider, shorter and courses more vertically when compared to the left main bronchus .It is approximately 2.5 cm long and reaches the root of the right lung at the level of T5, lying inferolateral and posterior to the right pulmonary artery .
It gives rise to three lobar bronchi, initially bifurcating into right upper lobe bronchus and bronchus intermedius . Bronchus intermedius further divides into right middle lobe and lower lobe bronchi .
At right pulmonary hilum:
- superiorly: arch of azygos vein
- inferiorly: right pulmonary veins
- anteriorly: right pulmonary artery (pulmonary veins anterior to pulmonary arteries)
- posteriorly: esophagus (azygos vein posterior to esophagus)
Right main bronchus is supplied by one single right bronchial artery . It arises from one of the following origins:
- proximal part of one of the upper posterior intercostal arteries (commonly right third posterior intercostal artery)
- a common trunk with the left superior bronchial artery
- the descending aorta