The left upper lobe bronchus is very short. It rapidly divides into two main branches : the upper lobe bronchus proper and the lingular bronchus.

The upper lobe bronchus divides into two segments, the apical dorsalis (B1+2) and the ventralis (B3).
The lingular bronchus divides into two segments, superior (B4) and inferior (B5).

upper lobe bronchus

lingular bronchus