The posterior segmental bronchus of the left superior lobe bronchus ramifies to form the bronchial tree of the posterior bronchopulmonary segment of the superior lobe. This segment is supplied uniquely by the posterior segmental bronchus; it forms a discrete functional unit.
In the majority of cases, the posterior segmental bronchus does not arise directly from the left superior lobe bronchus, but rather as a division of a trunk that supplies both the apical and superior bronchopulmonary segments; this trunk is termed the apicosuperior bronchus. It arises as one of two segmental bronchi from the superior lobe bronchus.
Last reviewed 01/2018