Superior Orientation of the Colored Apicoposterior Segment of the Left Lung

Description

Viewed from a superior orientation, the left upper lobe is segmented to isolate the apicoposterior bronchopulmonary segment (segmentum apicoposterius, S1+S2) in color against the surrounding parenchyma. The segment occupies the superoposterior portion of the upper lobe, extending toward the lung apex and lying posterior to the anterior segment (S3). Medially it approaches the mediastinal surface adjacent to the aortic arch region, while laterally it reaches the costal surface beneath the upper ribs. Segmental boundaries follow the course of intersegmental veins, and the segmental bronchus and artery run centrally within the colored wedge. Apicoposterior segment anatomy matters because left upper lobe resections and segmentectomies depend on respecting true bronchovascular territories rather than lobar outlines. A clear superior view helps you anticipate where B1+2 and A1+2 enter the segment relative to the superior pulmonary vein tributaries, which is the dissection plane when performing VATS or robotic S1+2 segmentectomy for a small peripheral NSCLC or a localized bronchiectasis focus. It also supports bronchoscopy teaching, since the combined apicoposterior segmental bronchus is a common source of labeling errors when learners extrapolate right-sided patterns onto the left. Use this illustration in thoracic surgery atlases, pulmonary anatomy modules, and radiology correlation content when mapping segment-based opacities on CT to a surgical target. It also reads well on a single lecture slide when you need fast orientation to the left upper lobe segments without the distraction of hilar detail. Anatomical accuracy verified by SciePro's Medical Advisory Board.