Posterior Segmental Artery of the Left Lung

Description

Arising from the left pulmonary artery near the hilum, the posterior segmental artery to the left upper lobe (A2) courses laterally and posteriorly toward the apicoposterior bronchopulmonary segment. Its branches run in close company with the segmental bronchus, then subdivide into smaller arterioles within the peribronchial connective tissue as they approach the distal acinar bed. Superiorly, the vessel lies beneath the arch region of the great vessels and the tracheobronchial airway, while the pulmonary veins track more anterior and inferior on their return to the left atrium. Clear separation of pulmonary arterial branching from the systemic circulation matters in left upper lobe surgery, where A2 must be identified and controlled during segmentectomy for early non small cell lung cancer or for focal bronchiectasis confined to the apicoposterior segment. This artery also anchors bronchopulmonary segment anatomy for learners, since the segmental artery and bronchus define the surgical plane more reliably than fissure morphology. Misidentification can compromise perfusion to adjacent segments or leave residual disease. Small but consequential. Use this artwork in thoracic anatomy teaching to pair bronchial and vascular segmentation, in cardiothoracic surgery atlases illustrating left upper lobe segmentectomy steps, or in radiology education comparing expected segmental arterial course with CT angiography findings in pulmonary embolism. Anatomical accuracy verified by SciePro's Medical Advisory Board.