Primary Oblique Pulmonary Fissures

Description

Oblique pulmonary fissures (fissurae obliquae) are shown as the major interlobar clefts separating the superior (upper) and inferior (lower) lobes, extending from a posterior, superior origin toward an anterior, inferior termination. On the right lung, the oblique fissure lies inferior to the horizontal fissure and forms the posterior boundary of the middle lobe, while on the left lung it constitutes the primary division between the upper lobe (including the lingula) and the lower lobe. Each fissure follows the contour of the pleural surface, with a posterolateral course that approaches the diaphragmatic surface inferiorly. Clear lobar boundaries. Understanding the oblique fissure is practical when you need to localize disease to a lobe or segment and anticipate how pathology spreads along pleural planes. In lobar pneumonia, atelectasis, or aspiration-related consolidation, fissural displacement on radiography or CT can flag volume loss and help differentiate lower-lobe collapse from pleural effusion. Surgeons also use the fissure as a landmark during video-assisted thoracoscopic lobectomy, and incomplete fissures are a known source of persistent air leak after resection. Educators can drop this artwork into thoracic anatomy lectures, cardiopulmonary block materials, and radiology primers that link surface anatomy to lobar localization on chest X-ray and axial CT. It also fits well in surgical atlases discussing fissure-based approaches to lobectomy and segmentectomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.