Collapsed Lung, Posterior View

Description

Posterior thoracic anatomy is centered on the trachea descending in the midline from the larynx to the carina, where the right and left main bronchi diverge inferolaterally toward their respective hila. Along the posterolateral chest, the right lung sits broader and more vertical than the left, with its lobes separated by the oblique and horizontal fissures, while the left lung is smaller with a single oblique fissure and a more pronounced cardiac impression anteriorly. Atelectatic lung parenchyma appears reduced in volume and gathered toward the posterior thoracic wall, with the bronchial tree and pulmonary vessels appearing crowded as the alveolar units lose aeration. Surface vascular markings trace the pleural outline and converge toward the root of the lung. A posterior view matters because dependent atelectasis commonly develops in supine patients, where gravity, reduced diaphragmatic excursion, and retained secretions favor collapse in the posterior basal segments. You teach this best from behind: diminished breath sounds and reduced tactile fremitus often localize posteriorly, and the pattern helps distinguish obstructive atelectasis (for example, a mucus plug after intubation) from compression atelectasis due to pleural effusion or pneumothorax, where the lung recoils toward the hilum and the pleural space becomes the problem to treat. Volume loss is the tell. Mediastinal shift toward the affected side supports obstruction, while shift away suggests a space-occupying pleural process. Use this illustration in respiratory anatomy and pulmonary pathophysiology courses to connect airway branching, lobar organization, and the mechanics of lung collapse. It also fits thoracic surgery and critical care teaching materials covering bronchoscopy for lobar obstruction, postoperative incentive spirometry, and chest tube placement planning in pleural disease. Anatomical accuracy verified by SciePro's Medical Advisory Board.