Heart, Lungs, and Diaphragm Viewed from a Rear Orientation

Description

Posterior thoracic anatomy is presented with both lungs flanking the mediastinum and the diaphragm forming the inferior boundary of the thoracic cavity. Each lung is organized into lobes, the right lung with superior, middle, and inferior lobes and the left lung with superior and inferior lobes, separated by oblique (and on the right, horizontal) fissures that remain appreciable even from the rear. At the medial surfaces, the pulmonary hila mark the entry of the main bronchi, pulmonary arteries, and pulmonary veins as the pulmonary roots, while the heart sits anterior to much of this field yet still contributes a posterior contour through the left atrium and adjacent ventricular surface. Tracheal bifurcation into the main bronchi lies superior to the hila, and the muscular diaphragm domes superiorly beneath the lower lobes. Clinically, this posterior orientation matches what you confront during a posterolateral thoracotomy or VATS port placement when planning exposure of the hilum for lobectomy, pneumonectomy, or vascular control. Hilar relationships matter because the pulmonary artery typically lies superior to the bronchus on the left, while right-sided hilar anatomy is more variable, a common source of wrong-structure risk when dissecting near the bronchus intermedius and upper lobe vessels. Phrenic nerve function is the other teachable point: injury along its course on the pericardium leads to hemidiaphragm elevation and postoperative dyspnea. Landmarks are unforgiving. Use this illustration for thoracic anatomy teaching in medical and physician assistant gross anatomy labs, for surgical atlases describing hilar dissection and mediastinal exposure, or for pulmonary and critical care lectures covering atelectasis patterns and diaphragmatic paralysis after cardiothoracic procedures. Anatomical accuracy verified by SciePro's Medical Advisory Board.