Heart, Lungs, and Diaphragm, Gross Anatomy

Description

Anterior thoracic viscera are arranged with the heart seated in the middle mediastinum between the right and left lungs, its apex directed inferiorly and to the left while the great vessels ascend superiorly toward the root of the neck. Each lung extends from the thoracic inlet to the diaphragm, with the right lung showing superior, middle, and inferior lobes separated by horizontal and oblique fissures, and the left lung divided into superior and inferior lobes with a cardiac notch along its anteromedial border. Superior to the hila, the trachea bifurcates into right and left main bronchi, which pass inferolaterally to enter the lung roots alongside pulmonary arteries and veins. Inferiorly, the dome-shaped diaphragm forms the floor of the thoracic cavity, its peripheral muscular slips converging on a central tendon. Spatial relationships in this region drive day-to-day clinical decisions. The close apposition of the pericardium to the diaphragmatic central tendon explains why pericarditis can refer pain to the shoulder via the phrenic nerve (C3 to C5) and why diaphragmatic paralysis produces an elevated hemidiaphragm with basal atelectasis on chest radiographs. Lobar anatomy matters in the operating room: surgeons plan a right middle lobectomy along the horizontal fissure, while bronchoscopic navigation follows the predictable branching from main bronchus to lobar and segmental bronchi. Use this artwork for thoracic anatomy lectures, respiratory mechanics teaching in physiology, or as a figure in cardiothoracic surgery, pulmonology, and anesthesiology publications that need an in situ relationship between myocardium, lobar lungs, bronchi, and diaphragm. Also well suited for patient-facing explanations of pneumothorax decompression landmarks and diaphragmatic dysfunction. Anatomical accuracy verified by SciePro's Medical Advisory Board.