Muscles and Bones of the Torso, Gross Anatomy

Description

Anterior thoracoabdominal anatomy is presented with skin removed to expose the superficial and intermediate layers of the chest wall in an African adult male. The pectoralis major spans from the medial clavicle and sternum toward the humerus, with pectoralis minor lying deep to it and coursing superolaterally from ribs 3 to 5 toward the coracoid process of the scapula. Between adjacent ribs, intercostal muscle layers occupy the intercostal spaces, while serratus anterior forms a lateral series of digitations along the midaxillary line, interposing between the thoracic wall and the scapula. The sternum sits in the midline anteriorly, ribs sweep laterally and posteriorly, and the clavicle caps the superior thorax as a strut of the shoulder girdle. Chest wall layering is the teaching point. This perspective clarifies how the pectoral musculature overlies the rib cage and intercostals, and why the serratus anterior occupies a strategic position for scapulothoracic motion and rib stabilization during forced inspiration. Clinically, it supports explanation of winged scapula after long thoracic nerve injury (often iatrogenic during axillary surgery or chest tube placement) and helps orient safe thoracostomy tube insertion through an intercostal space while avoiding the intercostal neurovascular bundle that runs along the inferior margin of each rib. Clear landmarks. Common use cases include gross anatomy lab manuals, musculoskeletal and respiratory block lectures, and procedural training content for intercostal nerve blocks, thoracentesis, and tube thoracostomy. It also fits atlases and patient-education figures discussing chest wall strains, pectoralis major rupture, and scapular dyskinesis in overhead athletes. Anatomical accuracy verified by SciePro's Medical Advisory Board.