Pectoralis Major and Minor, Anterior View

Description

Across the anterior thorax of an adult male, the pectoralis major forms a broad, superficial sheet spanning from the medial clavicle and sternum toward its lateral insertion on the proximal humerus at the lateral lip of the intertubercular sulcus. Deep to it, the pectoralis minor appears as a smaller triangular muscle running superolaterally from ribs 3 to 5 near their costal cartilages to the coracoid process of the scapula, placing it inferior and slightly lateral to the clavicle and anterior to the upper ribs. Surrounding osseous landmarks include the clavicles, sternum, costal cartilages, and anterior ribs, with the shoulder girdle framing the lateral chest wall. Anterior layering matters here because it clarifies what must be reflected and what must be protected during common chest and shoulder exposures: surgeons often detach or split fibers of pectoralis major for deltopectoral approaches, pacemaker pocket creation, and breast or chest wall reconstruction, while pectoralis minor lies immediately superficial to the neurovascular corridor to the axilla. The muscle’s relationship to the coracoid also helps explain thoracic outlet and pectoralis minor syndrome, where the brachial plexus and axillary vessels can be compressed beneath the tendon during scapular protraction. Clean planes. Real consequences. Use this artwork in gross anatomy lab manuals, orthopaedic and plastic surgery atlases, sports medicine teaching on shoulder adduction and internal rotation, and patient-facing education for pectoralis major rupture repair or chest wall reconstruction planning. Anatomical accuracy verified by SciePro's Medical Advisory Board.