Pectoralis Minor Muscle Beneath the Skin, Anterior View

Description

Centered on the anterior thoracic wall, the pectoralis minor is presented deep to pectoralis major, its fibers running superolaterally from the anterior surfaces of ribs 3 to 5 near their costal cartilages toward the coracoid process of the scapula. Medially, the muscle lies adjacent to the parasternal region and costochondral junctions, while laterally it approaches the axilla where its tendon disappears under the deltopectoral contour. Fine fascicular texture and overlying fascia clarify that this is a subcutaneous, layered dissection rather than a superficial muscle plate. Bilateral upper rib slips and neighboring digitations consistent with serratus anterior may be visible at the lateral thoracic wall. Pectoralis minor matters because it is both a scapular stabilizer and a landmark in the infraclavicular region: the axillary artery and cords of the brachial plexus are classically described in relation to it (first part medial, second part posterior, third part lateral). A tight or hypertrophied pectoralis minor can narrow the costocoracoid interval and contribute to pectoralis minor syndrome, an anterior form of thoracic outlet compression that mimics C8 to T1 radiculopathy or ulnar neuropathy. Short and actionable. For procedural anatomy, its medial and lateral pectoral nerves, and the nearby thoracoacromial vessels, are frequently encountered during deltopectoral and infraclavicular approaches. Use this artwork for teaching layered chest wall anatomy in gross anatomy, kinesiology, and physical therapy curricula, where students need to reconcile scapulothoracic mechanics with what lies deep to pectoralis major. It also fits surgical atlases and review chapters discussing infraclavicular blocks, axillary exposure, and anterior thoracic outlet evaluation. Anatomical accuracy verified by SciePro's Medical Advisory Board.