Pectoralis Minor Muscle Beneath the Skin, Lateral View

Description

Seen in lateral profile beneath a semi-transparent skin layer, the anterior thoracic wall is opened just enough to localize the pectoralis minor deep to pectoralis major, running from the anterior surfaces of ribs 3 to 5 near their costal cartilages to the medial border and superior surface of the coracoid process. Overlying fibers of pectoralis major form the superficial plane, while the pectoralis minor fascicles angle superolaterally toward the shoulder girdle. Superiorly, the muscle sits inferior to the clavicle and anterior to the upper ribs, creating a clear sense of depth between superficial chest contour and deeper scapulothoracic stabilizers. Depth matters here. Clinically, this view helps when teaching how scapular protraction and anterior tilt can narrow the retropectoralis minor space and contribute to neurovascular compression associated with pectoralis minor syndrome, a recognized subtype of thoracic outlet presentations. The coracoid insertion also serves as a surgical and procedural landmark, because the axillary artery and cords of the brachial plexus pass immediately posterior to pectoralis minor and are classically described in three parts relative to it. Palpation, injections, and release procedures make more sense when you can mentally place the muscle under the skin rather than as an isolated cadaveric dissection. Use this artwork in gross anatomy and kinesiology modules covering the shoulder girdle, in pain medicine or sports medicine teaching files addressing anterior shoulder and chest wall sources of paresthesia, and in surgical texts discussing infraclavicular exposure and axillary dissection planes. It also reads well in patient-facing materials that need an accurate lateral chest silhouette without sacrificing Terminologia Anatomica naming. Anatomical accuracy verified by SciePro's Medical Advisory Board.