Pectoralis Minor Muscle

Description

Arising from the anterior surfaces of ribs 3 to 5 near their costal cartilages, the pectoralis minor is rendered as three distinct muscular slips that converge superolaterally to a narrow tendon inserting on the medial border and superior surface of the coracoid process. The muscle lies deep to pectoralis major on the anterior thoracic wall, forming part of the anterior scapulothoracic interface and sitting anterior to the serratus anterior and intercostal musculature. Its fibers run obliquely upward and laterally, placing the coracoid process as the proximal landmark and the rib origins as the distal attachments in functional terms. Clear definition of the three slips matters because they frame the clavipectoral fascia and help orient the clinician to the axillary inlet, where the cords of the brachial plexus and the axillary artery travel deep to pectoralis minor. A common teaching and clinical reference is the pectoralis minor “level” concept, used to describe the relationship of the axillary artery and brachial plexus for blocks and for localizing pathology, and the muscle itself can contribute to pectoralis minor syndrome with neurovascular compression beneath its tendon near the coracoid. Small muscle, big landmark. Use this artwork in gross anatomy lab manuals, orthopedic and sports medicine texts on shoulder girdle mechanics, and anesthesia education materials discussing infraclavicular and axillary approaches where pectoralis minor is a constant anterior boundary. It also suits rehabilitation content on scapular protraction and anterior tilt patterns in the male thorax and shoulder. Anatomical accuracy verified by SciePro's Medical Advisory Board.