Pectoralis minor (left) (Musculus pectoralis minor)
Educational content only — not medical advice.
Anatomy
A thin triangular muscle beneath pectoralis major, from ribs 3–5 to the coracoid process of the scapula; the classic landmark dividing the axillary artery into three parts.
Origin & insertion
Anterior surfaces of ribs 3–5 near their costal cartilages, with the interposing external oblique aponeurosis. Medial border and superior surface of the coracoid process.
Action
Protracts, depresses and downwardly rotates the scapula; with the shoulder girdle fixed it lifts the ribs as an accessory inspiratory muscle.
Innervation
Medial pectoral nerve (C8–T1).
Clinical notes
Chronic tightness in rounded-shoulder posture compresses the brachial plexus and vessels beneath it (pectoralis minor syndrome) with hand paraesthesia; axillary surgery risks its nerve and vessels.
Related structures
Educational references
FAQ
What is the role of the Pectoralis minor (left)?
A thin triangular muscle beneath pectoralis major, from ribs 3–5 to the coracoid process of the scapula; the classic landmark dividing the axillary artery into three parts.
Why is the Pectoralis minor (left) clinically important?
Chronic tightness in rounded-shoulder posture compresses the brachial plexus and vessels beneath it (pectoralis minor syndrome) with hand paraesthesia; axillary surgery risks its nerve and vessels.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details