The pectoralis major muscle is a thick fan-shaped muscle which arises from the sternum and medial clavicle, inserting onto the lateral lip of the intertubercular sulcus of the humerus.
Origin
- Medial 1/2 of clavicle
- Anterior surface of sternum
- Costal cartilages 1-7
- Aponeurosis of external oblique
Insertion
- Proximal humerus (lateral intertubercular groove)
Action
- Adduction humerus
- Medial rotation humerus
- Flexion of the humerus
Innervation
- Medial and lateral pectoral nerves
Blood Supply
- Pectoral branch of the thoracoacromial trunk