Muscle
Pectoralis major
Anterior chest wall, arm adductor
High-yield
Adducts and medially rotates the arm; clavicular head flexes the arm. Innervated by both medial and lateral pectoral nerves.
Overview
A large fan-shaped muscle of the anterior chest wall with clavicular and sternocostal heads. It adducts and medially rotates the humerus.
Reference facts
- Origin
Clavicular head: medial half of clavicle. Sternocostal head: sternum, superior 6 costal cartilages, aponeurosis of external oblique
- Insertion
Lateral lip of the intertubercular groove of the humerus (crest of greater tubercle)
- Action
Adducts and medially rotates the humerus; clavicular head flexes and sternocostal head extends the flexed arm
- Innervation
Lateral pectoral nerve (C5–C7) and medial pectoral nerve (C8, T1)
- Blood supply
Pectoral branch of the thoracoacromial artery