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
Frequently asked questions
What does the pectoralis major do?
The pectoralis major adducts and medially rotates the humerus; clavicular head flexes and sternocostal head extends the flexed arm.
What nerve innervates the pectoralis major?
The pectoralis major is innervated by the lateral pectoral nerve (C5-C7) and medial pectoral nerve (C8, T1).
Where does the pectoralis major attach?
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).
What is the blood supply of the pectoralis major?
The pectoralis major is supplied by the pectoral branch of the thoracoacromial artery.