Pectoralis Major

The pectoralis major is a muscle of the anterior chest wall. It is a large fan-shaped muscle, which is composed of a sternal head and a clavicular head.

• Attachments: 
  • Clavicular head originates from the anterior surface of the medial clavicle.
  • Sternocostal head originates from the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle.
  • The distal attachment of both heads is onto the intertubercular sulcus of the humerus.
• Function: Adduction and medial rotation of the upper limb.
• Innervation: Lateral and medial pectoral nerves.
• Blood supply: Pectoral branch of thoracoacromial artery and branches from the internal thoracic artery.

By TeachMeSeries Ltd (2025)

Fig 1
The sternal and clavicular heads of the pectoralis major.