pectoralis major

Superficial muscle of the chest wall. Origin: 1) medial 1/2 of clavicle 2) anterior surface of manubrium 3) body of sternum 4) cartilages to the 1st 6 ribs 5) aponeurosis of the external oblique muscle Insertion: crest of greater tubercle of humerus Action: adducts & medially rotates arm Innervation: anterior thoracic nerve

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999