musculus pectoralis major

[TA] greater pectoral muscle: origin, clavicle, sternum, six upper costal cartilages, aponeurosis of obliquus externus abdominis. These origins are reflected in the subdivision of the muscle into clavicular, sternocostal, and abdominal parts; insertion, crest of intertubercular groove of humerus; innervation, medial and lateral pectoral; action, adducts, flexes, rotates arm medially.