Pectoralis Major

Pectoralis major muscle (lat. musculus pectoralis major) is a muscle on the anterior part of the chest. It arises from the anterior surface of the sternal part of the clavicle (pars clavicularis), from the sternum (pars sternalis) and from the cartilages of the true ribs (pars abdominalis). The muscle is inserted into the greater tubercle of the humerus.