pectoralis major muscle


pec·to·ra·lis ma·jor mus·cle

(pek'tōr-āl'is mā'jŏr mŭs'ĕl) Superficial thoracoappendicular muscle of chest; origin, clavicular part (pars clavicularis), medial half of clavicle; sternocostal part [TA] (pars sternocostalis), anterior surface of manubrium and body of sternum and cartilages of first to sixth ribs; abdominal part [TA] (pars abdominalis [TA]), aponeurosis of external oblique; insertion, crest of greater tubercle of humerus; action, adducts and medially rotates arm; nerve supply, anterior thoracic.
Synonym(s): greater pectoral muscle, musculus pectoralis major.

pectoralis major muscle

Chest wall muscle. Origin: medial half of clavicle, sternum, costal cartilages 4-6. Insertion: lateral edge of bicipital groove of humerus. Nerve: lateral and medial pectoral (C5-T1). Action: adducts and medially rotates arm. See also: muscle