- Pronunciation
- / ˌ p ɛ k t ə ˈ r eɪ l ɪ s ˈ m eɪ dʒ ər / PEK -tər- AY -liss MAY -jər
- Origin
- Clavicular head : anterior surface of the medial half of the clavicle ., Sternocostal head : anterior surface of the sternum , the superior six costal cartilages , and the aponeurosis of the external oblique muscle
- Insertion
- Lateral lip of the bicipital groove of the humerus , (anteromedial proximal humerus)
- Artery
- Pectoral branch of the thoracoacromial trunk
- Nerve
- Lateral pectoral nerve and medial pectoral nerve , Clavicular head : C5 and C6 , Sternocostal head : C7 , C8 and T1
- Actions
- Clavicular head : flexes the humerus Sternocostal head : horizontal and vertical adduction , extension , and internal rotation of the humerus, Depression and abduction of the scapula.
- Antagonist
- Deltoid muscle , trapezius
- Latin
- musculus pectoralis major
- Ta98
- A04.4.01.002