Pectoralis major muscle

From Freepedia

Image:Pectoralis major.png

Location

The clavicular head of the pectoralis major takes its origin from the anterior surface of the medial half of the clavicle. The sternocostal head takes its origin from the anterior surface of the sternum, the superior six costal cartilages, and the aponeurosis of the external oblique muscle.

Clavicular head : flexes the humerus</br> Sternocostal head : extends the humerus

As a whole, the pectoralis major adducts and medially rotates the humerus. It also draws the scapula anteriorly and inferiorly.

Innervation

• lateral and medial pectoral nerv
• the clavicular head is innervated by nerves from C5 and C6
• the sternocostal head is innervated by nerves from C7, C8 and T1

Blood supply

pectoral branch of the thoracoacromial trunk

Muscles of the upper limb

The muscles connecting the upper extremity to the vertebral column: levator scapulae muscle | rhomboid major muscle | rhomboid minor muscle | trapezius muscle | serratus anterior muscle | latissimus dorsi muscle The muscles connecting the upper extremity to the anterior and lateral thoracic walls: pectoralis major muscle | pectoralis minor muscle | subclavius muscle The muscles of the shoulder and musculotendinous cuff: deltoid muscle | infraspinatus muscle | subscapularis muscle | supraspinatus muscle | teres major muscle | teres minor muscle The muscles of the arm: anconeus muscle | biceps brachii muscle | brachialis muscle | triceps brachii muscle | coracobrachialis muscle The muscles of the forearm: brachioradialis muscle | extensor carpi radialis brevis muscle | extensor carpi radialis longus muscle | extensor carpi ulnaris muscle | extensor digiti minimi | extensor digitorum muscle | extensor pollicis longus muscle | flexor carpi radialis muscle | flexor carpi ulnaris muscle | flexor digitorum profundus muscle | flexor digitorum superficialis muscle | flexor pollicis brevis muscle | flexor pollicis longus muscle | pronator quadratus muscle | pronator teres muscle | palmaris longus muscle | supinator muscle The muscles of the hand: abductor pollicis brevis muscle | abductor pollicis longus muscle | adductor pollicis muscle | dorsal interossei muscles | extensor pollicis brevis muscle | palmar interossei muscles | palmaris brevis muscle | opponens digiti minimi muscle | opponens pollicis muscle | lumbrical muscles