Muscles Connecting the Upper Limb to the Thoracic Wall

Clavicle, sternum, and upper six costal cartilages

Pectoralis major origin

Lateral lip of bicipital groove of humerus

Pectoralis major insertion

Medial and lateral pectoral nerves from brachial plexus

Pectoralis major nerve

Adducts arm and rotates it medially; clavicular fibers also flex arm

Pectoralis major action

Third, fourth, and fifth ribs

Pectoralis minor origin

Coracoid process of scapula

Pectoralis minor insertion

Medial pectoral nerve from brachial plexus

Pectoralis minor nerve

Depresses point of shoulder; if the scapula is fixed, it elevates the ribs of origin

Pectoralis minor action

First costal cartilage

Subclavius origin

Clavicle

Subclavius insertion

Nerve to subclavius from upper trunk of brachial plexus

Subclavius nerve

Depresses the clavicle and steadies this bone during movements of the shoulder girdle

Subclavius action

Upper eight ribs

Serratus anterior origin

Medial border and inferior angle of scapula

Serratus anterior insertion

Long thoracic nerve

Serratus anterior nerve

Draws the scapula forward around the thoracic wall; rotates scapula

Serratus anterior action