Pectoral Min and Major

Anatomy

Pectoral Major

Origin	Clavicular part: anterior surface of medial half of clavicle Sternocostal part: anterior surface of sternum, Costal cartilages of ribs 1-6 Abdominal part: Anterior layer of rectus sheath
Insertion	Crest of greater tubercle of humerus
Action	Shoulder joint: Arm adduction, Arm internal rotation, Arm flexion (clavicular head), arm extension (sternocostal head); Scapulothoracic joint: Draws scapula anteroinferiorly
Innervation	Lateral and medial pectoral nerves (C5-T1)
Blood supply	Pectoral branches of thoracoacromial artery, perforating branches of internal thoracic artery

Pectoral Minor

Origin	Anterior surface, costal cartilages of ribs 3-5
Insertion	Medial border and coracoid process of scapula
Innervation	Medial and lateral pectoral nerves (C5-T1)
Blood supply	Thoracoacromial a. (pectoral and deltoid branches), superior thoracic a., lateral thoracic a.
Function	Scapulothoracic joint: draws scapula anteroinferiorly, stabilizes scapula on thoracic wall