DPT ~ Pectoral Region Muscles (AIONS)

subclavius origin

Junction of 1st rib and its costal cartilage

subclavius insertion

Inferior surface of middle third of clavicle

subclavius innervation

nerve to subclavius (C5, C6)

subclavius action

anchors and depresses clavicle

Serratus Anterior origin

External surfaces of lateral parts of 1st-8th ribs

Serratus anterior insertion

Anterior surface of medial border of scapula, including superior and inferior angles

serratus anterior innervation

Long thoracic nerve (C5, C6, C7)

serratus anterior action

Protracts scapula and holds it against thoracic wall; rotates scapula upward

pec minor origin

external surface of anterior end of ribs 3-5

pec minor insertion

Medial border and superior surface of coracoid process of scapula

pec minor innervation

Medial pectoral nerve (C8,T1); lateral pectoral nerve (variable)

pec minor action

Stabilizes scapula by drawing it anteriorly and inferiorly against thoracic wall.

pec major origin

Clavicular head: Anterior surface of medial half of clavicle.

Sternocostal Head: Anterior surface of sternum, superior 6 costal cartilages, aponeurosis of external oblique muscle

pec major insertion

lateral lip of intertubercular sulcus of humerus 

pec major innervation

Medial pectoral nerve (C8,T1); lateral pectoral nerve (variable)

pec major action

Adducts and internally rotates humerus; draws scapula anteriorly and inferiorly. Clavicular head flexes humerus and sternocostal head extends it from the flexed position.