Muscles of the Pectoral Region

What are the two portions of the pectoralis major?

Clavicular portion and sternocostal portion

Pectoralis Major: Clavicular Portion O

Clavicle

Pectoralis Major: Clavicular Portion I

Crest of the greater tubercle of the humerus

Pectoralis Major: Clavicular Portion N

Medial pectoral nerve & Lateral pectoral nerve

Pectoralis Major: Clavicular Portion A

Flexion*, adduction, internal rotation of the humerus

Pectoralis Major: Sternocostal Portion O

Sternum and costal cartilages

Pectoralis Major: Sternocostal Portion I

Crest of the greater tubercle of the humerus

Pectoralis Major: Sternocostal Portion N

Medial pectoral nerve & Lateral pectoral nerve

Pectoralis Major: Sternocostal Portion A

Extension*, adduction, internal rotation of the humerus

Pectoralis Major: Entire Muscle A

Insertion fixed: Elevation of the thorax during forced inhalation

Pectoralis minor O

Ribs 3-5

Pectoralis minor I

Coracoid process

Pectoralis minor N

Medial pectoral nerve

Pectoralis minor A

Origin fixed: Anterior tilt of the scapula

Insertion fixed: Elevate the thorax during forced inhalation

Serratus anterior O

Ribs 1-9

Serratus anterior I

Medial border of the scapula

Serratus anterior I

Medial border of the scapula

Serratus anterior A

Origin fixed: Abduction, upward rotation, depression of the scapula. Holds the scapula against the thoracic wall.

Insertion fixed: Elevation of the thorax during forced inhalation

Subscapularis O

Subscapular fossa

Subscapularis I

Lesser tubercle of the humerus

Subscapularis N

Upper and lower subscapular nerve

Subscapularis A

Internal rotation, stabilizes humeral head in the glenoid cavity