Pectoral Region

Question 1

Pectoralis Major

Answer 1

Origin: Clavicular head, Sternum and upper 6 costal cartilages

Insertion: Lateral lip of bicipital groove (intertubercular suclus)

Action: Adduct and medially rotates arm, flexes arm

Nerve: Medial and lateral pectoral nerves

Question 2

Pectoralis minor

Answer 2

Origin: 3rd-5th ribs near cartialges

Insertion: Coracoid process of scapula

Action: Depresses scapula, Elevates ribs of origin for deep inspiration

Nerve: Medial Pectoral

Question 3

Serratus anterior

Answer 3

Origin: Upper 8 ribs

Insertion: Medial border of scapula

Action: Rotates Scapula, Draws scapula forward around thoracic wall (protraction), Holds scapula against wall

Nerve: Long Thoracic Nerve

Question 4

Subclavius

Answer 4

Origin: 1st costal cartilage

Insertion: Clavicle

Action: Anchors and depresses clavicle during upper limb movements

Nerve: Nerve to subclavius