Pectoral Region of Thoracic

Question 1

Pectoralis major

Answer 1

Origin- Clavicular head: medial half of clavicle
Sternal head: sternum, superior 6 costal cartilages

Insertion- lateral lip of intertubercular groove of humerus

Innervation- lateral and medial pectoral nerves

Action- adducts, medial rotate, flexes and extends humerus

Question 2

Pectoralis minor

Answer 2

Origin- 3rd-5th ribs

Insertion- coracoid process of scapula; medial border of scapula

Innervation-medial pectoral nerve

Action- draws scapula inferiorly; helps hold scapula against thoracic wall

Question 3

Subclavius

Answer 3

Origin- 1st rib

Insertion- middle 3rd of clavicle

Innervation- subclavian nerve

Action- anchors and depresses clavicle

Question 4

Serratus anterior

Answer 4

Origin- 1st -8th ribs

Insertion- medial border of scapula

Innervation- long thoracic nerve

Action- hold scapula against thoracic wall; protracts and rotates scapula