Pectoral muscles

Question 1

What is the origin, insertion, innervation and function of the pectoralis major muscle

Answer 1

Origin:

• clavicular head: from anterior 2/3 of clavicle
• sternal head: from anterior sternum, costal cartilages of rib I to VI and aponeurosis of external oblique

Insertion:
-inserts into intertubercular sulcus

Innervation:
-medial and lateral pectoral nerves

Function:
-medial rotation, adduction and flexion of humerus

Question 2

What is the origin, insertion, innervation and function of the pectoralis minor

Answer 2

Origin:
-ribs 3-5

Insertion:
coracoid process of scapula

Innervation:
-medial pectoral nerves

Function:
-depression and protraction of shoulder

Question 3

What is the origin, insertion, innervation and function of the subclavius

Answer 3

Origin:
-rib I

Insertion:
-clavicle

Innervation:
-subclavian nerve

Function:
-depression of clavicle and stabilisation of sternoclavicular joint