Pectoral muscles

Question 1

What is the origin of the pectoralis major?

Answer 1

Medial half of clavicle and anterior surface of sternum, first seven costal cartilages, aponeurosis of external oblique

Question 2

What is the insertion of the pectoralis major?

Answer 2

Lateral lip of intertubercular sulcus of humerus

Question 3

What is the action of the pectoralis major?

Answer 3

Adduction, medial rotation and flexion of the humerus at the shoulder joint

Question 4

What is the innervation of the pectoralis major?

Answer 4

Medial and lateral pectoral nerves

Question 5

What is the origin of the subclavius?

Answer 5

Rib I at junction between rib and costal cartilage

Question 6

What is the insertion of the subclavius?

Answer 6

Groove on inferior surface of middle third clavicle

Question 7

What is the action of the subclavius?

Answer 7

Pulls clavicle medially to stabilise sternoclavicular joint; depresses tip of shoulder

Question 8

What is the innervation of the subclavius?

Answer 8

Nerve to subclavius

Question 9

What is the origin of the pectoralis minor?

Answer 9

Anterior surfaces of the third, fourth and fifth ribs, and deep fascia overlying the related intercostal spaces

Question 10

What is the insertion of the pectoralis minor?

Answer 10

Coracoid process of scapula

Question 11

What is the action of the pectoralis minor?

Answer 11

Depresses tip of shoulder, protracts scapula

Question 12

What is the innervation of the pectoralis minor?

Answer 12

Medial pectoral nerves

Question 13

What is the origin of the serratus anterior?

Answer 13

Anterior portions of first 8 ribs

Question 14

What is the insertion of the serratus anterior?

Answer 14

Internal surface of medial border of scapula

Question 15

What is the action of the serratus anterior?

Answer 15

Holds scapula against ribcage to prevent ‘winging’ of the inferior angle of the scapula

Question 16

What is the innervation of the serratus anterior?

Answer 16

Long thoracic nerve