Muscles of the Pectoral Region

Question 1

What muscles are in the pectoral region

Answer 1

Pectoralis major
Pectoralis minor
Serratus anterior
Subclavius

Question 2

Which is the most superficial muscle in the pectoral region

Answer 2

Pectoralis major

Question 3

What are the heads of pectoralis major

Answer 3

Sternal head

Clavicular head

Question 4

Where is the insertion of both heads of pectoralis major

Answer 4

Intertubercular sulcus of the humerus

Question 5

Where does the clavicular head of pectoralis major originate

Answer 5

From the anterior surface of the medial clavicle

Question 6

Where does the sternocostal head of pectoralis major originate

Answer 6

Anterior surface of the sternum
Superior 6 costal cartilages
Aponeurosis of the external oblique muscle

Question 7

What is the function of pectoralis major

Answer 7

Adduction of the upper limb
Internal rotation of the upper limb
Draws the scapula anteroinferiorly

Question 8

What nerves innervate pectoralis major

Answer 8

Lateral pectoral nerve

Medial pectoral nerve

Question 9

Where does pectoralis minor lie

Answer 9

Underneath pectoralis major

Question 10

Which muscles form the anterior wall of the axilla

Answer 10

Pectoralis major

Pectoralis minor

Question 11

Where does pectoralis minor originate

Answer 11

From 3-5 ribs

Question 12

Where does pectoralis minor insert

Answer 12

Coracoid process of the scapula

Question 13

What is the function of pectoralis minor

Answer 13

Stabilises the scapula

Draws it anteroinferiorly against the thoracic wall

Question 14

What nerves innervate pectoralis minor

Answer 14

Medial pectoral nerve

Question 15

Which muscle forms the medial border of the axilla

Answer 15

Serratus anterior

Question 16

Where does serratus anterior originate

Answer 16

Lateral aspects of ribs 1-8

Question 17

Where does serratus anterior insert

Answer 17

Costal surface of the medial border of the scapula

Question 18

What is the function of serratus anterior

Answer 18

Rotates the scapula (allowing the arm to be raised over 90 degrees)
Holds scapula against the ribcage

Question 19

Which nerves innervate serratus anterior

Answer 19

Long thoracic nerve

Question 20

Where is subclavius located

Answer 20

Directly underneath the clavicle

Question 21

Where does subclavius originate

Answer 21

From the junction of the 1st rib and its costal cartilage

Question 22

Where does subclavius insert

Answer 22

Inferior surface of the middle third of the clavicle

Question 23

What is the function of subclavius

Answer 23

Anchors and depresses the clavicle

Also provides minor protection to underlying neurovascular structures

Question 24

What nerves innervate subclavius

Answer 24

Nerve to subclavius

Question 25

What occurs with damage of the long thoracic nerve

Answer 25

Winging of the scapula

Question 26

What is the most common cause of long thoracic nerve injuries

Answer 26

Traction injuries