Upper Limb Muscular System

Question 1

What action does a muscle crossing on the anterior side of a joint produce?

Answer 1

Flexion

Question 2

What action does a muscle crossing on the posterior side of a joint produce?

Answer 2

Extension

Question 3

What action does a muscle crossing on the lateral side of a joint produce?

Answer 3

Abduction

Question 4

What action does a muscle crossing on the medial side of a joint produce?

Answer 4

Adduction

Question 5

Name three muscles in the anterior compartment that move and stabilize the shoulder.

Answer 5

• Subclavius
• Pectoralis minor
• Serratus anterior

Question 6

What is the function of the Subclavius muscle?

Answer 6

Stabilizes the pectoral girdle

Question 7

What action does the Pectoralis minor muscle perform?

Answer 7

Abducts the scapula

Question 8

What is the ‘boxer’s muscle’?

Answer 8

Serratus anterior

Question 9

Which muscles are involved in moving and stabilizing the shoulder in the posterior compartment?

Answer 9

• Trapezius
• Rhomboids major and minor
• Levator scapulae

Question 10

What is the primary action of the middle fibers of the Trapezius muscle?

Answer 10

Adducts and stabilizes the scapula

Question 11

What is the role of the Rhomboids major and minor muscles?

Answer 11

Adduct the scapula

Question 12

What is the function of the Levator scapulae muscle?

Answer 12

Elevates the scapula

Question 13

What are the four muscles collectively known as the rotator cuff muscles?

Answer 13

• Supraspinatus
• Infraspinatus
• Teres minor
• Subscapularis

Question 14

What is the primary role of the rotator cuff muscles?

Answer 14

Reinforce the shoulder joint

Question 15

What muscle is the prime mover for shoulder flexion?

Answer 15

Pectoralis major

Question 16

What action does the Coracobrachialis muscle perform?

Answer 16

Flexes and adducts the shoulder joint

Question 17

What is the prime mover for shoulder extension?

Answer 17

Latissimus dorsi

Question 18

What muscles are antagonistic to shoulder abduction?

Answer 18

• Pectoralis major
• Latissimus dorsi
• Teres major

Question 19

What initiates the first 10° of arm abduction?

Answer 19

Supraspinatus

Question 20

Which muscle becomes the prime mover for shoulder abduction after the initial 10°?

Answer 20

Deltoid

Question 21

Where are adductor muscles located relative to a joint?

Answer 21

On the medial side of a joint

Question 22

Name the three adductor muscles of the shoulder.

Answer 22

• Pectoralis major
• Latissimus dorsi
• Teres major

Question 23

What is the action of shoulder flexion?

Answer 23

Lifting the humerus in an anterior direction

Question 24

Which muscles contribute to shoulder flexion?

Answer 24

• Pectoralis major
• Anterior fibres of deltoid
• Coracobrachialis
• Biceps brachii

Question 25

What results from contraction of the latissimus dorsi?

Answer 25

Shoulder extension

Question 26

What occurs during lateral or external rotation of the shoulder joint?

Answer 26

The palm faces forward

Question 27

Which muscles are responsible for lateral rotation of the shoulder joint?

Answer 27

* Infraspinatus * Teres minor * Posterior fibres of deltoid

Question 28

What is the action of medial or internal rotation of the shoulder joint?

Answer 28

The palm faces downwards

Question 29

Which muscles are involved in medial rotation of the shoulder joint?

Answer 29

* Subscapularis * Pectoralis major * Latissimus dorsi * Anterior fibres of deltoid

Question 30

Which muscle is capable of flexing, extending, and abducting the arm?

Answer 30

Deltoid

Question 31

List the muscles mentioned in the summary slide for Topic 2.3a.

Answer 31

* Pectoralis major * Coracobrachialis * Serratus anterior * Latissimus dorsi * Teres major * Teres minor * Supraspinatus * Infraspinatus * Deltoid