MSK 2.1 - The Anterior and Posterior Arm

Question 1

What is the origin of the short head of the biceps brachii?

Answer 1

Coracoid process of the scapula

Question 2

Where does the biceps brachii insert?

Answer 2

The radial tuberosity

Question 3

Describe the shape and size of the biceps brachii

Answer 3

• Large

- Two heads which combine to form a belly at the level of the humeral shaft

Question 4

What is the nerve supply of the biceps brachii?

Answer 4

Musculocutaneous nerve (C5, C6)

Question 5

Give the actions of the biceps brachii (4)

Answer 5

• Flexion of the elbow
• Supination of the forearm
• Flexion of the humerus at the shoulder
• Stabilisation of the shoulder joint (long head)

Question 6

What happens if the tendon of the long head of the biceps brachii ruptures?

Answer 6

• Produces ‘Popeye sign’ upon flexion’

- Don’t notice any muscle weakness due to Brachialis and Supinator muscles

Question 7

What is the origin of the Brachialis?

Answer 7

The medial and lateral surfaces of the humeral shaft

Question 8

Where does the Brachialis insert? (2)

Answer 8

• Tuberosity of the ulna, distal to elbow joint

- Anterior surface of coronoid process of the ulna

Question 9

Describe the size of the Brachialis

Answer 9

Small but bigger than the Coracobrachialis

Question 10

What is the nerve supply of the Brachialis?

Answer 10

• Musculocutaneous nerve (C5 and C6)

- Radial nerve (C7)

Question 11

Give the actions of the Brachialis (2)

Answer 11

• Flexion of the forearm

- Protection of the elbow

Question 12

What is the origin of the Coracobrachialis?

Answer 12

Coracoid process of the scapula

Question 13

Where does the Coracobrachialis insert?

Answer 13

Medial side of the humeral shaft

Question 14

Describe the size of the Coracobrachialis

Answer 14

Small

Question 15

What is the nerve supply of the Coracobrachialis?

Answer 15

Musculocutaneous nerve (C5-C7)

Question 16

What are the actions of the Coracobrachialis?

Answer 16

• Flexion of the humerus

- Adduction of the humerus

Question 17

What are the four borders of the cubital fossa?

Answer 17

• Medial and lateral epicondyles
• Medial border of the brachioradialis
• Lateral border of pronator Teres
• Median cubital vein

Question 18

Give two clinically relevant features of the cubital fossa

Answer 18

• Feeling of brachial pulse medial to biceps tendon is relevant to taking blood pressure
• Medial cubital vein runs through which connects to basilic and cephalic veins both of which are common sites for venepuncture

Question 19

Give the names of the three heads of the triceps brachii

Answer 19

• Lateral
• Medial
• Long

Question 20

Where is the origin of the lateral head of the triceps brachii?

Answer 20

Between Teres minor and superior to groove of posterior surface of the humerus

Question 21

Where is the origin of the medial head of the triceps brachii?

Answer 21

Inferior to the radial groove on the posterior shaft of the humerus

Question 22

Where is the origin of the long head of the triceps brachii?

Answer 22

Infraglenoid tubercule of the scapula

Question 23

Where do all three heads of the triceps brachii insert?

Answer 23

The olecranon of the ulna

Question 24

What is the nerve supply of the triceps brachii?

Answer 24

The radial nerve (C7, C8)

Question 25

What is the action of the triceps brachii?

Answer 25

Extension of the elbow

Question 26

How is the triceps brachii clinically relevant?

Answer 26

A tap on the triceps tendon tests C7

Question 27

What is the origin of the long head of the biceps brachii?

Answer 27

Supraglenoid tubercule of the scapula