Upper Limb Muscles of the Arm

Question 1

What counts as the anatomical arm?

Answer 1

From the shoulder to elbow joint.

Question 2

What are the two compartments of the arm and the muscles in them?

Answer 2

Anterior: biceps brachii, brachialis and coracobrachialis.
Posterior: triceps brachii and anconeus.

Question 3

What are the proximal attachments of the biceps brachii?

Answer 3

Short head - tip of coracoid process of scapula.

Long head - supraglenoid tubercle of scapula.

Question 4

What is the distal attachments of the biceps brachii?

Answer 4

Tuberosity of radius and fascia of forearm via bicipital aponeurosis.

Question 5

What is the biceps brachii innervated by?

Answer 5

Musculocutaneous nerve (C5, C6, C7).

Question 6

What is the arterial supply for the biceps brachii?

Answer 6

Musculocutaneous artery.

Question 7

What is the action of the biceps brachii?

Answer 7

Supinates forearm and flexes forearm, short head resists dislocation of shoulder.

Question 8

What is the proximal attachment of coracobrachialis?

Answer 8

Tip of coracoid process of scapula.

Question 9

What is the distal attachment of the coracobrachialis?

Answer 9

Middle third of medial surface of humerus.

Question 10

What is the coracobrachialis innervated by?

Answer 10

Musculocutaneous nerve (C5, C6, C7).

Question 11

What is the arterial supply of the coracobrachialis?

Answer 11

Brachial artery.

Question 12

What is the action of the coracobrachialis?

Answer 12

Helps flex and adduct arm, resists dislocation of the shoulder.

Question 13

What is the proximal attachment of the brachialis?

Answer 13

Distal half of anterior surface of humerus.

Question 14

What is the distal attachment of the brachialis?

Answer 14

Coronoid process and tuberosity ulna.

Question 15

What is the brachialis innervated by?

Answer 15

Musculocutanous nerve (C5, C6, C7) and radial nerve (C5, C7).

Question 16

What is the arterial supply of the brachialis?

Answer 16

Brachial artery, radial recurrent artery.

Question 17

What is the action of the brachialis?

Answer 17

Flexes forearm in all positions.

Question 18

What are the proximal attachments of the triceps brachii?

Answer 18

Long head - infraglenoid tubercle of scapula.
Lateral head - posterior surface of humerus, superior to radial groove.
Medial head - posterior surface to humerus, inferior to radial groove.

Question 19

What is the distal attachment of the triceps brachii?

Answer 19

Proximal end of the olecranon of ulna and fascia of forearm.

Question 20

What is the triceps brachii innervated by?

Answer 20

Radial nerve (C6, C7, C8).

Question 21

What is the arterial supply of the triceps brachii?

Answer 21

Deep brachial artery.

Question 22

What is the proximal attachment of the anconeus?

Answer 22

Lateral epicondyle of humerus.

Question 23

What is the distal attachment of the anconeus?

Answer 23

Lateral surface of olecranon and superior part of posterior surface of ulna.

Question 24

What is the anconeus innervated by?

Answer 24

Radial nerve (C7, C8, T1).

Question 25

What is the arterial supply for the anconeus?

Answer 25

Recurrent interosseous artery.

Question 26

What is the action of the anconeus?

Answer 26

Assists triceps in extending forearm, stabilises elbow joint, may abduct ulna during pronation.