Anatomy of the Upper Limb

Question 1

How many muscles are in the anterior compartment of the upper arm?

Answer 1

3

forearm extensors: biceps brachii, brachioradialis + coracobrachialis (BBC)

Question 2

What nerve innervates the anterior compartment of the upper arm?

Answer 2

Musculocutaneous nerve (tapping C6 elicits)

Question 3

How many muscles are in the posterior compartment of the upper arm?

Answer 3

1
Triceps brachii (inserts onto the olecranon)

Question 4

What nerve innervates the posterior compartment of the upper arm?

Answer 4

Radial nerve (tapping C7 elicits)

Question 5

How many muscles are in the superficial segment of the anterior forearm compartment?

Answer 5

4
Flexor carpi radialis, flexor carpi ulnaris, palmaris longus + pronator teres
(all originate from the medial epicondyle)

Question 6

What nerve innervates the superficial segment of the anterior forearm compartment?

Answer 6

All supplied by the median nerve except the flexor carpi ulnaris which is supplied by the ulnar nerve

Question 7

How many muscles in the intermediate segment of the anterior forearm?

Answer 7

1

Flexor digitorum superficialis (splits into 4 tendons at the carpal tunnel which attach onto the middle 4 phalanges)

Question 8

What nerve supplies the intermediate segment of the anterior forearm?

Answer 8

Median nerve

Question 9

How many muscles are in the deep segment of the anterior forearm?

Answer 9

3
Flexor digitorum profundus, flexor pollucis longus, pronator quadratus
(flexor digitorum profundus splits into 4 tendons at the carpal tunnel and attaches onto the distal 4 phalanges)

Question 10

What nerve supplies the deep segment of the anterior forearm?

Answer 10

Median nerve, except the medial half of the flexor digitorum profundus which is supplied by the ulnar nerve

Question 11

How many muscles are in the superficial segment of the posterior forearm?

Answer 11

7
Brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digitorum minimi, extensor carpi ulnaris, anconeus

Question 12

What nerve innervates the superficial segment of the posterior forearm?

Answer 12

Radial nerve

Question 13

How many muscles are in the deep segment of the posterior forearm?

Answer 13

5

Supinator, abductor pollicis longus, extensor pollicis longus/brevis, extensor indicus proprius

Question 14

What nerve innervates the deep segment of the posterior forearm?

Answer 14

Radial nerve

Question 15

Which muscles of the deep segment of the posterior forearm act only on the thumb and index finger? (4)

Answer 15

Abductor pollicus longus
Extensor pollucis longus
Extensor pollucis brevis
Extensor indicus proprius