Anatomy (hands, wrist)

Question 1

What nerve innervates the intrinsic muscles?

Answer 1

Median nerve

Question 2

What nerve inervates the extrinsic muscles?

Answer 2

Ulnar nerve

Question 3

What intrinsic muscles are intervated by the median nerve?

Answer 3

1. Abductor pollicis brevis (palmar abduction)
2. Opponens pollicis (opposition)
3. Flexor pollicis brevis (superficial/thumb MCP flexion, deep head innervated by ulnar n.)
4. Lumbricals (radial side/MCP flexion, extension of IP)

Question 4

What intrinsic muscles are innervated by the ulnar nerve?

Answer 4

1. Abductor digiti minimi (abducts #5)
2. **Opponens digiti minimi (opposition of #V)
   3. Flexor digiti minimi **(flexion of MCP join, opposition of #5)
3. Adductor (adducts CMC joint of the thumb)
4. Lumbricals (ulnarside/MCP flexion, extension of IP #IV and #V
5. Palmer interossei (adduction, assist MCP flex, IP ext of IP joints #II-#V
6. Dorsal interossei (Abduction, assits with MCP flex, ext. of IP joints #II-#V)

Question 5

What extrinsic flexor muscles of the hand are innervated by the median nerve?

Answer 5

1. Flexor digitorum superficialis (flexs PIP joints)
2. Flexor digitorum profundus (flexion of DIP joints to #II and #III)
3. Flexor pollicis longus (flexs IP joint of thumb)

Question 6

What extrinsic flexors are innervated by the ulnar nerve?

Answer 6

1. Flexor digitorum profundus (flexs DIP joints to #IV-#V

Question 7

What extrinsic extensor muscles are innervated by the radial nerve?

Answer 7

1. Extensor digitorum communis (ext.MCP joints, contributes to extension of IP joints)
2. Extensor digit minimi (ext. of MCP #5 joint, contributes to ext of IP joints)
3. Extensor pollcis longus (extension of IP thumb)
4. Extensor pollicis brevis (extension of MCP and CMC thumb)
5. Abductor pollicis longus (abduction, ext. of CMC joint)

Question 8

What wrist flexors muscles are innervated by the median nerve?

Answer 8

1. Flexor carpi radialis (FCR)
2. Palmaris longus (PL)

Question 9

What wrist flexor muscles are innervated by the ulnar nerve?

Answer 9

1. Flexor carpi longus (FCL)

Question 10

What wrist muscles are innervated by the radial nerve?

Answer 10

1. Extensor carpi radialis brevis (ECRB)
2. Extensor carpi radialis longus (ECRL)
3. Extensor arpi ulnaris (ECU)