Wrist and Hand

Question 1

1. Which arm bone articulates predominantly with the carpal bones?
2. Name the carpal bones, moving lateral to medial, proximal to distal

Answer 1

1. radius

2. scaphoid, lunate, triquetrum, pisform, trapezium, trapezoid, capitate, hamate

Question 2

1. Which structure converts the carpal arch into the carpal tunnel?
2. Name 4 structures that pass through the carpal tunnel

Answer 2

1. flexor retinaculum
2. tendon of FDS
   tendon of FDP
   flexor policis longus
   median nerve

Question 3

1. Along which side of the hand does the radial artery run?
2. What part of the forearm and hand does the radial artery supply?
3. Along which side of the arm does the ulnar artery run?
4. What part of the forearm and hand does the ulnar artery supply?
5. How are the palmar arches related to the flexor tendons?
   a) superficial palmar arch
   b) deep palmar arch

Answer 3

1. lateral aspect of the forearm
2. posterolateral aspect of the arm and thumb and lateral side of index finger
3. medial
4. anteromedial aspect of forearm, and medial three and one half digits

5a) superficially
5b) deep

Question 4

1. What are the extensor hoods formed by?
2. Where do the slits insert?
3. Name two muscles that insert into the extensor hoods
4. What movements do the extensor hoods facilitate?

Answer 4

1. long tendons of the extensor digitorum and extensor policis longus muscles
2. lateral and medial slits arc around the PIP joint to insert distally to the DIP at the distal phalanx
3. lumbricals and interossei
4. simultaneous flexion of the MCP joint and extension of the IP joint

Question 5

1. What are the lateral and medial borders of the anatomical snuffbox formed by?
   a) medial border
   b) lateral border (2)
2. Name two structures contained in the anatomical snuffbox
3. What is the clinical relevance of the anatomical snuffbox

Answer 5

1a) tendon of extensor policis longus
1b) tendon of extensor policis brevis and adductor policis longus

2. radial artery
   radial nerve
3. if localised pain is reported in the anatomical snuffbox, a fracture of the scaphoid is the most likely cause.

Question 6

1. What is innervated by the median nerve?
2. Exceptions to this?
3. What is innervated by the ulnar nerve?
4. exceptions to this?
5. What structure accompanies the ulnar nerve closely?
6. What is the clinical relevance of this?

Answer 6

1. flexors of the forearm
2. flexor carpi ulnaris and medial two tendons of flexor digitorum profundus
3. intrinsic muscles of the hand
4. muscles of the thenar eminence (except adductor policis) and radial two lumbricals
5. ulnar artery
6. lacerations tend to involve both structures

Question 7

1. What joint does the flexor digitorum superficialis flex?
2. How can you test the action of this muscle?
3. What joint does the flexor digitorum profundus flex?
4. How can you test the action of this muscle?

Answer 7

1. proximal interphalangeal joint
2. pull back other fingers to hyperextend and counterract the FDP
   ask patient to extend the affected finger
3. distal interphalangeal joint
4. secure the PIP and MCP joints
   ask patient to flex finger

Question 8

1. What is pulled elbow caused by?
2. What ligament is affected?
3. What is the defect?

Answer 8

1. sudden pull on a child’s lower arm or wrist
2. annular ligament (which encircles the top of the radius) becomes dislocated from the top of the radius
3. child is unable to pronate/supinate

Question 9

1. What movement are the lumbricals responsible for?
2. what is the muscle structure of the radial two lumbricals?
3. What are they innervated by?
4. What is the muscle structure of the ulnar two lumbricals?
5. What are they innervated by?

Answer 9

1. flexion at the MCP joint and extension of the IP joints
2. unipennate
3. median nerve
4. bipennate
5. ulnar nerve

Question 10

1. Name the three muscles of the thenar eminence
2. What are they innervated by
3. Which muscle acts on the thumb but lies outside the thenar eminence?
4. What is its relation to the thenar eminence?
5. What is it innervated by?

Answer 10

1. opponens policis, abductor policis brevis, and flexor policis brevis
2. median nerve
3. adductor policis
4. lies deep to the thenar eminence
5. ulnar nerve

Question 11

Which interossei:

1. Abduct?
2. Adduct?
3. Where do the palmar interossei originate?
   a) digit 2
   b) digit 4 and 5?
   4) How many muscle bellies do the palmar interossei have?
4. where do the dorsal interossei insert?
   a) digit 2
   b) digit 4 and 5
5. What is the anatomy of the dorsal interossei of digit 3?
6. What are the interossei innervated by?

Answer 11

1. dorsal
2. palmar

3a) medial metacarpal
b) lateral metacarpal
4. 1

5a) medial side
b) lateral side
6. two tendons, inserting on both medial and lateral sides

7. Ulnar nerve

Question 12

1. How many nerves are there per digit?

2. What is the clinical relevance of this?

Answer 12

1. 4 - two palmar, two dorsal

2. doing a ring block

Question 13

1. What innervates the supinator?
2. What innervates the aconeus?
3. What innervates the protantor teres and quadratus?

Answer 13

1. radial nerve
2. radial nerve
3. median nerve

Question 14

In the hypothenar eminence, which muscle lies the deepest?

Answer 14

oponens digiti minimi