Upper limb 4

Question 1

Superficial layer of muscles in posterior forearm (6)

Answer 1

Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor digitorum
Extensor digiti minimi
Extensor carpi ulnaris

Question 2

Functions of ECRL + ECRB (2)

Answer 2

Both extend + abduct wrist

Question 3

Deep layer of muscle in posterior forearm (1)

Answer 3

Supinator

Question 4

Outcropping of deep layer of muscles in posterior forearm (4)

(think snuffbox)

Answer 4

Abductor pollicis longus
Extensor pollicis longus
Extensor pollicis brevis
Extensor indicis

Question 5

Functions of extensor digitorum (2)

Answer 5

Extend medial 4 digits

Extend wrist

Question 6

Functions of

• Abductor pollicis longus (3)
• Extensor pollicis longus (3)
• Extensor pollicis brevis (2)
• Extensor indicis

Answer 6

Abduct thumb, extend thumb at CMC joint, extend wrist

Extend IP + MCP of thumb, extend wrist

Extend MCP of thumb, extend wrist

Extend index finger

Question 7

Innervation of all muscles in posterior forearm

Answer 7

Radial

Question 8

Function of extensor digiti minimi

Answer 8

Extend 5th finger at MCP

Question 9

Function of extensor carpi ulnaris

Answer 9

Extend + adduct wrist

Question 10

Function of brachioradialis

Answer 10

Weak flexion of elbow

Question 11

Function of supinator

Answer 11

Supinate forearm

Question 12

Posterior interosseous nerve is a deep branch of

Answer 12

radial nerve

Question 13

Radial nerve divides into superficial and deep branches in the cubital fossa

What does the superficial branch supply

Answer 13

Sensation to dorsum of hand

Question 14

Pathology found in the dorsum of wrist

Answer 14

Synovial cyst/ganglion

Question 15

What deep muscles of the posterior forearm act on the thumb

Answer 15

APL
EPL
EPB

Question 16

What muscles form the medial and lateral boundary of the anatomical snuffbox

Answer 16

Medial - EPL

Lateral - APL + EPB

Question 17

What is the anatomical snuffbox

Answer 17

Shallow depression on lateral aspect of wrist on the dorsum

Question 18

What 2 carpal bones can you feel in the anatomical snuffbox

Answer 18

Scaphoid

Trapezium

Question 19

What artery is in the floor of the anatomical snuffbox

Answer 19

Radial artery

Question 20

In the snuffbox, the scaphoid and radius articulate to form part of the wrist joint

A blow to the wrist usually puts most force on what bone leading to fracture

Answer 20

scaphoid fracture

Question 21

The 4 tendons of extensor digitorum flatten to form

Answer 21

extensor expansion - triangular aponeurosis

Question 22

Muscles attaching to the dorsal extensor expansion (5)

Answer 22

Extensor digitorum
Lumbricals
Extensor indicis
Dorsal interossei
Palmar interossei

Question 23

Action of APL on wrist

Answer 23

Extension

Question 24

Actions of APL on thumb (2)

Answer 24

Abduct thumb, extend thumb at CMC joint,