Muscles of the posterior forearm

Question 1

What is the main action of the muscles in the posterior forearm?

Answer 1

Extension

Question 2

How many layers of muscles are there in the posterior forearm?

Answer 2

Two; superficial and deep

Question 3

What nerve innervates all the muscles in the posterior forearm?

Answer 3

The radial nerve

Question 4

How many muscles are in the superficial layer?

Answer 4

7

Question 5

Which muscles are in the superficial layer?

Answer 5

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

Question 6

What is the main action of the Brachioradialis?

Answer 6

Flexion at the elbow!*

Question 7

What does the Brachioradialis cover?

Answer 7

Radial artery

Radial nerve

Question 8

What innervates the Brachioradialis?

Answer 8

Radial nerve

Question 9

What is the postition of the Extensor carpi radialis brevis to the Extensor carpi radialis longus?

Answer 9

Deep

Question 10

What is the main action of the Extensor carpi radialis longus/brevis?

Answer 10

Extension at the wrist

Abduction at the wrist

Question 11

What innervates the Extensor carpi radialis longus/brevis?

Answer 11

The radial nerve

Question 12

What is the main action of the Extensor digitorum?

Answer 12

Extends the fingers at the metacarpophalangeal joint and interphalangeal joint

Question 13

What innervates the Extensor digitorum?

Answer 13

The radial nerve

Question 14

What is the main action of the Extensor digiti minimi?

Answer 14

Extends the little finger

Contributes to extension at the wrist

Question 15

What innervates the Extensor digiti minimi?

Answer 15

The radial nerve

Question 16

Where is the Extensor carpi ulnaris?

Answer 16

On the medial side of the posterior forearm

Question 17

What are the main actions of the Extensor carpi ulnaris?

Answer 17

Extension at the wrist

Adduction at the wrist

Question 18

What nerve innervates the Extensor carpi ulnaris?

Answer 18

The radial nerve

Question 19

Where is the Aconeus muscle?

Answer 19

Most medial in the forearm

Its fibres blend with the tendon of the Triceps brachii

Question 20

What is the main action of the Aconeus muscle?

Answer 20

Moves the Ulna during pronation

Extends at the elbow joint

Question 21

What innervates the Aconeus muscle?

Answer 21

The radial nerve

Question 22

What is wrist drop a sign of?

Answer 22

Radial nerve damage

Question 23

What is wrist drop?

Answer 23

Unopposed flexion as all the extensor muscles are paralysed

Question 24

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

Answer 24

5

Question 25

What are the muscles in the deep compartment of the posterior forearm?

Answer 25

``` Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis ```

Question 26

What is special about the Supinator muscle?

Answer 26

Has 2 heads with the radial nerve running between the 2

Question 27

What innervates the Supinator muscle?

Answer 27

The radial nerve

Question 28

What is the main action of the Supinator muscle?

Answer 28

Supination of the forearm

Question 29

Where is the Abductor pollicis longus?

Answer 29

Distal to the Supinator | Lateral side of the forearm

Question 30

What is the main action of the Abductor pollicis longus?

Answer 30

Abducts the thumb

Question 31

What innervates the Abductor pollicis longus?

Answer 31

Radial nerve

Question 32

Where is the Extensor pollicis brevis?

Answer 32

Medial and deep to Abductor pollicis longus

Question 33

What is the main action of the Extensor pollicis brevis?

Answer 33

Extends the Metacarpophalangeal joint of the thumb | Extends the CarpoMetacarpel joint of the thumb

Question 34

What innervates the Extensor pollicis brevis?

Answer 34

The radial nerve

Question 35

What is the main action of the Extensor pollicis longus?

Answer 35

Extends all joints of the thumb

Question 36

What innervates the Extensor pollicis longus?

Answer 36

The radial nerve

Question 37

What does the Extensor indicis allow?

Answer 37

The index finger to be independent of the other fingers during extension

Question 38

What innervates Extensor indicis?

Answer 38

The radial nerve

Question 39

What is the main action of Extensor indicis?

Answer 39

Extension of the index finger