Muscles of the Posterior Compartment of the Forearm Flashcards Preview

MRCS Anatomy - Upper Limb > Muscles of the Posterior Compartment of the Forearm > Flashcards

Flashcards in Muscles of the Posterior Compartment of the Forearm Deck (61)
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1
Q

What is the general function of the muscles of the posterior compartment of the forearm

A

Extension at the wrist and fingers

2
Q

Which nerve innervates the muscles of the posterior compartment of the forearm

A

Radial nerve

3
Q

What are the superficial muscles of the posterior forearm

A
Extensor carpi radialis brevis
Extensor carpi radialis longus
Extensor digitorum
Extensor carpi ulnaris 
Extensor digiti minimi
Brachioradialis
Anconeus
4
Q

Which superficial muscles of the posterior forearm share a common tendinous origin

A
Extensor carpi radialis brevis
Extensor digitorum
Extensor carpi ulnaris
Extensor digiti minimi
(At lateral epicondyle)
5
Q

In the distal forearm, where does the radial artery and nerve lie

A

Between brachioradialis and deep flexor muscles

6
Q

Where does brachioradialis originate

A

Proximal aspect of the lateral supracondylar ridge of humerus

7
Q

Where does brachioradialis insert

A

Distal end of the radius, just before the radial styloid process

8
Q

What is the function of brachioradialis

A

Flexion at the elbow

9
Q

What nerve innervates brachioradialis

A

Radial nerve

10
Q

Where does extensor carpi radialis longus originate

A

Supracondylar ridge

11
Q

Where does the extensor carpi radialis brevis originate

A

Lateral epicondyle

12
Q

Where do extensor carpi radialis longus and brevis insert

A

Metacarpal bones II and III

13
Q

What is the action of extensor carpi radialis

A

Extends and abducts the wrist

14
Q

Which nerve innervates extenor carpi radialis

A

Radial nerve

15
Q

Where does extensor digitorum originate

A

Lateral epicondyle

16
Q

Where does extensor digitorum insert

A

Tendon splits into 4 and inserts into the extensor hood of each finger

17
Q

What is the action of extensor digitorum

A

Main extensor of the four fingers at MCP and IP joints

18
Q

Which nerve innervates extensor digitorum

A

Radial nerve (deep branch)

19
Q

Where does extensor digiti minimi lie

A

Medially to extensor digitorum

20
Q

Where does extensor digiti minimi originate

A

Lateral epicondyle of the humerus

21
Q

Where does extensor digiti minimi insert

A

Extensor hood of the little finger

22
Q

What is the action of extensor digiti minimi

A

Extends the little finger

Contributes to extension at the wrist

23
Q

Which nerve innervates extensor digiti minimi

A

Radial nerve (deep branch)

24
Q

Where is extensor carpi ulnaris located

A

Medial aspect of the posterior forearm

25
Q

Where does extensor carpi ulnaris originate

A

Lateral epicondyle of the humerus

26
Q

Where does extensor carpi ulnaris insert

A

Base of metacarpal V

27
Q

What is the action of extensor carpi ulnaris

A

Extension and adduction of the wrist

28
Q

Which nerve innervates extensor carpi ulnaris

A

Radial nerve (deep branch)

29
Q

Where does anconeus lie

A

Medially and superiorly in the extensor compartment of the forearm
Blended with the fibres of triceps brachii

30
Q

Where does anconeus originate

A

Lateral epicondyle

31
Q

Where does anconeus insert

A

Posterior and lateral part of olecranon

32
Q

What is the action of anconeus

A

Extends and stabilises elbow joint

Abducts ulna during pronation of forearm

33
Q

Which nerve innervates anconeus

A

Radial nerve

34
Q

What is lateral epicondylitis

A

Inflammation of the periosteum of the lateral epicondyle - caused by repeated use of superficial extensor muscles

35
Q

What are the deep muscles of the posterior forearm

A
Supinator
Abductor pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor indicis
36
Q

Where does supinator lie

A

Floor of the cubital fossa

37
Q

What passes between the two heads of supinator

A

Deep branch of the radial nerve

38
Q

Where does supinator originate

A

Two heads:-
Lateral epicondyle of the humerus
Posterior surface of the ulna

39
Q

Where does supinator insert

A

Posterior surface of the radius

40
Q

What is action of supinator

A

Supinates forearm

41
Q

Which nerve innervates supinator

A

Radial nerve (deep branch)

42
Q

Where is abductor pollicis longus

A

Immediately distal to supinator

43
Q

Where does abductor pollicis longus originate

A

Interosseous membrane

Adjacent posterior surfaces of the radius and ulna

44
Q

Where does abductor pollicis longus insert

A

Lateral side of the base of metacarpal I

45
Q

What is the action of abductor pollicis longus

A

Abducts the thumb

46
Q

Which nerve innervates abductor pollicis longus

A

Radial nerve (posterior interosseous branch)

47
Q

Where does extensor pollicis brevis lie

A

Medially and deep to abductor pollicis longus

48
Q

Where does extensor pollicis brevis originate

A

Posterior surface of the radius and interosseous membrane

49
Q

Where does extensor pollicis brevis insert

A

Base of the proximal phalanx of the thumb

50
Q

What is the action of extensor pollicis brevis

A

Extends thumb at MCPJ and carpometacarpal joints

51
Q

Which nerve innervates extensor pollicis brevis

A

Posterior interosseous branch of the radial nerve

52
Q

Where does extensor pollicis longus originate

A

Posterior surface of the ulna and interosseous membrane

53
Q

Where does extensor pollicis longus insert

A

Distal phalanx of the thumb

54
Q

What is the action of extensor pollicis longus

A

Extends all joints of the thumb

55
Q

Which nerve innervates extensor pollicis longus

A

Radial nerve

56
Q

Where does extensor indicis proprius originate

A

Posterior surface of the ulna and interosseous membrane (distal to extensor pollicis longus)

57
Q

Where does extensor indicis proprius insert

A

Extensor hood of the index finger

58
Q

What is the action of extensor indicis proprius

A

Extends index finger

59
Q

Which nerve innervates extensor indicis proprius

A

Posterior interosseous branch of the radial nerve

60
Q

What is a sign of radial nerve damage

A

Wrist drop

61
Q

Where are the common sites of radial nerve damage

A

Axilla

Radial groove of the humerus