Session 6 - Muscles of the hand Flashcards Preview

Semester 2 - MSK > Session 6 - Muscles of the hand > Flashcards

Flashcards in Session 6 - Muscles of the hand Deck (58)
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1
Q

What are the two main muscle groups in the hand?

A

Extrinsic and intrinsic muscles

2
Q

Where are extrinsic muscles found and what do they do?

A

Found in the forearm and largely produce the forceful grip of the hand

3
Q

Where are intrinsic muscles found and what actions are they responsible?

A

Found within the hand and produce fine motor skills.

4
Q

What are the 6 intrinsic muscles of the hand?

A

Adductor pollicis, interossei, thenar, palmaris brevis, lumbricals and hypothenar muscles.

5
Q

What is B?

A

Abductor Pollicis Brevis

6
Q

What is the action of the abductor pollicis brevis?

A

Abducts the thumb

7
Q

What is the innervation of the abductor pollicis brevis?

A

Median nerve

8
Q

What is A?

A

Flexor pollicis brevis

9
Q

What is the action of Flexor pollicis brevis?

A

Flexes the metacarpalphalngeal joint of the thumb

10
Q

What is the innervation of flexor pollicis brevis?

A

Median nerve

11
Q

What is C?

A

Oppens pollicis

12
Q

What is the action of oppens pollicis?

A

Opposes the thumb by medially rotating and flexing the metacarpal on the trapezium

13
Q

What is the innervation of oppens pollicis?

A

Median nerve

14
Q

What is the hypothenar eminence?

A

A small eminence on the medial side of the palm at the base of the little finger, made up of three hypothenar muscles

  • Abductor digiti minimi
  • Flexor digiti minimi brevis
  • Opponens digiti minimi

 

15
Q

What hand is this?

How can hypothenar and thenar muscles be remembered? 

A

Right

A of A of A

Abductor pollicis brevis, Opponens pollicis, Flexor pollicis brevis, Adductor pollicis,  (thenar muscles)

Opponens digiti minimi, Flexor digiti minimi, Abductor digiti minimi (Hypothenar muscles)

16
Q

What muscle is A?

A

Oppens Digiti minimi

17
Q

Where does oppens digiti minimi lie?

A

Deep to the hypothenar muscles

18
Q

Where does oppens digiti minimi originat from?

A

The hook of hamate and associated flexor retinaculum

19
Q

What are the actions of the oppens digiti minimi?

A

Rotates the metacarpal of the little finger towards the palm, producing opposition

20
Q

What is the innervation of the opponens digiti minimi?

A

Ulnar nerve

21
Q

What is A?

A

Flexor digiti minimi brevis

22
Q

What is the action of flexor digiti minimi brevis?

A

Flexes the MCP joint of the little finger

23
Q

What is the innervation of flexor digiti minimi brevis

A

Ulnar nerve

24
Q

What is B?

A

Abductor Digiti Minimi

25
Q

What is the action of the abductor digiti minimi

A

Abducts the little finger

26
Q

What is the innervation of the abductor digiti minimi?

A

Ulnar nerve

27
Q

What is C?

A

Abductor pollicis brevis

28
Q

What is D?

A

Flexor pollicis brevis

29
Q

What is A?

A

Flexor digiti miimi brevis

30
Q

What is B?

A

Abductor digiti minimi

31
Q

What is A?

A

Adductor Pollicis

32
Q

What feature of the adductor pollicis is clinically important?

A

Radial artery passes through the space between its two heads

33
Q

What are the actions of the adductor pollicis?

A

Adducts the thumb

34
Q

What is the innervation of the adductor pollicis?

A

Ulnar nerve

35
Q

What is A?

A

Palmaris Brevis

36
Q

What is the action of palmaris brevis?

A

Wrinkles the skin of the hypothenar eminence and deepens the curvature of the hand, improving grip

37
Q

What is the innervation of palmaris brevis?

A

Ulnar nerve

38
Q

What are the lumbricals?

A

Four muscles each associated with a finger

39
Q

Why are the lumbricals important to finger movement?

A

They link the extensor tendons to the flexor tendons

40
Q

What is denervation of these muscles the basis of?

A

The ulnar claw and the hand of benediction

41
Q

What are the actions of the lumbricals?

A

They flex at the MCP joint and extend at the IP joints of each finger

42
Q

What is the innervation of the lumbricals?

A

The medial two lumbricals are innervated by the ulnar nerve. THe lateral two lumricals are innervated by the median nerve.

43
Q

What muscles are shown in the picture and how are they named?

A

Lumbrical muscles Numbered 1-4, with 1 being most lateral

44
Q

Where are the interossei muscles located?

A

Between the metacarpals (interosseous?)

45
Q

What are the two groups of interossei muscles?

A

The dorsal and palmar interossei

46
Q

What are the overall actions of the interossei?

A

Assist the lumbricals in flexion of the MCP, and extension at the IP joint

47
Q

What are the muscles shown in the picture known as?

A

Dorsal interossei

48
Q

What are the actions of the dorsal interossei

A

Abduct the fingers at the MCP

49
Q

What is the innervation of the dorsal interossei?

A

Ulnar nerve

50
Q

What are the muscles shown in the picture?

A

Palmar interossei

51
Q

What is the action of the palmar interossei?

A

Adducts the fingers at the MCP joint

52
Q

What is the innervation of the palmar interossei?

A

Ulnar nerve

53
Q

What is the carpal tunnel?

A

The carpal tunnels form an arch which has its base at the dorsum side of the hand.

54
Q

What is the carpal tunnel made up of?

A

Flexor retinaculum - Roof Pisifor and trapexium - sides Hamate, capitate and trapezoid - floor

55
Q

What are the contents of the carpal tunnel?

A

Median nerve and finger flexor tendons (flexor digitorum superficialis, flexor digitorum profundus and flexor pollicis longus)

 

56
Q

What is carpal tunnel syndrome?

A

Results from any lesion that significantly reduces the size of the carpal tunnel

57
Q

What are the symptoms of carpal tunnel syndrome, and how are they caused?

A

Paresthesia, hypothesthesia, anesthesisa. Progressive loss of coordination and strength in thumb, and inability to oppose thumb.

Caused by compression of median nerve

58
Q

How can carpal tunnel be treated?

A

Partial or complete surgical division of th flexor retinaculum may be necessary.