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):
1

What are the two main muscle groups in the hand?

Extrinsic and intrinsic muscles

2

Where are extrinsic muscles found and what do they do?

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

3

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

Found within the hand and produce fine motor skills.

4

What are the 6 intrinsic muscles of the hand?

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

5

What is B?

Abductor Pollicis Brevis

6

What is the action of the abductor pollicis brevis?

Abducts the thumb

7

What is the innervation of the abductor pollicis brevis?

Median nerve

8

What is A?

Flexor pollicis brevis

9

What is the action of Flexor pollicis brevis?

Flexes the metacarpalphalngeal joint of the thumb

10

What is the innervation of flexor pollicis brevis?

Median nerve

11

What is C?

Oppens pollicis

12

What is the action of oppens pollicis?

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

13

What is the innervation of oppens pollicis?

Median nerve

14

What is the hypothenar eminence?

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

What hand is this?

How can hypothenar and thenar muscles be remembered? 

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

What muscle is A?

Oppens Digiti minimi

17

Where does oppens digiti minimi lie?

Deep to the hypothenar muscles

18

Where does oppens digiti minimi originat from?

The hook of hamate and associated flexor retinaculum

19

What are the actions of the oppens digiti minimi?

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

20

What is the innervation of the opponens digiti minimi?

Ulnar nerve

21

What is A?

Flexor digiti minimi brevis

22

What is the action of flexor digiti minimi brevis?

Flexes the MCP joint of the little finger

23

What is the innervation of flexor digiti minimi brevis

Ulnar nerve

24

What is B?

Abductor Digiti Minimi

25

What is the action of the abductor digiti minimi

Abducts the little finger

26

What is the innervation of the abductor digiti minimi?

Ulnar nerve

27

What is C?

Abductor pollicis brevis

28

What is D?

Flexor pollicis brevis

29

What is A?

Flexor digiti miimi brevis

30

What is B?

Abductor digiti minimi

31

What is A?

Adductor Pollicis

32

What feature of the adductor pollicis is clinically important?

Radial artery passes through the space between its two heads

33

What are the actions of the adductor pollicis?

Adducts the thumb

34

What is the innervation of the adductor pollicis?

Ulnar nerve

35

What is A?

Palmaris Brevis

36

What is the action of palmaris brevis?

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

37

What is the innervation of palmaris brevis?

Ulnar nerve

38

What are the lumbricals?

Four muscles each associated with a finger

39

Why are the lumbricals important to finger movement?

They link the extensor tendons to the flexor tendons

40

What is denervation of these muscles the basis of?

The ulnar claw and the hand of benediction

41

What are the actions of the lumbricals?

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

42

What is the innervation of the lumbricals?

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

43

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

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

44

Where are the interossei muscles located?

Between the metacarpals (interosseous?)

45

What are the two groups of interossei muscles?

The dorsal and palmar interossei

46

What are the overall actions of the interossei?

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

47

What are the muscles shown in the picture known as?

Dorsal interossei

48

What are the actions of the dorsal interossei

Abduct the fingers at the MCP

49

What is the innervation of the dorsal interossei?

Ulnar nerve

50

What are the muscles shown in the picture?

Palmar interossei

51

What is the action of the palmar interossei?

Adducts the fingers at the MCP joint

52

What is the innervation of the palmar interossei?

Ulnar nerve

53

What is the carpal tunnel?

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

54

What is the carpal tunnel made up of?

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

55

What are the contents of the carpal tunnel?

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

 

56

What is carpal tunnel syndrome?

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

57

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

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

Caused by compression of median nerve

58

How can carpal tunnel be treated?

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