Muscles of the Hand Flashcards Preview

ESA 2- Musculoskeletal System > Muscles of the Hand > Flashcards

Flashcards in Muscles of the Hand Deck (73):
1

What can the muscles acting on the hand be divided into?

Two groups, extrinsic and intrinsic muscles

2

Where are the extrinsic hand muscles located?

In the anterior and posterior compartment of the forearm

3

What are the extrinsic hand muscles responsible for?

Control crude movements 
Produce forceful grip

4

Where are the intrinsic muscles of the hand located?

Within the hand itself

5

What are the intrinsic muscles of the hand responsible for?

Fine motor functions of the hand

6

What are the intrinsic muscles of the hand?

Adductor pollicis 
Interossei 
Thenar muscles 
Lumbricals 
Hypothenar muscles

7

What are the thenar muscles?

Three short muscles, the oppens pollicis, abductor pollicis brevis, and flexor pollicis brevis

8

Where are the thenar muscles located?

At the base of the thumb

9

What do the muscle bellies of the thenar muscles produce?

A bulge, known as the thenar eminence

10

What are the thenar muscles responsible for?

The fine movements of the thumb

11

What innervates the thenar muscles?

The median nerve

12

What is the largest of the thenar muscles?

Opponens Pollicis

13

Where does the oppenens pollicis lie?

Underneath the other two thenar muscles

14

What is the innervation of the opponens pollicis?

Recurrent branch of the median nerve (C8, T1)

15

What is the arterial supply of the opponens pollicis?

Superficial palmar branch of radial artery

16

What is the action of the opponens pollicis?

To oppose thumb, it draws 1st metacarpal medially to centre or palm and rotates it medially

17

Where is the abductor pollicis brevis found?

Anteriorly to the opponens pollicis, and proximal to the flexor pollicis brevis

18

What is the innervation of the abductor pollicis brevis?

Recurrent branch of medial nerve (C8, T1)

19

What is the arterial supply of the abductor pollicis brevis?

Superficial palmar branch of radial artery

20

What is the main action of the abductor pollicis brevis?

Abducts thumb, helps oppose it

21

Where is the flexor pollicis brevis found?

The most distal of the thenar muscles

22

What does the flexor pollicis brevis have?

Superficial head and deep head

23

What is the innervation of the superficial head of the flexor pollicis brevis?

Recurrent branch of median nerve (C8, T1)

24

What is the innervation of the deep head of the flexor pollicis brevis?

Deep branch of ulnar nerve (C8, T1)

25

What is the arterial supply of the flexor pollicis brevis?

Superficial palmar branch of radial artery

26

What is the main action of the flexor pollicis brevis?

Flexes thumb

27

What do the hypothenar muscles produce?

The hypothenar eminence

28

What is the hypothenar eminence?

A muscular protrusion on the medial side of the palm, at the base of the little finger

29

What are the hypothenar muscles?

Abductor digiti minimi
Flexor digiti minimi brevis 
Opponens digiti minimi

30

Where does the opponens digiti minimi lie?

Deep to the other hypothenar muscles

31

What is the innervation of the opponens digiti minimi?

Deep branch of ulnar nerve (C8, T1)

32

What is the arterial supply of the opponens digiti minimi?

Ulnar artery

33

What is the main action of the opponens digiti minimi?

Draws the 5th metacarpal anterior and rotates it, bringing 5th digit into opposition with thumb

34

Where does the abductor digiti minimi lie?

Most superficial of hypothenar muscles

35

What is the innervation of the abductor digiti minimi?

Deep branch of the ulnar nerve (C8, T1)

36

What is the arterial supply of the abductor digiti minimi?

Ulnar artery

37

What is the main action of the abductor digiti minimi?

Abducts 5th digit, assists in flexion of its proximal phalanx

38

Where does the flexor digiti minimi brevis lie?

Laterally to the abductor digiti minimi

39

What is the innervation of the flexor digiti minimi brevis?

Deep branch of ulnar nerve (C8, T1)

40

What is the arterial supply of the flexor digiti minimi brevis?

Ulnar artery

41

What is the main action of the flexor digiti minimi brevis?

Flexes proximal phalanx of 5th digit

42

How many lumbricals are there in the hand?

Four, one associated with each finger

43

What do the lumbricals do?

Link the extensor tendons to the flexor tendons

44

What is denervation of the lumbricals the basis of?

The ulnar claw and hand of benediction

45

What kind of muscles are the 1st and 2nd lumbricals?

Unipennate

46

What kind of muscles are the 3rd and 4th lumbricals?

Bipennate

47

What the the innervation of the 1st and 2nd lumbricals?

Median nerve (C8, T1)

48

What is the innervation of the 3rd and 4th lumbricals?

Deep branch of ulnar nerve (C8, T1)

49

What is the arterial supply of the lumbricals?

Superficial palmar arterial arch

50

What is the main action of the lumbricals?

Flex metacarpophalangeal joints 
Extend interphalangeal joints of 2nd-5th digits

51

Where are the interossei muscles located?

Between the metacarpals

52

What can the interossei muscles be divided into?

Two groups, the dorsal and palmar interossei

53

How many dorsal interossei muscles are there?

4

54

What kind of muscles are the dorsal interossei?

Bipennate

55

What is the innervation of the dorsal interossei?

Deep branch of ulnar nerve (C8, T1)

56

What is the arterial supply of the dorsal interossei?

Palmar metacarpal arteries 
Dorsal metacarpal arteries

57

What is the main action of the dorsal interossei?

Abduct 2nd-4th digits from axial line 
Act with lumbricals in flexing the metacarpophalangeal joints, and extending the interphalangeal joints

58

Where are the palmar interossei muscles located?

Anteriorly on the hand

59

How many palmar interossei are there?

3

60

What kind of muscles are the palmar interossei?

Unipennate

61

What is the innervation of the palmar interossei?

Deep branch of ulnar nerve (C8, T1)

62

What is the arterial supply of the palmar interossei?

Palmar metacarpal arteries

63

What is the main action of the palmar interossei?

Adduct 2nd, 4th and 5th digits toward axial line 
Assist lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints 
Extensor expansions of 2nd-4th joints

64

What is the palmaris brevis?

A small, thin muscle

65

Where is the palmaris brevis found?

Very superficially in the subcutaneous tissue of the hypothenar eminence

66

What is the innervation of the palmaris brevis?

Ulnar nerve

67

What are the actions of the palmaris brevis?

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

68

What shape is the adductor pollicis?

Large, triangular

69

What does the adductor pollicis have?

Two heads, oblique and transverse

70

How is the adductor pollicis involved in forming the deep palmar arch?

The radial artery passes anteriorly through the space between the two heads, forming the arch

71

What is the innervation of the adductor pollicis?

Deep branch of ulnar nerve (C8, T1)

72

What is the arterial supply of the adductor pollicis?

Deep palmar arterial arch

73

What is the main action of the adductor pollicis?

Adducts thumb toward lateral border of palm