L15: Muscles of the Forearm and Hand Flashcards Preview

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Flashcards in L15: Muscles of the Forearm and Hand Deck (76):
1

What are the two compartments of the forearm?

- Flexor/anteromedial compartment
- extensor/ posterolateral compartment

2

Flex the wrist =

flexor carpi

3

flex digits 2-5 =

flexor digitorum

4

flex the pollex =

flexor pollicis longus

5

pronate the forearm =

pronator

6

extend the wrist =

extensor carpi

7

extend the digits =

extensor digitorum/ extensor indices/ extensor digiti minimi

8

extend the pollex =

extensor pollicis longus

9

abduct the pollex =

abductor pollicis longus

10

supinate the forearm =

supinator

11

what muscles are on the superficial layer of the flexor (anteromedial) compartment?

- pronator teres
- palmaris longus
- flexor carpi radialis
- flexor carpi ulnaris

12

what muscles are in the intermediate layer of the flexor (anteromedial) compartment

- flexor digitorum superficialis

13

what muscles are in the deep layer of the flexor (anteromedial) compartment?

- flexor digitorum profundus
- flexor pollicis longus
- pronator quadratus

14

common origin of superficial flexor layer muscles?

- medial epicondyle of humerus; PT also coronoid process of ulna, FCU also olecranon process

15

Origin/insertion of pronator teres?

- medial epicondyle of humerus
- coronoid process of ulna

insertion: lateral midshaft radius

16

origin/insertion of flexor carpi radialis?

medial epicondyle of humerus

insertion: bases of metacarpal 2 and 3

17

origin/insertion of palmaris longus?

origin: medial epicondyle of humerus

insertion: palmar aponeurosis and flexor retinaculum

18

origin/insertion of flexor carpi ulnaris?

origin: medial epicondyle of humerus, also olecranon process

insertion: pisiform bone, hamate bone, and base of metacarpal 5

19

what layer is the flexor digitorum superficialis?

intermediate flexor layer

20

structure of flexor digitorum superficialis?

- gives rise to four tendons that pass through the carpal tunnel in two pairs - one superficial to the other

21

origin/ insertion of flexor digitorum superficialis

origin: medial epicondyle of humerus and adjacent anterior surfaces of ulna and radius

insertion: mid-lateral surfaces of middle phalanges of fingers 2-5

22

what layer is the flexor digitorum profundus?

deep flexor layer

23

structure of flexor digitorum profundus?

- gives rise to four tendons that pass through the carpal tunnel side-by-side

24

origin of flexor digitorum profundus?

- medial and posterior surfaces of ulna, medial surface of coronoid process, and interosseous membrane

25

insertion of flexor digitorum profundus

bases of distal phalanges of fingers 2-5

26

layer of flexor pollicis longus?

deep flexor layer

27

structure of flexor pollicis longus?

unipennate

28

origin/insertion of flexor pollicis longus?

origin: anterior shaft of radius and interosseous membrane

insertion: base of distal phalanx of thumb

29

What is carpal tunnel syndrome?

- median nerve compression due to swelling of tendon sheathes due to repetitive flexion-extension

30

what layer is the pronator quadratus?

deep flexor layer

31

structure of pronator quadratus

square and flat

32

origin/insertion of pronator quadratus

origin: anterior and medial surfaces of distal ulna

insertion: anterolateral surface of distal portion of radius

33

what are forearm pronators ?

- when fibres shorten the radius is pulled/rotated towards/ around the fixed ulna.

34

what muscles are in the superficial layer of the extensor compartment?

- brachioradialis
- extensor carpi radialis longus
- extensor carpi radialis brevis
- extensor digitorum
- extensor digiti minimi
- extensor carpi ulnaris

35

what muscles are in the deep layer of the extensor compartment?

- supinator
- extensor indicis
- 3 thumb muscles (abductor pollicis longus, abductor pollicis brevis, extensor pollicis longus)

36

what layer is the brachioradialis in?

superficial extensor layer

37

origin/insertion of brachioradialis?

origin: lateral supracondylar ridge of distal humerus
insertion: styloid process of radius

38

what layer is the extensor carpi ulnaris in?

superficial extensor layer

39

origin/insertion of extensor carpi ulnaris?

origin: lateral epicondyle of humerus

insertion: base of fifth metacarpal

40

what layer is the extensor digitorum?

superficial extensor layer

41

origin/ insertion of extensor digitorum?

origin: lateral epicondyle of humerus

insertion: four tendons into extensor expansions and distal phalanges of digits 2-5

42

what layer is the extensor digiti minimi in?

superficial extensor layer

43

origin/insertion of extensor digiti minimi?

origin: lateral epicondyle of humerus

insertion: posterior surface of proximal phalanx of little finger (5)

44

independent action of some digits is limited by??

connexus intertendineus

45

what layer is the extensor carpi radialis longus in?

superficial extensor layer

46

origin/insertion of extensor carpi radialis longus?

origin: lateral supracondylar ridge of humerus

insertion: base of metacarpal 2

47

layer of extensor carpi radialis brevis?

superficial extensor layer

48

origin/ insertion of carpi radialis brevis?

origin: lateral epicondyle of humerus

insertion: base of metacarpal 3

49

the extensor carpi radialis longus and extensor carpi radialis brevis start off superficial but travel??

deep distally

50

in the deep extensor layer, what are the pollicis muscles?

- abductor pollicis longus
- extensor pollicis brevis
- extensor pollicis longus

51

what layer is the supinator in?

deep extensor layer

52

origin/insertion of supinator?

origin: lateral epicondyle of humerus and proximal ulna

insertion: proximal radius

53

what is the other supinator of the forearm/hand?

biceps brachii

54

function of supinator?

- supinate the forearm
- wraps around radius when hand is moved into pronated position, lengthening its fibres
- concentric contraction of fibres reverses movement drawing it back into supinated position

55

what layer is the abductor pollicis longus in?

deep extensor layer

56

origin/insertion of abductor pollicis longus?

origin: dorsal shaft of radius and ulna

insertion: lateral MC I (and trapezium)

57

what layer are the extensor pollicis longus and extensor pollicis brevis in?

deep extensor layer

58

origin/ insertion of extensor pollicis longus and extensor pollicis brevis ?

origin: dorsal shaft of radius/ ulna and interosseous membrane

insertion:
brevis = base of proximal phalanx of thumb
longus= base of distal phalanx of thumb

59

what comprises the lateral wall of the anatomical snuff box

abductor pollicis longus and extensor pollicis brevis

60

medial wall of anatomical snuff box?

extensor pollicis longus

61

floor of anatomical snuff box?

mostly scaphoid, but also styloid process of radius (proximally) and trapezium (distally)

62

what layer is the extensor indicis?

deep extensor layer

63

origin/insertion of extensor indicis

origin: posterior surface of distal ulna and interosseous membrane

insertion: extensor expansion of index finger (joins tendon of ext. digitorum)

64

many forearm muscles cross the wrist and therefore?

may exert an action on the wrist joint

65

what are the 6 dedicated wrist muscles ?

- flexor carpi ulnaris
- extensor carpi ulnaris
- extensor carpi radialis brevis
- extensor carpi radialis longus
- flexor carpi radialis
- palmaris longus

66

function of muscles within the hand?

precision movements

67

what muscle makes up the hypothenar compartment?

digiti minimi

68

what muscle makes up the thenar compartment

pollicis

69

lumbricals means?

earthworm

70

origin/ insertion of lumbricals?

origin: tendon of flexor digitorum profundus

insertion: lateral edge of extensor expansion on first phalanx of digits 2-5

71

function of lumbricals?

flexes metacarpophalangeal joints but EXTENDS interphalangeal joints

72

nerve supply to lumbricals?

unlar nerve = claw hand

73

origin/ insertion of palmar interossei?

origin: side of metacarpals facing digit 3 (absent from this bone)

insertion: extensor expansion of first phalanx (except 3) on same side

74

function of palmar interossei?

adductors of digits (=PAD)

75

origin/insertion of dorsal interossei?

origin: sides of metacarpals

insertion: extensor expansion over first phalanx of digits 2-4 on both sides of no.3, but opposite for the other digits

76

function of dorsal interossei?

abductors of digits (=DAB)