L15: Muscles of the Forearm and Hand Flashcards
(76 cards)
1
Q
What are the two compartments of the forearm?
A
- Flexor/anteromedial compartment
- extensor/ posterolateral compartment
2
Q
Flex the wrist =
A
flexor carpi
3
Q
flex digits 2-5 =
A
flexor digitorum
4
Q
flex the pollex =
A
flexor pollicis longus
5
Q
pronate the forearm =
A
pronator
6
Q
extend the wrist =
A
extensor carpi
7
Q
extend the digits =
A
extensor digitorum/ extensor indices/ extensor digiti minimi
8
Q
extend the pollex =
A
extensor pollicis longus
9
Q
abduct the pollex =
A
abductor pollicis longus
10
Q
supinate the forearm =
A
supinator
11
Q
what muscles are on the superficial layer of the flexor (anteromedial) compartment?
A
- pronator teres
- palmaris longus
- flexor carpi radialis
- flexor carpi ulnaris
12
Q
what muscles are in the intermediate layer of the flexor (anteromedial) compartment
A
- flexor digitorum superficialis
13
Q
what muscles are in the deep layer of the flexor (anteromedial) compartment?
A
- flexor digitorum profundus
- flexor pollicis longus
- pronator quadratus
14
Q
common origin of superficial flexor layer muscles?
A
- medial epicondyle of humerus; PT also coronoid process of ulna, FCU also olecranon process
15
Q
Origin/insertion of pronator teres?
A
- medial epicondyle of humerus
- coronoid process of ulna
insertion: lateral midshaft radius
16
Q
origin/insertion of flexor carpi radialis?
A
medial epicondyle of humerus
insertion: bases of metacarpal 2 and 3
17
Q
origin/insertion of palmaris longus?
A
origin: medial epicondyle of humerus
insertion: palmar aponeurosis and flexor retinaculum
18
Q
origin/insertion of flexor carpi ulnaris?
A
origin: medial epicondyle of humerus, also olecranon process
insertion: pisiform bone, hamate bone, and base of metacarpal 5
19
Q
what layer is the flexor digitorum superficialis?
A
intermediate flexor layer
20
Q
structure of flexor digitorum superficialis?
A
- gives rise to four tendons that pass through the carpal tunnel in two pairs - one superficial to the other
21
Q
origin/ insertion of flexor digitorum superficialis
A
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
Q
what layer is the flexor digitorum profundus?
A
deep flexor layer
23
Q
structure of flexor digitorum profundus?
A
- gives rise to four tendons that pass through the carpal tunnel side-by-side
24
Q
origin of flexor digitorum profundus?
A
- 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)
