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Flashcards in upper limb muscles Deck (52)
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1

extrinsic muscles (back)

originate from torso
attach to bones of the shoulder (clavicle, scapula or humerus) organ used into superficial and deep layer

2

trapezius

extrinsic, superficial muscle in the back
origin: skull, nuchal ligament and spinous processes fo C7-T12
insertion: clavicle, acromion and scapula spine
innervation: motor - accessory nerve, proprioceptive - C3, C4
blood supply: cervicodorsal trunk
actions:
- upper fibres - elevate scapula and rotate it during arm abduction
- middle fibres: retract scapula
- lower fibres: pull scapula inferiorly

3

latissimus dorsi

extrinsic, superficial muscle in the back
strap-like muscle
origin: spinous processes of T7-T12, iliac crest, thoracolumbar fascia abd inferior 3 ribs
insertion: fibres converge into tendon attaching to intertubercular surface of sulcus of the humerus
innervation: thoracodorsal nerve
blood supply: thoracodorsal artery
actions: on upper limb
- extension
- adduction
- medial rotation

4

levator scapulae

deep, extrinsic muscle in the back
origin: transverse processes fo C1-C4
insertion: medial border of scapula
innervation: dorsal scapular nerve
blood supply: dorsal scapular artery
actions: elevates scapula

5

rhomboid major

deep, extrinsic muscle in the back
inferior to rhomboid minor
origin: spinous processes of T2-T5 vertebrae
insertion: medial border of the scapula
innervation: dorsal scapular nerve
blood supply: dorsal scapular artery
actions: retracts and rotates scapula

6

rhomboid minor

deep, extrinsic muscle in the back
superior to rhomboid major
origin: spinous processes of C7-T1 vertebrae
insertion: medial border of the scapula
innervation: dorsal scapular nerve
blood supply: dorsal scapular artery
actions: retracts and rotates scapula

7

anterior compartment (upper arm)

biceps brachii, coracobrachialis, brachialis
all innervated by musculocutaneous nerve
all supplied by branches of brachial artery

8

biceps brachii

anterior compartment of upper arm
2 headed, enters forearm and blends with deep fascia
innervation: musculocutaneous nerve
blood supply: brachial artery
origin:
- long head, supraglenoid tubercle of scapula
- short head, coracoid process
insertion: radial tuberosity via bicipital aponeurosis
actions:
- supination of forearm
- flexes arm at elbow and shoulder

9

coracobrachialis

anterior compartment of upper arm
origin: coracoid process
insertion: medial side of humeral shaft
innervation: musculocutaneous nerve
blood supply: brachial artery
actions:
- flexion of arm at the shoulder
- weak adduction of arm

10

brachialis

anterior compartment of upper arm
origin: medial and lateral surfaces of humeral shaft
insertion: ulna tuberosity
innervation: musculocutaneous nerve
blood supply: brachial artery
actions: flexion at elbow

11

posterior compartment (arm)

triceps brachii

12

triceps brachii

3 heads
origin:
- long head: infraglenoid tubercle
- lateral head: humerus, superior to radial groove
- medial head: humerus, inferior to radial groove
insertion: heads converge to one tendon - olecranon of the ulna
innervation: radial nerve
blood supply: profunda brachia artery

13

anterior compartment (forearm)

3 compartments: superficial, intermediate and deep

14

forearm - anterior, superficial compartment

flexor carpi ulnaris, palmaris longus, flexor carpi radialis, pronator teres
originate from common tendon - arises from medial epicondyle of humerus

15

flexor carpi ulnaris

in superficial, anterior compartment of forearm
origin: medial epicondyle + long origin from ulna
insertion: pisiform carpal bone
innervation: ulnar nerve
blood supply: ulnar artery
actions: flexion and adduction at wrist

16

palmaris longus

in superficial, anterior compartment of forearm
absent in ~15% population
origin: medial epicondyle
insertion: flexor retinaculum
innervation: median nerve
blood supply: ulnar artery
actions: flexion at the wrist

17

flexor carpi radialis

in superficial, anterior compartment of forearm
origin: medial epicondyle
insertion: base of metacarpals II and III
innervation: median nerve
blood supply: ulnar artery
actions: flexion and abduction at the wrist

18

pronator teres

in superficial, anterior compartment of forearm
origin: 2
- medial epicondyle
- coracoid process of ulna
insertion: laterally to mid-shaft of radius
innervation: median nerve
blood supply: ulnar, common interosseous arteries
actions: pronation of forearm

19

flexor digitorum superficialis

in intermediate, anterior compartment of forearm
median nerve and ulnar artery pass between its 2 heads
origin:
- one head from medial epicondyle
- one head from radius
insertion: middle phalanges of 4 fingers (tendons pass through carpal tunnel)
innervation: median nerve
actions:
- flexes wrist
- flexes metacarpophalangeal joints and proximal interphalangeal joints

20

forearm - anterior, deep compartment

3 muscles
flexor digitorum profundus, flexor pollicis longus, pronator quadratus

21

flexor digitorum profundus

in deep, anterior compartment of forearm
origin: ulna and associated interosseous membrane
insertion: distal phalanges of four fingers
(tendons pass through carpal tunnel)
innervation:
- medial half, ulnar nerve
- lateral half, median nerve
actions: flex interphalangeal joints and metacarpophalangeal joints and wrist

22

flexor pollicis longus

in deep, anterior compartment of forearm
origin: anterior surface of radius and surrounding interosseous membrane
insertion: base of distal phalanx of the thumb
innervation: median nerve
actions: flex interphalangeal joints and metacarpophalangeal joint of thumb

23

pronator quadratus

in deep, anterior compartment of forearm
origin: anterior surface of ulna
insertion: anterior surface on radius
innervation: median nerve
actions: pronates forearm

24

posterior compartment (forearm)

extensor muscles
all innervated by radial nerve
2 layers: deep and superficial

25

forearm - posterior, superficial compartment

7 muscles
4 share common tendinous origin at lateral epicondyle
brachioradialis, extensor carpi radialis longus and brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, aconeus

26

brachioradialis

in superficial, posterior compartment of forearm
origin: proximal aspect of lateral supracondylar ridge off humerus
insertion: distal end of radius
innervation: radial nerve
actions: flexes elbow

27

extensor carpi radialis longus and brevis

in superficial, posterior compartment of forearm
origin:
- longus, supracondylar ridge
- brevis, lateral epicondyle
insertion: metacarpal bones I and II
innervation: radial nerve
actions: extends and abducts wrist

28

extensor digitorum

in superficial, posterior compartment of forearm
main extensor of fingers
origin: lateral epicondyle
insertion: extensor hood of each finger
innervation: radial nerve
actions: extends medial 4 fingers at metacarpophalangeal and interphalangeal joints

29

extensor digiti minimi

in superficial, posterior compartment of forearm
lies medially to extensor digitorum
origin: lateral epicondyle of humerus
insertion: extensor hood of little finger
innervation: radial nerve
actions: extends little finger, contributes to wrist

30

extensor carpi ulnaris

in superficial, posterior compartment of forearm
origin: lateral epicondyle of humerus
insertion: base of metacarpal V
innervation: radial nerve
actions: extension and adduction of wrist

31

aconeus

in superficial, posterior compartment of forearm
blended with fibres to triceps
origin: lateral epicondyle
insertion: posterior and lateral part of olecranon
innervation: radial nerve
actions:
- extends and stabilises elbow joint
- adducts ulna during pronation of forearm

32

forearm - posterior, deep compartment

act on thumb and index finger (exception of supinator)
5 muscles
supinator, abductor pollicis longus, extensor pollicis brevis
extensor pollicis longus, extensor indicis proprius

33

supinator

in deep, posterior compartment of forearm
in floor of cubital fossa
branch of radial artery passes between heads
origin: 2 heads
- one from lateral epicondyle of humerus
- one from posterior surface of ulna
insertion: posterior surface of radius
actions: supinates forearm

34

abductor pollicis longus

in deep, posterior compartment of forearm
tendon contributes to lateral border of anatomical snuffbox
origin: posterior surface of radius and interosseous membrane
insertion: lateral side of base of metacarpal I
innervation: radial nerve
actions: abducts thumb

35

extensor pollicis brevis

in deep, posterior compartment of forearm
tendon contributes to lateral border of anatomical snuffbox
origin: posterior surface of radius and interosseous membrane
insertion: base of proximal phalanx in thumb
innervation: radial nerve
actions: extends metacarpophalangeal and carpometacarpal joints of thumb

36

extensor pollicis longus

in deep, posterior compartment of forearm
tendon forms medial border of anatomical snuffbox
tendon travels medially to dorsal tubercle to act as pulley
origin: posterior surface of ulnar and interosseous membrane
insertion: distal phalanx of thumb
innervation: radial nerve
actions: extends all joints of the thumb (carpometacarpal, metacarpophalangeal, interphalangeal)

37

extensor indicis proprius

in deep, posterior compartment of forearm
allows index finger to be independent of other fingers during extension
origin: posterior surface of ulna and interosseous membrane
insertion: extensor hood of index finger
innervation: radial nerve
actions: extends index finger

38

intrinsic muscles of the hand

located within the hand
control fine motor functions
thenar, hypothenar, lumbricals, interossei, palmaris brevis, adductor pollicis

39

thenar muscles

3 short muscles at base of thumb
produce bulge = thenar eminence
responsible for fine movements of the thumb
innervated by median nerve
opponens pollici, abductor pollicis brevis, flexor pollicis brevis

40

opponens brevis

thenar muscle (largest), underneath other 2
origin: tubercle of trapezium and associated flexor retinaculum
insertion: lateral margin of metacarpal of thumb
innervation: median nerve
actions:
- opposes thumb
- medially rotates and flexes metacarpal on trapezium

41

abductor pollicis brevis

thenar muscle - proximal to flexor pollicis brevis
origin: tubercles of scaphoid and trapezium and associated flexor retinaculum
insertion: lateral side of proximal phalanx fo thumb
innervation: median nerve
actions: abducts thumb

42

flexor pollicis brevis

thenar muscle, most distal
origin: tubercle of trapezium and associated flexor retinaculum
insertion: base of proximal phalanx of thumb
innervation: median nerve
actions: flexes metacarpophalangeal joint of thumb

43

hypothenar muscles

produce hypothenar eminence - muscular protrusion at base of little finger
similar to thenar muscles
all innervated by ulnar nerve
opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis

44

opponens digiti minimi

deep to other hypothenar muscles
origin: hook of hamate and associated flexor retinaculum
insertion: medial margin of metacarpal V
innervation: ulnar nerve
actions: rotates metacarpal of little finger towards palm - produces opposition

45

abductor digiti minimi

most superficial of hypothenar muscles
origin: pisiform and tendon of flexor carpi radials
insertion: base or proximal phalanx of little finger
innervation: ulnar nerve
actions: abducts little finger

46

flexor digiti minimi brevis

lateral to abductor digiti minimi
origin: hook of hamate and adjacent flexor retinaculum
insertion: base of proximal phlanax of little finger
innervation: ulnar nerve
actions: flexes MCP joint of little finger

47

lumbricals

4 in each hand, associated with each finger
crucial to finger movement - links extensor and flexor tendons
origin: tendon of flexor digitorum profundus
insertion: extensor hood
- each passes dorsally and laterally around each finger
innervation:
- lateral, median nerve
- medial, ulnar nerve
actions:
- flex at metacarpophalangeal joint
- extend at interphalangeal joint

48

interossei

intrinsic hand muscles
between metacarpals
divided in too 2 groups: dorsal and planar
assist lumbricals + own actions

49

dorsal interossei

most superficial of all dorsal muscles (palpable)
4 muscles
origin: lateral and medial surfaces of metacarpals
insertion: extensor hood and proximal phalanx of each finger
innervation: ulnar nerve
actions: abducts fingers at MCP joints

50

palmar interossei

located anteriorly on hand
3 muscles
origin: medial or lateral surface of a metacarpal
insertion: extensor hood and proximal phalanx of same finger
innervation: ulnar
actions: adducts fingers at MCP joints

51

palmaris brevis

small thin muscle, superficial in subcutaneous tissue of hypothenar eminence
origin: palmar aponeurosis and flexor retinaculum
insertion: dermis of skin on medial margin of hand
innervation: ulnar nerve
actions:
- wrinkles skin of hypothenar eminence
- deepens curvature of hand

52

adductor pollicis

triangular muscle with 2 heads
radial artery passes anteriorly between 2 heads
origin:
- one head from metacarpal III
- one head from capitate and adjacent areas of metacarpals II and III
insertion: base of proximal phalanx off thumb
innervation: ulnar nerve
actions: adductor of thumb