Posterior forearm and dorsum of the hand

Question 1

what is the origin and insertion of anconeus

Answer 1

lateral epicondyle of humerus to olecranon of ulna

Question 2

what is the function of anconeus

Answer 2

extension of elbow

Question 3

what is the nerve supply of anconeus

Answer 3

radial nerve (C7-C8 (T1))

Question 4

is anconeus part of the posterior compartment of the arm

Answer 4

may be considered as part of posterior compartment of forearm but lies on posterior surface of elbow

Question 5

is brachioradialis part of the posterior compartment of the forearm

Answer 5

may be considered as part of the posterior compartment of the forearm but lies on lateral surface of the forearm

Question 6

what is the origin and insertion of brachioradialis

Answer 6

distal humerus (supra-epicondylar ridge) to radius proximal to styloid process

Question 7

what is the function of brachioradialis

Answer 7

flexion of elbow, especially when forearm is in the semi-prone position

Question 8

what is the innervation of brachioradialis

Answer 8

radial nerve (C5,C6,C7) (before division into deep and superficial)

Question 9

brachioradialis crosses the ____ surface of the elbow

Answer 9

anterior

Question 10

anconeus crosses the ____ surface of the elbow

Answer 10

posterior

Question 11

where is the common extensor origin

Answer 11

lateral epicondyle of the humerus

Question 12

what is the function of the muscles in the posterior compartment of the forearm

Answer 12

extensors of the digits and wrist and adductor of the thumb and supinator

Question 13

what is the main nerve of the posterior compartment of the forearm

Answer 13

radial nerve

Question 14

what is the origin and insertion of extensor carpi radialis longus

Answer 14

distal humerus (supra-epicondylar ridge) to base of 2nd metacarpal

Question 15

what is the function of extensor carpi radialis longus

Answer 15

wrist extension and abduction

Question 16

what is the innervation of extensor carpi radialis longus

Answer 16

radial nerve (C6,C7) pre-division

Question 17

what is the origin and insertion of extensor carpi radialis brevis

Answer 17

lateral epicondyle of humerus to base of 3rd metacarpal

Question 18

what is the function of extensor carpi radialis brevis

Answer 18

wrist extension and abduction

Question 19

what is the innervation of extensor carpi radialis brevis

Answer 19

radial nerve (C7,C8) posterior interosseous branch

Question 20

extensor carpi radialis longus and brevis act with what muscle to abduct the wrist

Answer 20

flexor carpi radialis

Question 21

the radial nerve divides to give what

Answer 21

superficial sensory branch and a deeper motor branch

Question 22

what are the muscles supplied by the radial nerve before it divides

Answer 22

triceps brachii
anconeus
brachioradialis
extensor carpi radialis longus

Question 23

what is the origin and insertion of extensor carpi ulnaris

Answer 23

lateral epicondyle of humerus (small slip from ulna) to base of 5th metacarpal

Question 24

what is the function of extensor carpi ulnaris

Answer 24

wrist extension and adduction

Question 25

what is the innervation of extensor carpi ulnaris

Answer 25

radial nerve (posterior interosseous) (C7, C8)

Question 26

extensor carpi ulnaris acts with what muscle to adduct the wrist

Answer 26

flexor carpi ulnaris

Question 27

what is the origin and insertion of extensor digitorum

Answer 27

lateral epicondyle of humerus to dorsal expansion of digits 2-5 (not thumb)

Question 28

what is the function of extensor digitorum

Answer 28

extension of principally MCP but also PIP and DIP of digits 2-5 extends wrist

Question 29

what is the innervation of extensor digitorum

Answer 29

radial nerve (posterior interosseous) (C7, C8)

Question 30

as it nears the wrist extensor digitorum forms what

Answer 30

4 tendons - one for each finger

Question 31

what holds the tendons of extensor digitorum against the distal forearm

Answer 31

extensor retinaculum

Question 32

what is the origin and insertion of extensor digiti minimi

Answer 32

lateral epicondyle of the humerus to dorsal expansion of 5th digit

Question 33

what is the function of extensor digiti minimi

Answer 33

MCP PIP DIP extension of little finger | wrist extension

Question 34

what is the innervation of extensor digiti minimi

Answer 34

radial nerve (posterior interosseous branch) (C7, C8)

Question 35

why do we have an extra extensor for the little finger

Answer 35

support medial side of the hand against a surface when performing precision movements with the thumb and index finger e.g. writing

Question 36

what is the origin and insertion of extensor indicis

Answer 36

posterior surface of ulna (and interosseous membrane) to dorsal expansion of digit 2 (index finger)

Question 37

what is the function of extensor indicis

Answer 37

MCP PIP DIP extension of index finger | wrist extension

Question 38

what is the innervation of extensor indicis

Answer 38

radial nerve (posterior interosseous branch) (C7,C8)

Question 39

extensor indicis is deep/superficial

Answer 39

deep

Question 40

why do we have an extra extensor for the index finger

Answer 40

used in conjunction with the thumb for fine precision movements

Question 41

what 2 fingers have extra extensors since there is only one extensor for the digits

Answer 41

index and little finger

Question 42

what is the origin and insertion of extensor pollicis longus

Answer 42

ulna and interosseous membrane to base of distal phalanx of thumb

Question 43

what is the functino of extensor pollicis longus

Answer 43

CMC, MCP, IP extension of thumb | extends wrist

Question 44

what is the innervation of extensor pollicis longus

Answer 44

radial nerve (posterior interosseous) (C7, C8)

Question 45

what plane does extension of the thumb occur in

Answer 45

same plane as palm with thumb moving away from the palm

Question 46

what is the origin and insertion of extensor pollicis brevis

Answer 46

radius and interosseous membrane to base of proximal phalanx of thumb

Question 47

what is the function of extensor pollicis brevis

Answer 47

CMC and MCP thumb joint extension | extends wrist

Question 48

what is the innervation of extensor pollicis brevis

Answer 48

radial nerve (posterior interosseous) (C7,C8)

Question 49

extensor pollicis brevis and longus both contribute to the borders or what

Answer 49

anatomical snuffbox

Question 50

what is the origin and insertion of abductor pollicis longus

Answer 50

radius, interosseous membrane and ulna to base of 1st metacarpal

Question 51

what is the function of abductor pollicis longus

Answer 51

abducts thumb and extends it at CMC joint | extends wrist

Question 52

what is the innervation of abductor pollicis longus

Answer 52

radial nerve (posterior interosseous) (C7,C8)

Question 53

the thumb is abducted in what plane

Answer 53

away from the plane of the palm

Question 54

where is the smaller abductor of the thumb

Answer 54

in the thenar eminence

Question 55

what muscles does the thumb have and why

Answer 55

2 flexors 2 extensors 2 abductors 1 adductor - important role in creating different types of grip

Question 56

what is the origin and insertion of supinator

Answer 56

crest of ulna, lateral epicondyle of humerus, radial collateral and annular ligament of radius to lateral radius (proximal 3rd)

Question 57

what is the function of supinator

Answer 57

supination of forearm (rotates radius)

Question 58

what is the innervation of supinator

Answer 58

radial nerve (deep/posterior interosseous) (C7,C8)

Question 59

what is the deepest muscle in the posterior compartment of the forearm

Answer 59

supinator

Question 60

what is the most powerful muscle for supination

Answer 60

biceps brachii

Question 61

what nerves contribute to supination

Answer 61

musculocutaneous - biceps brachii | radial - supinator

Question 62

the radial nerve passes between the lamina of what

Answer 62

supinator

Question 63

describe the path of the deep branch of the radial nerve

Answer 63

emerges from supinator to form the posterior interosseous nerve that runs with posterior interosseous artery

Question 64

describe the path of the superficial branch of the radial nerve

Answer 64

overlies part of brachioradialis before running through the roof of the anatomical snuffbox to supply skin of dorsum of hand

Question 65

the flexor compartment is dominated by the ___ nerve and also contains the ____ nerve

Answer 65

median | ulnar

Question 66

muscles of the extensor compartment are supplied by what

Answer 66

radial nerve

Question 67

sensory to lateral side of dorsum of hand is supplied by what

Answer 67

superficial branch of radial nerve

Question 68

the radial artery is a terminal branch of what

Answer 68

brachial artery

Question 69

describe the path of the radial artery

Answer 69

supplies structures in the forearm, runs in the floor of the anatomical snuffbox and passes between the heads of adductor pollicis to enter the hand

Question 70

what does the radial artery contribute in the hand

Answer 70

forms most of the deep palmar arch but will also anastomose with the ulnar artery as part of the deep and superficial arches

Question 71

most of the muscles in the posterior compartment are supplied by the ... except ...

Answer 71

deep interosseous branch of the radial nerve except carpi radialis longus

Question 72

the deep artery of the posterior compartment is the ... which is a branch of the .... which is derived from the ...

Answer 72

posterior interosseous artery which is a branch of the common interosseous artery which is dervied from the ulnar artery

Question 73

does the dorsum of the hand have muscles

Answer 73

no - the dorsal interossei lie between the bones

Question 74

the dorsum has a layer of skin and subcutaneous fat that contains

Answer 74

a dorsal venous arch and cutaneous nerves

Question 75

how are the extensor tendons held to the wrist

Answer 75

extensor retinaculum

Question 76

how are the extensor tendons protected during movement of the tendon

Answer 76

each tendon is inside a small synovial sheath

Question 77

the roof of the anatomical snuffbox contains what

Answer 77

branches of the superficial branch of the radial nerve and cephalic vein

Question 78

what forms the floor of the anatomical snuffbox

Answer 78

scaphoid, trapezium and base of 1st metacarpal

Question 79

what is the medial border of the anatomical snuffbox

Answer 79

tendon of extensor pollicis longus

Question 80

what is the lateral border of the anatomical snuffbox

Answer 80

tendons of extensor pollicis brevis and abductor pollicis longus

Question 81

why is the anatomical snuffbox an area of interest

Answer 81

the radial artery runs across the bones of the floor and can be palpated as a pulse point

Question 82

the dorsal venous arch is a communication between

Answer 82

cephalic vein (lateral side) and basilic vein (medial side)

Question 83

is the dorsal venous arch always an arch

Answer 83

no - variation in vein patterns

Question 84

what lies superficially in the roof of the snuffbox

Answer 84

cephalic vein and radial nerve

Question 85

what lies deep in the floor of the anatomical snuffbox between the tendons

Answer 85

radial artery

Question 86

what are the flexor and extensor retinacula

Answer 86

fascia that hold down tendons

Question 87

what is the dorsal expansion

Answer 87

formed from connective tissue that allows the long flexors and short muscles of the hand to act on all 3 finger joints

Question 88

the dorsal expansion provides attachment for what

Answer 88

some of the intrinsic muscles of the hand that attach to the digits e.g. the lumbricals

Question 89

describe what the lumbricals do

Answer 89

they cross the anterior surface of the MCP joint so can flex it but because their tendon joins the expansion that wraps around the dorsum of the finger they can exert pull on the posterior surface of the PIP joint and can extend it

Question 90

what order do the tendons cross the dorsum of the hand | lateral to medial

Answer 90

- abductor pollicis longus and extensor pollicis brevis - extensor carpi radialis longus and brevis - extensor pollicis longus - extensor indicis and extensor digitorum - extensor digiti minimi - extensor carpi ulnaris

Question 91

on the dorsum of the wrist what tendon crosses most medially

Answer 91

Extensor carpi ulnaris

Question 92

on the dorsum of the wrist what tendon crosses most laterally

Answer 92

abductor pollicis longus and extensor pollicis brevis

Question 93

on the dorsum of the wrist what tendon shares a synovial sheath with extensor digitorum

Answer 93

extensor indicis

Question 94

on the dorsum of the wrist what tendon shares a synovial sheath with abductor pollicis longus

Answer 94

extensor pollicis brevis