Topic 5: Bones, Joints and Muscles of the Wrist and Hand

Question 1

radiocarpal (wrist) joint

Answer 1

classification: synovial, biaxial, condyloid (ellipsoid)
articular surfaces: distal end of radius, distal radioulnar joint articular disc, proximal row of carpal bones (except pisiform)
movements: flexion, extension, abduction, adduction and circumduction

Question 2

radial (lateral) collateral ligament

Answer 2

from styloid process of radius to scaphoid and trapezium
function: limits adduction of the hand

Question 3

ulnar (medial) collateral ligament

Answer 3

from styloid process of ulna to triquetrum and pisiform
function: limits abduction of the hand

Question 4

palmar radiocarpal ligament

Answer 4

from radius to carpal bones on anterior (palmar) side of hand
functions: limits extension of the hand, ensures the hand moves with the forearm during pronation and supination

Question 5

common carpometacarpal joint

Answer 5

synovial, multiaxial, plane
articular surfaces: distal row of carpals, base of metacarpals
movements: small gliding movements, increasing mobility from lateral to medial

Question 6

carpometaca

Answer 6

synovial, biaxial, saddle
articular surfaces: trapezium, base of 1st metacarpal
movements: abduction and adduction, circumduction, opposition

Question 7

metacarpophalangeal joints

Answer 7

classification: synovial, biaxial, condyloid
articular surfaces: head of metacarpals, base of proximal phalanx
movements: flexion, extension, adduction, abduction, circumduction

Question 8

interphalangeal joints

Answer 8

classification: synovial, uniaxial, hinge
articular surfaces: head of phalanx, base of adjacent phalanx
movements: flexion and extension

Question 9

pronator teres

Answer 9

anterior suferficial
Origin: medial epicondyle of humerus, coronoid process of ulna
Insertion: middle of convexity on lateral shaft of radius
Actions: pronator of the forearm and flexion of the elbow joint

Question 10

flexor carpi radialis

Answer 10

anterior, superficial
origin: medial epicondyle of humerus (common flexor origin)
actions: flexion and abduction of wrist joint

Question 11

palmaris longus

Answer 11

anterior, superficial
origin: medial epicondyle of humerus (common flexor origin)
action: flexion of wrist joint

Question 12

flexor digitorum superficialis

Answer 12

anterior, superficial
origin: medial epicondyle of humerus (common flexor origin)
actions: flexion of digits 2-5 and wrist joint

Question 13

flexor carpi ulnaris

Answer 13

anterior, superficial
origin: medial epicondyle of humerus (common flexor origin)
actions: flexion and adduction of wrist joint

Question 14

pronator quadratus

Answer 14

anterior, deep
origin: medial epicondyle of humerus (common flexor origin)
actions: pronation of forearm

Question 15

flexor digitorum profundus

Answer 15

anterior, deep
origin: medial epicondyle of humerus (common flexor origin)
actions: flexion of digits 2-5 and wrist joint

Question 16

flexor pollicis longus

Answer 16

anterior, deep
origin: medial epicondyle of humerus (common flexor origin)
action: flexion of thumb and wrist joint

Question 17

brachioradialis

Answer 17

Posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
Actions: flexion of forearm (at elbow joint) in mid-prone position

Question 18

extensor carpi radialis longus

Answer 18

posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
Action: extension and abduction of wrist joint

Question 19

extensor carpi radialis brevis

Answer 19

posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
action: extension and abduction of wrist

Question 20

extensor digitorum

Answer 20

posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
Action: extension of digits 2-5 and wrist joint

Question 21

extensor digiti minimi

Answer 21

posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
actions: extension of digit 5 and wrist joint

Question 22

extensor carpi ulnaris

Answer 22

posterior, superficial
Origin: lateral epicondyle of humerus (common extensor origin)
actions: extension and adduction of wrist joint

Question 23

supinator

Answer 23

posterior, deep
Origin: lateral epicondyle of humerus (common extensor origin)
actions: supination of forearm

Question 24

extensor indicies

Answer 24

posterior, deep
Origin: lateral epicondyle of humerus (common extensor origin)
actions: extension of digit 2 and wrist joint

Question 25

extensor pollicis longus

Answer 25

posterior, deep Origin: lateral epicondyle of humerus (common extensor origin) actions: extension of thumb and wrist joint

Question 26

extensor pollicis brevis

Answer 26

posterior, deep Origin: lateral epicondyle of humerus (common extensor origin) actions: extension of thumb and wrist joint

Question 27

flexor pollicis brevis

Answer 27

Attachments: - Superficial head: flexor retinaculum and trapezium bone - Deep head: trapezoid and capitate bones Innervation: median nerve Actions: flexion of the thumb, opposition, thumb adduction muscle of thenar eminence

Question 28

abductor pollicis longus

Answer 28

posterior, deep Origin: lateral epicondyle of humerus (common extensor origin) actions: abduction of thumb and extension of wrist joint

Question 29

abductor pollicis brevis

Answer 29

Attachments: middle third of radius and ulna, base of first metacarpal bone Innervation: radial nerve Actions: abduction of the thumb, extension of the thumb, radial deviation Muscle of thenar eminence

Question 30

opponens pollicis

Answer 30

Attachments: trapezium bone, first metacarpal bone Innervation: median nerve Actions: opposition of thumb, flexion of thumb Muscle of thenar eminence

Question 31

flexor digiti minimi

Answer 31

Attachments: hook of hamate, base of the proximal phalanx of the little finger Innervations: ulnar nerve Actions: flexion of little finger, opposition Muscle of hypothenar eminence

Question 32

abductor digiti minimi

Answer 32

Attachments: pisiform bone, base of the proximal phalanx of the little finger Innervations: ulnar nerve Actions: abduction of pinky, flexion and opposition Muscle of hypothenar eminence

Question 33

opponens digiti minimi

Answer 33

Attachments: hook of hamate, 5th metacarpal bone Innervations: ulnar nerve Actions: opposition, flexion Muscle of hypothenar eminence

Question 34

adductor pollicis

Answer 34

Attachments: - Oblique head: Bases of the 2nd and 3rd metacarpal bones, capitate and adjacent carpal bones, base of the proximal phalanx - Transverse head: Anterior surface of the shaft of the 3rd metacarpal bone, base of the proximal phalanx Innervation: Ulnar nerve Actions: adduction of thumb

Question 35

lumbricals

Answer 35

Attachments: tendons of the flexor digitorum profundus and extensor expansions Innervation: median or ulnar nerve Actions: flexion of MCP and extension of IP joints

Question 36

dorsal interossei

Answer 36

Attachments: metacarpal bones, base of the proximal phalanx Innervation: ulnar nerve Actions: abduction of fingers

Question 37

palmar interossei

Answer 37

Attachments: metacarpal bones, base of proximal phalanx Innervations: ulnar nerve Actions: adduction of fingers

Question 38

position of function of the hand

Answer 38

wrist: slight dorsiflexion fingers: slight flexion of IP joints, flexion at MCP joints thumb: opposed and slightly flexed advantages: stable wrist position, ligaments taut, allows prehensile grip, reduces prehensile grip

Question 39

normal digital sweep

Answer 39

- path taken by the fingers as the hand closes - long path desirable: allows grip of large objects - lumbricals and interossei moderate effect of long flexors and long extensors

Question 40

flexor retinaculum

Answer 40

- scaphoid and trapezium to pisiform and hamate - functions: prevent bowstringing, protect underlying structures

Question 41

extensor retinaculum

Answer 41

- attachments: radius, ulna, pisiform, triquetrum, ulnar collateral ligament - run to carpal bones and form seperate tunnels for extensor tendonds

Question 42

palmar aponeurosis

Answer 42

- triangular shaped sheet of fascia, extends from the flexor retinaculum, to the deep transverse metacarpal ligaments - protects underlying vessels and nerves - anchors skin - aids grip

Question 43

dorsal digital expansion

Answer 43

- forms an aponeurosis over the posterior surface of each finger - receives attachment from ED, lumbricals, interossei - simultaneous extension of the interphalangeal joints in each finger when releasing grip

Question 44

intertendinous connections

Answer 44

- Fibrous connections between bads of the extensor digitorum muscles just proximal to the MCP joints - Prevents independent extension of any one finger, ensures hand opens as a unit when releasing grip

Question 45

precision grip

Answer 45

- small objects - lateral digits only - thumb opposed, flexion of MCP of fingers, IPs may be flexed or extended e.g. pinch, lateral, lumbrical

Question 46

power grip

Answer 46

- large objects - whole hand - thumb abducting and adducting, flexion at all finger joints, palm cupped, wrist dorsiflexion e.g. cylindrical, spherical, hook and lateral