the hand Flashcards
hand organisation: describe the organisation, innervation, blood supply and function of the intrinsic muscles of the hand; digits: describe and demonstrate the movements of the fingers and thumb; describe the position, function and nerve supply of the muscles and tendons involved in these movements, differentiating between those in the forearm and those intrinsic to the hand
what is the deep fascia of the palm of the hand called, and 2 features of skin of palm
palmar fascia (thicker skin with no hair follicles)
what 2 specialisations of the palmar fascia form
palmar aponeurosis, fibrous digital sheaths
location of palmar aponeurosis in relation to long flexor tendons
well-defined region of palmar fascia in hand, overlying long flexor tendons of hand
proximal end of palmar aponeurosis
continuous with flexor retinaculum (transverse carpal ligament) and palmar longus tendon
distal end of palmar aponeurosis
forms four bands which are continuous with the fibrous digital sheaths of each finger
what are fibrous digital sheaths
tubes which contain flexor tendons and their synovial sheaths
what is the space between the palmar aponeurosis and bones of the hand separated into compartments by
extensions of fascia called septa (medial and lateral)
2 septa locations
medial septum (to little finger metacarpal) and lateral septum (to middle finger metacarpal)
what are the 3 compartments created by septa
hypothenar (medial, little finger), central, thenar (lateral, thumb)
what compartment is deep to the thenar compartment
adductor compartment
what muscle is contained within the adductor compartment
adductor pollicis muscle
5 bones/groups of bone in wrist and hand
radius, ulna (articulates via articular disc), carpals, metacarpals, phalanges
what are the 8 carpals (from lateral to medial and proximal then distal row)
scaphoid, lunate, triquetrum, pisiform (only proximal carpal to not articulate proximally), trapezium, trapezoid, capitate, hamate
3 groups of muscles in wrist and hand
anterior compartment of forearm (superficial and deep compartment muscles), posterior compartment of forearm muscles, intrinsic muscles of hand
4 (compartment) muscles of intrinsic muscles of hand
thenar compartment muscles, adductor compatment muscles, hypothenar compartment muscles, interossei and lumbricals
5 muscles of superficial anterior compartment of forearm
pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis
3 muscles of deep anterior compartment of forearm
flexor digitorum profundus, flexor pollicis longus, pronator quadratus
extensor compartment of forearm: 3 muscles that move wrist joint
extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris
extensor compartment of forearm: 3 muscles that move digits
extensor digiti minimi, extensor indicis, extensor digitorum
extensor compartment of forearm: 3 muscles that move thumb
extensor pollicis brevis, extensor pollicis longus, abductor pollicis longus
2 other muscles of forearm
brachioradialis, supinator
intrinsic muscles of hand: 3 thenar muscles
abductor pollicis brevis, flexor pollicis brevis, opponens policis
intrinsic muscles of hand: adductor muscle, and attachments
adductor pollicis, with a broad attachment to middle metacarpal bone, and narrow attachment to base of proximal phalanx of thumb
intrinsic muscles of hand: 3 hypothenar muscles
abductor digiti minimi, flexor digiti minimi, opponens digiti minimi
intrinsic muscles of hand: where do 4 lumbricals flex and extend at
flex at metacarpals, extend at interphalangeal joints
intrinsic muscles of hand: 2 types of interossei, and how many of each
palmar interossei (3), dorsal interossei (4)
intrinsic muscles of hand: function of palmar interossei muscles (PAD)
adduct digits
intrinsic muscles of hand: function of dorsal interossei muscles (DAB)
abduct digits
anterior tendinous anatomy: proximal and distal attachments of fibrous digital sheaths
level of metacarpal head to base of distal phalanx
anterior tendinous anatomy: what do fibrous digital sheaths and underlying bone form
osseo-fibrous tunnels
anterior tendinous anatomy: what run through the osteo-fibrous tunnels
long flexor tendons and their synovial sheaths
anterior tendinous anatomy: what is the name of the condensations formed by parts of the fibrous digital sheath
pulleys
anterior tendinous anatomy: function of pulleys
allow more functional use of long flexor tendons
anterior tendinous anatomy: name of 2 pulleys
annular, cruciform
anterior tendinous anatomy: what 2 tendons pass deep to flexor retinaculum in carpal tunnel, after passing the wrist joint, to enter a common synovial sheath
tendons of flexor digitorum profundus and flexor digitorum superficialis
anterior tendinous anatomy: how do the tendons of flexor digitorum profundus and flexor digitorum superficialis pass to respective digits
via digital synovial sheath (lubricate and prevent friction), contained within fibrous digital sheath
anterior tendinous anatomy: what digits have continuous sheaths with the common synovial sheath
little finger and thumb
anterior tendinous anatomy: what happens to the flexor digitorum superficialis tendon at the base of the proximal phalanx
splits around flexor digitorum profundus
anterior tendinous anatomy: where does the flexor digitorum superficialis tendon attach
anterior surface of middle phalanx
anterior tendinous anatomy: where does the flexor digitorum profundus tendon attach
distal phalanx (hence pierces flexor digitorum superficialis)
anterior tendinous anatomy: where does flexor pollicis longus have its own synovial sheath at
flexor retinaculum
anterior tendinous anatomy: where does flexor pollicis longus run to
distal phalanx of thumb
posterior tendinous anatomy: what holds all the extensor tendons of the hand to the dorsum of the wrist region
extensor retinaculum (at wrist, not as tough as flexor retinaculum, holding tendons down)
posterior tendinous anatomy: what surround the tendons on the posterior side of the hand
synovial tendon sheaths
posterior tendinous anatomy: function of synovial tendon sheaths
facilitate free movement of tendons
posterior tendinous anatomy: what joins long extensor tendons to digits on dorsum of hand
inter-tendinous bands
posterior tendinous anatomy: function of inter-tendinous bands
prevent free movement of one extensor tendon independently of others
posterior tendinous anatomy: what do the long extensor tendons flatten to form at the level of the metacarpals
extensor expansions, forming a hood on back of digit
posterior tendinous anatomy: what muscles distally attach to the extensor expansions of long extensor tendons (not bone), and what are their proximal continuation or attachments from
lumbricals (4, with proximal continuation from flexor digitorum profundus muscle) and interossei (proximal attachment between adjacent metacarpals, arranged along axial line of hand)
posterior tendinous anatomy: function of extensor expansions
intricately involved in movements of digits
posterior tendinous anatomy: what 3 joints does the extensor digitorum extend
metacarpal and interphalangeal joints, some part in extending wrist joint after maximal extension of digits
posterior tendinous anatomy: what 2 digits have their own individual long extensors
index finger and little finger
6 joints of region
distal radio-ulnar joint, wrist joint, intercarpal joints, carpo-metacarpal and inter metacarpal joints, metacarpo-phalangeal joints, interphalangeal joints
distal radio-ulnar joint type
pivot-type synovial joint
function of distal radio-ulnar joint
allows radius to rotate around ulna
what ligament is within the distal radio-ulnar joint, and what is it
triangular ligament, which is a triangular fibrocartilage articular disc
muscles moving distal radio-ulnar joint
supinator, biceps, pronator quadratus, pronator teres
wrist joint type
elipsoid synovial joint
location of wrist joint
between distal radius and its associated triangular fibrocartilage articular disc, with the proximal row of the carpal bones (not pisiform)
6 strong ligaments stabilising wrist joint
ulnar collateral ligament, radial collateral ligament, palmar radio-carpal ligament, palmar ulnocarpal ligament, dorsal radio-carpal ligament, inter-carpal ligaments
3 movements of wrist
flexion/extension, radial deviation (abduction) and ulnar deviation (adducion), circumduction
what 2 other joints allow flexion in wrist region
midcarpal joints, carpo-metacarpal joints
5 muscles providing flexion at wrist joint
flexor carpi radialis, flexor carpi ulnaris, long flexors of thumb and fingers, palmaris longus, abductor pollicis longus
4 muscles providing extension at wrist joint
extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, long extensors of thumb and fingers
5 muscles providing radial deviation (abduction) at wrist joint
flexor carpi radialis, extenor carpi radialis longus, extensor carpi radialis brevis, abductor pollicis longus, extensor pollicis brevis
2 muscles providing ulnar deviation (adduction) at wrist joint
extensor carpi ulnaris, flexor carpi ulnaris
intercarpal joints type
synovial
3 sets of intercarpal joints
joints between proximal carpal bones, joints between distal carpal bones, joints between proximal and distal carpal bones (midcarpal joints)
main movement occuring at carpal joints
gliding, augmenting the movement occurring at the wrist joint itself (especially flexion and radial deviation of the wrist)
carpo-metacarpal joint of thumb type
synovial joint of saddle variety
carpo-metacarpal joint of thumb location
articulation between trapezium and thumb metacarpal
why is the carpo-metacarpal joint of thumb clinically important
often becomes osteoarthritic
other carpo-metacarpal joints type
synovial elipsoid joints
other carpo-metacarpal joint locations
between the trapezoid, capitate and hamate with the metacarpals of the digits
order of rigidity of other carpo-metacarpal joints
index and middle finger > ring finger > little finger
what joints are present between metacarpals at their bases
plane synovial intermetacarpal joints
3 movements occuring at carpo-metacarpal and intermetacarpal joints
flexion/extension, radial deviation (abduction) and ulnar deviation (adducion), circumduction
metacarpophalangeal joints type
condylar synovial joints
metacarpophalangeal joints location
between metacarpal heads and proximal phalanges (knuckles)
2 movements occuring at metacarpophalangeal joints
flexion/extension, abduction and adduction
interphalangeal joints type
hinge synovial joints
movement occuring at interphalangeal joints
flexion/extension
what ligaments hold metacarpophalangeal and interphalangeal joints together, and function
radial and ulnar collateral ligaments (prevent abduction and adduction)
what collateral ligament of the thumb is clinically important, and why
ulnar collateral ligament of thumb, as often injured in skiing by falling on the outstretched thumb
location of volar plate
anterior surface of the proximal interphalangeal joint
what is the volar plate
dense condensation of fibrous tissue formed by collateral ligaments at front of proximal interphalangeal joint, and is frequently damaged
5 movements of thumb
abduction, adduction, extension, flexion, opposition
2 muscles that allow abduction of thumb
abductor pollicis longus, abductor pollicis brevis
2 muscles that allow adduction of thumb
adductor pollicis, first dorsal interosseous
3 muscles that allow extension of thumb
extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus
2 muscles that allow flexion of thumb
flexor pollicis longus, flexor pollicis brevis
muscle allowing opposition of thumb, and location
opponens pollicis (working at carpo-metacarpal joint, underneath palmaris brevis)
where else does opposition of thumb occur at, and what does it involve
metacarpo-phalangeal joint, involving abduction, flexion and then adduction
2 arteries supplying blood to hand
ulnar, radial
where does ulnar artery run in forearm, and where does it pass in the wrist
anterior compartment of the forearm, passing on ulnar side of palmar surface of wrist
what lies medial to the ulnar artery at the wrist
flexor carpi ulnaris (more medial), ulnar nerve (less medial)
3 branches of ulnar artery in forearm
common interosseous, anterior interosseous, posterior interosseous (behind interosseous membrane)
what does the ulnar artery run over, lateral to and through to reach the hand
runs over flexor retinaculum, lateral to pisiform, and through semi-rigid ulnar (Guyon’s) canal (with ulnar nerve)
2 branches of ulnar artery after reaching the hand
superficial palmar arch, deep palmar arch of ulnar artery
what else does the superficial palmar arch receive a contribution from
superficial palmar branch of the radial artery
what does the superficial palmar arch give off
3 common palmar digital arteries
what do the 3 common palmar digital arteries divide into
palmar digital arteries
where does radial artery run in forearm, and where does it lie in the wrist
lateral aspect of forearm, under cover of brachioradialis, and lies superficially on palmar aspect of radial side of wrist
how does the radial artery pass into the hand
crosses floor of anatomical snuff box, entering palm between two heads of first dorsal interosseous muscle, then passes between two heads of adductor pollicis muscle
what does the radial artery anastomose with to form the deep palmar arch
deep palmar branch of ulnar artery
what does the deep palmar arch give origin to
palmar metacarpal arteries
what do the superficial and deep palmar arterial arches have to drain them
palmar venous arches (deep drainage)
what do dorsal digital veins drain into
dorsal venous arch (superficial system), on dorsum of hand
what superficial veins does the dorsal venous arch give rise to laterally and medially; describe deep venous drainage of arm and forearm
cephalic vein laterally, basilic vein medially (join by median cubital veins); in forearm and arm, deep radial and ulnar veins exist, with drainage into venae comitantes and brachial veins
3 main nerves to hand
median, ulnar, radial
what does median nerve supply in forearm
main nerve of anterior compartment
what does ulnar nerve supply in forearm
contribution to medial muscles of anteiror compartment, but mostly pass into hand
what does radial nerve supply in forearm
posterior compartment
what nerves are purely sensory (muscles mainly in forearm and palmar region) and supply the digits
digital nerves
what does division of a digital nerve cause
anaesthesia in part of the digit
median nerve spinal cord levels
C6,7,8 T1
where does median nerve lie in wrist
superficially between tendons of flexor digitorum superficialis and flexor digitorum profundus, deep to palmaris longus
what accompanies the median nerve in carpal tunnel (except palmar cutaneous branch)
9 flexor tendons (flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus)
what does the median nerve pass under in the hand
flexor retinaculum
what 5 muscles is the median nerve motor supply of
3 thenar muscles, lateral (first and second) lumbricals
what are the 3 thenar muscles
abductor pollicis brevis, flexor pollicis brevis, opponens pollicis
how does the recurrent branch of the median nerve usually leave the main trunk
within carpal tunnel
what does the median nerve supply sensory supply to
palmar surface of thumb (palmar cutaneous branch), index and middle ringers, and lateral half of ring finger, as well as some of dorsal surface of these digits
ulnar nerve spinal cord levels
C8, T1
proximal to the wrist, what 2 branches does the ulnar nerve give off
palmar cutaneous branch, dorsal cutaneous branch
what does the palmar cutaneous branch supply
medial palm of hand
what does the dorsal cutaneous branch supply
medial half of dorsum of hand, including ring and little fingers
where does the ulnar nerve lie in the wrist
anteriorly, between the flexor carpi ulnaris medially and ulnar artery laterally (doesn’t go through carpal tunnel)
where does the ulnar nerve pass beyond the wrist, before dividing
passes over flexor retinaculum in ulnar canal with ulnar artery, just lateral to pisiform bone
2 branches of ulnar nerve distal to flexor retinaculum
superficial branch, deep branch
what does the superficial branch of the ulnar nerve supply
sensory to palmar surface of little finger, and medial side of wring finger
what does the deep branch of ulnar nerve supply
motor to hypothenar muscles, adductor pollicis, medial (third and fourth) lumbricals, all interossei (hence controls most muscles involved in fine movements of hand)
what are the 3 hypothenar muscles
abductor digiti minimi, flexor digiti minimi, opponens digiti minimi
radial nerve spinal cord levels
C5,6,7,8 T1
what are the 2 branches of the radial nerve after dividing superior to elbow
superficial radial nerve (sensory cutaneous), deep radial nerve (motor)
what does superficial branch of radial nerve supply sensory innervation to in hand
lateral two-thirds of the dorsum of the hand, dorsum of thumb, proximal portions of dorsal index and middle fingers
what is the direct continuation of the deep radial nerve, and where does this continuation occur
posterior interosseous nerve, as it passes between heads of supinator
what do the radial nerve and its continuations (deep radial
nerve and posterior interosseous nerve) supply
all extensor compartment muscles of arm and forearm (doesn’t supply any muscles in the hand)
structure of phalanges
base, shaft, head
how many phalanges in each digit
3, except thumb which has 2
