L6 - Anatomy of the hand Flashcards
SKELETON OF THE HAND & CARPAL BONES
i) what are the three main groups of bones that make up the hand?
ii) label the carpal bones in the diagram
iii) what part of the carpal tunnel do the carpal bones form?
iv) which carpal bone is most commonly fractured? give two possible complications of this
v) which two carpal bones does the flexor retinaculum attach to?
i) carpal, metacarpal, phalanges
ii) A - pisiform, B - triquetrium, C - lunate, D - scaphoid,
E - hamate, F - capitate, G - trapezioid, H - trapezium
iii) carpal bones form the floor of the carpal tunnel
iv) scaphoid is most commonly fractured
- slow recovery as there is poor blood supply to prox part
- can result in avascular necrosis
v) FR attaches to the tubercle of the scaphoid and trapezium
JOINTS OF THE HAND
I) label the diagram
ii) what type of joint in D? which two bones is it found between
iii) which joint is found between metacarpal and proximal phalanx?
iv) which joint is found between prox and distal phalanx?
i) A - radiocarpal joint (wrist), B - midcarpal/intercarpal,
C - carpometacarpal (distal carpal to metacarpal)
ii) D is a saddle joint - found between trapzeium and 1st MC
iii) metacarpal and prox phalanx = metacarpophalangeal
iv) interphalangeal - between prox and distal phalanx
WRIST JOINT
i) what is the joint called? and what type of joint is it? what is it reinforced by?
ii) does the ulna articulate directly with the carpal bones?
iii) what is the role of the ulna and radial collateral ligaments? where do these originate from?
iv) what is the role of the ligaments on the palmar and dorsal surface?
v) which movements does it allow? (5)
i) radiocarpal joint, synovial joint, reinforced by ligaments
ii) no - ulna does not articulate directly with carpal bones, there is a disk in between
iii) ulna and radial CL limit abduction and adduction
- originate from the styloid process of each bone
iv) ligaments on palmar/dorsal surface limit extension and flexion
v) allows adduction/abduction, flex/extension, circumduction
CARPOMETACARPAL JOINTS
i) what type of joint is it? what does cause? what is the one exception to this?
ii) which movement does the exception joint prinicipally allow?
iii) name the six movements it this joint allows
i) plane joint (two flat surfaces together) > limited movement
- exception = saddle joint between trapezium and metacarpal of D1
ii) saddle joint allows opposition
iii) extension, flexion, abduction, adduction, opposition, reposition
METACARPOPHALANGEAL JOINT
i) what type of joint is it? what does this allow?
ii) which four movements does this allow?
iii) which ligaments allows unifying of the metacarpals? which two digits is this not between? why?
iv) what is indicated by A?
i) condylar joints (oval > condylar surface) which allows movement in two planes
ii) flexion/extension and abduction/adduction
iii) deep transverse metacarpal ligaments
- not between digit 1 and 2 as they need to be mobile/oppose thumb
iv) deep transverse metacarpal ligaments
INTERPHALANGEAL JOINTS
i) what type of joint are they?
ii) what movements do they allow? (2)
iii) what IP joints are indicated by A and B?
i) hinge joints
ii) flexion and extension
iii) A - proximal IP joint (PIP)
B - distal IP joint (DIP)
PALMAR APNEUROSIS
i) what is it? what shape is it? what two types of fibres does it contain?
ii) what muscle is it continuous with? if a person does not have this muscle then what is it anchored to?
iii) how can it be clinically implicated? which digits does this affect? why?
i) thickened deep fascia under the skin
- triangular shaped
- contains longitudinal and transverse fibres
ii) continous with palmaris longus
- if no palmaris longus then anchored to the flexor retinaculum
iii) clin implicated in Dupuytrens contracture
- cant straighten digit 4/5 due to shortening of the longitud bands of the palmar apneurosis
- pulls digits 4/5 into flexion
what is indicated by A?
what muscle is shown as B?
which clinical condition implicates this structure?
A - palmar apneurosis
B - palmaris longus
implicated in dupuytrens contracture
LONG FLEXOR TENDONS > DIGITS
i) which part of the arm do these muscles sit? do they pass through the carpal tunnel?
ii) which two muscles extend to digit 2-5?
iii) which muscle extends to the thumb?
iv) what is the flexor retinaculum? where does it run from and to?what does it prevent?
v) which nerve runs alongside these tendons?
vi) what surrounds the tendons?
i) muscles in the anterior forearm
- yes they all pass through the carpal tunnel
ii) flexor digitorum superficialis and profundus
iii) flexor pollicus longus
iv) FR is the transverse carpal ligament
- runs from pisiform/hammate to trap and scaphoid
- prevents bowing of tendons (popping out)
v) median nerve
LONG FLEXOR TENDONS TO DIGITS
label diagrams A-E
A - flexor digitorium superficialis
B - flexor digitorium profundus
C - flexor pollicus longus
D - flexor retinaculum
E - median nerve
FLEXOR TENDON INSERTIONS
i) what do tendons enter as they extend into the digits?
ii) what two type of ligaments are found in the fibrous digital sheath?
iii) where does flexor digitorium profundus insert? what does FD superficialis insert?
iv) what is a veniculae?
v) label diagram
i) enter fibrous digital sheaths
ii) annular (straight) and cruciate ligaments (X)
iii) FDP inserts into the base of the distal phalanx
- FDS inserts into the base of the middle phalanx
iv) veniculae attached the tendons to the phalanges
v) A - fibrous digital sheath, B - annular ligament, C - cruciate ligament, D - synovial sheath, E - FDP, F - FDS
LONG EXTENSOR TENDONS TO DIGITS
i) what part of the arm do tendons from these muscles come from?
ii) name the three muscles that extend to digit 2-5
iii) name the three muscles that extend to the thumb
iv) label diagram
i) posterior forearm (extensor compartment)
ii) extensor digitorum, extensor digiti minimi, extensor indicis
iii) extensor pollicus longus, extensor pollicus brevis and abductor pollicus longus
iv) A- flexor retinaculum, B - extensor indicis, E - extensor digitorum, F - extensor dig min, G - extensor pol longus,
H - exten pol brevis, I - abductor pol longus, J - extensor hoods
EXTENSOR DIGITORUM INSERTION
i) what is the role of the extensor hood?
ii) what does each tendon split into? where does each part insert?
iii) which joints does extensor digitorum extend? (4)
iv) label diagram
i) form attachments for intrinisic muscles
ii) each tendon splits to a medial band > medial phalanx
2x lateral bands > distal phalanx
iii) wrist, MCP joints of D2,3,4,5 and prox/distal IP joints of 2,3,4,5
iv) A - tendon of extensor digitorum, B - extensor hood, C - medial band, D - lateral band
ANATOMICAL SNUFF BOX
i) what makes up the medial/posterior border? what makes up the lateral/anterior border? (2)
ii) what makes up the floor? (2 bones and 1 artery)
iii) what can be measured from here?
iv) which bone can be palpated here? why may this be done?
v) label diagram
i) medial/post border = extensor pol longus
- lat/ant border = abduc pol longus and extensor pol brevis
ii) floor = scaphoid and trapezium bone and radial artery
iii) measure radial pulse
iv) can palpate the scaphoid to see if it is fracture > tender
v) A - exten pol longus, B - abduc pol longus, C - extensor pol brevis, D - scaphoid bone, E - radial artery, F - trapezium bone
EXTENSOR HOODS
i) which two structures insert into these?
ii) label the diagram
i) lumbrical muscle and interosseous muscle insert
ii) A - extensor hood, B - inteross muscle, C - lumbrical
THENAR AND HYPOTHENAR MUSCLES
i) what is the role of the thenar muscles?
ii) what is the role of the hypothenar muscles?
iii) label diagram
iv) where do the muscles originate?
i) fine movements of thumb
ii) fine movements of digit 5
iii) A - thenar muscles, B - flexor retinaculum, C - hypothenar muscles
iv) muscles originate from flexor retinaculum and adjacent carpal bones
THENAR MUSCLES
i) name the three muscles? which is the deepest?
ii) which two carpal bones do they originate from? (plus flexor retinaculum)
iii) where does each muscle insert?
iv) name three movements that these muscles allow
v) label diagram
vi) which action is not done by these muscles?
i) flexor pollicis brevis, abductor pollicis brevis, opponens pollicis (deepest)
ii) orig from scaphoid and trapezium
iii) OP ins into first metacarpal
- APB and FPB ins into proximal phalanx of D1
iv) allows opposition of thumb (OP)
abduction (APB)
flexion (FPB)
v) A - opponens pollicis, B - abductor pollicis brevis, C- flexor pollicis brevis
vi) adduction
HYPOTHENAR MUSCLES
i) what are the three muscles? which is deepest?
ii) which two carpal bones do they originate from? (plus flexor retinaculum) where does each insert?
iii) what three actions do they allow?
iv) label diagram
i) flexor digiti minimi, abductor digiti minimi, opponens digiti minimi (deepest)
ii) orig from hammate and pisiform
- ODM ins into 5th MC, FDM and ADM ins into proximal phalanx of D5
iii) allow flexion, abduction and opposition
iv) A = ODM, B = FDM, C - ADM
ADDUCTION OF THE THUMB
i) which muscle is responsible for this?
ii) name the two heads of this muscle and where each originate from? where do they both insert?
iii) is this muscle deep or superficial to the thenar muscles?
iv) label diagram
i) adductor pollicis
ii) oblique head - from base of 2nd/3rd MC and carpal bones
- transverse head from 3rd MC
- both insert into the proximal phalanx of the thumb
iii) deep to thenar muscles
iv) A - oblique head
B - transverse head
BLOOD SUPPLY TO THE HAND
i) which aspect of the arm does the radial artery run down? which muscles does it sit under? which nerve does it run alongside?
ii) once at the wrist, which three things does it cross before it anastomoses with the ulna artery?
iii) which aspect of the arm does the ulnar artery run down? which muscle covers it? which palmar arch does it form?
iv) label diagram
i) radial runs down the lateral side of arm
- sits under brachioradialis muscle
- runs alongside sup branch of radial nerve
ii) ulnar artery goes through anatomical snuff box, pierces 1st dorsal interossi, forms deep palmar arch then anas with ulna artery
iii) ulnar artery runs down medial side and is covered by flexor carpi ulnaris
- forms superficial palmar arch
iv) A - radial artery, B - ulnar artery, C - brachial artery
DEEP PALMAR ARCH
i) where does it sit in relation to the long flexor tendons?
ii) what does it supply? (2)
iii) what two branches does the radial artery give off after it pierces the first dorsal interosseous muscle?
iv) label diagram
i) sits below long flexor tendons
ii) supplies D1 and lateral part of D2
iii) radial artery branches to princeps pollicis (to D1)
and radialis indicis (to lat D2)
iv) A - deep palmar arch
B - princeps pollicis
C - radialis indicis
SUPERFICIAL PALMAR ARCH
i) does it sit above or below long flexor tendons
ii) what artery is it predominantly made from?
iii) which branches does it give off first? what do these then form?
iv) what does it supply?
v) label diagram
i) sits above long flexor tendons
ii) predom made from the ulna artery
iii) first gives off common palmer digital arteries
- then forms proper palmer digital arteries
iv) supplies medial 1/2 of D2 to D5
v) A - ulnar artery, B - superficial palmer arch, C - common palmar digitial arteries, D - proper palmer digitial arteries
MEDIAN NERVE
label diagram
what are the two main nerves that supply the hand?
A - median nerve
B - carpal tunnel
C - palmar branch
D - recurrent branch
E - digital nerves
median and ulnar nerves supply the hand
ULNAR NERVE
i) does it pass through the carpal tunnel?
ii) what does the deep branch supply? (4)
iii) what does the superficial branch supply?
iv) what posture do you get after injury to the ulnar nerve at the wrist? explain. do you get this posture when injuring the ulnar nerve above the wrist? why?
v) label diagram
i) no
ii) deep branch > hypothenar muscles, all interossi, medial 2 lumbricals, adductor pollicis
iii) superficial branch sensory to skin 1/2 D4 and D5
iii) injury of ulnar nerve at wrist > clawed hand (D4/D5 MCP extension and IP joint flexion) due to loss of medial lumbricals therefore the pull of extensor digitorum profundus causes claw
- above wrist dont get posture as you also lose innervation of FDP
v) A - deep branch, B - superficial branch, C - ulnar nerve
injury to which nerve causes this posture?
injury to ulnar nerve at the wrist
