hand and wrist anatomy Flashcards
how many phalanges are in the hand?
14 phalanges
- 2 seamoid bones (tumb)
how many metacarpals are their?
5
how many carpal bones are in the hand/wrist?
8
what is the distal radius?
- forms small ulnar notch to acceps the ulnar head
- radial styloid process
what is the distal ulna?
- ulnar styloid process arises from madial surface
- ulnear head
What are the carpal bones?
- “Stop letting those people touch the cadaver’s hand”
- ScaphoidLunate Triquetrum Pisiform, Trapezium Trapezoid Capitata Hamate
3 main muscle groupd in the hand and wrist?
- flexor group on anterior side
- rotators on anterior side
- extensor on posterior side
Wrist and hand muscle flexors? Originates?
- anterior/ palmer/ volar
- originate at medial epicondyle of elbow or proximal ulna and insert at hand
flexors at the wrist and hand include? (5)
- flexor carpi radialis- flex
- flexor carpi ulnas- flex and adduct wrist
- palmaris longus- flexion
- flexor digitorum profundus- flex distal finger joints
- flexor digitorum superficialis- flex fingers
extensor location and function?
- dorsal and posterior
- extend from lateral epicondyle of elbow and insert at the hand
the extensor of the wrist and hand muscles include? (4)
- extensor carpi radialis longus- extend and abduct
- external carpi radialis brevis- extend and abduct
- external carpi ilnaris- extend and adduct
- external digitorum- extend fingers
deep extensors function and originate?
- act on the thumb
- originate at ulna and radius and interosseous membrane
deep extendors include? (3)
- abductor pollicis longus
- extensor pollicis brevis- extend prox phalanx thumb
- extensor pollicis longus- extend distal phalax
dorsal aspect of wrist contents?
- extensor tendons
- ganglia- assess scapholunate ligament
dorsal aspect of wrist 3 standard views?
- extensor compartments 3-6
- extensor compartments 1-2
- scapholunate ligament
scapho lunate ligament distal to?
- listers tubercle
lister’s tubercle on dorsal radius separates?
compartment 2 and 3
whats the triangular fibrocartilage complex?
provides cushioning for movement of radiocarpal and ulnar joint spaces
triangular fibrocartilage complex?
- provides cushioning for movement of radiocarpal and ulnar joint spaces
longitudinal flexor and extensor tendons of the hand protocol?
- assessment of tendons- especially flexors
- assessment of metacarpal phalangeal and interphalangeal joints
- use real-time examination during flexion and extension of the fingers
FDP tendon inserts into?
the base of the distal phalanx
FSD tendon inters into?
middle phalanx
what the snuff box?
- gap between extensors of tumb
- compartment 1 lies anteriorl y
- compartment 3 lies posteriorly
- radial atery lies in the floor
- radial styloid process is proximal
- base of 1st metacarpal is distal
- scaphoid and trapezium at floor
where is snuff box best appreciated during extension and abduction?
the fossa is best appreciated during extension and abduction of the thumb
rotators are responsible for?
- rotating the arm at the radioulnar joint
pronator quadratus?
- distal ulna and distal radius
- rotates arm medially
- pronate hand
tendon pulleys?
- fibrous sheaths that maintain the flexor tendons in place
- prevent bowstringing during flexion of the finger
- anular and cruciform parts
tendon pulleys sono appearance?
- thin hyporeflective band at the anterior margin of the flexor tendons
A2 pulley?
proximal phalanx pulley
A4 pulley?
middle phalanx pulley
function of pulleys?
tendons that run down our fingers are held in place by a series of ligaments called pulleys
- arch over the tendons forming a “tunnel-like” sheath
tendons =
stabilizers
what holds the tendons in place on the bones?
- ligaments in a tunnel- like arrangement hold the tendons in place on the bones
what is tenosynovium?
slippery coating, called tenosynovium, surrounds the tendons and keeps the tendons moving smoothly under the ligaments when the hand grasps objects.
annular pulleys (A1-A5)?
prevent palmar tendon dislocation and allow optimal function
what pulleys are generally not well demonstrated by ultrasound?
- cruciform pulleys
where are collateral ligaments found?
- on each side of each joint on the fingers and thumb
role of collateral ligaments?
- precent abnormal sideways bending
flexor tendon?
- flexor aspect at metacarpo-phalangeal joint
extensor tendon?
MCPJ with extension and flexion
interphalangeal joint?
- long axis view of 2nd prox interphalangeal joint, flexor aspect
- small quanitiy of fluid is normal
median nerve?
can be seen in carpal tunnel and in cubital fossa of elbow
ulnar nerve?
- can be seen medially in the wrist and posteriorly in the elbow
radial nerve?
- can be seen (with difficulty) postero-laterally in wrist and antero-laterally in elbow
contents of the guyon tunnel?
- ulnar nerve
- ulnar artery
borders of guyon tunnel?
- TRV carpal lig./ flexor retinaculum: posterior
- superficial palmar lig.: anterior
- pisiform and hamate mediallu
communicaition exists between the brances of the median nerve and ulnar nerve T or F
T
radial nerve?
- radial aspect of the wrist
- crosses the 1st extendor compartment to reach the dorsal wrist
radial nerve?
- radial aspect of the wrist
- crosses the 1st extendor compartment to reach the dorsal wrist
