Upper limb 4 Flashcards
3 functional groups of the posterior forearm
muscles that:
extend and abduct/adduct wrist
extend medial 4 digits
extend or abduct the thumb
3 muscles which extend and abduct/adduct wrist
extensor carpi radialis brevis (medial)
extensor carpi radialis longus (lateral)
extensor carpi ulnaris
action of extensor carpi radialis longus and brevis
extend and abduct wrist
What muscle helps the extensor carpi radialis longus and brevis abduct the wrist?
flexor carpi radialis
3 muscles that extend the medial 4 digits
extensor digitorum
extensor digiti minimi
extensor indicis
Action, origin and insertion of extensor digitorum
Action -> extend the wrist and digits
Origin -> lateral epicondyle
Insetion -> ends in tendon which goes under extensor retinaculum
(the lateral epicondyle is the common extensor origin)
Muscles that extend or abduct thumb
extensor pollicus longus
extensor pollicus brevis
abductor pollicus longus
What nerve innervates all muscles of posterior compartment of the forearm?
Radial nerve
What does the supinator muscle cover?
Neck and proximal part of the shaft of radius
Covering it completely except on medial side
Not on the fuckin medial side
Main action and the innervation of supinator muscle
Innervation -> Radial nerve
Action -> Supination of forearm
Where does the radial nerve divide into superficial and deep branches?
Cubital fossa
Branches of radial nerve
deep branch = posterior interosseous nerve
superficial branch -> sensory skin on dorsum of hand
what is the dorsal venous arch
Where the main superficial veins of the upper limb (cephalic and basilic) join in subcutaneous tissue on dorsum of hand
what is a syynovial cyst (ganglion)
Non tender cystic growths on dorsum of hand
Occur in synovial sheaths covering tendons
What is this
Colles fracture
Fracture of the distal radius
Causes a dinner fork deformity
due to falling on an extended wrist
(unlike a smith fracture which is caused by falling onto a flexed wrist or a direct blow to the dorsum of the hand)
Thumb joint type
synovial saddle
What tendons bound anatomical snuffbox laterally?
Abductor pollicus longus
extensor pollicus brevis
What tendon bounds anatomical snuffbox medially?
extensor pollicus longus
What is the Anatomical snuffbox
Shallow depression on lateral aspect of wrist
Occurs when thumb is fully extended
2 carpal bones in anatomical snuffbox
scaphoid
trapezium
Which artery lies on floor of anatomical snuffbox?
Radial artery
What nerve innervates EPL, EPB and APL?
Radial nerve
(it’s deep branch ->posterior interosseous nerve)
Main action of EPL and EPB on the thumb at the wrist joint
extend the thumb and wrist joint
APL main action of thumb at wrist joint
Abduction
(THE ABDUCTOR POLLICIS BREVIS IS A THENAR MUSCLE)
What forms the extensor expansions?
4 tendons of extensor digitorum
Where are extensor expansions?
Wrap around dorsum and sides of head of metacarpals and base of proximal phalanx`
Muscles attaching to extensor expansion
interossei
lumbricals
extensor digitorum
FDS
FDP
What does the synovial sheath of the hand create the risk of
Spread of infection between the thumbs and fingers
What is the benfit of the hand having a collateral circulation
It can be perfused when grasping
What arteries are mainly responsible for the superficial and dorsal arterial arches
Superficial -> ulnar artery
Deep -> radial
What is the test that you can do to check if the arterial arches of the hand are working
Allens test
What is an allens test used before
Before the radial artery is used for repeated ABGs or arterial lines
Checks that the hand can cope with only being perfused by the ulnar artery
What does the allens test involve
Occluding both the radial and ulnar arteries then get the pateint to keep on making a fist until their hand goes white
Then un-occlude just one of the arteires, and the hand should reperfuse in 15s
What condition commonly affects the palmar apponeruosis
Dupuytrens
What is the inervation of the deep anterior forearm muscles?
Flexor pollicis longus -> median nerve
Flexor digitorum profundus -> median & ulnar nerve
Protonator quadratus -> median nerve
What are the following type of hand joints:
- Wrist joint
- Thumn and tapezium
- inter-tarsal
- MPJ
- IPJ
- Condylar
- Saddle
- Plane
- Condylar
- Hinge
