MSK 4 Flashcards
How many bones form the wrist
8 carpal bones
What are these bones
- ) Proximal row Scaphoid and lunate: these articulate w radius
- ) Triquetral and pisiform
- ) Distal row: trapezium/trapezoid/capitate/hamate
What is the base of the thumb called
The thenar eminence
What is the blood supply of the hand?
Ulna artery
btw no venous drainage in palm of hand bc venous drainage is on back of hand
What are the names of the two arches present here
- ) The superficial palmer arch
2. ) The deep palmer arch
What are the lumbricals
Small muscles in hand that are attached to the flexor tendons
Two tendons in the fingers
- ) Flexor digitorum superficialis
2. ) Flexor digitorum profundus
Name of the membrane that surrounds the tendons
Synovial membrane
Role of the synovial membrane
Produces synovial fluid to let the two tendons (FDS/FDP) to slide
What is the retinaculum
Thick layer of fascia at the joint (at each finger)
Role of the retinaculum
Stops tendon pulling away from the bones when the joint is bending
The superficial tendon
- Divides into two tendons
- Passes round the deep tendon
- Inserts onto the middle phalanx
Role of the middle phalanx muscle
- Will contract (flex) the proximal interphalangeal joint
The deep tendon
- Passes through split
- Travels down to the distal phalanx
- Action: bend the distal interphalangeal joint
What are the connections between the two tendons
The vincula (how tendons get blood). Also lined with synovium
Details on the lumbrical muscle to the index finger
- Origin: the profunda tendon
- Passes round the lateral side of the index finger to insert
What is the action of the abductor pollicis brevis
Pull the thumb away from the palm of the hand
What is the action of the abductor pollicis brevis muscle
Pull the thumb away from the palm of the hand
What is the action of the flexor pollicis brevis muscle
Is attached to the proximal phalanx and will flex this joint
What is the action of opponens pollicis muscle
Is attached to the shaft of the metacarpal and down onto the carpus.
- It will rotate the thumb
What are the action of the adductor pollicis muscles
Pull the thumb towards the palm of the hand
What is the action of the abductor digiti minimi
Pulls the little finger away from the ring finger
What is the action of the flexor digiti minimi
Will flex the metacarpophalangeal joint
What is the action of opponens digiti minimi
Will rotate the metacarpal (so that the little finger faces the thumb)
What is the action of the dorsal interosseous muscles
Will pull the index finger away from the middle finger
How many dorsal interosseous muscles are there?
4 (one in each of the 4 web spaces)
Role of them
- ) Pull the index finger away from the middle finger
- ) Pull the middle finger away from its neutral position
- ) Pull the middle finger away from its neutral position BUT in the opposite direction from no.2
- ) Will pull the ring finger away from the middle finger
How many interrossi are there on the PALM of the hand
3
Role of the interrossi on the PALM of the hand
1.) Will pull the index finger towards the middle finger
2+3) Will pull the ring finger and the little finger towards the middle finger
Pneumonic for muscles of the hand
LLOAF LL: two lateral lumbricals O: Opponens pollicis A: abductor pollicis brevis F: flexor pollicis brevis
Nerve supply of the hand
LLOAF: supplied by the median nerve
Dorsal/palmer interrossi (+ some others): supplied by ulna nerve
