week 4 sem 2 functional anatomy of the hand Flashcards
extensor retinacula
attaches- radius ulna, pisiform, triquetrum, ulnar collateral ligament
- septa run to the carpal bones and form separate tunnels for the extensor tendons
functions of retinaculas
prevent bowstringing
- provide attachments
- converts anterior concavity of carpal bones into carpal tunnels
palmar aponeurosis
triangluar shaped sheet of facia extending from flexor retinaculum to deep transverse metacarpal ligaments
- protect underlying vessels and nerves
- anchores skin
- aids grip
intertendinous connections
fibrous connections bw the bands of the extensor digiotrum muscles just proximal to the MCP joints
- prevent independent extension of any one finger, ensures hand opens as a unit when releasing grip
dorsal digital expansion
forms an apernourosis oveer the posterior surface of each finger
- receieves attachment from ED, lumbricals, interossei
- ensures simultaneous extension of digits
fibrous flexor sheaths
fibro-osseus tunnels for the flexor tendon in the digits
sheath= anterior & bone= posterior
acts as a pulley for the flexor tendon binding onto the bone and preventing bow stringing
- increases efficentcy and leverage
synovial sheaths
function= allow friction free gliding
grip at rest
palm hallow
fingers flexed
thumb slightly opposed and slightly flexed
grip during function
wrist in slight dorsiflexion
fingers at slight flexion at IP joints more flexion at MCP
thumb opposed and slightly flexed
functional advantages of grip
- stable wrist position as ligaments taut
- long finger flexors are stretched therefore all force contraction exerted at finger joints rather than in taking up slack
- allows prehensile grip
- reduces the occurence of contractures
digital sweep
describes the path taken by fingertips as the hand closes.
- largest possible arc
- allows grip of large objects
power grip
-large objects
- often considerable force req
- whole hand
- maximal skin contact
- joint position: thumb abducted and adducting (adductor pollicus)
- flexion at all joints of the fingers
- palm cupped
- wrist dorsiflexed
precision grip
small objects- sometimes fragile
- usually less force required
- lateral digits only
- limited contact but high sensory acuity
joint position:
- thumb opposed
- CMC- FPB, FPL,ADDPOL
- MCP- FPL, FPB
- IP - FPL
flexion at MCP of fingers
- MCP- FDS, FDP
PIP- FDS, FDP
DIP- FDP
ventral roots upper region consist of vertabrea
C5, C6
ventral roots middle region consist of vertabrea
C7
ventral roots lower region consist of vertabrea
C8, T1
divisions come after and they split into?
come after trunks
split into an anterior and posterior division
divisions reunit into?
cords
trunks ( spinal nerves) are superior to
the clavicle
cords are superior to
the auxiallary artery
anterior division nerve supplies muscles that are
flexors
adductors
medial rotators
posterior division nerve supplies muscles that are
extensor
abductor
external rotator
nerves coming from the root branches
dorsal scapular
long throasic
nerves coming from the trunk branches
suprascapular
nerve to subclavius
rhomboids are inevated by
dorsal scapular nerve
the serratus anterior is inervated by the
long thoracic nerve
suprascapular nerve invervates which muscles
supraspinatus and infraspinatus
nerve to subclavius inntervates which muscle
subclavius
identifing muscleocutaneous
first branch, only goes to anterior arm
indentifing axillary nerve
it comes after musculocutaneous amd dives deep into the axilla
identifing the radial nerve
after the auxillary nerve and dives deep netween the heads of the triceps
identifing median nerve
formed by two nerves and runs down the middle of the anterior arm
identifing the ulnar nerve
most inferior. is only made up of one cord
axillary nerve RV, MD and SD
RV: C56
MD: deltoid teres minor
SD: skin over deltoid and shoulder joint
radial nerve RV, MD, SD
RV: C5678 T1
MD: all UL extensors, brachioradialis, supinator, abdPL
SD: skin of the posterior arm, forearm and hand (lateral 3 1/2 digits) wrist and elbow joints
musculocutaneous nerve RV, MD, SD
RV: C567
MD: coracobrachialis, biceps brachii, brachialis
SD: skin of lateral forearm to base of thumb (via lateral cutaneous nerve of forearm), eblow joint
median nerve RV, MD, SD
RV: C5678 T1
MD: FCR, PL both pronators FDS, FDP (lat), FPL, AbdPB, FPB, OppPoll, lat 2 lumbricals
SD: skin of the lateral 31⁄2 digits and corresponding palm, wrist and elbow jts
ulnar nerve RV, MD, SD
RV: C8,T1
MD: FCU, FDP (medial), PB, AbdDM, FDM, OppDM, med 2 lumbricals, AddPoll, all interossei
SD: skin of the medial 11⁄2 digits and corresponding palm, wrist jt
lateral pectoral major innervates
pec major
comes from lateral cord
Upper Subscapular innervates
Subscapularis
Thoracodorsal innervates
Latissimus Dorsi
Lower Subscapular
- lower Subscapularis & Teres Minor
Medial Pectoral nerve innervates
Pectoralis Minor & part of Major
