Arm Anatomy Flashcards
Where does the brachial plexus run on a person
Roots - posterior triangle of neck
Trunks - posterior to the middle third of the clavicle
Divisions - apex of the axilla
Cords - related to the axillary artery
Where are the parts of the brachial plexus found in relation to other structures
Roots - from foramina between scalenes anterior and medius
Trunks - at the base of the posterior triangle of the neck behind the 3rd part of the subclavian artery
Divisions - behind the middle 1/3 of the clavicle
cords - second part of the axillary artery
What is Erb’s paralysis
damage to the upper nerve roots of the brachail plexus - C5/6
gives rise to what is described as the waiter’s tip deformity
Paralysis of the arm abductors (supraspin and delt) leads to arm adduction
Paralysis of the external rotators (infraspin adn teres minor) leads to internal rotation
Paralysis of the flexors and supinators (bcieps, brachialis and brachioradialis) leads to forearm extension
sensory changes: radial side of the arm and forearm
what is klumpke’s paralysis
injury to the lower trunk of the brachial plexus
C8 T1
gives rise to what is called the claw hand deformity
paralysis of all intkrinsic muscles in the hand
paralysis of the wrist flexors except FCR
hyperextenstion of the MCPJs and flexion of the IPJs
sensory: ulnar border of forearm and hand
tell me about the axillary artery
divided by the pec minor into three parts
part 1 - one branch - superior thoracic (runs medial to serratus anterior and pec muscles)
part 2 - two branches - thoracoacromial (branches to deltoid, acromial, pectoralis, clavicular) and lateral thoracic (descends to serratus anterior)
part 3 - three branches - subscapular (largest, thoracodorsal branch and circumflex scapula which travels in the triangular space) anterior circumflex humeral (supplies humeral head: arcuate artery lateral to bicipital groove) and posterior circumflex humeral (in the quadrangular space with the axillary nerve)
mneumonic: screw the lawyer, save a patient
triangular space
borders:
superir teres minor
inferior teres major
lateral long hea dof triceps
contains circumflex scapular artery
quadrangular space
superior teres minor
inferior teres major
lateral humerus
medial long head of triceps
contains axillary nerve
posterior circumflex humeral artyert
triangular interval
superior terest major
lateral humerus
medial long head of triceps
contains profunda brachii and radial nerve
innervation of the rotator cuff
subscapularis - upper and lower subscapular nerves
supraspinatus - suprascapular nerve
infra spinatus - suprascapular nerve
teres minor - axillary nerve
surface marking of th coracoid
2cm inferior to the junction between the middle and lateral thirds of the clavicle
structures attached to the coracoid
ligaments
- coracoclavicular (trapezoid and conoid)
- coracoacromial
- coracohumeral
muscles
- pec minor insertion
- coracobrachailis origin
- short head of biceps origin
muscles inserted in the bicipital groove
PLT sandwich - lady between two majors
Pec major - lateral
latissimus dorsi - floor
teres major - medial
tendon of the long head of bicep runs in the groove
muscles responsible for should abduction
0-15 - supraspinatus
15-90 middle fibres of deltoid
over 90 - trapezius and serratus anterior as need upward rotation of the scapular and lateral rotation of the huerus
fractors decreasing stability of the shoulder joint
shallow glenoid
lax capsule with few ligaments
inferior aspect is not supported due to the quadrangualr space
what is the main stabilizer of the shoulder
rotator cuff
static restraints of the shoudler
unidirectional limitations to translatiion
labrm
version
conformity
negative intrarticular pressure
capsule
glenohumeral ligametns
dynamic restraints of the shoulder
syndrocnised contaction of the rotator cuff causing joint concavity compression. direct attachment fo the cuff to the capsule increases capuslar tensoin
what is a synovial joint
freely moving joint with the articulating surfacies covered in hyaline carticalge and seperated by a film of synovial fluid to act as a lubricant
fibrous capsule provides stability
synovial fluid is a trnasport medium and is produced by the synovial membrane
axillary nerve motor supply
deltoid
teres minor
axillary nerve sensory supply
skin to eh lower half of th edeloitd (badge patch)
INJURY to axillary nerve
inability to abduct the shoulder past 15 degrees
loss of sensation over the badgepatch
upper limb reflexes
c5/6 biceps
c7 triceps
supinator c6
myotomes upper limb
c5 flexion elbow
c6 wrist extensors
c7 elbow extensors
c8 long finger extensors
t1 small finger abductors
muscles flexing the elbow
biceps
brachialis
bacioradials
pronanor teres
FCR
articulations at the elbow
capitulum of humerus and radial head
trochlea of humerus and trochlear notch of ulna
olecranon of ulna and olecranon fossa of humerus
structures in the spiral groove
radial nerve profunda brachi vessels
run in triangula interal
clinical picture of radial nerve injury at spinal groove
wrist drop
finger drop
loss of senstion to the first webspace
origin of biceps brachii
coracoid short head
supraglenoid long head
insertion of biceps
radial tubersoty
origin of triceps
long head infraglenoid
lateral head and medial head posterior humerus
structure running between heads of humerus
radial nerve and profunda brachii run between the medial and lateral heads
superficial flexors of the forearm
pronator teres
FCR
palmaris longus
FCU
FDS
innervation of superfical flexors of the forearm
PT, FCR, PL, FDS - median nerve
FCU - ulnar
what attaches to the pisiform
FCU
what hooks around listers tuberle
EPL
deep flexors of the forearm
flexor digitorum profundus
flexor pollicus longus
pronator quadrarus
innervation of the deep flexors of the forearm
AIN
superficial extensors of the forearm
brachioradialis
extensor carpi radialis longus
extensor carpi radialis brevis
anconeus
exteensor digitorum
extensor digiti minimi
extensor carpi ulnaris
