Upper limb 1 Flashcards
What is the axilla?
pyramidal space below the shoulder joint
Function of axilla
passageway for vessels and nerves going to and from the upper limb
Anterior wall of axilla
pec major and pec minor (+subclavius)
Posterior wall of axilla
teres major + subscapularis
Medial wall of axilla
serratus anterior and thoracic wall
Lateral wall of axilla
intertubercular groove of humerus
The axillary artery is the continuation of which artery?
subclavian
at what anatomical point does the axillary artery start?
lateral border of 1st rib
Axillary artery continues beyond the axilla as which vessel?
brachial
At what anatomical point does the axillary artery become the brachial artery?
distal to inferior border of teres major
When may compression of axillary artery be necessary?
profuse bleeding due to severe injury of upper limb
What forms the brachial plexus?
ventral rami of C5-T1
major branches of brachial plexus
radial, ulnar, musculocutaneous, median, axillary
Which nerves roots form upper trunk?
C5+6
Erb’s point and clinical relevance
union of C5+C6
injury at birth or fall on shoulders (hyperextension) - paralyse arm muscles –> waiter’s tip
Waiters tip position
erb’s palsy
medially rotated with wrist flexed
Which group of muscles affected in erb’s palsy?
BBC muscles - musculocutaneous nerve
brachioradialis and deltoid - axillary nerve
Roots of lower trunk of brachial plexus
C8+T1
Klumpke’s palsy
intrinsic muscles of hand and ulnar flexors of wrist and fingers - claw hand
lower trunk affected
Cause of klumpke’s palsy
undue abduction of arm
How are the cords of the brachial plexus named?
relation to axillary artery
Brachial plexus nerves and their cords
musculocutaneous - lateral cord
axillary, radial - posterior cord
median - lateral and medial cord
ulnar - medial cord
Where do the cephalic and basilic veins arise?
cephalic - lateral end of dorsal venous arch
basilic - medial end of dorsal venous arch
What is the median cubital vein?
large communicating vein shunting blood from cephalic to basilic vein
Dermatome
area of skin supplied by one spinal segment
Where do all upper limb lymphatic vessels drain?
axillary LN
5 distinct axillary LN groups
pectoral subscapular apical central lateral
Why can infected umbilicus spread to axillary and superficial inguinal LN?
cephalic to umbilicus - axillary
caudal to umbilicus - inguinal
watershed region
Pectoral girdle
connects upper limb to axial skeleton
Upper limb and pectoral girdle articulating point
acromioclavicular joint
Clavicle break
middle and lateral 1/3 junction
AC joint
synovial plane
Sternoclavicular joint
synovial saddle
Movement of shoulder joint involves what?
AC, SC and shoulder joint
scapula-humeral rhythm
beyond 30 degrees for every 3 degrees of abduction 2 occurs at shoulder and 1 at scapula-thoracic
2:1
Elevation of scapula
levetor scapulae
trapezius
rhomboids
serratus anterior
Depression of scapula
lower trapezius and serratus anterior
protraction of scapula
serratus anterior
pec major and minor
Retraction of scapula
middle fibres of trapezius and rhomboids
Lateral rotation of scapula
superior and inferior trapezius
inferior serratus anterior
medial rotation of scapula
rhomboids, pec major, gravity, levator scapulae
Shoulder - joint type and what each part is
synovial ball and socket
ball is humeral head and socket is glenoid cavity
Rim of cartilage around glenoid cavity
glenoid labrum
Glenoid labrum function
insertion for structures
deepens socket and increases SA
Glenohumeral ligament strengthens…
anterior aspect of joint
Coracohumeral ligament strengthens…
superior aspect of joint capsule
Coraco-acromial arch parts
acromion
coracoid process
coracoacromial ligament
function of coraco-acromial arch
prevents displacement of humeral head
What part of shoulder joint is weakest and why?
inferior part
not protected by any muscles or ligaments
Which shoulder bursa communicates with joint cavity?
subscapular
subacromial bursa function
facilitate movement of supraspinous tendon and deltoid over joint capsule
subacromial bursa injury
dislocation of glenohumeral joint
4 rotator cuff muscles
teres minor
subscapularis
supraspinatous
infraspinatous
Glenohumeral joint movements - rotator cuff
abduction, external and internal rotation
Rotator cuff main function
stability
Deltoid attachments
lateral spine of scapula
across acromion
lateral third of clavicle
Anterior fibres of deltoid
flex and medially rotates
Middle fibres of deltoid
abduction
Posterior fibres of deltoid
extend and laterally rotate
Nerve supply to deltoid
Axillary - C5/6
Common injury trapping axillary nerve
surgical neck of humerus fracture
Loss of sensation - axillary nerve
regimental badge area - lateral arm
Origin of pec major fibres
medial third of clavicle, sternum and rubs
Pec major - shoulder
flex, adduct and internally rotate humerus
Deltopectoral triangle
space below clavicle - between deltoid and pec major
subclavian vein
nerve supply of serratus anterior
long thoracic nerve - C5-7
Injury to long thoracic nerve and when this could happen
winged scapula
surgery for breast cancer
Superior fibres of trapezius - scapula
elevates
Medial fibres of trapezius - scapula
retracts
Inferior fibres of trapezius - scapula
depress
Trapezius innervation
CN 11 - spinal accessory nerve
Teres major on shoulder joint
adduct and medially rotate
Lattisimus dorsi on shoulder
extends, adducts and medially rotate
Lateral or external rotation of shoulder
teres minor and infraspinatus
