Upper Limb Flashcards
What bones are part of the pectoral girdle?
clavicle
scapula
manubrium of sternum
what is the blood supply to the upper limb?
subclavian
axillary
brachial
At what point does the subclavian artery become the axillary artery?
When the subclavian arteries cross the lateral edge of the 1st rib, they enter the axilla, and are called axillary artery
At what point does the axillary artery become the brachial artery?
The axillary artery becomes the brachial artery at the lateral border of the teres major muscle.
Which arteries come off the axillary artery?
At the level of the humeral surgical neck, the posterior and anterior circumflex humeral arteries arise. They circle posteriorly round the humerus to supply the shoulder region. The largest branch of the humerus also arises here; the subscapular artery.
Which artery does the brachial artery give off?
Profunda brachii
deep artery of the arm
runs on the posteior side of the arm along the radial groove
At what point does the brachial artery branch to form the radial and ulnar arteries?
The brachial artery descends down the arm immediately posterior to the median nerve. As it crosses the cubital fossa, underneath the brachialis muscle, the brachial artery terminates by bifurcating into the radial and ulnar arteries. The two arteries anastamose in the hand, by forming two arches, the superficial palmar arch, and the deep palmar arch
Explain what happens to a fractured clavicle
2-5 % of adult fractures
most common site is the junction at the lateral 1/3 and medial 2/3 of the clavicle.
The lateral end of the clavicle is pulled inferiorly by the arm, medially by pec major. The medial end is pulled superiorly by the SCM
What does the clavicle protect?
brachial plexus
underlying vessels
apex of lung
what are the movements of the scapula?
elevation/ depression
protatction/retraction
upward rotation/ downward rotation
What are the movements at the glenohumeral joint?
flexion/extension
abduction/adduction
medial and lateral rotation
circumduction
Which musles are the chief flexors at the glenohumeral joint?
pec major (clavicular part) deltoid anterior (coracobrachialis assisted by biceps brachii which stabilises the joint)
Which muscles are the chief extensors at the glenohumeral joint?
Latissumus dorsi Deltoid posterior ( teres major, long head of triceps brachii help stabilise the joint)
Which muscles are the chief abductors at the glenohumeral joint?
deltoid
1st 10 degrees of abduction initiated by supraspinatus
180 degrees of shoulder abduction: 120 degress at glenohumeral joint and 60 degrees occurs at scapulothoracic joint
Which muscles are the chief adductors at the glenohumeral joint?
pec major
lat dorsi
(gravity is prime mover)
Which muscle is the chief medial rotator at the glenohumeral joint?
subscapularis
Which muscle is the chief lateral rotator at the glenohumeral joint?
infraspinatus
What are the 4 rotator cuff muscles?
supraspinatus
infraspinatus
teres minor
subscapularis
Explain what happens in a dislocation of the glenohumeral joint
Mainly anterior dislocations. GH joint is fully abducted and tilts head of humerus inferiorly. The humeral head is forced anteriorly and inferiorly – into the weakest part of the joint capsule.
Glenoid labrum may be stripped and makes joint weaker
Arm is adducted and moves inferiorly
loss of rounded profile of shoulder
What nerve can be damaged due to a dislocation of the shoulder joint?
Axillary nerve injury
leads to paralysis of deltoid and loss of sensation
test C5 dermatome
Which lymph nodes are present in the axilla?
apical central pectoral subscapular humeral