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
Where does the upper limb lymph mainly drain to?
humeral and central nodes
What other lymphatics drain to axillary nodes?
lymphatics of the lateral breast drain into pectoral and subscapular lymph nodes
What is the physiological scapulothoracic joint?
physiological joint formed by an articulation of the anterior scapula and the posterior thoracic rib cage. It is musculotendinous in nature and is formed predominantly by the trapezius, rhomboids and serratus anterior muscles
What is winging of the scapula?
due to dysfunction of the serratus anterior
The serratus anterior muscle originates from ribs 2-8, and attaches the costal face of the scapula, pulling it against the ribcage. The long thoracic nerve innervates the serratus anterior.
If this nerve becomes damaged, the scapula protrudes out of the back when pushing with the arm.
What can a radical mastectomy lead to?
Lymphoedema in the distal part of the upper limb, due to removal of lymph nodes after treatment
What can axillary lymph node clearance lead to?
Injury to thoracodorsal nerve which supplies the latissimus dorse
Injury to long thoracic nerve which supplies serratus anterior
But trapezius has to work harder during abduction as serratus anterior is no longer available to help rotate the scapula
What are the name of the joints at the elbow?
humeroulnar
humeroradial
proximal radioulnar
Which nerve is at risk of injury due to a mid shaft humeral fracture?
Radial nerve
Sensory testing at the back of the hand on the first dorsal interosseus web of skin
Which nerve is at risk of injury due to supracondylar fracture?
Median nerve
This fracture can lead to ischaemia of the rest of the arm due to compression of the brachial artery
Which nerve is at risk of injury due to a medial epicondyle fracture?
ulnar nerve
it passes behind the medial epicondyle
What muscles group attach to the medical epicondyle?
flexors of the forearm
What type of joint is the elbow joint?
hinge joint
pivot joint
What is found in the anterior compartment of the forearm?
flexors e.g flexor digitorium superficialis pronators median nerve ulnar nerve radial artery ulnar artery
What is found in the posterior compartment of the forearm?
extensors e.g extensor digitorum
supinators
radial nerve
posterior interosseus artery
What joints are found in the hand?
distal radioulnar radiocarpal intercarpals carpometacarpals metacapalphalangeals interphalangeals
What articulations are found at the wrist?
radius articulates with scaphoid and lunate
ulna does not articulate with carpals
What is a Colle’s fracture?
fracture of the radius. A fall onto an outstretched hand causing a fracture of the distal radius. The structures distal to the fracture (wrist and hand) are displaced posteriorly. It produces what is known as the ‘dinner fork deformity’.
What is a Colle’s like fracture?
fracture of radius and ulna.
What is a Smith’s fracture?
A fracture caused by falling onto the back of the hand. It is the opposite of a Colles’ fracture, as the distal fragment is now placed anteriorly.
What is carpal tunnel syndrome?
Inflammation of a group of extensor muscle tendon sheath e.g adductor policus longus and extensor policus brevis
leads to compression of the median nerve and atrophy of the thenar muscle group
What are the name of carpal bones in the proximal row?
scaphoid
lunate
triquetrum
pisiform
What are the names of the carpal bones in the distal row?
trapesium
trapezoid
capitate
hamate
What is an Allan’s test?
This tests for a blockage of the anastomoses of the radial and ulnar arteries in the hand
The ulnar artey can be compressed, there is no collateral circualtion and radial artery supply may be insufficient
What is the motor and sensory innervation of the musculocutaneous nerve?
Motor: flexors of the arm
Sensory: skin over lateral forearm
What is the motor and sensory innervation of the median nerve?
Motor: flexors of the forearm
Sensory: skin over lateral palm (1-3.5 digits)
What is the motor and sensory innervation of the ulnar nerve?
Motor: intrinsic hand muscles
Sensory: skin over medial dorsal and plantar palm (3.5-5 digits)
What is the motor and sensory innervation of the axillary nerve?
Motor: deltoid, teres minor
Sensory: skin over deltoid
What is the motor and sensory innervation of the radial nerve?
Motor: extensors of upper arm and forearm
Sensory: skin over posterior arm and wrist. Dorsal hand (base of thumb and 1-3 digits)
What muscles are flexors of the elbow?
biceps brachii
assisted by brachialis and brachioradialis
What muscles extend the elbow?
Triceps brachii
assisted by anconeus
What are the chief supinator muscles?
biceps brachii
supinator
What are the chief pronator muscles?
pronator teres (elbow) pronator quadratus (wrist)
What are the boundaries of the cubital fossa?
superior: imaginary line between medial and lateral epicondyles
medial: pronator teres
lateral: brachioradialis
floor: brachialis and supinator
roof: brachial and antebrachial fascia reinforced by bicipital aponeurosis
