Flashcards in Lecture 5: Nerves and Vasculature Upper Limb Deck (57):
When does the Subclavian artery become the axillary artery?
When it passes the lateral border of the first rib
What 3 important arteries come off the subclavian artery?
Vertebal artery, internal thoracic and thyrocervical trunk (Giving rise to the inferior thyroid)
Which important branches come off the axillary artery?
The anterior and posterior circumflex humeral
Which muscle divides the axillary artery into 3 parts?
Which important branches come off the brachial artery?
Profunda Brachii (Giving rise to the radial collateral) and superior and inferior ulna collateral
Which foramina does the vertebral artery pass through?
What is subclavian steal syndrome?
Occlusion of the subclavian artery, proximal to the vertebral artery origin, causing reverse flow in the ipsilateral vertebral artery
When does the axillary artery become the brachial artery?
At the inferior border of teres major
Where does the brachial artery divide?
In the cubital fossa
What does the profunda brachii artery supply?
Posterior compartment of the arm
What 2 vessels travel through the triangular interval and the spiral groove?
The profunda Brachii artery and the radial nerve
How are brachial vessels commonly injured?
Penetrating and blunt trauma, usually associated with humeral fractures
What is the difference in prognosis of a injury to the brachial artery proximal to the profunda brachii or distal to it?
Proximal = 50% loss of limb
Distal = 25% loss of limb
What are the peri-articular anastomosis and what do they do?
Network of anastomosis of the brachial and profunda brachii arteries in the arm, with the radial and ulna arteries in the fore-arm
They ensure bloodflow to the fore-arm even of the elbow is fully flexed
What does the radial artery supply?
The anterolateral aspect of the fore-arm, including flexors and extensors
What does the ulnar artery supply?
The medial side of the forearm, mainly flexors and pronators
Where does the anterior interosseous artery supply?
The middle of the flexor compartment
What does the posterior interosseous artery supply?
The middle of the extensor compartment
What important branches does the ulnar artery give off in the fore-arm?
Anterior and posterior ulnar recurrent arteries and the common interosseous artery (Giving rise to the anterior and posterior interosseous arteries)
How does the radial artery pass to the palmar side of the hand?
Pierces the first dorsal interosseous muscle and passes between the two heads of adductor pollicis
Where can the brachial pulse be palpated in the mid-arm?
In the cleft between biceps and triceps
N.B. At this point it's just inferior to the medial nerve
What is the arrangement of the 3 structures in the cubital fossa?
Tendon, most lateral. Artery, in the middle and median nerve, most medial
Where can the radial and ulnar arteries be palpated at the wrist?
Lateral to the tendons of flexor carpi radialis and ulnaris respectively
The cephalic and basilic drain which parts of the hand?
Cephalic = Lateral side of dorsal venus arch
Basilic = Medial side of dorsal venus arch
The ulnar artery supplies which part of the hand?
Mainly the medial 3.5 digits
The radial artery supplies which part of the hand?
Mainly the lateral 1.5 digits
After running through the deltopectoral triangle what does the cephalic vein do?
Pierces the clavipectoral fascia and drains into the axillary vein
What is a useful site for venepuncture?
Median cubital vein
What are venae comitantes?
2+ veins that accompany an artery so that pulsations aid return
Which arteries of the arm are accompanied by venue comitantes?
Deep and superficial palmar arches, radial and ulnar and brachial
How is the axillary vein formed?
When the venue comitantes of the brachial artery merge with the basilic vein
When does the axillary vein become the subclavian vein?
After it passes under the clavicle
How does the subclavian vein drain into the heart?
Joins the internal jugular to form the brachiocephalic veins which join to form the SVC
What is Erb's palsy?
It's common in newborn when there is stretching of the neck during delivery, causing damage to the C5, C6 nerve roots, leading to paralysis of the muscles of the shoulder and the arm supplied by C5, C6
What are the clinical features of Erb's palsy?
Arm hangs limply by side
"Waiter's tip" position
adducted shoulder- Due to loss of abductors
Medially rotated arm- Due to loss of lateral rotators
Extended elbow - Loss of flexion by brachialis and biceps
Pronated forearm - Loss of supination by biceps
How can Erb's palsy occur in adults, and what is the prognosis?
Violent falls on the side of the head and shoulder, forcing the two apart
The prognosis depends upon the degree of damage, function may return within months or may be permanent
What investigation would be carried out to confirm Erb's palsy in an adult?
An MRI shows nerve root damage
Can Erb's palsy be cured?
Yes, with a nerve transplant
What is Klumpke's Palsy?
Damage to the inferior trunk of the brachial plexus C8, T1 - Ulnar nerve
Is Klumpke's palsy more or less common than Erb's palsy?
How does Klumpke's palsy occur?
In newborns when the upper limb is pulled excessively and in adults when the upper limb is suddenly pulled superiorly
What are the clinical features of Klumpke's palsy?
Paralysis of the intrinsic muscles of the hand and ulnar flexes of the wrist and digits
Imbalance of the intrinsic and extrinsic muscles leads to claw hand
What does claw hand occur in?
Klumpke's palsy (Damage to the ulnar nerve)
What is claw hand?
Hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints
Due to paralysed lumbricals of digits 4 and 5
What is the cubital tunnel?
a tendinous arch between the humeral and ulnar heads of flexor carpi ulnaris
What passes through the cubital tunnel?
The ulnar nerve
What is the second most common entrapment syndrome?
Cubital tunnel syndrome
What 3 things may cause cubital tunnel syndrome?
1. Constricting fascial bands
2. Direct compression
3. Occupational activities from repetitive flexion and extension
What are the symptoms of cubital tunnel syndrome?
Same as Klumpke's palsy
What is the treatment of cubital tunnel syndrome?
Initially, anti-inflammatories then surgery if unresolved
What other syndrome may also be associated with Klumpke's palsy? and why?
Because sympathetic neuron's supplying the head originate from T1
What is radial nerve palsy?
Injury to the radial nerve in the spiral groove results in wrist drop as an inability to extend wrist and metacarpophalangeal joints due to paralysis of extensor muscles of the forearm
Why is triceps weakened rather than paralysis?
Because a branch to the long head is given off before the damage
How can the median nerve be injured at the elbow?
By supra condylar fractures or pronator teres syndrome
What does median nerve damage result in?
The hand of Benediction
What is the hand of benediction?
Inability to flex digits 1-3