Nerve and Blood Supply to the Upper Limb Flashcards
Name some of the common causes of brachial plexus injury
Disease, stretching or wounds to the lateral cervical or axilla regions
What is superior brachial plexus injury known as?
Erb-Duchenne palsy
What is inferior brachial plexus injury known as?
Klumpke palsy
What is meant by a superior brachial plexus injury?
Involves damage to C5-C6 nerves
What is meant by an inferior brachial plexus injury?
Involves damage to C8-T1 nerves
What are the consequences of a superior brachial plexus injury and why?
Loss of sensation of lateral aspect of arm (C5-C6 dermatome) and paralysis of deltoid, biceps and brachialis
How will an individual with Erb-Duchenne palsy present?
limb will be adducted to the shoulder, medially rotated and elbow extended
Name the two nerves from the posterior cord of the brachial plexus
Axillary and radial nerves
How will an individual with Klumpke palsy present?
hand appears clawed due to ulnar nerve palsy
Name the three nerves from the anterior cord of the brachial plexus
Median, musculocutaneous and ulnar
Describe the motor and sensory innervation of the axillary nerve
MOTOR: shortest terminal branch and goes under shoulder joint and supplies deltoid muscle
SENSORY: lateral arm
How can damage to the axillary nerve be caused and how would the patient present?
CAUSE: dislocated shoulder or fracture of humerus neck
SYMPTOMS: paralysis of deltoid and loss of sensation over lateral arm
Describe the sensory and motor innervation of the radial nerve
MOTOR: all of the extensor muscles in posterior forearm
SENSORY: between thumb and index finger on dorsum of the hand
How can damage to the radial nerve be caused and how would the patient present?
CAUSE: fractures to humerus midshaft (as nerve runs right next to the humerus in a groove)
SYMPTOMS: weakened elbow extension and wrist drop and loss of sensation in web between thumb and index finger
Describe the sensory and motor innervation of the ulnar nerve
MOTOR: intrinsic muscles of the hand
SENSORY: little finger and medial palm
How can damage to the ulnar nerve be caused and how would the patient present?
CAUSE: fracture to medial epicondyle of humerus
SYMPTOMS: loss of sensation in little finger and medial palm
Describe the sensory and motor innervation of the median nerve
SENSORY: sensation to thumb and index finger
MOTOR: digit flexors and muscles moving thumb
How can damage to the median nerve be caused and how would the patient present?
CAUSE: supracondylar fractures and compression/laceration of the wrist
SYMPTOMS: paralysis of digit flexors and muscles moving thumb, and long-term caused atrophy of thenar muscles, giving ‘ape-hand’, also a loss of sensation in thumb and index finger
What movement would you use to test the radial nerve?
thumbs up (if can’t there is damage)
What movement would you use to test the ulnar nerve?
peace out sign (claw hand usually if damage, so can’t extend fingers)
What movement would you use to test the median nerve?
‘fist-bump’ action as if there is damage will not be able to flex the fingers in this way
Where is the brachial plexus palpable?
Superior border of the clavicle
State the nerve roots of the brachial plexus
C5-T1 mainly, potential for C4 and T2
Where is the C4 dermatome?
top of shoulder
Where is the C5 dermatome?
lateral arm
Where is the C6 dermatome?
lateral forearm and thumb
Where is the C7 dermatome?
middle finger
Where is the C8 dermatome?
little finger
Where is the T1 dermatome?
strip of skin of medial forearm up to chest
What are the different subdivisions of the brachial plexus?
Nerve roots, trunks, divisions, cords, terminal branches
Where can you locate the radial pulse?
lateral to the tendon of the flexor carpi radialis muscle
Where can you locate the ulnar pulse?
lateral to tendon of the flexor carpi ulnaris muscle (deeper so more difficult to find and lies under pisiform)
Where can you locate the brachial pulse?
medially to the distal tendon of the biceps brachii
What type of blood supply is present around joints?
Collateral
Describe the arterial blood supply to the upper limb
The subclavian artery becomes the axillary artery as it passes through the axilla. Then the humeral circumflex branches off from the axillary artery. The axillar artery then branches into the deep brachial artery, the brachial artery and the ulnar collateral arteries (medial). The brachial and deep brachial then reconnect to form the radial artery. The ulnar nerve then branches from the brachial artery and travels medially . These then form the deep palmar arch, superficial palmar arch and digital arteries.
What is compartment syndrome?
A condition resulting from increased pressure within a confined body space (especially of the leg or forearm)
Describe the venous drainage of the upper limb
The right subclavian vein splits into the cephalic (lateral) and axillary veins (medial). The axillary vein then splits into the brachial vein (middle of arm) and basilica vein (medial). The median cubital vein reconnects the basilica vein and cephalic veins to continue the cephalic vein. The basilica vein continues to the hand. The brachial vein splits into the radial and ulnar veins and goes on to supply the deep plasma veins, superficial palmar and digital veins.
What are the superficial veins of the arm?
basilic vein, cephalic vein and median cubital vein
