Vessels and Nerves of the Upper Limb Flashcards
What is knowledge of the major arteries of the upper limb crucial for?
- Assessing perfusion of the upper limb - Assessing injuries - Managing bleeding - Avoiding puncturing arteries when trying to access veins - Obtaining an arterial blood sample for an ABG
What is knowledge of the major veins of the upper limb crucial for?
- Venepuncture and cannulation; - Assessing injuries - Managing bleeding
What is knowledge of the major nerves, dermatomes and myotomes is crucial for?
- Assessing patients for signs of nerve injury - Conducting a peripheral neuro examination
Where do the subclavian arteries arise?
From the brachiocephalic trunk on the right and from the arch of the aorta on the left
Where does the subclavian artery travel?
Under the clavicle
What does the subclavian artery continue as?
The axillary artery in the axilla
What does the axillary artery continue as?
The brachial artery in the arm
What does the brachial artery bifurcate into?
The radial and ulnar arteries - these supply the forearm and hand
There are anastomoses between the radial and ulnar arteries in the hand. What is the purpose of this?
Ensure perfusion of the hand is maintained in the event that one of these arteries is injured
Where do the circumflex humeral arteries arise?
From the axilla
- Anterior circumflex humeral
- Posterior circumflex humeral
Why are the anterior and posterior circumflex humeral arteries at risk of damage?
Form an anastomotic network around the surgical neck of the humerus and can be damaged in cases of fracture
What marks the boundary between the axillary artery becoming the brachial artery?
The lower border of teres major
Where does the brachial artery course?
Down the anterior aspect of the arm
What important branch does the brachial artery give rise to?
Profunda brachii (deep artery of the arm)
Describe the course of the profunda brachii i.e. what groove? what does it travel with?
Leaves brachial artery and travels behind the humerus and travels with the radial nerve in the radial groove of the humerus (posterior aspect)
What does the profunda brachii supply?
Supplies structures in the posterior aspect of the upper arm (e.g. triceps brachii).
Where does the brachial artery bifurcate?
In region of the cubital fossa
What is the anastomotic network surrounding the elbow joint?
Branches from radial and ulnar arteries form anastamoses with other branches of the brachial artery as well as terminal branches of the profunda brachii.
This forms collateral pathways
Purpose of collateral pathways in the arm?
The arm has relatively good anastomotic supply. This means that it is well protected from ischaemia in cases of temporary or partial occlusion of arteries.
What branch does the ulnar artery give rise to?
The common interosseous artery in the forearm
What does the common interosseous then divide into?
Anterior and posterior interosseous arteries, which supply deeper structures in the forearm.
What does the anterior interosseous arteries supply?
Supplies anterior compartment of forearm
What does the posterior interosseous artery?
Passes through the interosseous membrane to supply the posterior compartment of the forearm
What happens to the radial and ulnar arteries when they reach the hand?
They anastamose by forming 2 arches - the superficial palmar arch, and the deep palmar arch.
What route does the radial artery take to the hand?
Down the lateral part of the forearm (near thumb), through the anatomical snuffbox, through the muscle that sits in that region, and emerges into the palm of the hand
Where can the radial pulse be palpated?
The radial pulse can be palpated in the distal forearm, immediately lateral to the prominent tendon of the flexor carpi radialis muscle.
What are the superficial and deep palmar arteries formed by?
Anastamoses between the radial and ulnar arteries
Describe the blood supply of the hand
The hand has a rich arterial supply with many anastomoses between vessels. This allows the hand to be perfused even when under high resistance to flow (such as when grasping or applying pressure).
What branches do the superficial and deep palmar arteries give rise to?
Branches that supply the metacarpal region, the digits and the thumb
Describe arrangement of digital arteries
Digital artery sits either side of each digit
What vessels are at risk in serious fractures of the clavicle?
Subclavian / axillary artery
What vessels are at risk during fractures of the surgical neck of the humerus?
Anterior/posterior circumflex humeral arteries
What vessels/nerves are at risk during fractures of the humeral shaft?
Profunda brachii artery, radial nerve (run alongside each other)
What vessels are at risk during supracondylar fractures (just above epicondyles of the humerus)?
Brachial artery
What can rupture of the brachial artery cause?
Ischaemia of the forearm muscles
What do injuries near the cubital fossa risk?
Damage to brachial artery
What do injuries to the forearm risk?
Damage to radial and ulnar arteries
What arteries are at risk during injury to the wrist? Why are these vessels more vulnerable here?
Radial and ulnar arteries - these are relatively superficial at the wrist so are more vulnerable
What are the 2 systems of veins in the upper limb?
Superficial and deep
What do the deep veins of the upper limb follow?
The arteries
Where do the superficial veins of the upper limb lie?
In the subcutaneous tissue - can often be seen and / or palpated under the skin
What veins are used for venepuncture and cannulation?
Superficial
Do superficial and deep veins communicate with each other?
Yes - superficial veins drain into deep veins
How are the deep veins of the upper limb named?
The deep veins share the name of the artery they accompany.
E.g. subclavian vein, axillary vein
What are the anterior and posterior circumflex humeral arteries paired with?
Paired with deep veins (same name), these eventually drain back into the axillary vein
Are the anterior and posterior circumflex humeral veins deep or superficial?
Deep