Arteries of the Upper Limb Flashcards
Where does the arterial supply to the upper limb begin?
In the chest, as the subclavian artery
Where does the right subclavian artery arise from?
The brachiocephalic trunk
Where does the left subclavian artery arise from?
Branches directly off the arch of the aorta
When do the subclavian arteries enter the axilla?
When they cross the lateral edge of the 1st rib
What are the subclavian arteries called when they enter the axilla?
The axillary arteries
Where does the axillary artery pass?
Through the axilla, just underneath the pectoralis minor muscle
What is the axillary artery enclosed in?
The axillary sheath
What arises from the axillary arteries?
The posterior and anterior circumflex humeral arteries
Subscapular artery
Where do the posterior and anterior circumflex humeral arteries, and the subscapular artery arise?
At the level of the humeral surgical neck
What do the posterior and anterior circumflex humeral arteries do?
Circle posteriorly around the humerus to supply the shoulder region
What does the axillary artery become?
The brachial artery
Where does the axillary artery become the brachial artery?
At the level of the teres major muscle
What is an aneurysm?
A dilation of a blood vessel to more than twice its original size
How common are axillary artery aneurysm?
Rare
What can axillary artery aneurysms occur as a result of?
Atherosclerosis
Thoracic outlet syndrome
Trauma
What can happen with axillary artery aneurysms?
The dilated portion of the axillary artery can compress the brachial plexus
What is the result of the compression of the brachial plexus by an aneurysm?
Produces neurological symptoms such as paresthesia and muscle weakness
What is the definitive treatment for an axillary artery aneurysm?
Surgical- involves removing the aneurysm and reconstructing the vessel wall using a graft
When does the axillary artery become the brachial artery?
When it reaches the lower border of the teres major
Why is the brachial artery important?
It is the main source of blood for the arm
What does the brachial artery give rise to?
The profunda brachii
Where does the brachial artery give rise to the profunda brachii?
Immediately distal to the teres major
What is the profunda brachii?
The deep artery of the arm
Where does the profunda brachii travel?
Along the posterior surface of the humerus, running in the radial groove
What does the profunda brachii supply?
Structures in the posterior aspect of the arm
How does the profunda brachii terminate?
By contributing to a network of vessels
Where does the brachial artery descend down the arm?
Immediately posterior to the median nerve
Where does the brachial artery terminate?
As it crosses the cubital fossa, underneath the brachialis muscle
How does the brachial artery terminate?
By bifurcating into the radial and ulnar arteries
What protects the arm from temporary or partial occlusion of the brachial artery?
The arm has a relatively god anastomotic supply
What happens if the artery is completely blocked, or severed?
It is a medical emergency
Why is blockage or severance of the brachial artery a medical emergency?
The resulting ischaemia of the forearm can cause necrosis and paralysis of the muscles in the forearm
What happens when there is necrosis and paralysis of forearm muscles?
The affected muscles are replaced to some degree by scar tissue, and shorten considerably, causing a characteristic flexion deformity called Volkmann’s contracture
What does the radial artery supply?
The posterior aspect of the forearm
Where does the ulnar artery supply?
The anterior aspect of the forearm
What happens to the radial and ulnar arteries?
They anastomose in the hand, by forming two arches, the superficial palmar arch and the deep palmar arch
Why does the hand have a very good blood supply?
Because it has many anastomosing arteries
What does the good blood supply of the hand allow?
For the hand to be perfused when grasping, or applying pressure
What is true of a good majority of the arteries in the hand?
They are superficial
What does a lot of the arteries in the hand being superficial allow for?
Heat loss when needed
What happens to the ulnar and radial arteries in the hand?
They interconnect to form two arches, from which branches to the digits emerge
What does the radial artery supply in the hand?
Contributes mainly to supply of the thumb and the lateral side of the index finger
What does the ulnar artery supply in the hand/
Contributes mainly to the supply of the rest of the digits (not the thumb) and the medial side of the index finger
How does the ulnar artery move into the hand?
Anteriorly to the flexor retinaculum, and laterally to the ulnar nerve
What happens to the ulnar artery in the hand?
It divides into two branches, the superficial palmar arch, and the deep palmar branch
What arises form the superficial palmar arch?
The common palmar digital arteries
What do the common palmar digital arteries supply?
The digits
What does the superficial palmar arch anastomose with?
A branch of the radial artery
Where is the superficial palmar arch found?
Anteriorly to the flexor tendons in the hand, but just deep to the palmar aponeurosis
How does the radial artery enter the hand?
Dorsally, crossing the floor of the anatomical snuffbox
What happens to the radial artery once in the hand?
It turns medially and moves between the heads of the adductor pollicis
What forms the deep palmar arch?
The radial artery anastomosing with the deep palmar branch of the ulnar artery
What does the deep palmar arch give rise to?
Five arteries supplying the digits
