Movement lecture 4: Vasculature of the upper limb Flashcards
What is the first branch of the subclavian artery?
Vertebral
What is the second branch of the subclavian artery?
Internal thoracic
What is the third branch of the subclavian artery?
Thyrocervical trunk
What is subclavian steal syndrome?
Occlusion of the subclavian artery proximal to the vertebral artery origin causing reversed flow in the ipsilateral vertebral artery. Blood is stolen from the circular vertebrobasilar system (Circle of Willis) to supply the distal territory of the occluded or stenosed artery. Radial pulse much weaker on affected side.
Where does the subclavian artery become the axillary artery?
Lateral border of the first rib. Divided into thirds by pectoralis minor muscle.
- First part superior to muscle
- Second part deep to muscle
- Third part inferior to muscle
Where does the axillary artery become the brachial artery?
Inferior border of teres major.
What are the three main branches coming off the brachial artery before its bifurcation?
- Profunda brachii
- Superior ulnar collateral artery
- Inferior ulnar collateral artery
Where is the bifurcation of the brachial artery into radial and ulna?
Cubital fossa
What are the features of the profunda brachii artery?
- Deep artery of the arm
- Supplies the posterior compartment of the arm
- Wraps around posterior surface of humerus
- Runs in radial groove with radial nerve.
What does the degree of ischaemia after brachial injury depend on?
Degree of ischaemia after brachial artery injuries depends on whetherinjury is proximal or distal to profunda brachii
Ligation of the brachial artery proximal to the profunda brachii artery will result in a loss of limb in about 50% of cases whereas amputation occurs in 25% of cases with ligation distal to profunda brachii
What are the peri-articular anastamoses?
Network of anastomoses of brachial and profunda brachii arteries in the arm with radial and ulnar arteries in the forearm.
Ensures blood flow to the forearm even if elbow is fully flexed.
What is supplied by the radial artery?
Supplies the anterolateral aspect of the forearm including flexors and extensors
What is supplied by the ulnar artery?
Runs through forearm with the ulnar nerve
Supplies the medial side of forearm – mainly flexors and pronators
Gives off common interosseous artery (trunk) near its origin.
This divides into anterior and posterior interosseous arteries which supply the middle of the flexor and extensor compartments respectively.
What happens when the radial artery enters the hand?
Passes dorsally and crosses the floor of the anatomical snuff box.
Pierces 1st dorsal interosseous muscle and passes between the transverse and oblique heads of adductor pollicis to enter the palmer surface of the hand.
How does the ulnar artery enter the hand?
Enters the hand through the ulnar canal (Guyon’s canal) superficial to the flexor retinaculum.
How do the ulnar and radial arteries anastamose within the hand.
Superficial and deep palmer arches (not present in all of the population).
How many pulse points can you find in the upper limb?
Six:
- Axillary
- Brachial x 2 (mid arm and cubital fossa)
- Radial x 2 (wrist and anatomical snuffbox)
- Ulnar
Where does the superfical venous drainage come from?
Begins with dorsal venous arch which receives blood from digits.
Where does the cephalic vein drain from?
Drains lateral side of dorsal venous arch.
Where does the basilic vein drain from?
Medial side of dorsal venous arch.
Where is the median cubital vein?
Median cubital vein lies superficial to bicipital aponeurosis (ie roof of cubital fossa): useful site for venepuncture
What are the venae comitantes?
Two veins (sometimes more) that closely accompany an artery in such a manner that the pulsations of the artery aid venous return.
Vena comitantes accompany all of the major arteries of the upper limb.
What are the features of the venae comitantes of the upper limb?
Venae comitantes drain blood from the superficial and deep palmer arches to the vessels accompanying the radial and ulnar arteries
These continue to the cubital fossa, where they unite to form venae comitantes of the brachial vein
These venae comitantes merge with the basilic vein in the axilla to form the axillary vein.
What are the features of the axillary vein?
Formed by union of basilic vein and brachial venae comitantes
Receives blood from the cephalic vein
Renamed subclavian vein after it passes under clavicle
What are features of the subclavian vein?
Joins internal jugular vein to form brachiocephalic veins
The two brachiocephalic veins join to form the superior vena cava
