ICL 4.3: Upper Extremity Vasculature Flashcards
which arteries does the aorta give rise to?
on the left side, the aorta gives rise to the left subclavian artery and the left common carotid artery
on the ride side, the ascending aorta gives rise to the brachiocephalic trunk –> the brachiocephalic trunk then divides into the right common carotid artery and the right subclavian artery
what is the major artery that supplies the upper extremities?
right subclavian artery
what does the subclavian artery travel along side of?
the subclavian artery travels with the brachial plexus posterior to the anterior scalene muscle and anterior to the middle and posterior scalene muscles
they then enter the cervical axillary passageway to get to the upper extremity
so it travels between the anterior and middle scalene muscles which both attach to rib 1
what are the 3 parts of the subclavian artery?
these were all named in relationship to the anterior scalene muscle
- medial section
the medial section branches off into the vertebral artery, thyrocervical trunk, internal thoracic artery and costocervical trunk
- posterior section
- lateral section
what are the branches of the thyrocervical trunk?
they thyrocervical trunk is a branch of the medial portion of the subclavian artery; then the thyrocervical trunk branches into:
- supra scapular artery
- transverse cervical artery
then the transverse cervical artery branches into the dorsal scapular artery and the superficial cervical artery
what is the pathway of the suprascapular artery? what does it travel along side of?
it travels along with the suprascapular nerve which originates from C5 and C6 = superior trunk of the brachial plexus
the suprascapular nerve travels to the supraspinatus and infraspinatus through the scapular notch = entrapment location
but the supra scapular artery travels over the scapular notch to supply blood to the supraspinatus and infraspinatus
“airforce goes over while navy goes under”
what is the course of the transverse cervical artery?
it travels right over, anterior to the anterior scalene
this then branches into the superficial cervical artery and dorsal scapular artery
where do you find the dorsal scapular artery?
medial segment of the subclavian artery –> thyrocervical trunk –> dorsal scapular artery
however, 75% of the time, the dorsal scapular artery can come off of the lateral segment of the subclavian artery –> it then goes between the superior and middle trunks of the brachial plexus**
what is the relationship between the axillary artery and the subclavian artery?
the subclavian artery BECOMES the axillary artery
once subclavian hits the lateral border of rib 1 it becomes the axillary artery
what are the segments of the axillary artery?
it’s divided into thirds by the pectoralis minor muscle at its attachment to the coracoid process
pec minor attaches to ribs 3-5 and attaches to coracoid process so if you peel it back you’ll see all 3 segments of the axillary artery! the pec minor is your landmark!
what is anastomosis?
a connection of two arteries
what is one of the most clinically important anastomosis in the body?
the scapular arterial anastomosis
this is important because lets say there’s damage to the 2nd region of the axillary artery, then you can bypass this damage through collateral circulation!
the arterial anastomosis provides increased protection for circulation around the shoulder to supply the arm, forearm and hand – the collateral circulation allows supply of the 3rd part of the axillary artery in the event of occlusion of the 2nd part
so the 3rd segment of the axillary artery (subscapular artery) is communicating with the 1st segment of the subclavian (dorsal scapular artery)
in the event of a slowly occurring occlusion, blood flow of the subscapular artery reverses direction, providing circulation to the third part
but if there’s rapidly occurring occlusion like with trauma, blood flow through that collateral pathway might not be enough to sustain viability of the limb
what are the branches of arteries coming of the 2nd region of the axillary artery?
- thoracoacromial artery
the thoracoacromial artery then has a bunch of little branches coming off of it that supply the bones and muscles in the area (calcite, acromion, deltoid, pectoral)
- lateral thoracic artery
runs right down the ribcage on the serratus anterior muscle – the long thoracic nerve also runs down the ribcage and innervates the serrates anterior!
what’s the function of the superior thoracic artery?
it’s a branch of the first region of the axillary artery
it supplies the 1st and 2nd intercostal spaces and part of the upper breast
what are the branches of arteries coming of the 3rd region of the axillary artery?
- subscapular artery
it bifurcates and gives rise to the circumflex scapular artery which wraps around the lateral border of the scapula to the back of the scapula – it also gives rise to the thoracodorsal artery
- anterior circumflex humeral artery (tiny)
- posterior circumflex humeral artery (huge**)
the anterior and posterior circumflex humeral arteries wrap around the surgical neck of the humerus and anastomose
how can you differentiate between the posterior and anterior circumflex humeral arteries?
the posterior circumflex humeral artery is way larger
it becomes posterior by traveling with the axillary nerve through the quadrangular space
what are the borders of the quadrangular space?
teres major and minor, long head of the tricep, and the humerus
boundaries include the teres minor superiorly, the long head of the triceps medially, the teres major inferiorly, and the surgical neck of the humerus laterally
what is the relationship between the brachial and axillary artery?
the brachial artery is the continuation of the axillary artery
it starts at the inferior border of teres major
it will travel with the median and ulnar nerve through the arm
what is the first branch of the brachial artery?
the profounda (deep) brachial artery
its goal is to get into the posterior compartment of the arm where are the extensors are so it actually wraps around and goes through the radial groove along with the radial nerve!
what does the brachial artery bifurcate into?
once the brachial artery gets to the cubital fossa at the elbow under the distal biceps muscle ligament, it branches into the ulnar and radial arteries
what is the course of the radial artery in the forearm?
it travels with the superficial radial nerve
deep to the brachioradialis muscle
it moves to the posterior hand by crossing the “anatomical snuff box” on the dorsum of the hand
on the anterior wrist, this artery is a common place to draw arterial blood or place a blood pressure catheter
what is the course of the ulnar artery in the forearm?
the ulnar artery supplies most of the intermuscular branches and compartments of the anterior forearm
in the distal 2/3 of the forearm it travels with the ulnar nerve and crosses the wrist just lateral to the ulnar nerve superficial to the flexor retinaculum in Guyon’s canal
the ulnar artery meets up with the ulnar nerve after the ulnar nerve passes through the ulnar groove at the medial epicondyle (elbow, funny bone)
what are the branches of the ulnar artery?
so the main branch of the ulnar artery distal to the cubital fossa is the common interosseous artery
the common interosseous artery then branches into the anterior and posterior interosseous arteries
they’re called this because they are anterior and posterior to the interosseous membrane between the radius and ulna, respectively
then the anterior interosseous artery pierces the interosseous membrane at the pronator quadratus muscle and forms an anastomosis with the posterior interosseous artery which then supply the median nerve!
what are the borders of Guyon’s canal?
the roof is the volar carpal ligament
the floor is the flexor retinaculum (transverse carpal ligament)
what does the ulnar artery become once it crosses into the wrist?
the ulnar artery becomes the superficial palmar arch, completed by the superficial palmar branch of the radial artery (anastomosis)
the supply the superficial and deep tissue of the hand
this arch is located just proximal to the distal palm crease, and is separated from the deep arch by the digital flexor tendons and the lumbrical muscles
what does the radial artery become once it crosses into the wrist?
deep palmar arch
the radial artery lateral to FCR tendon, passes from anterior to posterior by circling around distal radius, crosses anatomical snuffbox and pierces 1st dorsal interosseous muscle to enter the anterior palm
it becomes the deep palmar arch (which is closed by the deep branch of the ulnar artery), which is located just proximal to the middle palmar crease
what is the pathway of the digital arteries?
the common digital arteries branch off of the superficial palmar arch and travel towards the fingers
once the common digital arteries get to the metacarpal-phalangeal joint, they branch off and become the proper digital arteries
HOWEVER, the proper digital arteries do NOT anastomose, the are end arteries!!! so if there is a proximal laceration on the finger, the distal part of the finger won’t get any blood flow from collateral arteries
what artery specifically supplies the pointer finger?
radialis indicis
what artery specifically supplies the thumb?
- princeps pollicis
2. dorsalis pollicis
what is the Allen’s test?
it’s to verify that the radial and ulnar arteries anastomose in the deep and superficial arches of the hand
- Occlude both the radial and ulnar arteries at the wrist
- Have “patient” open and close the hand to drain blood
- Release the ulnar artery while keeping pressure on the radial artery.
- Immediate return to normal coloration implies that the ulnar artery is supplying the hand. In this case, the radial artery may be cannulated safely.
- The test may be repeated with the radial artery released with pressure maintained over the ulnar artery. This implies that the radial artery is supplying the hand
what is the venous drainage of the upper limb?
venous drainage occurs in two parallel arranged systems of veins
- Deep System = deep to circumferential deep fascia (“sausage skin fascia”); capable of handling ALL the venous drainage alone (so you could get rid of the superficial system and you’d still get blood return to the heart)
- Superficial System =
within superficial fascia; physiologically, operates to maintain skin temperature; can be eliminated entirely without any adverse effects to the patient, including swelling
what is the venae comitantes?
deep veins in all but the most proximal regions of the limbs are arranged intimately around the arteries with two or 2 or 3 linear veins which have frequent anastomoses with each other
when we talk about deep veins, it’s when there are 3 or 4 deep veins wrapping around an artery and there’s tons of little venous connections that loop them together
so sometimes when you can’t find an artery in lab, it might be because it’s covered by the venae comitantes
where is the cephalic vein found?
it’s a superficial vein on the lateral side of the arm that does NOT run with an artery
it’s located in the delt-pectoral groove
it needs to be protected in cases of axillary trauma so if you compromise the axillary vein you need a plan B which is actually your cephalic vein!
where is the basilic vein found?
it’s a superficial vein that runs down the medial side of the arm
it eventually drains into the axillary vein just like the cephalic vein!!
the axillary vein is actually formed by the basilic and brachial veins coming together –> the axillary vein continues proximally and becomes the subclavian vein at the lateral border of the first rib
what is the function if the median cubital vein?
it connects the cephalic and basilica veins!
this is where you draw blood!!!!
what are the 3 main superficial veins?
- cephalic (lateral)
- basilic (medial)
- median cubital vein
