Does anyone here know SPECIFICALLY how anastamoses work at the elbow joint and scapula? i am very confused and my anatomy exam is approaching very soon. thanks in advance.
Anastamoses
- Thread starter bhop
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I am not sure exactly what you are looking for but an anastomosis is simply when an artery/vein/etcetera splits and then reconnects later. An example would be the way that the ulnar collateral artery splits from the brachial artery and then reconnects later into the ulnar artery (a branch off the brachial artery). In the region of the scapula this is important probably because of subclavian steal syndrome?
Someone please correct me if I am wrong. I am not a surgeon.
Someone please correct me if I am wrong. I am not a surgeon.
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Uhh- it is not important at the scapula because of subclavian steal. Subclavian steal occurs because the proximal subclavian artery is occluded, so the vertebral artery flows backwards, cutting off circulation to the brain... and you get the fainting or whatever.
An anastomosis is a system where blood can reach a certain area via alternate routes (sort of just like what you said) -- there's branching, then meeting up again. The anastomosis around the scapula is very important because it allows blood to flow from the subclavian to the axillary, regardless of how the joint is positioned. You need to know all the arteries that form this anastomosis. You can find this in Netter I'm sure. I think it's circumflex scapular, suprascapular, and dorsal scapular arteries, and some minor ones... if you ligate or occlude one of these, your shoulder can still get blood!! What if you ligate your subclavian or axillary? Suprascapular + dorsal scapular arteries can flow to the circumflex scapular artery, so your arm still gets blood. This is the *key* -- still getting blood despite occlusions in some areas.
That way if you have an occlusion, blood will still be able to flow past that occlusion, just through *some other* means... yeah, splitting and rejoining, and perhaps reversal of blood flow in some cases -- and if one part of the split is occluded, the other part can take over.
Even if you are a resident, this is still kind of basic anatomy 🙂
I'm pretty sure I'm right... but, anatomy was a long time ago.
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Here is an example of arteries that anastomes around the scapula:
Suprascapular and transverse cervical from the thyrocervical trunk anastomose w/ the circumflex scapular a. and subscapular a. respectively . Also, the internal thoracic to the anterior intercostals to the lateral thoracic a. to axillary a would be another route.
Around the ulna:
I just think that the ulnar and radial arteries anastomose at the elbow joint (humero-ulnar joint).
For us the point made was that at EVERY joint there is a lot of collateral ciculation taking place (I think in case of an injury there will be alternate routes). I hope this helped.
Suprascapular and transverse cervical from the thyrocervical trunk anastomose w/ the circumflex scapular a. and subscapular a. respectively . Also, the internal thoracic to the anterior intercostals to the lateral thoracic a. to axillary a would be another route.
Around the ulna:
I just think that the ulnar and radial arteries anastomose at the elbow joint (humero-ulnar joint).
For us the point made was that at EVERY joint there is a lot of collateral ciculation taking place (I think in case of an injury there will be alternate routes). I hope this helped.
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here is a pic of the elbow anastamoses. If the pic doesn't show up here is the link http://www.bartleby.com/107/Images/small/image526.jpg
What is usually tested, in my experience, is to be able to trace a path around a blockage. So in the elbow, the profunda brachii artery connects to the radial recurrent, and the superior/inferior ulnar collaterals connect to the anterior/posterior ulnar recurrent. Then there is a cross connection between those two routes so that blood can flow in any of those arteries from any of the others.
So the question would be something like, trace the path of blood around a blockage in the brachial artery just proximal to the bifurcation into the ulnar and radial artery, to the index finger? It would go, from the beginning, aorta, sublcavian (right side is brachiocephalic first), axillary, brachial, profunda brachii, radial recurrent, radial, superficial palmar arch, common palmar digital, proper palmar digital arteries, aterioles, capillaries, tissue exchange.
The anastomoses also functions while the elbow is fully extended because that leads to a partial brachial artery blockage. So the blood takes the path of lower resistance.
hope that helps
What is usually tested, in my experience, is to be able to trace a path around a blockage. So in the elbow, the profunda brachii artery connects to the radial recurrent, and the superior/inferior ulnar collaterals connect to the anterior/posterior ulnar recurrent. Then there is a cross connection between those two routes so that blood can flow in any of those arteries from any of the others.
So the question would be something like, trace the path of blood around a blockage in the brachial artery just proximal to the bifurcation into the ulnar and radial artery, to the index finger? It would go, from the beginning, aorta, sublcavian (right side is brachiocephalic first), axillary, brachial, profunda brachii, radial recurrent, radial, superficial palmar arch, common palmar digital, proper palmar digital arteries, aterioles, capillaries, tissue exchange.
The anastomoses also functions while the elbow is fully extended because that leads to a partial brachial artery blockage. So the blood takes the path of lower resistance.
hope that helps
