so we'll finish blood vessels with a look at these systemic veins and there is of course pulmonary veins bringing blood back to the heart from the lungs but that's pretty basic we'll just focus on all these other veins bringing blood back from other places sometimes simple sometimes like gonads and liver and such are a little bit more complex and we'll talk about those here's many of the vessels will discuss although not all again a lot of these brachial radial and ulnar and popliteal and fibula will be familiar terms and will match the arterial system in fact they'll be in the same position because these arteries and veins tend to run counter currently right next to each other but just based off this list you'll see I skipped some that will are unique to the venous system and they don't have a partner in the arterial system so let's just peek at the heart one more time before we move on make sure we know about the superior vena cava inferior vena cava and the opening of the coronary sinus where the ordinary vessels can get their used up blood back into the heart and as we look at the head and move down the body you'll notice by my count there's seven areas we learn about that the arterial and venous system are slightly mismatched for different reasons so on this slide there's a few things and I'll point these out as we go one is that there is no need for a Circle of Willis or anything that drains blood away in this case the drainage system for the brain includes the superior and inferior sagittal sinus 'iz and at least superior maybe inferior to is embedded in the falx cerebri that sheet of dura mater that's inside the longitudinal fissure separating the cerebral hemispheres and both of those drain into the sigmoid sinus sigmoid is shaped like Sigma which is kind of s-shaped a little bit I guess so the signal sinus is there it punches a hole through the jugular foramen and as it comes out it's changes its name to the internal jugular vein look at this internal jugular vein it goes all the way down in the external jugular vein that's pulling in blood from the face and such is going to parallel the external but they never connect remember there's a common carotid artery that Forks like this but we don't have the same for the jugular they're just like this two parallel jugulars one external one internal like they're a Tyrael system there is a vertebral vein and a subclavian vein going under the clavicle but there is no brachiocephalic trunk there's brachiocephalic veins instead on both sides both sides have a brachiocephalic vein it's short just like the brachiocephalic trunk in the arterial system and same on both sides so more like a cat as we mentioned in the last video and then those drained into the superior vena cava which dumps the blood into the right atrium going down the arm or should I say coming up the arm since all this venous blood of course is moving back up this way we have a radial and ulnar vein matching the arterial system and a brachial vein going right down the middle of the arm matching the arterial system but over on the superficial veins we have some extra veins so the median cubital vein is here in the fossa of your arm that little crook of your elbow and the median cubital vein is the typical vein for blood draws median means towards the middle a cubit is like an old tiny measurement from the tip of your fingers to the crook of your elbow it's a cue it and some cubital is referring to that that region the basilic vein is more towards the base of your arm whereas the cephalic vein I don't know why they named it this but I assume and probably right that this is the head of the humerus and the cephalic vein travels right up and past the head of the humerus so Sepp means head this vein is near the head of the humerus so extra routes for blood to return up the arm we mentioned the subclavian vein that's matchy-matchy with the arterial system the intercostal veins matching matchy with the arterial system but the venous system has these other vessels that drain the thorax the azygos and Hemi azygos veins zygote is a paired structure so a means on this is an unpaired vein again I'm not sure the name of this but it doesn't have a pair on the other side you know it doesn't it's not like the brachial veins where there's one on the left and one on the right this is unpaired but there is something called the Hemi azygos vein kind of a half unpaired vein and that's running next to the azygos vein kind of drains into it so you're just gonna look for kind of this strange diamond shape here and the azygos being the more medial vessel of the thorax Hemi azygos being off to one side okay now we're heading down in or should I say coming up we're coming up the inferior vena cava back towards the heart but I'm gonna go in the same order I do the arterial system it's gonna head downwards right here there's a cluster here right about where the celiac trunk is but that is not anything like the celiac trunk in fact all these little tubes are little veins coming from the liver so those are all hepatic veins we'll talk about why that is and why that's there an upcoming slide here's the renal vein straining the kidneys those are you know equivalent to the renal arteries same spot and all of that the gonad Elaine's are one of these weird things we'll talk about in a second actually here's a lumbar vein here there's one here here here those are pretty similar to the lumbar arteries and then eventually there is this split where the inferior vena cava splits into the common iliac vein and then the common iliac vein splits again one bit goes internal towards the inside of your thigh that's the internal iliac artery and one stays more towards the outside and goes on to become the femoral vein and the tibial vein all that stuff and that's the external iliac vein what about these go nate'll things though well notice that on the right hand side the go nataline is draining into the IVC into the inferior vena cava that's kind of like what you'd expect right the kidneys dump their blood right into the IVC the lumbar areas do it Ilia claims or let's do it so kind of a typical thing would be the organ has its own vein goes into the IVC but look at this left go nataline it's the blood is coming up from the gonads and then it dumps into the left renal vein and then that carries the blood back to the IVC that's the difference we're talking about here clinically there's lots of places that look at this but if you look at about a hundred people you'll find that on the left side just about everyone goes into the left renal vein so this kind of weird thing on the left side where the blood goes into the renal vein and then finally gets to the IVC then if you look at the other side again almost everybody on the right hand side the blood goes into the IVC so weird why does this happen well how about when does it happen there's lots of papers that look at the embryo logical origin of this weird bilateral change and the short story is that just like we have little tails and webbed fingers and such and those go away through our embryological development there are different pathways in our circulation as we're fetuses and embryos and those change over time and what happens on the left side of our body doesn't change the same way as the changes on the right side of the body and they talk about these um sub cardinal and super cardinal veins as being the blood vessels that typically you would think would change the same way but don't that's not really an answer to why I don't know that there is an answer to why it might just be one of those things a signaling cascade that causes this to happen but I can tell you that there's also papers on the clinical significance of this kind of thing and especially in males this differential flow pattern can result in I had to look this up they are what do they call them very you know seals or something that it's like varicose veins in your scrotum so there is a clinical consequence of this differential left versus right go nate'll a blood drainage pathway okay here we're in the portal system and like pretty much all of this is different than the arterial system because in your digestive organs are kind of related abdominal organs you're mostly just bringing the clean blood there to supply the organs with nutrition and carry away waste but these digestive organs are doing some messy work you know what I mean I mean the blood vessels around your rectum and anus and coal in and your intestines your spleen where you're chewing up all these old red blood cells like it's generating a lot of slop I don't want to call it dirty blood I mean the blood coming back from your intestines could have toxins but it will also be very very nutrient rich because all the carbs and the sugars and stuff from your food are now in that blood but you can't just dump this stuff in the IVC and then carry it up to the right atrium of the heart you're gonna get endocarditis you're gonna infect your heart lining so instead this blood needs to be processed by the liver so that's why this whole portal system is number six this is our sixth example of things that are different on the venous side because all of this is different so you can see we still have some vessels name the same thing we still have a superior mesenteric vein draining blood from similar places as the arterial system drop blood inferior mesenteric vein bringing blood back the splenic vein but look all this blood ends up in this big tube called the hepatic portal vein this is a portal an entry way into the liver the hepatic area after the liver does its thing then the blood needs to get going back to the heart and that's where you have the hepatic veins so you have a hepatic portal vein and you have hepatic veins here's another way to look at this there's just one vessel bringing blood to the liver hepatic artery proper let's bring blood to the liver but you have to veins that are bringing blood back to the heart the hepatic portal vein brings that dirty or nutrient but also toxin rich blood into the liver and the hepatic veins carry that blood all the way back to the heart then we finished with the legs they're pretty straightforward just as in the arterial system the common iliac vein branches into the internal and external iliac vein when it goes past the femur we call it the femoral vein when it goes behind the knee we call it the popliteal vein it branches again to the front of the tibia the back of the tibia towards the fibula those all have the same names as their arterial partners but we'll finish with number seven of seven these extra veins in the leg the greater saphenous and small saphenous veins greater saphenous is this really large vein it's on the inside of the thine leg and this is the one it's fairly superficial and if like you know I always say if you see Uncle Frank and his swim shorts at the family reunion barbeque or something like this is the one that can tend to get varicose vein E and be even more visible under the skin this is also a good vein to chop off to use in bypass surgery for coronary bypass if you have some plaque blockage in some of your coronary arteries this vein since it's so superficial it's easy to get at since it's heart surgery you could have like two teams you know when working on the heart getting things prepped and the other down in the leg working on this so it's kind of far away from the heart but recently also I'm not a heart surgeon so I'm looking this stuff up out of curiosity but recently the grapes greater saphenous vein has fallen into second place and they're tending to use the internal thoracic artery because it makes sense to me someone was probably like hey you know we got the chest all opened up here maybe we should use one of these vessels and there's other advantages to it if you're interested at all in bypass surgery look up the mammary artery it's also called the internal thoracic artery and how they use it because they don't just chop out a piece to make a bypass they leave one piece and tack and drape it and super good stuff if you're not into it then you're all done