 Good day everybody. Dr. Sanjay Sanyal, Professor Department Chair. So this is going to be a demonstration of the aorta and the inferior vena keva. This is a supine cadaver. I am demonstrating from the right side the camera person is on the left side. This structure that we see in front of us, this is the inferior vena keva and this structure is the aorta. The aorta as we know is to the left of the inferior vena keva. Let's take a look at the extent of the aorta. This is the aortic hiatus where my instrument is pointing right now. This is at the level of T12 and the aorta divides into the two common ideagartaries at the level of L4. So T12 to L4 is the extent of the aorta. Now let's take a look at the branches of the aorta. The branches are divided into what are known as the vascular plane concept. What is this vascular plane concept? We have three unpaired visceral branches. This is the first one. This is the celiac trunk which is coming at the level of T12. The next one, this is the superior mesentric coming out the level of L1 and this is the inferior mesentric at the level of L3. So these are three unpaired visceral branches. The celiac trunk supplies the foregut, superior mesentric supplies the midgut and the inferior mesentric supplies the hindgut. The inferior mesentric continues into the pelvis as the superior rectal artery and we can see that and it supplies the rectum. The next set of branches are the paired visceral branches. The first set of branches are this. This one here which I have lifted up and this one. These are the renal arteries. In this particular cadaver, there are not one but two separate distinct renal arteries coming from the aorta. The first set are the ones which I lifted up just now. They are supposed to come out at the level of approximately the level of L1 but in this particular cadaver we see yet one more artery coming from the aorta on this side as well as on this side and they are coming separately and they are entering into the kidney on both the sides. So that is the first set of paired visceral branches. The next set of paired visceral branches are this one here. This is the left testicular artery and this is the right testicular artery which comes out at the level of approximately L2. The next paired visceral branch we can see only on the right side this one here which I have lifted up. This is the right supra renal artery. We do not see the left supra renal artery. The supra renal glands as we know receives branches from many sources. One of them is from the aorta and that is what we see here. So these are the paired visceral branches. The next set of branches are the paired parietal branches. The first set of paired parietal branches are the inferior phrenic arteries which we cannot see because we have to remove the fascia and the liver. The next set is the subcostal artery which goes below the 12th rib that also we cannot see in this dissection. But what we can see are the four lumbar arteries. To see that let me push the aorta here and we can see the branches coming from the aorta. These are the lumbar arteries. On the right side and when I pull on this side we can see branches going on this side also. So these are the lumbar arteries and they are the ones which supply the posterior criminal wall. So these are the paired parietal branches. Now let me mention some clinical correlations pertaining to the aorta. One of the important clinical correlation is aneurysm of the abdominal aorta which is usually a result of atherosclerotic damage to the tunica media. The aneurysm if it does occur it occurs usually between the origin of the renal artery and the bifurcation of the aorta into the two common iliacs. So this is the location of the aneurysm of the abdominal aorta in which case the inferior myocentric artery arises from the apex of the aneurysm. When a patient has an aneurysm of the abdominal aorta it produces an expansile pulsation sometimes which can be not only felt but can also be seen on the anterior abdominal wall especially if the person is thin. If an aneurysm as seen by ultrasound if the diameter of the aneurysm is more than six centimeters it is more likely to rupture. So therefore we have to treat it before it ruptures because after rupture mortality rate increases exponentially. In a thin person we can normally feel the pulsation of the abdominal aorta at this level where my finger is located we can feel it against the L4 lumbar vertebra where the lumbar vertebra forms a normal laudotic curve. In elderly person or as the age advances there can be calcification of the tunica media and we can feel an axial crackling which we can feel and we can feel a little bit here also. That is known as monkeybergs medial calcific sclerosis. This is a plain excerpt of the abdomen to show monkeybergs medial calcific sclerosis of the abdominal aorta and the iliacs. Superbocentric artery as it crosses over the left renal vein it can compress the left renal vein and also in a male the left gonadal testicular vein and produce what is known as the left renal vein entrapment syndrome and left testicular varicose. Let me mention some clinical applications of the abdominal aorta. The applications pertain to aotogram and angiogram. The usual route for angiogram is the femoral artery. The cannula is inserted through the femoral artery it goes through the external iliac arteries goes to the common iliac artery and then it enters into the aorta and after that under a C arm an immediate intensive fire we can cannulate either the inferior eccentric artery the superior eccentric artery the celiac trunk and get the respective angiograms. This is a selective celiac artery angiogram and this is a supramicentric angiogram to show the distribution of the vessels. We can cannulate the renal arteries and we can get the renal angiogram. This is a selective renal artery angiogram to show the segmental renal arteries and not only that we can continue the cannulation and we can do even coronary angiograms. This is a left coronary angiogram to show the left anterior descending and the left circumflex and this is an RCA angiogram to show the right coronary artery. So this is a very useful application of the aorta and its angiograms. Now let's take a look at the inferior vena keva which I told you is on the right side of the aorta. Abdominal extent of the inferior vena keva is much longer than the aorta. The inferior vena keva starts in the abdomen from its cable hiatus which is at the level of T8 on the right side and it ends at the level of L5 where it divides into the two common iliacs. However the visible extent of the inferior vena keva is much less than its actual extent. The visible extent is only from here to here. After it enters into the liver after that the inferior vena keva is not visible. Neither is it visible when it goes through the diaphragm, neither is it visible when it goes immediately after that into the right atrium. So this is the actual visible extent of the inferior vena keva. The hepatic veins which enter into the inferior vena keva inside the liver are also not visible. Tributaries of the inferior vena keva match the branches of the aorta but there are some differences. For example the inferior vena keva does not receive any counterpart of the celiac artery or the supramacentric artery or the inframacentric artery. Instead the supramacentric vein and the inframacentric vein which are the counterparts of these arteries they drain into the portal vein. There is no counterpart of the celiac artery. There is distinct renal vein and we can see the renal vein here. We can see the left renal vein is much longer than the right renal vein because the inferior vena keva is on the right side and the left renal vein receives the left esticular or the gonadal vein and it also receives the left suprary renal vein. The left renal vein is also used for splenorenal shunt because the spheric vein is situated just one centimeter above the left renal vein. The left renal vein can get compressed as I mentioned by the superior misentering artery. We can see the vein on this side also and here we can see the renal vein is arising as one trunk and it's immediately dividing into two and entering into the right kidney. The inferior vena keva receives the right suprary renal vein. However the left suprary renal vein does not drain into the inferior vena keva. Instead as we can see here it drains into the left renal vein. Inferior vena keva as I mentioned a little while back receives three hepatic veins inside the liver. However the hepatic artery actually is a branch of the celiac trunk. Now I'm going to show you something very unique. I have retracted the inferior vena keva to show the lumbar veins. There are four lumbar veins which drain into the inferior vena keva and we can see them on the right side. Fifth lumbar vein opens into the external iliac vein and that we can see here. This is the fifth lumbar vein. These four lumbar veins which we are seeing on the right side they have a communicating vein which runs up like this and it is a very thin walled vein and it is located within the fascia so therefore we have to see it very closely here itself and we can see that vein where it's being traced by my instrument here. This is called the ascending lumbar vein which has communications with l4, l3, l2, l1. This ascending lumbar vein as it goes up just below the 12th rib it unites with the subcostal vein and after that on the right side it becomes known as the azegous vein which then enters into the thorax through the aortic hiatus in the diaphragm. We have a similar situation occurring on the left side though it is not visible where instead of azegous vein we have the hemi-azegous vein which is also formed in exactly the same way and this also enters into the thorax and then at the level of T8 it opens into the azegous vein. So we can see the formation, the beginning of the formation of the azegous vein in the form of ascending lumbar vein here. This rains the structures in the posterior abdominal wall. So these are all the structures which I wanted to show you pertaining to the aorta and the entry of vena keva in the abdomen in the posterior abdominal wall. Thank you very much for watching Dr. Sanyal signing out. Give it always the camera person. If you have any questions or comments please put them in the comment section below. Have a nice day.