 This is a dissection demonstration of the vascular structures in the abdomen after removing all the viscera. So, as you can see, we have removed the liver and we have removed everything and cleaned up. So, this is the entire posterior abdominal wall with the entire vascular structures in between. So, let's try to make sense of what we can see in front of us. Straight away, let's turn over to the most important vessels. This is the abdominal aorta. And we can see the abdominal aorta is entering the abdomen through this region here. This is the aortic hiatus. The hiatus is at the level of T12. From the T12 level, it divides at the level of L4 into the two iliacs, the right and the left common iliac. And further down, it will divide into internal and external iliac. So, this is the length of the abdominal aorta in the abdomen. The abdominal aorta is on the left side and on the right of the abdominal aorta is the inferior vena cava. The inferior vena cava enters the abdomen through this hiatus that you can see here. This is in the central tendon of the diaphragm on the right side. This is at the level of T8. This portion which is missing is actually the portion which was inside the liver. Since we have removed the liver, therefore, we cannot see this part here. And this is the other portion where we had to cut off to remove it from the liver. And it extends all the way from T8 and it divides a little lower than the abdominal aorta at the level of L5 into again, right in the left common iliac vein. So, therefore, the inferior vena cava is larger in the abdomen than the aorta. However, we can see only a small portion of it because once it enters the liver, we cannot see it. And thereafter, it goes through the diaphragm and it immediately enters into the right atrium. So, therefore, it does not also have any intrathoracic component. So, that's about these two great vessels. Now, let's take a look at the branches that we can see here. Right after as it emerges, almost at the point where it is emerging the abdominal aorta, it gives off these two branches. We can see them here. One branch going on the left side and one branch coming on the right side. These are the inferior phrenic arteries. And the inferior phrenic arteries not only supply the inferior surface of the diaphragm, but the inferior phrenic arteries also give branches to the supraignal gland. And we can see it is giving branch to the right supraignal gland. And here it is also giving branch to the left supraignal gland. So, the inferior phrenic arteries. Then we have this artery here. This is the celiac trunk. And we can see the celiac trunk has got three branches. The largest is this, this phrenic. The second largest is the common hepatic artery. And then the smallest is the left gastric artery. This phrenic artery gives many branches before going to the spleen. The common hepatic artery gives off this branch, which you can see this is the gastrodiogonal artery. And then after it makes a curve up and becomes the hepatic artery proper, which goes to the liver in the extra hepatic portal triad. And the left gastric artery, it runs in the lesser curvature. And it also gives a branch. We can see this is an esophageal branch, which supplies this portion, which is the abdominal segment of the esophagus. So, this is the celiac trunk. This is at the level of D12. Then we have this one. This is the superior miscentric artery, which is at the level of L1, unpaired miscellaneous branch. Celiac trunk is a branch of the foregut. Superior miscentric is a branch of the midgut. And we can see that it gives numerous branches. The first branch that it gives off, which has been removed, is the inferior pancretico-diogonal, which runs in the pancretico-diogonal junction. The second branch is this one. This is the middle colic artery. Then it gives rise to the right colic stem, which divides into an heliocolic and right colic artery, which will further supply the right side of the colon. And these other numerous branches, which are just a few of them, these are the gingeral and helial arteries. So these are the branches from the superior miscentric artery. Then we have the next unpaired miscellaneous branch, that is this one here. This is the inferior miscentric artery. This is the artery of the hindcut. And we can see this arises at the level of L3, and it gives branches to the descending colon. This is the left colic artery. And it gives numerous other branches, which we can see here. These are all the sigmoid arteries. Typically, there will be sigmoid 1, sigmoid 2, sigmoid 3. And after that, the rest of the artery will continue into the pelvis as the superior rectal artery. So these are the three unpaired visceral branches. Apart from that, we can see numerous branches coming out along the lumbar abdominal wall, both on this side as well as on that side. These are the various lumbar arteries. Another important artery that arises from the abdominal artery is this one on the left side and this artery on the right side. This is the testicular artery or the gonadal artery. In the case of female, it will be the ovarian artery. And this is running with the testicular vein. We can see and it is running and entering through the internal ring of the inguinal canal on this side, as well as the internal ring of the inguinal canal on this side. So these are the gonadal vessels. And finally, as we have already mentioned, abdominal artery divides into the two common iliacs. Since we have already cut the kidney, we can see the cut portion of the renal arteries here. This is one cut portion of the renal artery and the other cut portion of the renal artery coming out from the abdominal artery is this one. So this is the right renal artery and this is the left renal artery. This is the left renal artery. We can also see the abdominal artery giving branches to the left supra-renal man and it is giving branch to the right supra-renal man. Right supra-renal man, left supra-renal man receive branches from the inferior fending artery, abdominal artery and from the renal arteries. So these are the paired visceral branches of the abdominal artery. Now let us take a look at the divisions of the segmental arteries of the kidney. Each kidney receives five segmental arteries. So we can see that as the renal artery gives the renal high lump, it divides into five branches. Superior, inferior, anterior superior, anterior inferior and posterior. So we can see that these are the various one, two, three, four, five. These are the five segmental branches of the renal artery on the right side. Let us try to trace the similar segmental branches of the renal artery on the left side. There should be five. We can see one, two, three, four, five. So here also we can see five segmental arteries on the left side. And the segmental arteries are named thus. They are named as superior, inferior, anterior superior, anterior inferior and posterior. So these are the segmental arteries which divide the kidney into five surgical segments and therefore it enables us to do what is known as segmental nephrectomy. Arteries run behind the veins. Thank you very much for watching. Dr. Sanjay Sanyal.