 Good day everybody. Dr. Sajju Sanyal, Professor's Department chair. This is going to be a demonstration of the Cologne and its blood supply. I'm standing on the right side and I'm holding the camera to bring up to speak. This structure that we see here, this is the C cup. This is the ascending Cologne. This is the transverse Cologne. And further down, this is the descending Cologne. And then it is continuing as a sigmoid Cologne and it's disappearing to the rectum in the pelvis. This is a single contrast barium enema of the Cologne to show its various parts. This white structure that we see here, this is the tinia coli. This is the terminal ilium here. This is the iliocecal junction. And this is the appendix. Sica is the only portion of the Cologne which is as white as its long. 7.5 centimeters wide, 7.5 centimeters long. This is the iliocecal junction. The tinia coli are longitudinal bands of smooth muscle which are in three bundles. And they are named according to their relationship with the transverse Cologne. The one which is in relation to the mesocolon is called the tinia mesocolica. The one which is in relation to the great romantum is called tinia omentalis. And the free one is called the tinia liberea. The Cologne had multiple fatty projections arising from the tinia coli which are known as appendices epiploid gate. And we have removed those fatty projections because they were obstructing the view and they were very large in this particular cadaver. Transverse Cologne is the only portion of the Cologne which has got a true mis-entry and that is called the mesocolon, transverse mesocolon. The melcoli vessel runs in the transverse mesocolon and it also forms part of the bed of the stomach on which the stomach is resting. The sigmoid Cologne also has a mis-entry and that is called the mesosigmoid which has been removed. The mesosigmoid is V-shaped and running under the apex of the V is the left ureter which may be injured in sigmoidectomy. Now let's take a look at the blood vessels here. We have completely removed all the contents of the abdomen and we can see the blood vessels here. This artery that I have lifted up here, this is the supramiscentric artery. This is the artery of the mid-gut and the branches that we can see here, these are all the colic arteries. And the branches that we can see coming out in the terminal end, these are some of the gingeral and the ilial arteries. There are hundreds of them which supply the mid-gut. And this artery that we see here, this is the inferior mis-entry artery which is the artery of the hind-gut. Before I tell you about the details of the colic arteries, let me draw your attention to these arteries that I have picked up here. If you notice that they form an arterial anastomosis along the margin of the colon. This arterial anastomosis along the margin of the colon is referred to as the marginal artery. And we can see it is forming a continuous arcade all around the inner border of the colon. And from the marginal arteries we have these branches coming out. These are the straight arteries which go and supply the colon from their mis-entry side or from the inner side. So this is the ultimate blood supply of the colon. But where do these arteries come from? Ideally, supramiscentric artery which is this one here is supposed to supply the mid-gut portion of the colon. That is the junction between the right two-thirds of the transverse colon and the left one-third of the transverse colon. And the inferior mis-entry artery is supposed to supply the descending colon that is the hind-gut and it's the sigmoid and the rectum. So therefore they're supposed to be total of four colic arteries. But in this particular cadaver there is a variation and we see only three colic arteries. So let's take them one by one. This artery that I have picked up here this is the heliocolic artery. And the heliocolic artery is arising from the supramiscentric artery as we can see. And it is dividing into a descending branch and an ascending branch, the colic branch. This is then an astromosing with this next artery which is again dividing into an ascending branch and a descending branch. Supramiscentric artery is giving this third branch here. This is also dividing into an ascending and a descending branch. And ascending and the descending of each of these arteries is forming the marginal artery which I mentioned in the beginning. We do not see a distinct left colic artery coming from the inframiscentric artery. Instead we see that the inframiscentric artery is giving rise to these branches here. This is a sigmoid branch. This is another sigmoid branch. And the rest of the inframiscentric is then continuing into the pelvis where it becomes known as the superior rectal artery. However there is a distinct left colic vein. And this is uniting with the superior rectal vein and it is forming the inframiscentric vein which runs in the free border of the paradural fossa where there can be an internal herniation and this vein may be injured. So this is the arterial supply of the colon. What is the significance of this? If we were to do a right hemicolectomy for any reason, we need to ligate the heliocolic artery and we need to ligate what would have been the right colic artery. And after removing this segment of the colon, we take the terminal ilium and anastomosis with the transverse colon in what is called the iliotransverse anastomosis. If for some reason we have to do a left hemicolectomy, we have to ligate what should be the left colic artery and if necessary part of the sigmoid. And then risk this portion of the colon and then do a colorectal anastomosis. And by the same argument, we may have to do a sub-total collectivity where we ligate the middle colic artery. In this case, as I mentioned that there is an anatomical variation. Colonic cancer is not very uncommon and these type of resections are necessary depending on the location of the colonic cancer. For some reason in this particular cadaver, the sigmoid vessels, the veins especially, and the veins coming from the pelvis, they were highly thrombosed. One possibility which is a strictly a hypothesis is that this particular cadaver, when during life had undergone a penile implant and all the veins in this lower part of his abdomen and perineum are thrombose, which may be responsible for this. So these are some of the points which I want to mention to you about the blood supply of the colon and the few essential morphological features of the colon with the clinical correlations. Thank you very much for watching. Dr. Sanjay Sanyal, signing out. If you have any questions or comments, please put them in the comment section below. Have a nice day.