 to be the section and demonstration of the entire colon. So starting from here, we can see this is the terminal ilium. There's the enosicum junction, and there's the secum. This is the ascending colon. This is the transverse colon. The junction between the ascending colon and the transverse colon, this region. This is the region of the hepatic flexure. And we can see it was attached to the posterior abdominal wall by means of the phrenopolic ligament. The transverse colon, then this portion was attached to the abdominal wall by the phrenopolic ligament. And then we have the descending colon, continuing as the sigmoid colon here. And we can see the sigmoid here. The sigmoid is S-shaped and goes deep into the pelvis. So this is the full extent of the colon. Now let's mention a few landmarks that we can see them here. Let's start from the iliocecal junction. If we look at the iliocecal junction, we can see these blood vessels coming here. This is the iliocoleg artery. And we can see the iliocoleg artery is dividing into a secal branch and an ilial branch. If you were to trace it, we find a small fold of petronium which we have removed here above the ilium. This is the superior iliocecal fold. This is the potential site of internal herniation. And when we are trying to release the intestinal hernia, we can cut this artery here. Likewise, if you were to look behind, we can see yet another fold here, where my finger is gone in. This is the inferior iliocecal fold. This is also a potential site of hernia. But here there is no blood vessel, and we can see that. This is referred to as the bloodless fold of trees. So that is the iliocecal junction. Now let's come to the secom itself. The secom is a unique part of the colon insofar that its length and its width are approximately same. 7.5 centimeters, 7.5 centimeters. So this is the secom. There's a small space behind the secom that is known as the retrocecal space. The rest of the colon was attached to the posterior terminal wall. The next thing we notice is this band that you can see here. And we can see the band is stopping here. This is one of the tinnia coli. Tinnia coli is a condensed, low-student smooth muscle. There are three of them named tinnia libida, tinnia vesu colica, tinnia omentalis. We notice fatty projections from the tinnia coli. These are known as appendicitis epiploid K. These can sometimes undergo torsion, in which case it is known as epiploidic appendegitis. The next thing I would draw your attention to are the tinnia coli and the transverse colon also here. When we are looking at the transverse colon, we must remember two things. The transverse colon is one of the two parts of the colon which has got a mesentery. And we can see the mesentery here. This is the transverse vesu colon. That is on the deep surface of the transverse colon. And extending from the superficial surface of the transverse colon, we have this structure here, which should not be confused with the vesu colon. This is the greater momentum. And finally, let's take a look at the sigmoid colon. If you trace it, we find that it is making an S shape. That's why it is called sigmoid colon. Having mentioned this, now let me show you the vascularity of the colon. Again, we are starting from the right side. We can see the blood vessel here. This is the terminal division of the superior mesentery artery, namely the heliocolic artery. And we have cut it here. And the other cut portion is here. This is the last branch of this superior mesentery. It divides into a secret branch and an elial branch. Secret branch divides it into an ascending and a descending. And one of the descending branches continues behind the elium, and it supplies the bendings. We can see it another branch here. Then we see it another branch here. So this is the right colic branch. This is the middle colic branch. Now we are in the descending colon. The descending colon is part of the hindgut because the junction between the midgut and the hindgut is in the transverse colon. Right two-thirds of the left one-third. So this supply is by the inferior mesentery artery. And we can see these are the branches of the inferior mesentery artery. And we can see the inferior mesentery artery starting from the L3 level of the aorta here. The inferior mesentery artery is giving rise to the left colic artery. And they again divide into an ascending and descending. And thereafter, the inferior mesentery artery gives multiple sigmoid branches. And we can see the sigmoid branches here. S1, S2, S3. And they all give multiple branches. And finally, the last branch of the inferior mesentery continues into the pelvis as the superior rectal artery. So having mentioned the main arteries supplying the colon. I will draw your attention to this artery here. This is the marginal artery. Marginal artery is not one artery. It's an arterial anastomosis. An arcade which goes all the way around. So this is the marginal artery. Marginal, it goes all the way on the mesentery side of the colon. And it continues on this side also in the transfer space of colon. And we can see the marginal artery on this side also. This is the marginal artery. And we can see the marginal artery here also. So therefore, the marginal artery, as the term implies, it goes all the way around the inner margin of the colon. And how is it formed? It is formed by the anastomosis of ascending, descending, right, left, ascending, descending branches of each colic artery. From the marginal artery, we can see multiple branches going to the colon. These are the straight arteries. And the arteries accompany the veins. And we can see the same thing here also. From the marginal arteries, we can see branches going to the colon. So lymph nodes in relation to the marginal arteries are called paracolic lymph nodes. So this is the blood supply of the colon and the venous drainage of the colon because arteries accompany the veins. All these run within the layers of the masonry. Now we are going to open up three or four representative sections of the colon. And my assistants are going to do it and we just see the interior of each of them. My resistance opened up some representative sections of the colon. We opened up the sacrum, ascending colon, transverse colon and descending colon. But we could not make out much of the interior because it was filled with thecal matter. That's all we wanted to show about the colon. Thank you very much for watching. If you have any questions or comments, please put them in the comment section below. Dr. Sanjay Sanyal signing out. Have a nice day.