 The demonstration of the entire colon. So let's start from here. This is the terminal idea. This is the heliosecule junction. This is the cecum. The unique thing about the cecum is that it is as wide as it is long. Three inches in either direction. There's a small space behind the cecum which is referred to as the retro-cecal space which is the most common site of location of the appendix. In this particular patient the appendix has been removed. Then we have the sending colon. This is the location of the hepatic flexion. Then this is the transverse colon. This is the location of the spleenic flexion. This is the descending colon and here end up by my assistant we have the S-shaped structure here. This is the rectum. So these are the parts. This muscular structure band that we see here is the tiniacoli and I will name the tiniacoli in the transverse colon. These small dilatations that we see here these are the host tray of the circulations. These host tray are produced because the tiniacoli which is actually a longitudinal muscle is slightly shorter and therefore as it pulls it has to produce these dilatations which are known as the host tray. So these fatty structures which are attached to the tiniacoli these are known as epiploic appendices or appendices epiploic and these can rarely be the site of torsion and given frame known as epiploic appendigitis. Let us come to the transverse colon to show you the some features of the transverse colon. This is the remnant of the greater momentum which hangs over the transverse colon. The portion above that is called the gastrocolyclic element. This is the miscentry of the transverse colon that is called the transverse mesocolon. Let us take a look at the tiniacoli here in the transverse colon. This tiniacoli that we see here this is the place where the tremendous hanging over this. So therefore this is called the tiniacomentalis. There is a tiniacoli which is hidden inside the transverse mesocolon that is called the tiniam mesocolon. And therefore the third tiniacoli which is in between which is neither related to the momentum or to the mesocolon that is called the tiniam libera. And these are the three terminologies which continue into the ascending colon and into the descending colon. The three tiniacoli merge at the base of the appendix and the appendix does not have a tiniacoli and these three tiniacoli get dissipated at the recto sigmoid junction. So therefore the rectum also does not have tiniacoli. So these are the structures that we see on the external surface. The colon is approximately 1.5 meters long. Now let us take a look at the blood supply of the colon. This artery that we have lifted up here this is the superior mescentric artery and this is the inferior mescentric artery. So this is the artery of the midcut. This is the artery of the hindcut with its accompanying vein on the other side. We can see this first branch here. This is the middle colic artery. We supply the transverse colon and it divides into a left and a right branch. This branch that we see here this is the ilio colic artery which divides into an ilial branch and a secret branch which of course divides into further branches. This is the right colic artery which divides into a descending branch and ascending branch. Now let us come to the descending colon. This is the inferior mescentric artery and we can see it is giving multiple branches. These are the left colic arteries. Normally there should be one but here we have multiple left colic arteries dividing into ascending, descending and all these ascending and descending arteries they are astromos and they form what is known as marginal artery. We can see the part of the marginal artery here. We can see another marginal artery here and the marginal artery here. We can see another marginal artery here. So all these ascending and descending they form the marginal artery and extrinsic from the marginal artery we have the straight arteries which go to the colon. Coming to the sigmoid. Sigmoid has got multiple branches minimum three and we can see this is sigmoid one, sigmoid two, sigmoid three and these also participate in the same and they form a marginal artery and from there straight arteries go into the sigmoid. Sigmoid colon is the other part of the colon which has got a mesentry and what we have picked up is actually the mesentry of the sigmoid or the meso sigmoid and finally the rest of the inferior mesentric artery continues down into the pelvis as the superior rectal artery. So this is the arterial supply and the veins accompany the arteries. Now what we have done is we have opened up some representative parts of the colon. This is the cecum that we have opened up and the purpose of opening up the cecum was to show the elial opening and we can see this is the elial opening. So therefore this projection that we see here inside this is the elial papilla. It is a nipple like projection and at the tip of the papilla we have this opening which is the elial opening and we can when I put my instrument I can feel it in the terminal area. So this is the we cannot see the pentagonal opening because this is my fingers disappeared this is the location of the appendix. Appendix has been removed. Now let us open up a segment of the transverse colon. This is a segment that we have opened up here. In an ideal living situation the transverse colon lumen should be triangular and the mucosal folds should be circumferential in contrast to the ascending and descending colon whether mucosal folds are partial or semi-lunar. So transverse colon circumferential other parts semi-lunar but here because this is a cadaveric specimen cadaveric preservation artifact has changed the features. Now let us open up ascending colon and we can see this is a segment of the descending colon that we have opened up and this is the interior of the descending colon. In a living specimen again we would have seen the typical mucosal pattern. The descending colon and the sigmoid colon are the most common size of diverticulosis which is very common on the left side of the colon. I have lifted up the sigmoid colon here on its base entry and if this were to undergo rotation which can happen and that is known as sigmoid volvulus. If we delay then this portion of the sigmoid will undergo gangrene because the blood vessels get compressed and then we may have to do what is known as sigmoid ectomy. When we are doing a sigmoid ectomy we have to remember that this is the attachment of the sigmoid mesocolon onto the posterior abdominal wall what is known as the attachment of the mesosigmoid and that is an inverted V shape and passing under the apex of the V we have the left sided iliac vessels and over that will be the left ureter. So we have to safeguard both these structures when we are doing a sigmoid ectomy and finally we have something called colostomy when we bring out this loop of colon out and there's something called an ileostomy when we bring out a loop of iliac wound. So these are some of the features which I wanted to mention about the ascending, descending and transverse colon. Thank you very much for watching.