Caecum and Appendix – Large Intestine

00:01 So if we look at the individual parts of the large intestine, then here we have seen these diagrams before.

00:05 We are looking at the cecum and the appendix. And here again we can see we have got the Ileum we can see the appendix here radiating away from the cecum.

00:14 And this is a posterior view, as if you are looking at the cecum and the appendix through my posterior abdominal wall, so we can see the Ileum is radiating away to the left in this direction. And what we can see is radiating from the appendix are these three bands of longitudinal muscles.

00:33 There we have the mesocolic tenia, which attaches to the mesocolon or mesocolon attaches to this taenia colic. We also have the omental taenia coli where the greater omentum is coming from this one.

00:47 And then we have the free taenia which I mentioned previously doesn't have anything attached to it.

00:55 So we have these three bands of longitudinal muscle. And if this was a piece of small intestine, then obviously we would have that complete layer.

01:04 Here we can we have got the cecum and appendix again.

01:09 But this time the cecum and the initial portion of the ascending colon has been opened up. So now we can see the opening of the Ileum into the large intestine. We can see the cecum here. We have got nice look of opening for the appendix which is the slender blind ended-pouch.

01:31 And then we have got the cecum which is that little bag, little sac.

01:36 And then we have got the ascending colon which will pass up in this direction.

01:39 The appendix is anchored via the mesoappendix, is quite a small piece of mesentery the mesoappendix.

01:48 And the position of the appendix as we can see in this diagram here is incredibly variable. So we can see the, even though we open up the right inguinal region and we should be able to locate the appendix.

02:04 It may actually need some rooting around to find it. Because the tail of the appendix is the kind of tip can project into numerous different directions. Here we see aligned posterior to the Ileum. We see it aligned anterior to the Ileum here.

02:17 Here we can see a poking on the straight down as the continuation of ascending colon And here we can see actually tucked underneath the cecum. So although it's there it may need some rooting out.

02:34 So if we just stick to the appendix for little bit longer, then the function of the appendix is not really that well understood in the human.

02:43 In the lower animals, it's important in being able to digest grass and various other aspects of digestion. But in the human it's really a lymphoid tissue it helps to produce white blood cells and a part of the lymphatic system Now because it's a narrow blind ended pouch, it can actually become blocked. And If it becomes blocked by faeces and then it can actually can swell and become inflamed. And that creates appendicitis if it was to become inflamed and potentially become infected. Now we mentioned this when we looked at the surface anatomy but now we understand the anatomy of the appendix a bit more. We may be able to appreciate the position of the appendix in this right inguinal region and again we can locate the umbilicus, we can locate the anterior superior iliac spine. And then align down between these two points. And then align a third of the way from the anterior superior iliac spine to the umbilicus. So about here it's going to be what's known as the McBurney's point.

03:59 And that is the position of the appendix. So it can be very painful appendicitis. And the pain initially being felt in the midline where we just have this dull ache. But with time, the pain can progress to this lower right quadrant in association with the McBurney's point.