Welcome, in this video we're going to follow the food. I will show you the intestines and organs the food passes on it's way through the abdomen. I will only show the abdominal part of the digestive tract. We will not show the mouth and the thoracic esophagus in this video. Let's first orient ourselves. This is a view in the abdomen. The abdominal wall has been removed. The structure you see lying here folded upward is the ligaments. It's not relevant in this video. Further you see the inferior edge of the liver protruding below the rib cage. Prominently visible covering the largest part of the abdomen is the greater omentum. Let's start our tour. I lift the liver. At the top of abdomen out of sight here, the esophagus traverses the diaphragm and enters abdomen. The esophagus continues for a very small distance as abdominal esophagus and then enters the stomach. Here, we see the stomach, it has a J form, it's inner curvature is called the lesser curvature. It's outer curvature is the greater curvature. At the lesser curvature there is a membrane connecting the stomach with the liver, the lesser omentum. And at the greater curvature also a membrane emerges, the fat-ridden greater omentum. When we follow the stomach we arrive at this thick bulge. It's the pylorus, the valve between the stomach and the duodenum. It allows small amounts of food to pass through the duodenum each time the duodenum has processed the previous food. The duodenum is the first part of the three part of the small intestine. The duodenum has a C shape. It's fixed to the back wall. To seer the duodenum better, we need to have a look from the other side, from the right side of the body. You see a close up here, let's orient ourselves again. The head of the person is to left of the video now. You see a piece of the skin over the right thorax and protruding below it is the liver. Once more, here is the folded ligaments. As well as the greater omentum. In the depth is the stomach. The can be seen in close up here. Next, this curved intestine is the duodenum. Embedded in the C is the head of the pancreas. The risks at the pancreas lies behind the stomach. It can be seen on the [INAUDIBLE] later on in this section, where the stomach is moved to the side displaying the pancreas. Digestive juices from the pancreas are excreted from the pancreas into the duodenum. Also, bile is deposited in the duodenum. The bile is stored temporarily in the gallbladder, which can be seen here hanging from the posterior inferior side of the liver. We return to the wide view. The duodenum courses posterior of the transverse colon. I insert a probe and follow the duodenum. To show where it goes, I must lift the greater omentum and the transverse colon. And we see the probe emerging again here. To give you a better view of the duodenum, here's a shot later on in the section, where we have to attach the intestines from the back wall which allows us to fold upwards the intestines. And this exposed the duodenum completely. You can clearly see it has a C shape and it's connected with the back wall. At a certain point, the intestine separates from the back wall and becomes mobile. This is the point where, by definition, the second part of the small intestine, the jejunum starts. This point is called the duodenojejunal flexure, or in clinical practice the point of Treitz. We can see that the duodenum is fixed to the back wall and immobile, and as from this point onwards, the Treitz point, the intestine becomes mobile. As said intestine is called jejunum from here onwards. We now return to this section at its previous point in time where the intestines were still attached to the back wall. At the location where the jejunum starts, the Treitz point, the intestine seems to emerge as a fountain from the depth. The Treitz point is a major landmark in abdominal surgery. One can imagine this as when opening the abdomen, the small bowel can be followed backward up to this point where it seems to disappear in the depths. We follow the jejunum, it is connected to the back wall with membrane called the mesentery. The mesentery contains the blood vessels to and from the intestines. Because of this flexible connection to the back wall via the mesentery, the small intestines are move all here. One can move them around easily as you can see. Let's follow the intestine. It courses for a couple of meters. The first two-fifths of this mobile section of the small intestine is named jejunum, thereafter is called ileum. There is no signpost indicating the change from jejunum to ileum. Rather the properties of the intestines change gradually from the duodenum to the ileum. But this cannot be seen well in this body. In daily practice, the names duodenum and ileum simply indicate the first part and the second part of the mobile section of the small intestine. Finally, we arrive at the last octennial part of the ileum where the small intestine connects to the large intestine. The first part of the large bowel is this free sac, it's called the cecum. In some languages it's called the blind intestine derived by the fact that if one follows the root of the food, the cecum can be imagined to be bypassed as a blind pouch. Suspended from the cecum is the appendix. In the majority of cases the appendix is fold upwards behind or posterior to the cecum. The appendix is shown clearly now here. After the cecum follows the colon. The colon consists of four parts. The ascending, transverse, descending, and sigmoid colon. And the colon surrounds the duodenum and ileum. Here, we see the first part, the ascending colon. It is fixed to the back wall. And in this body, buried in fat that's contained in the peritoneum that covers it. When the S in the colon reaches the superior right end of the abdomen, where the liver lies, it makes a sharp turn to become the transverse colon. This corner is called the right colic flexure, or the hepatic flexure, after the Latin word for liver, hepar. The colon is now called transverse colon. The transverse colon crossed the abdomen from its right to its left side. Note that it's movable and that the greater omentum is connected to it. Arriving at the left superior corner of the abdomen, the colon once more makes a sharp turn and turns downwards to become the descending colon. This corner is named the left colic flexure or splenic flexure, after the spleen that lies in its vicinity. The descending colon, just as the ascending colon, it's fixed to the back wall and it can be seen here buried in peritoneal fat again. Then I move away the small bowel to expose the last part of the colon, the sigmoid colon. The sigmoid colon has an S shape. It derives it's name from the Greek letter Sigma. the sigmoid colon is once again movable as it is connected to the back wall via. Finally, the large intestine dives into the depths of the pelvis. There it is named the rectum. The rectum courses through the anus, where the digestive tract ends and opens to the exterior. We cannot see direct to the anus on this overview picture. So in this video we saw the whole digestive tract, at least its abdominal part, following it from the esophagus, via the stomach, the small intestines, the large intestines, all the way to it's end at the anus.
