Colon disease surgery
In clinical practice, the disease of the colon accounts for a relatively high percentage of the treated diseases. Colon cancer is the second leading cause of death in adults.
The colon is divided into several segments: the cecum, the colon up, the transverse colon, the descending colon, the sigmoid colon and the rectum. Particularly the sigmoid colon and rectum have not determined the exact boundary. The sigmoid colon begins at the edge of the pelvis with the sigmoid network. Then connected to the rectum in the third sacred vertebrae. The rectum is the distal segment of the colon, about 15 cm long, with 2 segments, the proximal segment located in the peritoneum and the distal segment outside the peritoneum. The peritoneum covers the rectum and then covers it again on the pelvic floor to form a sac that is called a sac with Douglas.
The ascending colon and the right half of the transverse colon are supplied with blood by the upper mesenteric artery. The descending colon and the left half of the transverse colon are supplied with blood by the lower mesenteric artery. The lower part of the rectum is supplied with blood by the haemorrhoid arm of the inner pelvic or inguinal artery.
The veins also have the same distribution as the arteries.
Microscopic, unlike the small intestine, the colon does not have villi. The absorption surface of the lumen is flat with many straight tubular cavities. These niches extend to the stratum lining, lined with mucus-secreting radio cells and sometimes endocrine cells. The mucosal surface is covered with absorption cells. These cells have surface microvilli towards the lumen. Microvilli, which are less numerous in the small intestine but also form an outer coating with fibrous glycoprotein. Paneth cells, most present in the depths of the cavities, are scattered in the right colon. In the intestinal mucosa, there is tissue. The cell morphology in the colon is similar to that in the small intestine. The nerve in the intestine consists of the Auerbach network (between the sphincter layer and the longitudinal muscle), Meissner network (in the submucosa). Both of these networks consist of clusters of nerve ganglion cells connected to non-myeline post-ganglion fibres.
In clinical practice, the disease of the colon accounts for a relatively high percentage of the treated diseases. Colon cancer is the second leading cause of death in adults. Haemorrhoids, which are very common, are also a cause of discomfort.
The colon, along with the stomach, is the two most important places of the gastrointestinal tract in terms of clinical and pathological aspects.