Colon
The large intestine refers to the end section of the digestive tract.
This organ is located in the abdominal cavity and in the pelvic area.
Anatomists divide the large intestine into several sections: the cecum with the appendix, the colon (ascending, transverse, descending, sigmoid) and rectum.
The average diameter of the large intestine ranges from four to ten centimeters. The large intestine is one to two meters long.
The cecum is located at the junction of the ileum into the large intestine. The length of the organ is 6-8 cm, the average diameter is 7 cm.
The cecum passes into the ascending colon with two bends - the right (hepatic) and left (splenic). Between the bends in the abdominal cavity, it passes into the transverse colon, the length of which is on average 40-50 cm. Its position depends on age, as well as on the type of physique. On the left side of the abdominal cavity, the transverse intestine passes into the descending intestine.
The descending intestine, reaching the left iliac fossa, passes into the sigmoid colon, the length of which varies from 16 to 67 cm. This intestine has the form of two loops, the size and shape of which are subject to significant individual variations. The sigmoid colon is placed intraperitoneally and is covered on all sides by the peritoneum. The mesentery is attached to the posterior abdominal wall, which ensures its mobility.
The rectum is the end of the colon. The narrowest part of it, passing through the perineal region, is called the anal (anus) canal. The anal canal ends with an opening - the anus (anus).
In the anatomical structure of the intestinal wall, four layers are distinguished - the mucous membrane, the submucosa, the muscular layer and the serous membrane.
The inner layer of the large intestine is the mucous membrane. Throughout the intestine is covered with a cylindrical epithelium, and in the anal canal area - with a cylindrical and squamous (flat) epithelium. In some areas (in the area of the anorectal junction), the anal canal is lined with anoderm - a special type of epithelial lining that does not contain sebaceous glands and hair follicles.
The mucous membrane forms numerous folds. In the ampullar section they are transverse, in the anal section - longitudinal. There are three permanent folds of the transverse type - upper, lower and middle. The submucosa is a connective tissue containing lymphatic and blood vessels. The muscular layer consists of the external longitudinal and internal circular muscles.
Colon functions
Let's list the main functions of the colon:
- The digestive function of the colon consists in the final processing of food debris with enzymes (excretion of water and residual nutrients). In the cecum, the process of compaction of the liquid contents of the intestine begins;
- Suction - water and nutrients are distributed from the blind, ascending and descending parts of the colon to all organs through the blood and lymph channels;
- Muscular (motor) - the large intestine increases or decreases the frequency of muscle contractions, thereby ensuring the continuous movement of the chyme along the alimentary canal.
In addition, the large intestine through the anus removes toxic and useless substances for the body.
Colon inflammation
Inflammation of the colon (colitis) is the most common disease of the gastrointestinal tract.
The causes of inflammation of the colon can be gross errors in nutrition, various infections, ingestion of household and industrial poisons. In some cases, inflammation occurs repeatedly as an independent disease of an immune nature, or as a result of disorders that have occurred in the small intestine or stomach.
Currently, there are chronic, acute, ulcerative and spastic inflammation. Symptoms of the manifestation of the disease are the appearance of mucus and blood in the feces, loss of strength, lethargy, fever, increased gas formation, diarrhea, loss of appetite.
Ulcerative colitis is an inflammation of the colon mucosa, accompanied by the formation of ulcers. With this form of inflammation, most often periods of exacerbation are replaced by periods of remission. The first sign of ulcerative colitis is cramping pain in the lower abdomen.
With spastic colitis, the patient's feces resemble dense lumps in shape.
Colon polyps are called outgrowths of the intestinal mucosa. A similar proliferation of mucous membranes can be in the form of a ball, mushroom, hemisphere (without a leg or on a leg).
Colon polyps are benign neoplasms that most often develop into cancer (five to ten years after their formation). The proliferation of polyps significantly slows down intestinal motility, which can lead to intestinal obstruction.
Most often, the formation of polyps is asymptomatic, but sometimes the proliferation of the mucous membrane is accompanied by pain, the appearance of mucus and blood in the stool. Colonoscopy is the main method for diagnosing polyps.
Large intestine - treatment
Treatment of the large intestine consists in the appointment of a special diet and medicines (antiseptics, analgesics, antispasmodics, laxatives, sedatives, vitamins, bacterial drugs), medicinal enemas. The medicinal enema is one of the most effective methods of treating the colon.
All types of colon polyps are surgically removed. For cauterization of polyps in medicine, the method of electrocoagulation is used.
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