The sigmoid colon (SC) is considered to be the lower part of the colon colon, which passes into the rectum, so it participates in the process of transporting feces and their further excretion from the human body.
So, the sigmoid colon is located in the region of the upper opening of the small pelvis, is directed transversely to the right side of the pelvis, then turns to the left and, reaching the midline, goes down, where at the level of the third sacral vertebra it passes into the rectum. At the same time, its length varies from twenty to seventy-five centimeters (most often this indicator is equivalent to forty-five centimeters).
The sigmoid colon has two bending loops that descend into the pelvic cavity. The size and shape of these loops is different and depends on the structure of the human body, they are adjacent to the left ilium and descend into the pelvic cavity, with one of them facing down and the other up. That is why the sigmoid colon is S-shaped. In seventy cases out of a hundred, the length of the SK loop varies from twenty five to forty five centimeters, it is called normosigma. If its size is less than twenty-five centimeters, the sigmoid colon is called brahisigma. The outer diameter of the intestine is six centimeters, so if this size is exceeded, it can be argued that its walls are thickened.
SK is covered by the peritoneum on all sides, and has a mesentery, that is, a fold by which the intestine is attached to the abdominal wall, fifteen centimeters long, which provides it with great mobility. This fold in its structure has two sections, one eight centimeters long, and the other ten. That is why SC has the ability to move both into the pelvic cavity and towards the stomach or liver. It should be noted that the mesentery crosses the ureter, ovarian and iliac vessels located in the lateral surface, as well as the lumbar and ileal muscles, the left joint joint. Then it passes to the surface of the vertebrae of the sacral department and ends at the level of the third vertebra.
The sigmoid colon, the location of which allows it to come into contact with the small intestines or be spliced with them, can also come into contact with all organs of the abdominal cavity (except the pancreas) and the pelvic cavity.
It should be noted that quite often (in the presence of a long mesentery) the colon sigmoid colon moves into the ileum, therefore, it is necessary to be able to distinguish it from the cecum. It is not difficult to do this, you just need to remember that the omental processes, which are not blind in the gut , depart from the SC .
We emphasize once again that the sigmoid colon, the location of which is described above, has a variable morphology and anatomy, since they will depend on the processes that occur in it, as well as on the physique of a person, his age characteristics and many other factors.
At the place of transition of the descending intestine into the sigmoid, a narrowing of the lumen is observed, this phenomenon is called the Bali sphincter. It is located at the level of the upper part of the ilium and has a length of up to two centimeters. Thus, the outer diameter of the intestine located behind this zone is from two to four centimeters, and in the sphincter zone - up to two centimeters.
Also, the sigmoid colon location of the sphincter (narrowing of the lumen) has in the middle, this structure is called the Muthier sphincter, but it can move further from its center. In this case, the external diameter of the intestine behind this zone is from two to six centimeters, and in the Moutier zone is from one to three centimeters.
Thus, now it became known not only where the sigmoid colon is located, but also its anatomical features. It plays an important role in the activity of the human body.