Thick gut, its functions, departments and structure

The large intestine represents the lower part of the human digestive tract, in which the final stage of digestion is carried out, in particular - the formation of feces.

The name of the colon was due to the fact that its walls are much thicker walls of the small intestine due to the greater thickness of the

connective tissue and muscle layers.


The human intestine consists of the following divisions: the

  • blind, which also contains the appendix( appendix);
  • rim, which in turn consists of the following sections: ascending, transverse,
  • , as well as sigmoid colon;
  • is a straight line, consisting of an enlarged part( ampullae of the rectum) and a constricted part( the anal canal) that ends with an anus.

A thick intestine originates from a short section called an iliac-hypnotic choroid. This segment is located immediately after the opening of the ileum of the small intestine.

From the ileum and hypothalamic damper, the appendix is ​​cut off from the appendix, the length of which is from 8 to 13 cm.

Further, the small intestine passes into the colon, which has received its name due to its surrounding the abdominal cavity. This is the longest section of the large intestine - its length is up to 1.5 m, and the diameter - 6 - 6.5 cm. The initial segment of the colon is called ascending, such segments - transverse and descending intestine. The rim is attached to the back of the peritoneum with the help of a special peritoneal fold - ripples.

Muscles that grip the colon, stimulate the process of movement of food remains through the intestines. Of each portion of the breastbone fed into this gut, approximately a third is excreted from the digestive canal in the form of feces. The other part( water) is absorbed into the intestinal wall.

The rectum ends with an anal canal. Anal hole is covered by a sphincter, which consists of striped and smooth muscles. The muscle that forms the sphincter consists of the inner and outer parts. The internal sphincter is constantly tense( with the exception of the moment of defecation), which prevents the outflow of stool from the outside, and its functioning is largely controlled by the nervous system, in contrast to the intestinal mucous membrane, which occurs reflexively.

The inner part of the walls of the colon is lined with a mucous membrane, which facilitates the movement of feces and protects the walls of the intestine from the destructive effects of digestive enzymes and mechanical damage. Thus, the structure of the colon is maximally adapted to the process of digestion of food and the removal of unnecessary waste from the body.

Position( topography)

The initial area of ​​the large intestine is located in the right iliac region. In this area, the end segment of the small intestine falls almost at right angles. The cecum is located 4-5 cm above the center of the inguinal ligament. In some cases, it is slightly lower or higher.
The ileum loops adhere to the lower and left to the intestine.

The back surface of the ascending colon is adjacent to the fascia that covers the iliac muscle, and to the fascia of the right kidney. The back wall of this gut is separated from the fasciitis of retroperitoneal fiber.

A large omentum and loops of the small intestine adhere to the left and to the front of the ascending intestine.
The transverse colon is located in the right hypochondrium, as well as in the peritoneum and in the left hypochondrium. The average part of it, in some cases, reaches the level of the navel or even located below.
In the front, the transverse gut is applied to the anterior abdominal wall, but separated from it by a large septum. In the upper part, it adjoins to the lower part of the liver, from below - to the loops of the small intestine, from the back to the very bottom of the 12th-digestive tract and pancreas.

The transverse colon due to its location conventionally divides the abdominal cavity into two floors: the upper( it contains the stomach, liver, spleen) and the lower( consists of all loops of the small intestine).

The lowered rectum in the upper part adjoins to the front of the left kidney. In the front, this gut is covered with loops of the small intestine.

Sigmoid colon is located in the left iliac fossa, as well as in the upper part of the cavity of the pelvis.

The rectum is found in a drainage formed by a sacrum and a coccyx. In men, the rectum adjoins the loops of the small intestine and the bladder, in women - the uterus and the upper part of the posterior wall of the vagina.

All sections of the large intestine are separated from each other due to the presence of special valves, which ensure the movement of food masses in only one direction.

The length of the colon

In children, the length of the large intestine depends directly on age. Thus, in a newborn baby its length ranges from 66 to 67 cm, at the age of one year - 83 cm, at a three-year-old child - 86 cm, at 7 years old - 108 cm, 10 years - 118 cm. These figures may vary slightly depending on the type of body, body weight and individual characteristics of the child's body.

In adults, body length is about 160 cm. The inside diameter of the intestine is 5-8 cm, while it decreases in the direction from the cecum to the straight line. The thickness of the walls of the colon is from 2 to 3 mm, with the reduction this index varies to 4-5 cm. The thickness of the walls of the rectum - a little more - from 2.4 to 8 mm.

Blood supply and innervation

Blood supply to the body is provided by two major vessels that depart from the abdominal aorta. These are the upper and lower erythema arteries.

Innervation is provided with the help of the branches of the upper and lower mesh gauze and the branches of the cervical plexus.

Nerve branches of the upper plexus innervate the appendix, blind, ascending and transverse gut.

Closer to the intestinal walls the branches are divided into smaller branches.

The rectal innervation is provided with the help of branches coming from the sacral part of the sympathetic trunk.

Differences of the

intestine and colon Despite the fact that both the small and large intestines take an important part in the digestive process and are anatomically located close to each other, there are a number of differences between these organs.

The main differences between the thickness and the small intestine are as follows:

  • diameter of the large intestine is greater than fine( 5-8 cm vs. 2.5-4 cm);
  • color of the colon - grayish-ash, and thin - pink, more intense;
  • the longitudinal muscle of the walls of the small intestine is evenly distributed, and the muscles of the large intestine form three separate strips that extend along the intestines. Also, the walls of the colon have bulging and circular furrows with pronounced circular musculature;
  • , in contrast to the small intestine, the walls of the large intestine form septal appendages that contain fatty tissue;
  • in the colon is the process of digestion and absorption into the body through the bloodstream of almost all nutrients, while in the large intestine, digestion is virtually non-existent( with the exception of the absorption of some fat-soluble vitamins), and the formation of fecal matter occurs.

The main functions of the body

The colon, as an important part of the digestive system, performs a number of functions:

  • excretory function: intestinal excretion of undigested residues, mainly fiber, as well as many toxins from the body that are absorbed by the walls of the colon through the bloodstream;At the same time, uric acid, urea, creatinine and other substances are removed from the human body;
  • is a final digestion that occurs under the influence of enzymes that come directly from the small intestine, as well as enzymes of the large intestine;thus subjected to rotting decomposition of proteins, resulting in the formation of indole, phenol, clathol and other toxins;
  • synthesis of vitamins: in the large intestine, vitamins E, K, B6 and B12 are synthesized;
    protective function: the microflora of the large intestine provides protection against the reproduction of pathogenic microflora;
  • is the formation of fecal masses, which consist of fiber, bacteria, products of decomposition of bile pigments, mucus and other components.

Thus, the body is extremely important in the process of digestion.

It is especially important that the intestines are populated with predominantly useful bacteria that contribute to the normal digestive process and prevent reproduction of pathogenic microflora.

The process of digestion in the large intestine and the movement of the food masses in this organ is carried out reflexively, regardless of the will of the person. At the same time, the functions of the colon have a great influence on the diet and the state of the nervous system, as under the influence of stress, the emergence of spasms in certain parts of the intestine and, as a consequence, a violation of the normal process of digestion of food. Therefore, for normal functioning of an organ it is necessary not only to organize a regular meal, but also to normalize the emotional state.