In this article we will look at the functions of the rectum and its significance. We will also get acquainted with its anatomical structure, analyze in detail the role of the layers of which it consists, and study the processes of blood supply.
Introduction to the rectum
The rectum is necessary for the body to accumulate feces. It originates in the region of the cape, then descends into the cavity of the small pelvis, located in front of the sacrum. Such a structure forms 2 bends moving from the front to the back and are called the upper and lower. The upper one is convex in the direction of the concavity of the sacrum, and the lower one looks into the coccyx area. Sometimes it is called perineal.
Top & End
Features of the structure and functions of the rectum depend primarily on its constituent elements, departments, cells and location. One of these components is the upper part of the organ and its final part.
The upper section is a kind of ampulla, the diameter of which is usually in the range of 8-16 cm, but this number may increase due to, for example, atony. This educationis located in the pelvic cavity and expands at one end.
The end part is represented by a circle pointing down and back, and its continuation is in the anal canal. After passing through the pelvic floor, it ends with an opening. The size of the circumference formed varies less than that of the upper section, and corresponds to 5-9 cm. The size of the intestine ranges from 13 to 16 cm, but about 65-85% of it falls on the pelvis, and the remaining centimeters form the anal section.
The structure of the mucous membrane
The functions of the human rectum are largely determined by its mucous membrane. The mucous membrane forms a numerous number of longitudinal folds, which is possible due to its developed submucosa. These folds can easily be smoothed out due to stretching of the intestinal wall. The anal canal has folds with a permanent appearance; there are eight to ten of them. These formations have special depressions lying between them, and are called anal sinuses (clinicians), which are clearly expressed in children. It is clinicians who accumulate in themselves a special mucus that facilitates the passage of feces through the anal canal. The anal sinuses are also called anal crypts. They most often serve as an entrance door for microorganisms. The tissue thickness, located between the anus and sinuses, includes a plexus of veins. In addition to longitudinal folds, the upper rectum has transverse folds. These formations are very similar to the semilunar folds of the sigmoid colon.
Description of muscleshells
The structure and functions of the rectum also depend and are determined by the muscular membrane, consisting of 2 layers, namely: circular and longitudinal. The circular (inner) layer begins to thicken in the upper part of the perineum. It is in this area that the internal sphincter is formed, which ends at the junction of the skin and the anal canal. The longitudinal layer covers both the anterior and posterior sections of the intestine, equally. In the lower part, the longitudinal fiber begins to intertwine with the muscular one, which rises towards the anus, and also often intertwines with the external sphincter.
Thanks to this, we can conclude that the rectum has the features of a conductive section of the digestive canal and is similar to the esophagus. There is a similarity between these structures in the process of development: both ends of the primary gut during embryogenesis undergo a breakthrough of the blind end of the tube. In the esophagus, this occurs with the pharyngeal membrane, and in the rectum, with the cloaca. Both channels have musculature consisting of two continuous layers.
Topographic details
The functions of the rectum can be described with topographic information. Behind the organ are two sections of the spine, sacral and coccygeal. And in front of the male representatives, the intestine is adjacent to the seminal vesicles and the vas deferens. The rectum of women borders in the anterior area with the posterior vaginal wall and uterus. It is separated from these structures by a layer formed by connective tissue.
The proper fascia of the rectum and the anterior surface of the sacral and coccygeal spine do not have fascial bridges between them. This simplifies operations to remove the intestine and its fascia, which has covered the vessels. Doctors have no particular problems with this.
Performed functions of the rectum. Description
One of the functions of the rectum is to retain food residues that have not had time to be absorbed in the cavity of the small intestine, as well as water. This includes a large number of substances of organic nature and products that have undergone bacterial decay, and also contains substances that cannot be digested, for example, fiber. There is also bile, bacterial organisms, s alts.
In connection with the functions of the rectum, there are observed processes such as the breakdown of food that is not digested in other parts of the food section. And the formation of feces. In the large intestine, digestive juice is constantly secreted, containing the same set of enzymes as in the small intestine, but with a less pronounced effect. Gas is also collected here.
The key function of the rectum is the removal of waste products from the life process. Or, in other words, the removal of feces from the body. Mostly this process is regulated by the consciousness and will of a person.
Disturbance of the function of the rectum, as a rule, is the result of a sedentary lifestyle, poor nutrition, neuro-emotional overload, etc. Most often, such stressful situations lead to constipation. Todisruption of the intestines, affecting the process of defecation.
Circulation processes
The blood supply to the rectum is due to the unpaired upper rectal and two paired rectal. A well-developed network of vessels of the sigmoid colon makes it possible to preserve the unpaired rectal artery, namely its marginal vessels, full blood supply even due to high intersections of the rectal paired arteries and the sigmoid.
The middle paired arteries emerging from the branches of the iliac arteries sometimes develop differently, and sometimes they are absent. And yet, in some situations, they can play a key role in the process of blood supply.
Inferior arteries, originating from the internal pudendal artery, supply the external sphincter and skin. Plexuses from the veins are located in a wide variety of layers of the intestinal walls. Among them are:
- submucosal plexus - has an annular shape, consists of a submucosa and venous trunks, and is also associated with two other plexuses;
- subfascial plexus;
- subcutaneous plexus.
In closing
If we talk briefly about the function of the human rectum, we can sum it up like this. This body is responsible, first of all, for the place of storage of feces and the reservoir for the accumulation of gas. It also breaks down undigested food and removes waste products from the life process.
