Few people know what the intestines are, in full, but this is a rather complex and important human organ. Even the slightest malfunction in its work or a violation of its blood supply can lead to dangerous diseases. Moreover, most of the food received is absorbed by the intestines and disturbances in its work lead to exhaustion of a person. In this regard, every person should have at least elementary knowledge about the blood supply to the intestines, its functions and diseases.
Blood supply to the large intestine
Intestine is thick and thin. Each is represented by a separate blood supply system. The blood supply to the colon begins with the superior and inferior mesenteric arteries. The watershed zone of the basins of both arteries is defined by the boundary between the middle and posterior sections of the primary intestine.
The superior mesenteric artery descendsduodenum. It then splits into smaller branches. They go to the small intestine and then to the large intestine.
The blood supply to the large intestine is carried out by three branches of the artery, each of which provides blood circulation in its area. One of the arteries runs along the ileum to the ileococcal angle. The other is along the ascending colon and part of the colon. And the last - third - large artery feeds the transverse colon with blood.
The descending colon is supplied by blood flow through the inferior mesenteric artery. The sigmoid is fed in the same way.
The descending colon is the border, after which the descending artery divides into processes, in the amount of 2 to 6 sigmoid arteries. Then they follow the intestine, called the upper colon.
The superior rectal artery supplies the rectum.
The blood supply is not limited to the intestines - veins and arteries provide blood circulation in the muscles, as well as the soft tissues of the peritoneum and subperitoneum.
The circulation is built with independent anastomoses with the portal and inferior vena cava. In the transverse colon, descending and ascending colon, blood supply is carried out by veins that have the same names as the arteries that feed these areas.
Small intestine
What is special about this organ department? The blood supply of the distal intestine, as well as its other components, is constantly subjected to overload and blood flow disturbances. This is due to the factthat sections of the small intestine are constantly in motion due to the passage of food. The diameter of the intestines changes, which should lead to permanent kinks in the blood vessels. But this does not happen due to the arcade arrangement of the blood vessels.
The ascending and descending branches of the arteries, arcade after arcade, anastomose with each other. There can be from 4 to 6 such arcades at the end of the small intestine, while only a first-order arc is observed at the beginning of the intestine.
Arcaded intestinal blood supply allows the intestines to move and expand in any direction. And with various pathologies, loops of the small intestine can be isolated without disturbing the entire blood circulation.
Intestinal function
Where is the gut? It is located in the abdominal cavity between the stomach and anus. Hence the conclusion follows: its main function is the excretion of food waste from the body. But this is not its only role in the body, there are a number of others:
- Strengthening immunity. The intestine performs this function in two ways - it does not allow dangerous microorganisms to enter the body, producing immunoglobulin and T-lymphocytes.
- During the secretory function, the intestine produces a number of enzymes and hormones necessary for the body to absorb food.
- Motor function is to move food along the entire length of the intestine to the anus.
- You need to understand that the intestines are a digestive organ, so its main function is to absorb useful trace elements and transfer them from food directly tohuman blood. For example, almost all glucose enters the blood through the walls of this organ. All these processes occur at the molecular level - the intestines do such a delicate job.
Intestine length
The length of the human intestine throughout life is constantly changing. First, it is due to age. In infancy, the total length of the intestines exceeds the height of a person by 8 times, and after the growth of the body stops - only 6 times. The intestines grow especially rapidly during the transition from dairy to solid foods.
Since the muscle tone of this organ is different for all people, the length of the intestines in an adult can vary from 3 meters to 5. It is known that all the muscles of a person relax after his death, and the intestine after death lengthens to 7 meters.
The diameter of the smallest intestine is from 2 to 4 cm, it is called the jejunum. And in the widest place in the large intestine, its diameter is 14-17 cm.
The diameter of an organ changes along its entire length, and on an individual basis. And where one person has a thickening of the intestine, another may have a narrowing.
How the gut works
The human intestine is represented by two sections - thin (longer) and thick (short but wide). The blood supply of the intestines in its different parts, as well as the functions, are very different. Between the sections of the intestine there is a special valve that does not let food from the large intestine back up. Food always moves in one direction - through the duodenum down to the straight lineintestine and further to the anus.
Muscular tissue of the intestinal walls is a structure of longitudinal and transverse fibers. They move without signals from the central nervous system, that is, a person does not control his peristalsis. Impulses of movement through the intestines are transmitted through nerve fibers, widely braiding the entire intestine.
It is known where the intestine is located - in the abdominal cavity, but it does not just hang there - the intestines are attached to the walls of the peritoneum with special ligaments.
During the day, the human intestine secretes up to 3 liters of special juice, saturated with various alkalis. This feature of it allows you to digest food passing through the organ.
All intestines have a similar structure - from the inside they are covered with a mucous membrane, under it there is a submucosa, then muscles and a serous layer covers them.
The small intestine is represented by several departments that have their own functions. For example, in the duodenum there is a special duct through which bile from the liver enters it, finally digesting the food that has passed through the stomach.
The jejunum, immediately following the duodenum, breaks down peptins and disaccharides into elementary particles - amino acids and monosaccharides.
The next intestine - the ileum - absorbs bile acids and cyanocobalamin.
The large intestine is also a complex structure. It includes the descending and ascending colon, the sigmoid, rectus and blind process, ending in the appendix.
The main job of the large intestine is to remove fluid from the chyme by absorbing it throughwalls and stool formation.
The large intestine ends with the rectum with receptors and anal sphincters located in it. With pressure on the receptors of the stool, the brain receives a signal that the rectum is full and gives the command to start defecation. The sphincters then relax and release the stool.
What diseases the intestines are prone to
The intestine is a very important organ for life in the human body. Like any organ, it is subject to various diseases, any of which leads not only to pain in the abdominal cavity, but also affects the general well-being of a person and the state of the whole organism. For example, with severe diarrhea, a person rapidly loses body weight and strength. In the absence of treatment for such a pathology, the patient may simply die of exhaustion.
The type of disease also determines where the pain occurs. Everyone knows that with inflammation of the appendix, pain most often occurs in the lower right side of the abdomen.
Major bowel diseases include ulcerative or infectious colitis, duodinitis, Crohn's disease, intestinal obstruction, enterocolitis, enteritis and tuberculosis.
There are a number of other pathologies, but they occur much less frequently - intestinal stenosis, duodenal hypertension, irritable bowel syndrome.
Symptoms of bowel disease
The main symptom of developing pathologies in the intestines is loose stools or constipation, nausea,general weakness, blood in the stool. But the main thing is the pain. It can occur in any part of the abdominal cavity and be of varying intensity. It can be constant or jerky.
If one or more of these symptoms appear, you should immediately consult a doctor. Only a specialist will be able to correctly diagnose the disease and prescribe adequate treatment.
Diagnosis of bowel diseases
Diagnosing bowel disease is very difficult. To do this, the doctor must collect as much information as possible about the patient's condition, as well as about the processes taking place in his intestines.
First of all, a detailed history is taken. The doctor asks the patient about the symptoms he is experiencing. About what kind of stool the patient has, how often he feels the urge to defecate, and most importantly, what kind of pain a person has - its strength, location, duration.
The information about the presence of rumbling in the stomach and flatulence, that is, the waste of gases, matters. The doctor pays attention to the appearance of the patient. If he has dry and thin skin, weak brittle hair, pallor of the face and general weakness, this, coupled with information obtained from the anamnesis, can help diagnose various diseases of the small intestine.
Using the method of palpation, the specialist establishes the exact location of the onset of pain, and also determines the shape and size of the colon. With the help of such a seemingly simple method, for example, inflammation of the appendix is diagnosed, since other methods in this case are not very informative.
Instrumental diagnostics are also widely used. After allwhat is intestine? This is an organ inside the abdominal cavity, which means it can be studied using ultrasound or a more informative MRI.
Specialists who study the intestines
If you have any problem with your stomach, you need to see a doctor. But not only a gastroenterologist is able to accurately diagnose and prescribe treatment. He may need to consult an oncologist and a surgeon for this. Especially if the treatment involves surgery.
Conclusion
The intestine is a delicate organ in the human body. It is responsible for many processes in the body. Violation of the blood supply to the intestines can lead to various diseases, so at the first symptoms of pathologies, you should immediately consult a doctor.
