The intestines are an underestimated and often very neglected organ that has a huge impact on our physical and mental he alth. The intestines are part of the digestive system and are divided into the large intestine and the small intestine. Each of them has slightly different functions. There is a reason it is said that the gut is our second brain. In addition to digesting the intestines, they are also responsible for our well-being. How does the intestine work? What is their structure and length?

Intestinesis an extremely sensitive organ, very hard-working and responsible, and also extremely influential. If you consider what overweight, depression, colds, and itchy skin rashes have in common, you find that these are interdependencies that stem from your gut. It is there that numerous processes that are responsible for the absorption of valuable substances from food take place, but this way also enters the body of many intruders. Some people even grow stronger with what we eat. And the obvious evidence of this is worse well-being, weight gain or weight loss, weakened immunity, skin changes. It is worth knowing how this most important part of the gastrointestinal tract functions in order to make its work easier and save yourself a sensation in the stomach.

Intestines - what do you need to know about them?

Small intestine

The small intestine, 7 meters long, is twisted into loose loops. If we look inside it, it turns out that it does not look like a pipe smeared with food. Its walls are shiny as velvet, moist and pink. It is sparkling clean! Few people know that only the last meter of the large intestine comes into contact with faeces: what is in front of it is surprisingly clean (and to a large extent odorless).

To some people, the small intestine may seem a bit chaotic in structure; the heart is divided into chambers, the brain has hemispheres, and everything is twisted here. However, under the microscope, you can see that the numerous folds and protrusions are planned with extreme precision to give us a larger area of ​​absorption in a small "area".

Were it not for the numerous folds, we would need a small intestine 18 meters long (for digestion)! On only one square millimeter of the intestinal epithelium, as many as 30 villi protrude into the food mass, and each of them has numerous branches - microvilli. They, in turn, have ends made of sugar structures, resembling deer antlers (the so-calledglycocalyx).

The digestive surface is as much as one hundred times larger than the surface of the skin. It makes sense. It takes space, accuracy and time to finely break up whatever we ingest from the outside into tiny particles that can be absorbed and become part of ourselves.

In the small intestine, the consumed food is finally fragmented. Just behind the inlet (from the stomach), there is a small hole on its wall, the so-called wart. It looks a bit like the salivary glands in the mouth. It is in this way that the digestive juices get into the food mass. Thanks to them, large particles of proteins, fats or carbohydrates are dissolved so that they can pass through the walls of the intestine and reach the blood.

Kneads each portion of the pulp, spreads it on all sides and penetrates with the help of villi movements. The bowel movements are governed by one principle: just keep going. For this they have a special mechanism called the perist altic reflex.

In each intestinal villi there is a tiny blood vessel, fed with particles taken from the food. All the blood vessels in the small intestine connect and pass through the liver, which tests what we've eaten for harmful substances and toxins.

All the energy that drives the organs of our body is obtained in the small intestine. However, one should not expect an injection of vitality immediately after the end of the meal. At this point, many people feel rather tired, lethargic.

This is because more blood goes to the digestive organs. The brain, as scientists point out, is then less supplied with blood, and therefore we feel tired. From the point of view of the intestines - they work better when we are lazy and relaxed, and the blood is not full of stress hormones. Therefore, a busy book lover will digest lunch much more efficiently than a constantly tense high-level manager.

About an hour after digesting a meal, the intestine starts cleaning its corridors. This process is called an expertly traveling motor complex. For us, on the other hand, the inner cleaner can be heard as a rumbling in the stomach. In fact, this sound does not come from the stomach, but from the small intestine and does not mean hunger, but … readiness to continue working.

Blind intestine

At the junction of the small intestine with the large intestine, there is a seemingly unnecessary additional corridor (it resembles an uninflated oblong balloon). This is the cecum, which ends with an appendix. It is responsible for looking at foreign bacteria in food debris. Disarms the intruder if necessary.

It is also a magazine containingcarefully selected good bacteria that can be used, for example, during acute diarrhea.

Large intestine

The large intestine consists of a series of protrusions - it resembles a string of beads. It is not curled up in loops, but rather fits around the small intestine, like a thick picture frame. It works its own way on what the small intestine has failed to absorb. There aren't many villi here anymore, but there is a microworld of intestinal bacteria that break down the last food debris.

And these bacteria are of great interest to our immune system. Valuable cells are found on the walls of the large intestine, and the aforementioned appendix consists almost entirely of immune lymph tissue.

When the next meal is already absorbed in the small intestine, the colon does not care at all. For about 16 hours, she diligently processes all the leftovers from the first meal. The amount of water and s alt excreted is also precisely measured at the last meter of the digestive tract. This apothecary accuracy allows the body to save a whole liter of fluid. If it weren't for the large intestine, we would have to drink a liter more each day.

Intestinal bacteria

In total, the digestive tract contains about 2 kg of bacteria, viruses and fungi. However, the vast majority (90%) are bacteria. All microorganisms that live in the human body are called microbiota.

Those living in the intestines contribute to digestion, detoxification, co-creation of the protective barrier of the immune system, fermentation of certain nutrients, production of vitamins such as biotin, vitamin K and short-chain fatty acids. Microbiota also increases the absorption of calcium and iron. It is thanks to her that the appropriate pH in the digestive tract is maintained.

Interestingly, about a third of the bacteria that live in the gut is the same for all people, while the remaining two-thirds are individual for each person. However, some trends were observed and several enterotypes (intestinal types) were distinguished depending on what type of bacteria is currently dominant.

There are three types to choose from, and individual bacterial families have their own specific characteristics (they like specific food, choose company in the form of other bacteria, and also produce enzymes or vitamins):

  • Enterotype I with dominant Bacteroides , masters of breaking down carbohydrates. However, it is suspected that they may contribute to excess weight, as they are very fond of saturated fatty acids. In the intestines of people who like to eat, for example, sausage, Bacteroidesoccur much more often. Enterotype I produces more biotin (vitamin B7, also known as vitamin H), vitamin B2 and vitamin C.
  • Enterotype II with Prevotella dominance . It is more common in vegetarians, but it is also found in carnivores. Diet is not the only factor that plays a role in the colonization of the intestines by specific bacteria. Its speci alty is the production of vitamin B1 (thiamine) and folic acid.
  • Enterotype III with Ruminococcus dominance . It occurs most often. Bacteria in this group are fond of plants and are likely to produce heme.
Worth knowing

How do you know that the intestines are working properly? Much can be seen from the frequency and quality of your bowel movements. We also have various types of research at our disposal.

Blood tests help to recognize inflammatory diseases, food hypersensitivity and the presence of parasites.

  • Imaging tests, i.e. computed tomography, X-ray (with contrast), ultrasound of the abdominal cavity. Such tests help to detect, for example, defects, excesses and diverticula, i.e. bulges of the large intestine (pockets), which may cause inflammation or even a fistula.
  • Gastroscopy allows you to see the initial section of the small intestine - duodenum, as well as the stomach and esophagus.
  • Colonoscopy enables a comprehensive analysis of the final section of the small intestine and the entire large intestine for the appearance of polyps or other lesions (including cancerous). It is performed using a colonoscope - a long, flexible tube with a camera attached, inserted through the rectum of a large intestine.
  • Hydrogen tests - they are performed in order to confirm or rule out gastrointestinal symptoms and those related to food intolerance (lactose, fructose), and bacterial overgrowth of the small intestine (SIBO). The first (comparative) measurement is made on an empty stomach, and the next, at regular intervals, after the patient is given a standard dose of lactose. The test confirms intolerance if the exhaled air shows an increase in the concentration of hydrogen above a certain level.
  • Stool examination. It helps to detect the presence of occult blood, which indicates pathological changes (e.g., hemorrhoids, polyps, neoplasms) in the large intestine. Microbiological analysis of stool gives a quantitative and qualitative picture of the bacteria and fungi present in the intestine.

What hinders the intestines?

Does your stomach hurt after eating? Squeezes? Makes strange noises? The abdominal rebellion manifests itself in different ways. To avoid this, check to see if you are inconveniencing his work. There is no hard evidence for thisScientific research, but a growing number of gastroenterologists believe that the growing number of people with bowel disease is related to lifestyle and diet. These are the gut's worst enemies.

  • Stress . The contractions and movements of the large intestine are controlled by the nervous system and hormones. A tense life can result in painful cramps, constipation, and diarrhea.
  • Alcohol . Eating it can increase the population of gas-producing bacteria up to a thousandfold. After all, some of them use it as food (which is easy to feel when trying fermented fruit).
  • Large portions of junk food . They are a challenge for the digestive system due to the amount that is processed at one time. At the same time, there is little profit (for the body) - mainly fat and sugar, which (in large amounts) can support the growth of less beneficial bacteria in the large intestine.
  • Antibiotics . They are sometimes necessary in treatment, but you always have to remember that they strongly decompose and rearrange bacteria in the intestines. Also the beneficial ones. Even a short, 5-day antibiotic treatment can destroy nearly 1/3 of the intestinal microbes, so you need to balance the proportions with the appropriate probiotic, which will be indicated by your doctor. Different strains of bacteria must be given to improve immunity and different strains to improve digestion.
Worth knowing

Author: Getty Images

Dov Sikirov, an Israeli doctor, asked the volunteers to try to pass stools in different positions: sitting on an ordinary toilet seat like a throne, laboriously hanging over an extremely small toilet bowl, or simply squatting, as we do outdoors. He found that, on average, defecation in a squat position lasted only about 50 seconds and was felt by the subjects as complete. The same action, carried out in a sitting position, took an average of 130 seconds and did not give the feeling of complete success. Why is this happening? The mechanism responsible for closing the intestines is designed so that it does not fully open when seated. Around the intestine, like a lasso loop, a muscle is wrapped, which, when we sit or stand, pulls it up to form a crease, such as is sometimes formed on a rubber water hose. The end of the digestive tract essentially straightens when you squat (or your knees are closer to your belly). Then everything comes out more efficiently, like on a string.

  • How to have a he althy defecation? It's not as easy as you think
  • The cerebral and intestinal axis - why the intestines are the "second brain"?
  • Intestinal diseases

Category:

Gastrology