It is here that the body takes everything from food, well, almost everything. A thorough and targeted chemical treatment of various nutrients takes place here. Here it is decided whether the eaten is assimilated. Guess what kind of place this is so unusual? Yes, it is the small intestine that plays such a role in our body.
After acid and mechanical processing of food by the stomach, the latter enters the small intestine. And the processes taking place here are more subtle. Here the body “transfers” minerals, fats, vitamins, carbohydrates and, of course, proteins to the blood by various methods. If a person is seriously ill in the small intestine, the body actually remains hungry constantly. It is good that such diagnoses are not very common.
The small intestine is not very long. On average, only 6 meters. The total area of this tube is not so big. How to be the body, because you need to learn almost everything here? The way out is the special structure of the small intestine: on its surface there is truly a huge number of microscopic folds, this significantly increases the overall surface, which is important for the absorption of nutrients (as scientists call nutrients in general). But this is not limited to this. Still on the inner surface of the small intestine are villi. And on them - even more subtle structures - microvilli. The villi contain blood vessels and lymph vessels, which many nutrients enter.
Cells lining the inner surface are adapted to absorb digested food molecules. Fats enter the lymphatic system, all other substances into the blood. From there, to the liver, which regulates the intake of food sugar in the blood.
The human small intestine is not stationary, it has a muscle layer in the structure of the wall, and therefore it constantly moves rhythmically. This process is called peristalsis. In general, he is very slow. When this happens (and the process looks like small waves), the villi move, which also increases the amount of contact with food molecules. On the surface of the intestine there are special depressions - crypts, in them flows of various small digestive glands open . The entire intestine is a very intelligent and complexly organized system. It has its own regulatory mechanisms, for example, some substances secreted by one area stimulate the work of areas into which food gets further.
Within the small intestine, three sections are distinguished: firstly, the duodenum, secondly, lean and, thirdly, the ileum. Immediately after the stomach, the food acquires a very acidic reaction, which may be unfavorable for other departments that are not adapted to such Ph. What to do to an organism in this situation? Of course, highlight the alkali. This is what the Brunner glands do. A neutralization reaction takes place - and stomach acid will no longer cause ulcers in the intestines. In the jejunum, the processes of digestion proper are completed; wall enzymes help in this.
Why is the small intestine called exactly what it's called? The point is its diameter, compared with its large intestine 3-4 cm - the figure is very modest. Thick is 3 times wider, but it is this structure that allows the small intestine to perform its thin work - to absorb nutrients. Already at the end of it, the ileum, substances are practically not absorbed, only bile partially returns through the blood to the liver through the walls of the intestine. And already the colon can “afford” any volumes - this is quite enough for the absorption of water.
As you can see, the small intestine is a very complex organ, on which the state of the body depends most directly. After all, it depends on her whether we should be strong, smart and beautiful, or not be. Therefore, you need to pay attention to the health of your intestines and be treated in time if necessary.