The human digestive tract. The structure of the intestine

The structure of the intestine includes thin and thick sections. The thin department starts immediately after the stomach. An adult has a length of about five meters. The normal state of this department does not imply the presence of harmful or useful microorganisms. In the course of many diseases that cause the violation of enzyme functions, it creates a medium suitable for the reproduction of microbes. Pathogenic microbes carry the infection, which is accompanied by severe diarrhea, bloating, rumbling, pain in the navel. Non-pathogenic microbes cause discomfort and bloating in the abdomen.

The large intestine is a continuation of the small intestine. The border between them is a mucous membrane. It prevents the penetration of the contents and microorganisms of the thick section back into the thin section. Close to this flap is an appendix (appendix).

The structure of the intestine, in particular its thick section, includes the cecum, ascending, transverse and descending colonic and sigmoid, ending with a rectum. It is radically different from the structure of the delicate department. The fat department, in addition, performs completely different functions.

A normal microflora is a dynamically balanced, complex ecosystem. It is characterized by a specific composition, which includes more than five hundred species of bacteria. The main representatives of these include anaerobic bifidobacteria and aerobic lactobacilli.

The intestinal microflora regulates cholesterol and the exchange of bile acids, prevents the proliferation of pathogenic microorganisms , thus ensuring the stability (colonization resistance) of the organ. In addition, the internal ecosystem participates in the processes of enzymatic protein, fat digestion, as well as the assimilation of cellulose, high-molecular carbohydrates and nucleic acids.

The intestinal microflora is an active participant in electrolyte metabolism, synthesis of substances of antibacterial activity, vitamins K, B, ascorbic acid. Thus, the resistance of the whole organism to unfavorable external influences increases. Functions of microflora also include detoxification of endogenous and exogenous substrates. In this case, some microbes are able to change the chemical composition of toxic substances, neutralizing them. The intestinal ecosystem participates in stimulating peristalsis (motor activity) of the organ and normalizing the process of removing its contents from the body.

The microflora is divided into resident (transitory), transitory (transitory), non-pathogenic (useful), conditionally pathogenic (useful in small numbers and in its place), pathogenic (harmful, causing infection). The composition and quantity of microbes present varies constantly, but the ratio of quality and quantity remains certain. Thus, dynamic equilibrium is maintained. With a sharp imbalance, a dysbacteriosis occurs.

As mentioned above, the intestinal parts perform a different function. The thin section is responsible for the implementation of the basic mechanisms of digestion of food and the absorption of nutrients into the lymph and blood. In this case, the intestinal motility is provided by the motor activity of the inner circumferential and outer longitudinal muscles. At the same time, the chyme is mixed with the juice secreted by the pancreas and the organ itself, as well as the progress of the chyme. The muscular structure of the intestine allows you to perform rhythmic segmentation, pendulum, tonic and peristaltic contractions in the thin section.

The thick part of the organ serves as a reservoir. Here, the accumulation of contents and the periodic removal of processed foods from the body. The muscular structure of the intestine in this area allows peristaltic, pendular, anti-peristaltic, propulsive contraction, as well as rhythmic segmentation.