Digestion in the human small intestine

The role of the small intestine in digestion is very important and, it can be said, is the final stage in the hydrolysis of food to the final substances that are necessary for our body.

General information about the human small intestine

The main stages of digestion are concluded in the small intestine, which is the longest organ, with a suction surface area of ​​almost 200 square meters. It is in this part of the gastrointestinal tract that most of the nutrients, as well as poisons, toxins, drugs, and xenobiotics that are ingested by the oral route are absorbed. In addition to digestion, absorption and transportation of all these substances, the functions of hormone secretion as well as immune defense are performed in the small intestine.

The small intestine includes 3 departments:

• duodenum;
• jejunum;
• ileum.

However, between the last two departments there is no clearly defined border.

All sections of the small intestine are layered and have 4 shells:

• mucous membranes;
• submucosal;
• muscular;
• serous.

How is digestion in the small intestine?

Food from the stomach enters the duodenal section, where it is exposed to bile, as well as pancreatic and intestinal juices. Digestion in the human small intestine works more towards absorption of nutrients, and therefore it is here that the final digestion of the eaten food occurs with the help of intestinal juice, which consists of three groups of enzymes. In this case, there are two types of digestion in the small intestine: the cavity and the parietal. Unlike striped parietal digestion in the small intestine bears about 80% of the final stages of hydrolysis and at the same time absorption of substances consumed in food.

Enzymes produced by the glands of the small intestine can split only short chains of peptides and sugars, which get there because of the preliminary "work" with the food of other organs. After the complete breakdown of food products into glucose , vitamins, amino acids, fatty acids, minerals, etc., an important process of their absorption into the blood takes place. Thus, the cells of the whole human body are saturated.

Still the cells of the epithelium of the small intestine form a so-called mesh, through which only completely cleaved substances will be passed through, and unchanged molecules of starch or protein, for example, can not penetrate and are transported for further "processing".