The gastrointestinal tract is part of the human digestive system. It also includes glands that produce secrets necessary for the full course of the digestive process.
The gastrointestinal tract is a very long (up to 10 m) tube, which in many places is twisted in the form of loops. It begins with the opening of the mouth, and ends with the anus. The parts of which the gastrointestinal tract consists smoothly pass into each other. This is the stomach, oral cavity, esophagus, pharynx, small intestine, colon and rectum.
The process of crushing food and its chemical changes begins in the mouth. It is here that it is saturated with saliva, chewed.
Next, the crushed food enters the throat - an irregularly shaped tube that tapers down, and at the end of the front part it is slightly flattened. By the way, with the help of the pharynx, the breathing process also occurs, in connection with which it also applies to the respiratory system.
A swallowed lump of food enters the esophagus - a narrow, more than twenty-centimeter tube. It connects the stomach and pharynx. Peristalsis of the esophagus helps the food lump move further. As a result of active muscle contraction, after five seconds it appears in the stomach - a wide part of the digestive canal. In an adult, this organ has a volume of from 1.5 liters to 2.5 liters, and in men it is more than in women. An empty stomach is not stretched, it is in a state of contraction. The food lump, which has got into its upper part, pushes the walls of the organ and, with peristaltic, translational movements, moves to the lower part. During this transition, it is impregnated with gastric juice, which is secreted by the glands of the stomach before eating (reflexively) and from direct contact with it. Each new portion pushes the previous one further. The food lump is in the stomach for three to ten hours, this time is enough to saturate the juice secreted by the glands of this organ.
Then, through the sphincter, which periodically opens, it enters the small intestine, which is the longest section of the digestive canal, up to six meters. It consists of a skinny, duodenum, and ileum. Here the processing of the food lump ends with enzymes, nutrients are absorbed, and proteins, carbohydrates and fats are broken down. Thanks to the movements of the muscles of the small intestine, it mixes and advances.
In the colon, the remaining substances, water, continue to be absorbed. In it, masses of feces are formed, which enter the rectum and exit through the anal canal. It contains plexus of veins, in the area of which there is such a common disease of the gastrointestinal tract as hemorrhoids.
In general, the causes of diseases of the digestive system are very diverse. Their distribution is directly dependent on social conditions, on the place of residence, on the age of the patient, his gender, on the nutritional characteristics that have developed historically.
One of the main reasons is the modern rhythm of life. It is noted that city residents are more likely to suffer from neurosis of the stomach and intestines. They are also more susceptible to those people whose professions are associated with emotional stress.
The second factor affecting the development of diseases in which the gastrointestinal tract suffers is a violation of the regime and quality of nutrition.
In addition, inflammation of the gastrointestinal tract is provoked by helminthiases and infectious diseases (hepatitis, dysentery, foodborne toxicoinfections).
Whatever the reason, adequate treatment should be carried out by a professional doctor. Since self-medication often does not lead to an improvement in the situation, but to its aggravation. After taking medications for a long time (including home-made products) without the supervision of a doctor, acute inflammation of the stomach or colon can go into the chronic stage. The risk of developing a stomach ulcer or damage to the digestive tract with fungi is great (for example, after prolonged use of antibiotics).