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Most of the nutrients to sustain the human body gets through the gastrointestinal tract.
However, the conventional foods that people eat: bread, meat, vegetables – the body cannot use directly for their needs. For this, food and drinks should be divided into smaller parts – individual molecules.
These molecules are transported by the blood to cells for building new cells and producing energy.
How food is digested?
The process of digestion involves mixing food with gastric juice and moving it through the gastrointestinal tract. During this movement, the food is divided into components, which are used for the needs of the body.
Digestion starts in the mouth when chewing and swallowing food. And ends in the small intestine.
How does food move through the digestive tract?
Large hollow organs of the gastrointestinal tract – the stomach and intestines have a muscle layer, which causes their walls to move. This movement allows food and liquid to move through the digestive system and be mixed.
The reduction of the gastrointestinal tract is called peristalsis. It is similar to the wave which with the help of muscles moves along the entire digestive tract.
The muscles of the intestines create a constricted portion, which is slowly moving forward, pushing food and liquid.
The process of digestion
Digestion begins in the mouth. When you chew food it is plentifully moistened with saliva. Saliva contains enzymes that begin to breakdown starch.
Swallowed food passes into the esophagus which connects the throat and stomach. At the junction of the esophagus and stomach, there is a muscle ring. This is the lower sphincter of the esophagus, which opens at a pressure of ingested food and passes it into the stomach.
The stomach has three basic tasks:
1. Storage. To make a large amount of food or liquid, muscles of the upper part of the stomach relax. This allows the walls of the organ to stretch.
2. Mixing. The lower part of the stomach is reduced to food and liquid mixed with gastric juice. This juice consists of hydrochloric acid and digestive enzymes, which help in the breakdown of proteins. The walls of the stomach secrete large amounts of mucus, which protects them from the effects of hydrochloric acid.
3. Transportation. Mixed food enters from the stomach into the small intestine.
From the stomach, the food passes into the upper part of the small intestine – the duodenum. Here the food is exposed to the juice of the pancreas and enzymes of the small intestine, which AIDS in the digestion of fats, proteins, and carbohydrates.
Here food is processed in the bile produced by the liver. Between meals, bile is stored in gallbladder. While eating it is pushed into the duodenum, where it mixes with food.
The bile acids dissolve the fat in the intestinal contents of about the same as fat from the pan: they break up into tiny droplets. After the fat is minced, it is easily split by enzymes into components.
Substances obtained from the split enzymes are absorbed through the walls of the small intestine.
The mucosa of the small intestine is covered with tiny fibers that create a huge surface area, allowing it to absorb a large number of nutrients.
Through the special cells, these substances from the intestine enter the blood and spread throughout the body for storage or use.
The undigested part of food arrives in the large intestine in which the absorption of water and some vitamins takes place. Wastes after digestion are formed into the stool and are removed through the rectum.
What disrupts the work of the gastrointestinal tract?
1. Bad habits: Smoking and alcohol consumption
2. Food poisoning
3. Unbalanced diet
The most important
The gastrointestinal tract allows the body to break down food into simple compounds, which can build new tissue and get energy.
Digestion occurs in all parts of the gastrointestinal tract from the mouth to the rectum.
More about the digestive system work watch in the video below:
