Digestion
The digestion is the process that transforms the food we eat into substances that the body needs for its other vital processes. The substances generated are assimilated by each of our internal systems for their proper functioning.
In the process, it is produced in the digestive system, which is made up of the gastrointestinal tract (large intestine, small intestine, stomach, esophagus, mouth, and anus), the liver, the pancreas, and the gallbladder. The mouth, esophagus, stomach, small intestine, pancreas, liver and large intestine are also involved.
The bacteria (intestinal flora) present in the intestines, the circulatory and nervous systems also intervene.
Digestion takes place not only in humans, but also in other multicellular living beings, and even in a cell.
How is it produced?
When we swallow food, the tongue pushes the food down the throat and into the esophagus. During this task, the epiglottis prevents us from drowning by expanding its membrane over the trachea.
The brain signals the muscles of the esophagus to begin peristalsis (symmetrical contractions and relaxations). When food reaches the end of the esophagus, the lower esophageal sphincter relaxes and opens, allowing food to pass into the stomach. When we feel reflux it means that this ring called the sphincter opens when it should not allow acids to go to the esophagus.
Once the food reaches the stomach, the muscles of this organ mix the food together with the gastric juices. Afterwards, the small intestine receives its contents little by little, the chyme, which is the contents of the stomach.
In the small intestine, your muscles mix food with digestive juices from the pancreas, liver, and intestine and push that mixture forward to continue digestion and receive more chyme. The walls of the small intestine absorb water and broken nutrients into the bloodstream. The waste digestion pass the large intestine.
What is not digested is called waste. They may also include those old cells that make up the gastrins , secretin, and other hormones of the lining of the gastrointestinal tract. Stool is produced in the large intestine and is pushed into the rectum through contraction and relaxation (peristalsis).
At the end of the large intestine the rectum is located. Stool will be stored there until evacuation.
Importance of digestion
Our body needs nutrients that it does not produce on its own; We have to provide them through food and drink. During digestion , nutrients are chemically broken down into very small parts, so that the body can assimilate the resulting substances faster and thus produce the energy necessary to keep them standing, to grow, to replenish cells, etc.
From digestion we can basically obtain these general substances:
- Fatty acids and glycerol that are produced with the breakdown of fat.
- The sugars that serve to provide us with energy are generated with the breakdown of carbohydrates.
Examples of digestion
- Mechanical digestion: through chewing, peristalsis and swallowing, transformations in food take place, such as changes in size, texture and physical state.
- Chemical digestion. Its main elements are saliva, chyme, food bolus, enzymes, gastric juice and chyle. These help break down food chemically.