Digestive system
The digestive system is in charge of absorbing and distributing the nutrients that enter our body through food.
Parts of the digestive system
This apparatus is mainly composed of the digestive or intestinal tract, liver, pancreas and gallbladder.
The intestinal tract is a set of hollow organs that are connected through a tube that extends from the mouth to the anus. These organs or cavities are the mouth, esophagus, stomach, small intestine, large intestine, and anus.
For its part, the small intestine has three areas: the duodenum, jejunum and ileum , in that order. The large intestine has the appendix, the cecum, the colon, and the rectum. The appendix (which is like a bag) is attached to the cecum, that is, it is at the beginning of this intestine.
Another of the protagonists of the digestive process is the intestinal flora. It is a series of microorganisms that help digest food.
The nervous and circulatory systems are also part of digestion . Nerves and hormones provide control of the digestive process.
How does the digestive system work?
What digestion does specifically is to chemically break down food and liquids into smaller parts, and the whole apparatus is in charge of transporting it so that all this process occurs, in addition to discarding what will not be of benefit to the body.
When food has been chemically broken down into very small parts, the body absorbs and transports the nutrients to where they are needed, that is, to certain organs. The large intestine assimilates water , and the waste products of digestion become feces.
The peristalsis is the process that transports food into the intestinal tract. The large, hollow organs of the digestive tract have a muscle that makes their walls move. This movement pushes food and liquids through the tract and mixes them. Each muscle in the walls has the function of pushing and relaxing to allow the movement of food.
Example of the process in the digestive system
Food enters through the mouth and begins to moisten with saliva when chewing. Then, swallowing begins its journey through the gastrointestinal tract into the esophagus. In this the tongue intervenes, which pushes the food towards the throat. Tissue called the epiglottis expands over the windpipe to prevent food from taking a path other than the esophagus and choking.
The brain then signals the muscles of the esophagus to begin peristalsis. When the bolus reaches the end of the esophagus, the lower esophageal sphincter relaxes allowing food to enter the stomach. The sphincter then closes to prevent what we know as reflux, meaning that food and gastric juices try to go into the esophagus.
The stomach mixes food and liquids together with digestive juices so that everything becomes the so-called chyme. The stomach slowly empties the chyme into the small intestine.
The small intestine mixes the chyme with the digestive juices of the pancreas, liver and intestine, and then pushes the mixture forward to continue the digestion process. As it does so, the walls of this intestine absorb water and digested nutrients to add to the bloodstream.
It is in the large intestine where the waste from the digestive process is processed. Also included are the remnants of the lining of the gastrointestinal tract. The large intestine also absorbs water and transforms liquid waste into stool. Peristalsis ends when you move stool back into the rectum.
The final part of the large intestine, the rectum, stores the stool until the moment of defecation, at that moment it pushes it out of the anus.