How The Digestive System Works
The organs and other body parts that constitute the digestive system have the common goal of turning what we eat and drink into nutrients that the body can use in one of two ways – either to grow cells that are needed for the purpose of bodily functions, or alternatively to use as energy to fuel those bodily functions. When functioning properly, the digestive system either breaks down the molecules of food and drink into smaller molecules, or it carries it to another part of the digestive system. Once the molecules are small enough for the body to be used to build cells or fuel the body, the digestive system (and the parts that aid the digestive system) then carry it to the cells of the body that use what the digestive system has been digesting.
There are six steps involved in accomplishing the task that the digestive system does. All of these six steps require movement through the system and a wave-like movement called peristalsis accomplishes the movement. Muscles that propel the food and liquid along the digestive tract accomplish peristalsis. Here are the six steps that are taken during the whole process of digesting what we eat and drink:
The process begins when the body smells or tastes food and drink and salivates because of hunger or thirst as part of getting ready to eat or drink. We put the food and drink into our mouth and the first movement (swallowing) occurs. This first movement is a voluntary movement. It is voluntary because we decide to swallow, it is a conscious act on our part to do the swallowing. Once this first act of movement (swallowing) is accomplished all the other movements along the digestive tract are not involuntary. Involuntary means that the body automatically does it without our having to make the decision for the movement to happen. Our nerves control this involuntary movement action.
The second step happens in the esophagus, which is what connects the throat and the stomach. The stomach is the first organ in the involuntary process that is under the control of our nerves. The esophagus moves what we eat and drink from the back of our throat to the entrance of our stomach.
The third step involves the ring like valve that closes the passage between the two organs (esophagus and stomach). When the food gets near to the ring, the muscles around the ring relax and allow food to pass from the esophagus into the stomach.
This is when the food enters the stomach, and completes the three tasks of the stomach. The three tasks that the stomach has to do with the food are to store it, mix it, and then empty it.
At the top of the stomach is the large muscle that relaxes in order to accept the large volumes of food and liquid that we take in each day. This is also where the stomach stores the food and liquid right after it accepts the material.
At this point the lower part of the stomach gets into the action, by mixing the food, liquid, and digestive juices that are produced by the stomach. This mixing action is accomplished by muscle action.
The last task of the stomach is to empty the contents of the stomach into the small intestine.
This stage is where the food is digested into smaller molecules while it is in the small intestine . It dissolves the molecules of food by the juices of the pancreas, liver, and intestine, and then mixes the contents of the intestine and pushes them forward to allow for further digestion.
The final step in the digestion process is where the nutrients from all of the digested material need to be absorbed by the walls of the intestine. The parts of the material that are not to be used as nutrients for the growth of cells or energy for the body are called “wastes”. The waste products are made up of not only the unused parts of what has been digested, but also of food parts that are known as “fiber”, older cells that have been shed by the mucosa. All of these waste products are now moved into the colon. Once in the colon the waste products remain for approximately one to two days until muscles move them along to be expelled as a bowel movement out your anus.
The end result of any of the tasks of the digestive system not functioning properly is a digestive system disorder. This could either be because of a congenital issue or because of some kind of illness that has affected the digestive process.