Human Digestion Summary

Human Digestion Summary
September 12, 2013
Professor Jose Alvin Fuentes

    The digestive system provides two main functions, absorption and digestion. The main part of the digestive system is the gastrointestinal tract also referred to as the GI tract. This runs all the way from the mouth to the anus, about thirty feet long. The GI tract is made up of the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus. The transit time is the amount of time it takes for food to pass through the length of the gastrointestinal tract. Transit time normally takes anywhere from twenty-four hours to seventy-two hours. The time it takes is affected by the composition of the diet, physical activity, emotions, medications and illness.
As a person enters food into their mouth, their teeth chew up the food which then moves the food into the pharynx where it is swallowed. The food, or later known as bolus, moves from the pharynx and into the esophagus. The esophagus is connected to the stomach where the bolus is mixed with acid to be broken down and become a semi-liquid mass. The process in the stomach usually lasts between two to six hours, with the help of nearby organs such as the liver, gallbladder, and pancreas. These organs secrete enzymes and bile that speed up the process. The semi-liquid mass, now labeled as chime, enters the small intestines where the majority of the digestion process continues as well as the absorption of nutrients. It is important for the small intestine to do this because absorbing the nutrients from the foods eaten is important to have as a healthy functioning system. The left over material or material not absorbed in the small intestines will then enter into the large intestines. The colon which is part of the large intestines will do this job. This will be the last part of the absorption process because what material that is not absorbed in the colon, will become. feces and it is extracted from the body. The feces...