The Digestive Process
The Digestive Process
The human digestive tract is a group of muscles and organs that help your body make use of the food that you are consuming. By definition the digestive system is the body system composed of organs that break down complex food particles into smaller, absorbable products. The digestive tract and alimentary canal are names for the tubular organs that extend from the mouth to the anus. The whole system, including the pancreas, liver, and gallbladder, is sometimes called the gastrointestinal system according to Sizer & Whitney (2017). Mailman (2015) explains that each part of the digestive tract is adapted to reduce the size of food particles, either mechanically or enzymatically, until they are small enough to be absorbed into the body. The National Institute of Diabetes and Digestive and Kidney Diseases (2013) states that digestion begins in the mouth with chewing and ends in the small intestine, as food passes through the GI tract, it mixes with digestive juices, causing large molecules of food to break down into smaller molecules, these are some of the more mechanical aspects of digestion that will be explained later on.
Sizer & Whitney (2017) explains that the job of mechanical digestion begins in the mouth, where large, solid food pieces such as bites of meat are torn into shreds that can be swallowed without choking with chewing adding water in the form of saliva to often rough or sharp foods to prevent them from tearing the esophagus. After the food is chewed and swallowed down the esophagus the stomach uses the upper muscles to let food enter and the lower muscles mixes the food with digestive juice. In the lower half of the stomach the food is then churned and broken down and then absorbed into the body by starches, proteins, and fats. The small intestine comes into play as well, by performing a series of actions called peristalsis which is the wavelike muscular squeezing of the esophagus, stomach, and small intestine that pushes their contents along as stated by Sizer & Whitney (2017). After the food is pushed in to the smaller intestine by peristalsis it then goes into the large intestine, in which the body reabsorbs water and retains fiber to create feces to release excess waste.
When people typically thing of digestion you often-associate digestion with what transpires internally inside your stomach but, it starts well before food actually reaches your stomach. After reviewing the mechanical portion of the digestive system one must look at the chemical aspect of the digestive system. Upon eating your favorite foods the digestion begins in the mouth as an enzyme in saliva starts to rapidly break down starch and also breaking down the fat. One important factor for saliva is that it washes away food particles that would otherwise cause decay in your mouth as stated by Sizer & Whitney (2017). Now once the food reaches the stomach protein digestion begins with the cells inside the stomach releasing gastric juice, a mixture of water, enzymes, and hydrochloric acid to activate protein digesting enzymes to initiate the digestion of proteins which is the stomachs main function. After the food digests through the stomach the process in the small intestine, where the liver and gall bladder contribute bile that emulsifies fat, and the pancreas and small intestine, donates enzymes that break down food to nutrients. ( Sizer & Whitney, 2017, p.86) “The small intestine empties into the large intestine, where some bacterial digestion occurs, which produces mostly small fatty acid molecules. The debris from these bacteria adds to the bulk of the undigested material. Muscle contraction propels these feces through the large intestine until it is eliminated by defecation. Sphincters control the final evacuation.”(Mailman, 2015).
When people typically thing of digestion you often-associate digestion with what transpires internally inside your stomach but, it starts well before food actually reaches your stomach. After reviewing the mechanical portion of the digestive system one must look at the chemical aspect of the digestive system. Upon eating your favorite foods the digestion begins in the mouth as an enzyme in saliva starts to rapidly break down starch and also breaking down the fat. One important factor for saliva is that it washes away food particles that would otherwise cause decay in your mouth as stated by Sizer & Whitney (2017). Now once the food reaches the stomach protein digestion begins with the cells inside the stomach releasing gastric juice, a mixture of water, enzymes, and hydrochloric acid to activate protein digesting enzymes to initiate the digestion of proteins which is the stomachs main function. After the food digests through the stomach the process in the small intestine, where the liver and gall bladder contribute bile that emulsifies fat, and the pancreas and small intestine, donates enzymes that break down food to nutrients. ( Sizer & Whitney, 2017, p.86) “The small intestine empties into the large intestine, where some bacterial digestion occurs, which produces mostly small fatty acid molecules. The debris from these bacteria adds to the bulk of the undigested material. Muscle contraction propels these feces through the large intestine until it is eliminated by defecation. Sphincters control the final evacuation.”(Mailman, 2015).
Mailman, D. (2015). Digestive tract (comparative anatomy). Salem Press Encyclopedia Of Science,
National Institute of Diabetes and Digestive and Kidney Diseases (2013, September 01). The digestive system & How it Works. https://www.niddk.nih.gov/health-information/digestive-diseases/digestive-system-how-it-works
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