The digestive process is one of the most complex processes in the human body. There are eight stages in the digestive process from the time we ingest food into the mouth and excrete it from the anus. The eight stages include the following in order of process: mouth, esophagus, stomach, small intestine, jejunum/ileum, colon, rectum, anus. The salivary glands in the mouth, along with mastication, begin the digestion process. The salivary glands secrete enzymes like salivary amylase. Peristalsis begins in the esophagus which is an involuntary reflex that helps move food toward the stomach. Mucus is secreted at this stage. Food is stored in the stomach for up to a period of four hours and involves mechanical and chemical digestion like the mouth. Physical contact secretes pepsin and chemical digestion is achieved through the secretion of gastrin. Once the food is into the duodenum of the small intestine chemical digestion continues to occur. The pancreas secretes enzymes which break down polysaccharides and polypeptides and the intestine releases peptidases, sucrase, multase, lactase and other enzymes which break down disaccharides into monosaccharides. Lipase breaks down fats into glycerol and fatty acids. The gall bladder secretes bile once the digestive process reaches the jejunum/ileum. The food then moves to the colon where it is absorbed into the blood stream over a twelve hour period, during which time mucus is secreted and haustral churning and mass peristalsis occur (The Human 2). Defecation of unused waste products occurs through the rectum and is excreted through the anus.
The liver is not only the largest internal organ weighing as much as four pounds, but it is also one of the most useful organs in the body. One of its primary functions is to filter blood as well as carry blood from the pancreas and spleen, “The liver cells help the blood to assimilate food substances
...