DIGESTIVE SYSTEM Digestion begins in mouth with mechanical chewing, assisted by enzymes, such as Amylase for starch break-down to glucose. Various carbohydrates begin the digestion process in the mouth due to this mechanical (chewing) process, as does initial (digestion) of proteins. Food moves through esophagus by way of PERISTALSIS (muscular contractions), as it does through the entire digestive tract. The base of esophagus is the Cardiac Sphincter, and the Pyloric Sphincter muscle prior to emptying into the Duodenum (first 12" small intestine) constricts the base of the stomach. The stomach is a "holding tank" where most all digestion takes. It has a volume of between 2-4 liters (about 2-4 qts.), a low pH, between 1.5 and 2.5. This assists in chemical of food materials, as well as activating protein enzymes, such as PEPSIN. While the protein digestion in the mouth began by chewing, it is basically completed in the stomach by digestive enzymes. A mucus lining prevents digestion stomach wall tissue. Very little absorption takes place in stomach.
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This note was uploaded on 11/08/2011 for the course BIOLOGY BSC1086L taught by Professor Leostouder during the Fall '10 term at Broward College.