First, a video to improve listening. It is for children but the pronunciation is very clear and I think you can understand it without problems.
absorption: The process in which nutrients pass into the blood stream, where they can circulate throughout the body; occurs mainly in the small intestine.
amylase : This enzyme helps break down complex starch molecules into simpler sugar molecules.
cecum: The first part of the large intestine, where waste enters from the small intestine.
celiac disease: An immune reaction to a food protein called gluten, which is found in grains.
chemical digestion: Digestion in which large food molecules are broken down into small nutrient molecules. It takes place mainly in the small intestine.
colon: The second part of the large intestine, where excess water is absorbed. After the excess water is absorbed, the remaining solid waste is called feces.
constipation: Having three or less bowel movements each week.
digestion: Process of breaking down food into nutrients.
digestive system: Body system that breaks down food, absorbs nutrients, and gets rid of solid food waste.
duodenum: The first part of the small intestine; site where most chemical digestion occurs.
enzyme: A substance, usually a protein, that speeds up chemical reactions in the body.
esophagus: The narrow tube that carries food from the pharynx to the stomach.
food intolerance: Occurs when the digestive system is unable to break down a certain type of food.
gall bladder: A small, pear-shaped structure below the liver; stores substances from the liver until they are needed by the small intestine.
gastritis: Inflammation of the lining of the stomach.
gastrointestinal (GI) tract: Organ of the digestive system; a long tube that connects the mouth with the anus.
ileum: The third part of the small intestine; covered with villi; the few remaining nutrients are absorbed in the ileum.
jejunum: The second part of the small intestine; where most nutrients are absorbed into the blood; lined with tiny “fingers” called villi.
large intestine: A relatively wide tube that connects the small intestine with the anus where excess water is absorbed from food waste. It consists of three parts: the cecum, colon, and rectum.
mechanical digestion: Digestion in which large chunks of food are broken down into small pieces. It takes place mainly in the mouth and stomach.
peristalsis: Involuntary muscle contractions which push food through the digestive system.
pharynx: Connects the mouth to the rest of the digestive tract; also connects the mouth and nose to the rest of the respiratory system.
rectum: The third part of the large intestine; where feces accumulates. As the rectum fills, the feces become compacted. The feces are stored in the rectum until they are eliminated from the body.
small intestine: The narrow tube between the stomach and large intestine where most chemical digestion and absorption of nutrients take place.
stomach: A saclike organ located between the end of the esophagus and the beginning of the small intestine. In the stomach, food is further digested both mechanically and chemically.
stomach ulcer: A sore in the lining of the stomach.
villi : Contain microscopic blood vessels; nutrients are absorbed into the blood through these tiny vessels; located on the jejunum and the ileum.