Term | Definition |
Digestion | The process of breaking down food taken by an organism into smaller elements that the organism can use to live, grow and repair itself. |
Mechanical Digestion | The initial stage of physically breaking down food into smaller pieces. Occurs in the mouth. Teeth chew the food and the tongue manipulates it. |
Chemical Digestion | The separation of food into its molecular components by chemical means. Begins in the mouth with the digestion enzymes in saliva. Continues in the stomach. Completed in the small intestine. |
Tongue | Made of skeletal muscles. Covered in papillae. |
Papillae | Bumpy structures that house taste buds. |
Uvula | Hangs from the middle of the roof of the mouth (soft palate) that prevents food from entering the pharynx when we swallow. |
Salivary Glands | They secrete saliva which mixes with food. |
Esophagus | Lined with circular and longitudinal muscles. Covered in a lubricant called mucin. Circular ring at the lower end controls the flow of food into (or out of) the stomach. |
Stomach | Food enters from the esophagus. Muscular, j-shaped, sac-like organ. Interior lining is covered with millions of gastric glands. Has 3 muscular layers. Muscular layers help break the food down and the gastric juices mix to form chyme. |
Pyloric Sphincter | A circular muscle layer between the stomach and the small intestine. Contracts and relaxes to control the flow of food leaving the stomach. |
Duodenum | U-shaped. Shortest and widest section. Has many folds that contain small, visible, finger-like projections called villi. |
Villi | Small, finger-like projections. Functions to increase the absorptive surface of the intestine. |
Jejunum | Contains more folds and intestinal glands than the duodenum. Breaks down remaining proteins and carbohydrates for absorption. |
Ileum | ... |
Caecum | The blind end of the large intestine. The appendix is attached to the caecum but it plays no role digestion. Plays some roles in fighting infection. |
Colon | The main part of the large intestine. The undigested food passes up, along and down the ________. |
Feces | The mass of undigestible material that remains at the end of the colon. |
Peristalsis | The term given to the movement of food through the digestive tract. A series of wave-like muscular contractions and relaxations. |
Hydrolysis | Water molecules are inserted between the bonds in macromolecules which breaks them down into smaller particles. Sped up by enzymes. |
Liver | Produces bile salts from cholesterol. Used to break up fat. Also recycles, stores and detoxifies. |
Pancreas | Source of several enzymes. Helps to change pH of chyme before it enters the duodenum. |
Gall Bladder | Stores bile produced in the liver for use later on. |