The digestive system breaks down food into smaller molecules that can be absorbed and used by the body. It consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. Food is mechanically and chemically broken down at each stage as it moves through the system. The mouth chews food, the stomach churns and adds acid, and the intestines further break down food with enzymes before nutrients are absorbed and waste is eliminated.
5. Mechanical Digestion Same volume of food Small total surface area Larger total surface area A larger surface area speeds up digestion saliva saliva saliva
12. REGION OF FOOD TUBE STRUCTURES INVOLVED BEHAVIOR MOUTH Teeth Tongue Salivary Glands Chewing (physical/mechanical digestion) Moves food Chemical digestion of starch esophagus muscles peristalsis STOMACH Stomach lining Mixing of food with gastric juice (HCl) producing chyme Protein digestion Churning of food (mechanical) SMALL INTESTINE Duodenum Ileum Liver Gall bladder Pancreas Final digestion Absorption Produces bile (digest fats/neutralize stomach acids) Stores bile Releases enzymes to help digestion LARGE INTESTINE Colon Rectum anus Removal of waste; reabsorb water and salts Storing waste excretion
14. Assessment Criteria Points Self-Assessment Teacher’s mark A. Identified the main functions of the digestive system. 3 B. Listed the different structures of the 4 major areas of the digestive system 3 C. Described the behavior of each structure 3 D. Explained how the behavior of the different structures relate and contribute to the functions of the digestive system. 3 E. Properly organized ideas in a flowchart 3 F. Poster is artistically made and neatly presented 1 Total Points 16