assignment about Digestive System PPT.ppt
- 2. Digestion • Phases Include 1. Ingestion 2. Movement 3. Mechanical and Chemical Digestion 4. Absorption 5. Elimination
- 3. Digestion • Types – Mechanical (physical) • Chew • Tear • Grind • Mash • Mix – Chemical • Enzymatic reactions to improve digestion of – Carbohydrates – Proteins – Lipids
- 4. Digestive System Organization • Gastrointestinal (Gl) tract – Tube within a tube – Direct link/path between organs – Structures • Mouth • Pharynx • Esophagus • Stomach • Small intestine • Large Intestine • Rectum 4
- 5. Mouth • Teeth mechanically break down food into small pieces. Tongue mixes food with saliva (contains amylase, which helps break down starch). • Epiglottis is a flap-like structure at the back of the throat that closes over the trachea preventing food from entering it. It is located in the Pharynx.
- 6. Esophagus • Approximately 20 cm long. • Functions include: 1. Secrete mucus 2. Moves food from the throat to the stomach using muscle movement called peristalsis • If acid from the stomach gets in here that’s heartburn. Mouth, Pharynx and Esophagus Video
- 7. Stomach 7 • J-shaped muscular bag that stores the food you eat, breaks it down into tiny pieces. • Mixes food with Digestive Juices that contain enzymes to break down Proteins and Lipids. • Acid (HCl) in the stomach Kills Bacteria. • Food found in the stomach is called Chyme.
- 8. Small Intestine • Small intestines are roughly 7 meters long • Lining of intestine walls has finger-like projections called villi, to increase surface area. • The villi are covered in microvilli which further increases surface area for absorption. 8 Crash Course Review
- 9. Small Intestine • Nutrients from the food pass into the bloodstream through the small intestine walls. • Absorbs: – 80% ingested water – Vitamins – Minerals – Carbohydrates – Proteins – Lipids • Secretes digestive enzymes 9
- 10. Large Intestine • About 1.5 meters long • Accepts what small intestines don’t absorb • Rectum (short term storage which holds feces before it is expelled).
- 11. Large Intestine • Functions – Bacterial digestion • Ferment carbohydrates – Absorbs more water – Concentrate wastes
- 12. Accessory Organs The Glands • Not part of the path of food, but play a critical role. • Include: Liver, gall bladder, and pancreas
- 13. Liver • Directly affects digestion by producing bile – Bile helps digest fat • filters out toxins and waste including drugs and alcohol and poisons. 13
- 14. Gall Bladder • Stores bile from the liver, releases it into the small intestine. • Fatty diets can cause gallstones
- 15. Pancreas • Produces digestive enzymes to digest fats, carbohydrates and proteins • Regulates blood sugar by producing insulin Web Page Reinforcement Video
- 17. On a sheet of paper, write the name of each colored organ: • Green: • Red: • Pink: • Brown: • Purple: • Green: • Yellow:
- 18. How’d you do? • Green: Esophagus • Red: Stomach • Pink: Small Intestine • Brown: Large Intestine • Purple: Liver • Green: Gall Bladder • Yellow: Pancreas Great Job!
- 19. References and Links • Your Digestive System and How It Works – Digestive system diagram comes from this site • The Real Deal on the Digestive System • Pancreas: Introduction and Index • Your Gross and Cool Body - Digestive System • Laurentian Regional High School Data Base - you must know the Username and Password