1. The Digestive System

2. Your digestive system What is Digestion? ◦ Put it into words… The mechanical and chemical breaking down of food into smaller parts so they can be absorbed into the body.

3. Your digestive system The digestive system is a series of organs and glands that break down food into it’s simplest forms for energy

4. The GI Tract The Gastrointestinal Tract ◦ Is the muscular tube that extends from the mouth to the esophagus, stomach, small intestines, large intestines, to the anus ◦

5. The Mouth Mastication (chewing) occurs Liquids added to food by the salivary glands ◦ Enzyme amylase breaks down starch Epiglottitis closes off the pathway to the lungs

6. The Esophagus Upper Esophageal Sphincter Peristalsis takes over Lower Esophageal Sphincter (entrance to the stomach)

8. Peristalsis Due to Smooth muscle

9. The Stomach Strongest muscle of the GI Tract Adds liquids, enzymes and grinds food into a semi-liquid mass called chyme Food exits through pyloric sphincter

10. The Stomach Degrades proteins using Hydrochloric Acid and Pepsin Has a protective lining which protects the body from gastric juices

11. The pH Scale

12. The Liver Creates Bile which is key to emulsifying fat ◦ Bile stored in the gallbladder Stores glycogen (storage form of glucose) ◦ Has a role in regulating blood sugar Stores most minerals and vitamins Receives all nutrients that are taken in through digestion and packages them for other organs and cells

14. The Small Intestine Made up of the Duodenum, Jejunum and the Ileum Bile reaches the chyme from the gall bladder and pancreas Majority of nutrient absorption occurs here

15. The small intestine Covered with villi to increase surface area which allows maximum absorption to occur

16. Pancreas Part of your Endocrine system Secretes enzymes which help further break down energy nutrients Releases bicarbonate which neutralizes the acidic chyme arriving from the stomach

18. Large Intestine Anything that makes it through to the small intestines Water and other fluids are absorbed as well as some nutrients Some fiber is broken down and absorbed by bacteria living here, the rest leaves the body

19. Common Digestive Problems Choking Acid Reflux Ulcers Diarrhea Vomiting Irritable Bowel Syndrome

20. Acid reflux a.k.a. Heartburn The lower esophgeal sphincter allows stomach acids into the esophagus Causes ◦ Eating/drinking too much ◦ Tight clothing ◦ Being overweight ◦ Change in body position

21. Ulcers Weakening in the lining of the stomach or intestines Leads to internal bleeding, very painful Possibly stomach cancer Causes ◦ Bacterial infection ◦ Anti-inflammatory drugs ◦ Excessive gastric acid secretion

22. Other factors affect digestion Sleep ◦ Repair and maintenance Physical Activity ◦ Improves muscle tone and function Mental State ◦ Affects the nerves and hormones during healthy digestion Variety of foods in one’s diet

23. A Summary of Digestion http://www.youtube.com/watch?v=A7jKCfx-0Mo