The Digestive System

1. The Digestive System

2. 3 Functions of the Digestive System 1. Digestion -

3. 3 Functions of the Digestive System 1. Digestion – The mechanical (physical) and chemical breakdown of foods for use by the body’s cells.

4. 3 Functions of the Digestive System 2. Absorption

5. 3 Functions of the Digestive System 2. Absorption – The passage of digested food from the digestive tract into the circulatory system. Where does most absorption take place?

6. 3 Functions of the Digestive System 2. Absorption – The passage of digested food from the digestive tract into the digestive system. Where does most absorption take place? SMALL INTESTINE

7. 3 Functions of the Digestive System 3. Elimination

8. 3 Functions of the Digestive System 3. Elimination – The expulsion of undigested food or body wastes.

9. Ingestion • The taking of food into the body • Eating/Drinking

10. Structures of the Mouth • Teeth • Break the food you eat into smaller pieces • Tear, Chomp, & Grind food

11. Mastication • The process of chewing.

12. Structures of the Mouth • Tongue • Forms food into a ball to prepare for swallowing • Contains taste buds – allows you to taste food

13. Structures of the Mouth • Salivary Glands: 3 pair • Secrete Saliva • Lubricates and moistens food making it easier to swallow

14. Saliva • A watery solution containing an enzyme (amylase) that starts breaking down carbohydrates into simple sugars.

15. Ooops! Wrong Pipe • Two passageways in the back of the throat. (pharynx) • Esophagus- food pipe leads to stomach • Trachea- wind pipe leads to lungs.

16. Uvula Food does not go out the nose When swallowing. Flap of tissue that covers the nasal passage so….

17. epiglottis Food does not enter the lungs Flap of tissue that covers the trachea so….

18. Digestion Starts in the mouth

19. Esophagus • 10 inch long muscular tube connecting the mouth & stomach • Food take about 9 seconds to travel through the esophagus • A sphincter muscle separates the esophagus from the stomach

20. 1. Which arrow points to the esophagus? 3. 2. 4. 5. 6.

21. 1. Which arrow points to the esophagus? 3. 2. 1. 4. 5. 6.

22. Peristalsis • A series of involuntary muscular contractions

23. The Stomach • Hollow saclike organ enclosed in a muscular wall. • Continues the breakdown of food • Stores food– controlling the rate at which it enters the small intestine • Mixes food & gastric juices

24. Gastric Juice • Secretions from the stomach lining that contain pepsin and hydrochloric acid • Pepsin is an enzyme that breaks down protein. • Hydrochloric acid kills harmful bacteria taken in with food.

25. Gastric Juice • Did you know… • Hydrochloric acid in your stomach is strong enough to dissolve metal. • If it weren’t for it’s mucus lining, your stomach would digest itself.

26. Chyme • A creamy, fluid mixture of food and gastric juices

27. The Small Intestine • This is where the major part of digestion & absorption takes place • 20 – 23 feet long • 1 inch in diameter • 3 parts » duodenum, jejunum, ileum • Lined with millions of villi

28. 1. Which arrow points to the Small Intestine? 3. 2. 4. 5. 6.

29. 1. Which arrow points to the Small Intestine? 3. 2. 4. 4. 5. 6.

30. The Large Intestine • 5 – 6 feet long • 2½ inches in diameter • Contain harmless bacteria

31. The Large Intestine • Water is re-absorbed from the waste. and enters the bloodstream. • Waste (feces) collect in the last 4 to 6 inches of the colon known as the rectum.

32. Large Intestine (Colon) When the rectum is full nerve endings are stimulated to eliminate wastes in a process called defecation. Waste or feces are eliminated through an opening called the ANUS.

33. 1. Which arrow points to the Large Intestine? 3. 2. 4. 5. Which arrow points To the rectum? 6.

34. 1. Which arrow points to the Large Intestine? 3. 2. 5. 5 4. Which arrow points To the rectum 6. rectum 6.

35. One Long Tube The digestive or Alimentary Canal is one long tube from the mouth through the esophagus, into the stomach through the small intestine into the large intestine and out the anus.

36. Organs that aid in digestion

37. The Liver • Filters drugs, alcohol & other poisonous substances from your blood. • Stores vitamin A,D,E and K • Removes worn out red blood cells.

38. Liver The largest gland in the body Produces bile- a greenish fluid that helps “emulsify” fat. Your body’s chemical factory regulating most of the main chemicals in the body.

39. 1. Which arrow points to the Liver? 3. 2. 4. 5. 6.

40. 1. Which arrow points to the Liver? 3. 2 2. 4. 5. 6.

41. Liver Functions

42. Gallbladder • A small, pear-shaped sack 3-4 inches long • Located underneath the liver • Stores bile (a yellowish-green, bitter fluid important in the breakdown of fats)

43. 1. 3. 2. 4. 5. 6.

44. Pancreas • Produces the hormone insulin • Produces:

45. 1. 3. 2. 4. 5. 6.

46. Summary Digestive System

47. Problems of the Digestive System • Indigestion • A burning discomfort in the upper abdomen • May be caused by eating too much, eating too quickly, eating certain foods, stomach disorders or stress

48. Problems of the Digestive System • Heartburn • A burning pain in the center of the chest that may travel from the tip of the sternum to the throat • Caused by acid reflux – a backflow of stomach acid into the throat

49. Problems of the Digestive System • Gas • A certain amount of gas in the stomach or intestine is normal • Excessive amounts may be caused by certain foods and may cause discomfort

50. Problems of the Digestive System • Nausea • A feeling of distress, fullness, and weakness that usually precedes vomiting • It can be caused by motion, pathogens, medicines, drugs or other substances in the stomach