Human Digestive System

1. Human Digestive System From start to finish

2. Write the black • Just read the green

3. WHAT DO YOU KNOW ABOUT THE DIGESTIVE SYSTEM?

4. Follow along on pg. 93 of your workbook

5. Functions of the digestive system • Cells can’t use most food as it comes in • Breaks down food  molecules (remember matter?) = small enough to enter cells • Eliminate undigested food as feces (poop)

6. Using pg. 167 of textbook, fill in pg. 93 in workbook

7. Check your answers • The digestive tract (in order of pg. 93): • Mouth • Pharynx • Esophagus • Stomach • Small intestines • Large intestines • Rectum

8. Digestive glands (in order of pg. 93) • Salivary glands (mouth) • Liver • Gastric glands (stomach) • Pancreas • Intestinal glands • Gall bladder

9. The digestion system

10. Digestive system model

11. Homework : workbook pg. 94

12. Follow along in workbook pg. 95

13. Digestion is changing (transformation) of food into nutrients so can be used by the body

14. Mechanical transformation- physically breaking food  smaller pieces to prepare for chemical transformation (breakdown).

15. Chemical transformation- complex molecules simple molecules using digestive secretions (chemicals)

16. Nutrients= food molecules absorbed by the body (microscopic) • Absorption- passage of nutrients from digestive tract to blood to be taken to cells.

17. Processing food in the digestive system: • Ingestion & propulsion of food • Digestion of food • Absorption of nutrients • Elimination of fecal matter (poop)

18. Food moves along digestive system by: • Deglutination = swallowing -mouthpharynxesophagus

19. Peristalsis= contractions of muscles behind food to push it along -esophagus, stomach, large and small intestines

20. Before food can be used by the body it needs to undergo changes (transformations) to become nutrients. These are mechanical transformations and chemical transformations.

21. Follow along on pg. 96 of workbook

22. Chewing = cut, crush and grind food - in mouth • Churning = muscle contractions mix food with secretions from digestive glands - stomach and small intestines muscle

23. Chemical transformations= • Complex molecules  simple molecules by secretions.

24. Gland secretions location targets Salivary gland saliva Mouth Starch (complex carbohydrates) Gastric Glands Gastric juice protein stomach Intestinal Glands Intestinal juice Proteins, carbohydrates, fats Small intestine Small intestines Proteins, carbohydrates, fats Pancreas Pancreatic juice Small intestines fats Liver Bile

25. Digest.wmv

26. Lab 50- observing a mechanical and chemical change • Long lab but cool

27. Water, minerals, vitamins = directly absorbed without transformations

28. Nutrients requiring chemical transformation Amino acid Carbohydrates glucose Fats Fatty acid Glycerol

29. Bile activity (#52)

30. Discussion: textbook pg. 194-5 Q 4& 6 (skip 5)

31. Homework workbook pg. 97 & 98

32. Digestive System Facts • It takes 3 hours for food to move through the small intestine. • Food drying up in the large intestine can last 18 hours to 2 days. • In your lifetime, your digestive system may handle about 50 tons. • The average person eats about 1.4 kg of food per day.

33. Digestive System Facts • The intestines are at least 7.5 meters long in an adult. • Chewing food takes from 5-30 seconds. • Digestion from mouth to anus takes about 72 hours. • Food sloshing in the stomach can last 3-4 hours.

36. Bill Nye Digestion