Topic : Digestive System Aim : Describe the parts and functions of the digestive system.

1. Topic: Digestive System Aim: Describe the parts and functions of the digestive system. Do Now: Take out the Chemistry homework sheet. HW: Ditto – Midterm Review: Cells (both sides) Food Label Activity due Tuesday!

2. Did you know.... • Americans eat about 700 million pounds of peanut butter. • Americans eat over 2 billion pounds of chocolate a year. • In your lifetime, your digestive system may handle about 50 tons!! • What you ate for breakfast, that was not digested will come out in about 48 hours-normally. • From intake to outlet, the digestive tract is about thirty feet long.

3. Function • Breakdown of food into pieces small enough for nutrients to diffuse into cells

5. Path of Food

6. 1.Mouth (oral cavity) TEETH Incisors Canine Premolars Molars “Wisdom”tooth Tongue Salivaryglands Opening of asalivary gland duct

7. Mechanical digestion (teeth)

8. http://kidshealth.org/misc/movie/bodybasics/digestive_system.htmlhttp://kidshealth.org/misc/movie/bodybasics/digestive_system.html

9. These glands may become swollen and painful if you develop certain conditions, such as mumps

10. Chemical digestion (STARCH) • Salivary glands secrete saliva

11. Did you know.... We make 1 to 3 pints of saliva a day Your teeth started growing 3 months before you were even born. The hardest substance in your body is the enamel on your teeth. As you are sitting there listening, more than 100 million germs are swimming, feeding, reproducing, and making waste in the area behind your lips. In your mouth there are more living things than there are people in Australia and Canada combined…

13. 2. Epiglottis • Small flap of tissue • Covers windpipe when you swallow • Prevents choking

16. 3. Esophagus esophagus

18. Tube that pushes food down into stomach by PERISTALSIS • NO DIGESTION

20. Did you know.... An adult esophagus ranges from 10 to 14 inches in length, and 1 inch in diameter

21. Opening to stomach from the esophagus

22. 4.Stomach

25. Chemical digestion of proteins • Mucus lining (protection) http://www.youtube.com/watch?v=gfDrdilQsGY&feature=related

26. Did you know.... An adult’s stomach can hold approximately 1.5 liters of material. Food sloshing in the stomach can last 3-4 hours. The stomach's wall is lined with three layers of powerful muscles.

27. Topic: Digestive System Aim: Describe the parts and functions of the digestive system. Do Now: Take out the Chemistry homework sheet and cell homework sheet. HW: Ditto – Cell Transport and Respiration Food Label Activity due Tuesday!

28. 5.Small intestine http://kidshealth.org/misc/movie/bodybasics/digestive_system.html

29. Length = 4-7 meters

30. Duodenum first part of the SI

31. Where MOST chemical digestion occurs • Digestion ENDShere

33. Lined with VILLI: folds that absorb nutrients into the blood

36. 6.Large intestine

37. The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past. Surgical removal of the appendix causes no observable health problems. http://www.youtube.com/watch?v=9fN6sm5hu48 http://www.youtube.com/watch?v=1o8TpVcrTdg&feature=fvwp&NR=1

38. NO DIGESTION • Absorption of water • Forms feces (undigested food)

39. If you squeezed out all of the bacteria that lives in your intestines, you could almost fill up a coffee mug. Anyone want a sip?

40. Did you know.... Within the colon, a typical person harbors more than 400 distinct species of bacteria.

42. 7.Rectum • Last part of large intestine • Stores feces

43. 8.Anus • Where feces is egested out of the body