1. Digestive Tract

2. Digestive Tract Digestion: The mechanical and chemical breaking down of food into smaller components

4. Teeth

5. Mouth

6. Uvula

7. Tongue Cancer

8. Salivary Glands

9. Parotid Mass

10. Salivary Duct

11. Digestive Tract: Mouth, Teeth, Tongue, and Glands

12. Digestive Tract: Mouth, Teeth, Tongue, and Glands Tearing Grinding Tearing and grinding /Cuspid /Bicuspid Cutting

13. Digestive Tract: Mouth, Teeth, Tongue, and Glands

14. Digestive Tract: Mouth, Teeth, Tongue, and Glands

15. Digestive Tract: Mouth, Teeth, Tongue, and Glands

16. Digestive Tract: Mouth, Teeth, Tongue, and Glands Saliva contains enzymes (i.e. amylase , which breaks down starch). In other organisms like insects, salivary glands are often used to produce proteins like silk or glues

17. Digestive Tract: Mouth, Teeth, Tongue, and Glands Our tongues have several taste buds. Taste buds are receptors that send messages to the brain

18. Digestive Tract: Mouth, Teeth, Tongue, and Glands The saliva, teeth, mouth, and tongue form a food bolus This bolus goes on into the next part of the digestive tract

19. Pharynx

20. Epiglottis

21. Digestive Tract: Pharynx and Epiglottis The epiglottis prevents food from going into your lungs through the larynx The pharynx connects the oral cavity to the next part of the digestive system (the epiglottis and esophagus)

22. Digestive Tract: Pharynx and Epiglottis

23. Esophagus

24. Digestive Tract: Esophagus Esophagus: Muscular tube through which food passes from the pharynx to the stomach

25. Digestive Tract: Esophagus Peristalsis: Radially symmetrical contraction of muscles which forms a wave down the muscular tube.

26. Digestive Tract: Esophagus Means “ empty space” The esophagus is made up of circular and longitudinal layers of muscles (performs peristalsis ). The inside is lubricated with mucous membranes

27. Digestive Tract: Esophagus

28. Stomach

29. Digestive Tract: Stomach

30. Digestive Tract: Stomach Lower esophageal sphincter: If the lower esophageal sphincter is not closed properly, stomach acid enter the esophagus and cause heartburn Also known as cardiac sphincter

32. Digestive Tract: Stomach Why doesn’t the acid burn through the stomach? The rugae lining the stomach continuously secretes mucus to protect the stomach The rugae allow the stomach to expand dramatically (up to 1 litre)

34. Stomach: Ulcer

36. Digestive Tract: Stomach

37. Stomach: Pyloric sphincter

38. Digestive Tract: Stomach Pyloric Sphincter: Strong ring of smooth muscle which connects stomach to small intestines. Enables chyme (semi-digested food from stomach) to enter the duodenum.

39. Chyme

40. Small Intestine

44. Pancreas: Also produces insulin from the Islets of Langerhans Digestive Tract: Duodenum, Pancreas, & Gall Bladder

45. Digestive Tract: Duodenum, Pancreas, & Gall Bladder Gall Bladder: Stores bile produced by the liver. Bile emulsifies fats to allow greater surface area for fat enzymes ( lipases ) to work

46. Digestive Tract: Duodenum, Pancreas, & Gall Bladder Bile is made from cholesterol and bile salts The resulting molecule is like dish detergent

47. Digestive Tract: Duodenum, Pancreas, & Gall Bladder Gallstones: Crystallization of bile components ( primarily cholesterol ). Causes: -diet -body weight -bile duct motility -gall bladder motility

48. Gallstones

49. Gallstones

50. Gallstones

51. Digestive Tract: Jejunum Jejunum: Roughly 2.5 meters long. Absorption takes place here Jejunum

52. Digestive Tract: Jejunum Jejunum: Lined with longitudinal and circular muscles to perform peristalsis . Has structures called villi .

54. Villi

55. Digestive Tract: Ileum Ileum: -2.4 meters long -absorption (has villi) -also absorbs vitamin B12 and bile salts

56. Digestive Tract: Ileum

57. Caecum

58. Digestive Tract: Caecum & Appendix Caecum: -first part of the large intestine -Attached to the appendix

59. Digestive Tract: Caecum & Appendix Caecum: -separated from the ileum by the ileocaecal valve.

60. Digestive Tract: Caecum & Appendix Appendix: -blind-ended tube -believed to shelter beneficial bacteria for digestion -can become infected ( appendicitis )

61. Appendix

64. Colon Cancer

67. Diverticulosis

70. Digestive Tract: Rectum, Anal Canal, Anus Anal sphincter: Exterior and interior sphincters pull the anus up over the exiting feces

71. Intestines