1. Chapter 17 – Part 4 Watch an overview of the intestines and abdominal cavity. This video is graphic as it uses a cadaver. https://www.youtube.com/watch?v=EJt4YDPLpzE&feature=related Intestines

2. a  "curtain-like" membrane that covers the intestines, stores fat and lays like a drape Coverings: 1. Greater Omentum

3. Stores fat for quick use by liver

4. suspends portions of the small intestine from the posterior abdominal wall 2. Mesentery

5. Small Intestine – 3 parts start at the pyloric sphincter

6. first part of the small intestine. • Food, still mixed with gastric juice is squirted into it from the stomach. • The food is now a semi liquid, highly acidic mush. • It needs to be neutralized and digestion needs to be continued… The Duodenum

7. Small, soluble food molecules are absorbed through the wall of the small intestine • To absorb food molecules efficiently the small intestine has three main adaptations…….

8. The small intestine is very long -6m long • The inner surface on the intestine is folded • Each cell is covered with microvilli • increasing the surface area in contact with digested food will increase absorption (up to 60 times more absorption) 1. Large Surface Area

9. Wall of small intestine

10. ‘finger-like folds in the surface of the small intestine’ (Singular – villus)

11. Intestinal villi - increase surface area to absorb nutrients, connect to vessels

13. Each villus has an extremely thin wall -only one cell thick -rapid absorption • electrolytes and water • through diffusion, osmosis, and active transport • absorbed into blood 2. Thin Wall

14. Each villus is supplied with blood vessels to receive the absorbed foods -glucose/amino acids/vitamins/minerals are absorbed into blood capillaries -products of fat digestion absorbed into lacteal 3. Good Blood Supply

15. Homework – do this animation. Make sure you digest a number of different types of foods. Note how they are digested differently. http://kitses.com/animation/swfs/digestion.swf

16. peptidase – breaks down peptides into amino acids • sucrase, maltase, lactase – break down disaccharides into monosaccharides • lipase – breaks down fats into fatty acids and glycerol • enterokinase – converts trypsinogen to trypsin • somatostatin – hormone that inhibits acid secretion by stomach • cholecystokinin (cck) – hormone that inhibits gastric glands, stimulates pancreas to release enzymes in pancreatic juice, stimulates gallbladder to release bile • secretin – stimulates pancreas to release bicarbonate ions in pancreatic juice Secretions of Small Intestine

17. Enzyme Summary

18. mixing movements • peristalsis – pushing movements • segmentation – ringlike contractions • overdistended wall triggers peristaltic rush resulting in diarrhea Movements of the small intestine

19. Large Intestine

20. Cecum Appendix Colon (4 parts)    Cecum    Ascending    TransverseDescendingSigmoid Rectum Anus

21. Secretes mucus,  reabsorbs water and electrolytes, contains bacteria to aid in digestion  (intestinal flora) Mass Movements (defecation) - removes undigested food The main job is  WATER REABSORPTION... Function of Large Intestine

22. Simple columnar epithelium Large Intestinal Wall

23. Any indigestible food (e.g. fiber) passes into the large intestine (colon). • Water is absorbed back into the body. • Where has this water come from? • The food becomes a solid waste called feces. • Feces are stored in the rectum and removed through the anus. This removal is called EGESTION. Egestion

24. slower and less frequent than those of small intestine • mixing movements • peristalsis • mass movements usually follow meals Movements

25. Everybody Poops

26. water • electrolytes • mucus • bacteria • bile pigments altered by bacteria provide color • smell produced by bacterial compounds Feces

27. How to Make Fake Poop...

28. LABEL THIS!

30. Practice makes perfect. Click to access all the answers. 1.  esophagus 2.  liver 3.  stomach 4. pyloric sphincter 5.  duodenum 6.  pancreas 7.  jejunum 8.  ileum 9.  cecum 10. appendix 11.  ascending colon 12.  descending colon 13.  sigmoid colong 14.  anus

31. IBS  - Irritable Bowel Syndrome – normal structure of bowel

32. Crohn’sDisease - autoimmune

33. Appendicitis

34. Hernia intestines poke through abdominal muscles

36. Celiac disease foods containing gluten (protein), immune system responds by damaging or destroying villiWithout healthy villi, a person becomes malnourished, no matter how much food one eats.

37. Colon Cancer Colonoscopy is a screening technique to detect cancer.  See Katie Couric's Colonoscopy