Digestive System You are what you eat Oh

Digestive System You are what you eat Oh my!!!!

A. Overview of structure 1. Esophagus 2. ? ? ? 3. Stomach 4. Liver 5. Pyloric valve 6. Pancreas 7. Duodenum 8. Jejunum 9. Ileum 10. Ileocecal valveappendix 11. colon

B. Mouth 1. 2. 3. 4. 5. 6. 7. 8. Different types of teeth Functions of tongue Uvula Salivary glands Salivary amylase Food bolus Mechanical digestion Deglutition http: //www. youtube. co m/watch? v=wq. MCzu. Ii. P a. M

C. Esophagus 1. 10” long 2. Stratified squamous epithelium 3. Hiatal hernia 4. GERD 5. Peristalsis of bolus 6. http: //www. youtube. com/watch? v=Qn_Q 0 q. KXzg

D. Stomach 1. 2. 3. 4. 5. 6. 7. 8. 9. Cardiac region Fundus Body Pyloric region Pyloric sphincter Rugae-full can hold 4 liters Storage tank Mechanical breakdown http: //www. youtube. com /watch? v=hp. S 5 k. Mn_B 0 I& feature=related

9. Gastric pits a. Produce gastric juice b. Intrinsic factor-needed for absorption of vit B c. Chief cells-pepsinogen d. Parietal cells-HCl e. Mucous neck cells f. Enteroendocrine cells-D and G cells produce hormones g. rennin

10. Stomach physiology a. b. c. d. e. f. Pepsinogen to pepsin Pepsin proteolytic Rennin No other chemical digestion Very little absorption Aspirin and alcohol

11. Gastric motility a. b. c. d. e. f. Peristalsis begins upper half Increases in force 3 ml or less squirts through Rest is refluxed back into stomach http: //www. youtube. com/watch? v=hp. S 5 k. Mn_B 0 I http: //www. youtube. com/watch? v=o 18 Uyc. WRsa. A&feature =related

E. Small intestine 1. 7 -13 feet 2. Suspended by mesentery 3. Duodenum “twelve finger widths”-5% 4. Jejunum “empty”-40% 5. Ileum “twisted intestine”-60% 6. Ileocecal valve 7. Major digestive structure

8. Structures adapted to increase surface area a. b. c. d. Plicae circularis Microvilli Villi Lacteallymphatic capillary e. Modifications decrease in significance toward ileum f. Peyer’s patches increase in number

9. Duodenum a. Shortest segmentinteresting features b. Pancreas opens here c. Bile enters from liver d. Brunner’s glands in tunica submucosa-alkaline mucous e. Crypts of Lieberkuhnintestinal juice relatively enzyme poor but release lysozyme-antibacterial enzyme

10. Movements in small intestine a. b. c. d. e. f. g. Modified peristalsis Peristalsis starts in duodenum Starts strong and dies down Next peristaltic wave starts further down Moves food a little further on Second type of muscular activity Segmentation http: //www. youtube. com/watch? v=Gd. Nt. Rom -Pvs h. Kind of like making meatloaf i. Random contractions superimposed upon peristaltic waves

11. Food breakdown via action of pancreas a. Carbo and protein digestion already begun b. No fats digested c. 3 -6 hours d. Endocrine function e. Pancreatic juices -huge amount of digestive enzymes -pancreatic amylase -trypsin, chymotrypsin digest proteins -lipases -rich supply of bicarbonate

12. Liver-huge number of functions a. Most important digestive function production of bile b. Fat emulsifier c. Stored in gall bladder d. Large droplets scattered into small e. Increases surface area for digestion f. Also improves fat and cholesterol absorption g. Excretion of bilirubin h. 500 -1000 ml per day

13. Gall bladder a. b. c. d. About size of kiwi fruit Stores bile Concentrates bile Gall stones

F. Large intestine-a. k. a. colon 1. 5 feet but larger in diameter 2. Extends from 3. Parts 4. Appendix 5. Longitudinal muscle not continuous-three bands 6. haustra

7. Functions of large intestine a. Few nutrients-remains for 12 -24 hours b. No digestive enzymes c. Resident bacteria -many different species -sometimes described as the forgotten organ -evolved in a mutualistic relationship -metabolize remaining nutrients -make vitamin K and B complex -keep out harmful species d. Dry residual material e. Lubricate material for defecation

8. Propulsion of Residue and defecation a. Haustral contractions b. Mass movements c. Sphincter muscles

9. Imbalances a. b. c. d. Diverticulosis Diverticulitis Diarrhea Constipation