Digestion

1. Digestion

2. Digestion I. Functions of the digestive system 1. _________________ 2. _________________ 3. _________________ 4. _________________ 5. _________________

3. Digestive System Video

4. II. Digestive Structure & Function A. Organization 1. Alimentary Canal (GI tract). a. _________ b. _________ c. _________ d. _________ 2. Accessory Organs a. Located _______ or __________ the GI tract.

5. B. Digestive Processes 1. __________________ 2. __________________ 3. __________________ 4. __________________ 5. __________________ 6. __________________

6. Review • State the functions of the digestive system. • Name & describe the 6 processes of the digestive system.

7. III. Features of the Digestive System A. Peritoneum 1. _________ –serous membrane that lines the abdominal pelvic walls. 2. _________ (serosa) – lines the organs. 3. _________________ – Space within the abdominal pelvic cavity. 4. ________________ supportive ligament for liver. 5. __________________ - connective tissue that holds many abdominal organs in place. 6. ________________________- mesentery that connects the lesser curvature of the stomach to the liver and diaphragm. 7. __________________ (mesentery proper) – mesentery connecting the greater curvature of the stomach to the transverse colon.

8. 8. The greater omentum is usually __________, double ________ mesentery that extends inferiorly and loops back to the colon creating a cavity known as the ___________________. 9. Greater omentum usually fills with _______________. 10. _________________- abdominal organs that lie behind the peritoneum.

9. B. Wall Structure of the Alimentary Canal 1. ____________ – Mucus membrane that lines the lumen. 2. _____________ – Loose connective tissue (blood & lymph tissues). 3. ______________ – muscle (circular & longitudinal fiber). 4. ____________ – Visceral peritoneum, outer covering.

10. Review • What is the functions of the mesenteries, greater & lesser omentum? • What are the layers of the digestive tract?

11. IV. Digestive Organs of the Alimentary Canal. A. Mouth & Accessory Organs 1. _________________ 2. _________________ 3. ___________ – large muscular organ. _______________-attachs tongue to floor of mouth. 4. __________________

12. a. Deciduous ________ by 2 yrs. b. Permanent ________ between ,17-25 yrs. 1. _____________ – chisel – cutting 2. _____________ – cone shape – tearing 3. _____________ 4. __________ – broad & flat - grinding

13. c. Structure 1. ___________ – visible part of the tooth. * _________ – protection, hardest substance of the body. *Cells _______ shortly after tooth break through, ______________ of repair. 2. ____________ – between two regions. 3. _________ – below gums. 4. ____________ – slightly harder than bone, surrounds pulp cavity. 5. ____________-Soft connective tissue (blood & nerve).

14. Review • List the functions of the lips, cheeks, & tongue. • What are deciduous and permanent teeth? Name the different kinds of teeth? • Describe the parts of a tooth. What are dentin, enamel, & palate?

15. 6. Salivary Glands a. __________ – ______water, .____solutes 1. Liquid medium for ________ food particles. 2. ____________ for swallowing. 3. Enzymes – _____________ – destroys ____________. _________________ – ___________ chemical digestion of ___________________ b. Glands 1. _______ – Largest in front of ears. 2. _________________ – floor of mouth for mucus. 3. ____________ – under tongue, for mucus.

16. c. Digestion in Mouth 1. __________ IN THE _________. 2. ________________ – Chewing. 3. _____________ – compact mass of food & salvia. B. Pharynx & Esophagus 1. _________________ food from the mouth to the stomach ____________ further processing a. ______________ b. ______________ c. ______________ 2. Deglutition a. ___________ – bouls moves to the back of the mouth b. Pharyngeal- reflex begins with the _______ of the soft palate, then pharyngeal muscles _________to force food through the pharynx. __________ is tipped _________. c. Esophageal- swallowing by ___________ waves

17. Review • What is the function of saliva? • Name the salivary glands. • What is the job of the esophagus?

18. C. Esophagus 1. ____________ tube 2. _______ inches long 3. _________ when not propelling food 4. Behind ___________ 5. _____________________ – opening of esophagus 6. Esophageal sphincters a upper b. Lower esophageal sphincter – valve that __________________ upward movement. ________________ – weak & permits leakage of stomach juices which irritation to esophagus. D. ________________ – _________ & ________ Digestion 1. Stomach a. __________________ – 10 inches long b. _______________ – deep folds in inner lining c. _______________________– Convex d. ______________________ – Concave

19. e. Four Regions 1. ___________ – Opening that receives food. 2. ___________ – Expanded regions above cardia, temporary holding regions. 3. ___________ – Main part. 4. ___________ – Narrow inferior region f. Sphincter – ____________ within stomach 1. ___________ – Esophagus & Stomach 2. ___________ – Stomach & small intestines

20. 2. Stomach Wall a. _________ basic layers 1. __________ -gastric pits -gastric glands ________ – HCL, Intrinsic factor ________ – ___________ -> ________ ________ – Mucus -Gastric Juices _______ L/day 2. ___________ 3. ___________ Additional layers that mix & churn 4. ___________

21. 3. Function of Stomach a. ____________________ – mixing & churning b. ____________________ – Gastric juices 1. ____________ – _________ (_________ to prevent it from digestion of own cells) 2. ____________ – _________ which activates pepsinogen to pepsin. 3. ___________________ breaks down nearly ______ _________. 4. ____________ – Coats to prevent digestion of stomach. -gastric ulcers

22. c. Absorption 1. _________ 4. ___________ 2. _________ 5. ___________ 3. _________ 6. ___________ d. Propulsion – __________________ 1. ____________- small food particles & gastric juices. 2. ____________- weak contraction which mixes food with stomach secretions. 3. ____________- stronger contractions that force chyme toward and through the pyloric sphincter. e. Intrinsic Factor ___________ & ____________ – aids in Vitamin _______ ________________ by small intestines, which is important in ____________ production.

24. Review • Describe the parts of the stomach. • How are the stomach muscles different from those in the esophagus?

25. Digestion from the inside

26. f. Regulation of Stomach Function 1. Beginning of Digestion -Primary by ____________________ center of the brain & hormones – _______________ Brain (___________) ___________ _____________ - Smell, think, see, hear _____________ -Gastric Glands Gastirc Juices Continued Reflex (Stretching of stomach by food) 2. Ending of Digestion ___________________ -Presence of _______ in upper ___________ triggers nerve reflex to stimulate contraction of the pyloric valve, which prevents more acid from entering .-Secretin & Cholecystokinin (CCK) ____________________________. ________________ stomach peristalsis & stimulate pancreatic enzyme & bile into small intestines.

27. 3. Regulation a. Controlled by the ____________ _________ & ____________ 1. _______________ -Released into the bloodstream because of the _______________ in the ___________________. - ___________ the gastric secretion. -Causes __________ to release __________ ions to _______________ the ____________. 2. _______ -Release in response to _______ & _________ into the small intestines. -Cause the __________ to release pancreatic juices. -Digestion to release ________________. -____________ gastric juices & peristalsis.

29. 4. Small Intestines A. Structure 1. ____________ segment of the GI tract (_____ ft). 2. _____ inch in diameter. 3. Three segments - _____________ receives chyme from the stomach, _____ in long. -__________ – _____ft -_________________- _____________ ft – unites the small & large intestines - ________________

30. B. Wall of intestines – Same ______ layers with modification - increase SA by ______ X’s circular folds mucosa & submucosa villi _________ – lymphatic vessel microvilli

31. Small Intestines

32. C Layers 1. _____________ a. cells -______________ – have microvilli, produce digestive enzymes, absorb digested food. - _____________ – produce mucus. - _____________ – produce regulatory hormones. - ____________ (Paneth’s cell)- help protect from bacterial infection. b. glands _______________ – secretes water & mucus. ______________ – produce mucus. 2. _______________ ______________ – only in walls of duodenum for neutralizing. (_____________) – fights off infection. 3. _______________ 4. _______________

33. C. Function 1. Completes __________ digestion a. _______________________ – pancreatic duct b. ______________ – common bile duct - __________- proteins - disaccharides- disaccharides into monosaccharides. (maltose & isomaltose) 2. Absorption – _________ site of __________ absorption (duodenum & jejunum). 3. Propulsion – mix & move contents toward the large intestines. __________________ - through the intestine. __________________ – mixing in short segments a. Diarrhea – _________ b. Constipation – _________

34. Review • 1. What secretions complete the chemical digestion of food particles? • 2. What nutrients can be absorbed by the intestinal walls? • 3. How are the layers of the small intestine modified for their function? • 4. What are circular folds, villi, & microvilli in the small intestine? What are their functions?

35. 5. Large Intestines - ___________ of _________ - Process of _________ A. Structure 1. _____ ft long, ______in in diameter 2. 4 segments. a. _______- ______________ material from the ileum. Short ______ like segment below ________ valve. _________________________ – appendicitis. b. ____________- _______________ absorption site _____________ _____________ _____________ _____________

36. B. _________ – ________of fecal material C. ______________ – ____________ to the _____________. ______________ – __________- ____________. ______________- ___________ - _____________

37. D. Wall of intestine 1. Same four layers with modification. -__________ – _____ villi, has deep folds, large number of ________ secreting cells to bind contents together & for easier defecation. -____________- deep folds -____________ – __________ bands __________ form pouches called – ________. -Anal Canal – __________ to reduce ___________ during defecation.

38. 2. Function a. Mucosa _______ much of the remaining ______ & _____________ in ______. b. ____________ – feces ____% water & ___% ______________ wastes. c. _________ is a result of _______ altered by _______________. 1. _________ there than anywhere else in the body. 2. Produces _____________ 3. metabolism produces _______, ______, ________, ______________. 4. Most of gas is _________________. 3. Defecation or Elimination a. Propulsion (peristalsis of feces through the large intestines (_________ hrs) for colon. ____________ movements- _________hrs , moves contents 20 cm towards anus. b. __________ until the rectum is _______ c. Once full, nerve receptors in rectal wall stimulate defecation reflex. __________________________ reflex

39. Review • 1. What are the divisions of the large intestines? • 2. What is the function of the large intestines? • 3. How is chyme converted to feces? • 4. Describe the defecation reflex.

40. V. Accessory Organs A. Pancreas – ______ range of ________ 1. Structure a. _______ ______ _________ b. _______ – exocrine secretory cells. Pancreatic juices into the pancreatic ducts & fuses with the common bile duct. c. I____________________ – Produces __________ & ___________ 2. Function a. ______/day b. Pancreatic _________ – ____________ c. ______________– _____________ d. _____________ – _____________ e. Pancreatic ___________ – __________ f. __________________ – breaks down _______ & ______

41. Pancreas Video

42. B. Liver – _________ internal organ of the body at 1.36 Kg. 1. Structure a. _______ or sections 1. Right – _____ 2. Left – _______ b. ________ and _______– _______ sub divisions of the lobes. c. ____________ – gateway to the liver d. Hepatic ______- oxygen _______ blood to the liver e. Hepatic ______ – oxygen ______ blood from the liver to the vena cava. f. Hepatic _____________ – oxygen poor blood but high in nutrients to the liver. g. __________-smaller divisions . h. Portal _______ three structures 1. hepatic __________ 2. hepatic __________ 3. hepatic __________ i. Hepatic ___________ j. Hepatic ______________ k. __________________

44. Liver

45. Liver Lobules

46. k. (cont.)___________ – Liver cells arranged in columns around a central vein. l. _______________ – Phagocytic cells that remove bacteria from the blood that came from the digestive tract. m. _________________- Secrete bile. n. __________________________ o. __________________________ p. Common _________________ q. ______________________ opening in small intestines from the common bile duct and the pancreatic duct.

47. 2. Function a. Secretion of Bile, _________ ml/day -Emulsification of _________. -_________ of vitamin _____________________. -________________-bile pigments b. Metabolism of lipids -_______________ – package of fat for transport & storage. -_________ – transports cholesterol to liver – beneficial in repair, growth, but tends to accumulate in the body spaces when not used. -_________ – Transport cholesterol to cells-production of hormones, harmful-atheroscerosis. -VLDL’s c. Stores glycogen, vitamins A, D, B12 d. _____________ harmful substances in the blood stream – alcohol.

48. 3. Control of Bile secretion & release a. _____________– liver b. _____________ – gall bladder c. ___ % of bile is ___________ in the ________

49. Digestion, Absorption and Transport

50. Co Transport