1. Gastroenterology
Chapter 3 1

2. Anatomy of the GI System:
-Upper gastrointestinal system includes:
Oral Cavity & Pharynx
Esophagus
Stomach
-Lower gastrointestinal system includes:
Small Intestines
large Intestines 2

3. Physiology of the GI System:
Upper gastrointestinal system: 1. Begins the digestion of nutrients. Lower gastrointestinal system: 2. Finish the digestion of nutrients 3. Nutrient absorption 4. Prepare non-digestible food for waste removal

4. Anatomy Specifics: Oral Cavity Physical (Mechanical) Digestion:
-Mouth: Contains the teeth; tongue;
hard palate; and soft palate, & uvula.
-The teeth tear, chew, and grind the food during the process of mastication.
-The tongue moves food toward the teeth and mixes food with saliva.
Chemical Digestion:
-Saliva (contains enzymes) secreted by the three salivary glands:
parotid glands,
sublingual glands
submandibular glands
-The main enzyme (salivary amylase) chemically begins the digestion of carbohydrates. 4

5. Pharynx:
-Swallowing or deglutition moves food into the throat or pharynx.
-When food is swallowed, the epiglottis closes the entrance to the larynx, so that food doesn’t pass into the trachea. 5

6. Figure 3-3 Salivary glands6

7. Esophagus:
-A flexible, muscular tube that connects the pharynx to the stomach.
-food is able to pass through the esophagus by muscular contractions called peristalsis. 7

8. Stomach: -Divided into four areas: 1. cardia 2. fundus 3. body
4. pylorus
-Function: digest proteins.
-The gastric mucosa (interior lining) is arranged in thick, deep folds known as rugae which expand as the stomach fills with food.
-Sphincter Muscles:
lower esophageal and pyloric 8

9. The wording in Fig. 3-4 needs to be revised. See text page 3-126.
Figure Stomach 9

10. Small Intestine:
-The small intestine is a long, hollow tube that receives chyme from the stomach.
-around feet long
-It is divided into three regions:
1. duodenum
2. jejunum
3. ileum
-lined with villi to increase surface area for nutrient absorption; villi secrete lactase for digestion of carbs.
Functions: finish nutrient digestion; nutrient absorption. 10

11. Figure 3-5 Small and large intestines11

12. Large Intestine:
-A larger diameter hollow tube that receives undigested material and water from the small intestine.
-about 6-7 feet long
-Regions:
1. cecum
2. appendix
3. colon*
4. rectum
5. anus
-Four quadrants of the colon: ascending, transverse, descending , and sigmoid.
Functions: prepare undigested food for removal from the body; reabsorb as much water as possible; bacteria synthesize vitamin K. 12

13. Accessory Organs: part of the digestive system, but food does not travel to these organs.
Liver:
-The liver is the largest solid organ in the body, located in the upper right abdominal cavity.
-Function: produces bile; stores glycogen; acts as a filter for your blood; regulates glucose and amino acids; makes plasma proteins & blood clotting factors.
Gallbladder:
-Is found posterior to the liver; sits underneath it.
-Function: concentrates and stores bile from the liver; sends bile to the small intestine through the common bile duct. 13

14. Figure 3-6 Biliary tree 14

15. Pancreas: -Is found posterior to the stomach.
-Function: secrete digestive enzymes into the pancreatic duct which leads to the duodenum; also is an organ of the endocrine system. 15

16. Physiology of Digestion
There are two parts to digestion:
1. Mechanical
2. Chemical (enzymes)
-Mechanical Digestion: mastication, deglutition, and peristalsis to break down foods. 16

17. Chemical Digestion - Enzyme Action:
Oral Cavity: Salivary Amylase in saliva begins the digestion of carbohydrates.
Stomach: digestion of proteins.
1. Gastrin- hormone causes the release of HCl &
Pepsinogen.
2. Hydrochloric Acid (HCl) mixes with Pepsinogen to make Pepsin. 17

18. Small Intestine: all chemical digestion is completed.
1. Cholecystokinin (hormone) stimulates the gallbladder to release bile which is sent to the small intestines for lipid (fat) digestion.
2. Pancreas secretes enzymes and sends them to the duodenum:
Amylase- carbs
Lipase- lipids
Protease- proteins
Nuclease- nucleic acids 18

19. Abdomen and Abdominopelvic Cavity Structures:
-The walls of the abdominopelvic cavity are lined by peritoneum, a membrane that secretes peritoneal fluid.
-Omentum is part of the peritoneum which supports the stomach and covers the small intestine.
-The peritoneal fluid fills spaces between the organ; allows them to slide past each other.
-The blood supply to the stomach, small intestine, liver, gallbladder, and pancreas comes from the celiac trunk of the aorta. 19

20. Alimentary Canal & Accessory Structures End of Test #1 Material.
Figure Gastrointestinal system.
(Robert W. Ginn/PhotoEdit Inc.)
End of Test #1 Material. 20

21. Ch. 3 Gastroenterology: Diseases and Conditions
Eating
-Anorexia
-Dysphagia
-Polyphagia
Mouth and Lips
-Cheilitis
-Sialolithiasis
-Stomatitis
-Glossitis 21

22. (Centers for Disease Control and Prevention [CDC])
Figure Glossitis
(Centers for Disease Control and Prevention [CDC]) 22

23. Esophagus and Stomach -Dyspepsia -Esophageal varices -Gastritis
-Gastroenteritis
-Gastroesophageal reflux disease (GERD)
-Heartburn
-Hematemesis
-Nausea and vomiting (N&V)
-Peptic ulcer disease (PUD)
-Stomach cancer 23

24. (David M. Martin, M.D./Photo Researchers, Inc.)
Figure Gastric ulcer
(David M. Martin, M.D./Photo Researchers, Inc.) 24

25. Duodenum, Jejunum, Ileum
-Ileus
-Intussusception
-Volvulus 25

26. Cecum and Colon -Appendicitis -Colic -Colon cancer -Diverticulum
-Dysentery
-Gluten enteropathy
-Inflammatory bowel disease (IBD)
-Irritable bowel syndrome (IBS)
-Polyp 26

27. (David M. Martin, M.D./Photo Researchers, Inc.)
Figure Diverticula
(David M. Martin, M.D./Photo Researchers, Inc.) 27

28. Figure 3-13 Diverticulitis and polyposis28

29. Figure 3-14 Crohn’s disease29

30. Figure 3-15 Colonic polyps (Staats/Custom Medical Stock Photo, Inc.)30

31. Rectum and Anus
-Hemorrhoids
-Proctitis
-Rectocele 31

32. Defecation and Feces -Constipation -Diarrhea -Flatulence -Hematochezia
-Incontinence
-Steatorrhea 32

33. Abdominal Wall and Abdominal Cavity
-Adhesions
-Hernia
-Peritonitis 33

34. (Custom Medical Stock Photo, Inc.)
Figure Peritonitis
(Custom Medical Stock Photo, Inc.) 34

35. Liver -Ascites -Cirrhosis -Hepatitis -Hepatomegaly -Jaundice
-Liver Cancer 35

36. Hepatitis is the most common chronic liver disease.
-Hepatitis A
-Hepatitis B
-Hepatitis C
-Hepatitis D
-Hepatitis E 36

37. (Dr. M.A. Ansary/Photo Researchers, Inc.)
Figure Jaundice
(Dr. M.A. Ansary/Photo Researchers, Inc.) 37

38. (Gca/Photo Researchers, Inc.)
Figure Liver cancer
(Gca/Photo Researchers, Inc.) 38

39. Gallbladder and Bile Ducts
-Cholangitis
-Cholecystitis
-Cholelithiasis 39

40. Pancreas
-Pancreatic cancer
-Pancreatitis 40

41. Laboratory and Diagnostic Procedures:
Blood Tests
-Albumin
-Alkaline phosphatase (ALP)
-ALT and AST
-Bilirubin
-GGT
-Liver function tests (LFTs) 41

42. Gastric and Feces Specimen Tests
-CLO test
-Culture and sensitivity (C&S)
-Fecal occult blood test
-Gastric analysis
-Ova and parasites (O&P)
Radiologic Procedures
-Barium enema
-Cholangiography
-Computerized axial tomography
-Flat plate of the abdomen
-Gallbladder ultrasound
-Magnetic resonance imaging (MRI) scan
-Oral cholecystography (OCG)
-Upper gastrointestinal series (UGI) 42

43. Figure 3-25 Endoscopic retrograde cholangiopancreatography43

44. Medical and Surgical Procedures:
Medical Procedures
-Insertion of nasogastric tube 44

45. Surgical Procedures -Abdominocentesis -Appendectomy -Biopsy
-Bowel resection and anastomosis
-Cholecystectomy
-Choledocholithotomy
-Colostomy 45

46. Figure 3-28 Colostomy and stoma (Pearson Education/PH College)46

47. Surgical Procedures -Endoscopy -Exploratory laparotomy -Gastrectomy
-Gastroplasty
-Gastrostomy
-Hemorrhoidectomy
-Herniorrhaphy
-Jejunostomy
-Liver transplantation
-Polypectomy 47

48. Figure PEG tube 48

49. Endoscopic Procedures
-Esophagoscopy
-Gastroscopy
-Esophagogastroduodenoscopy (EGD)
-Sigmoidoscopy
-Colonoscopy 49

50. Abbreviations