Presentation on theme: "Chapter 29 Disorders of Gastrointestinal Function"— Presentation transcript:
1 Chapter 29 Disorders of Gastrointestinal Function Essentials of PathophysiologyChapter 29 Disorders of Gastrointestinal Function
2 Pre lecture Quiz true/false Two of the major causes of gastric irritation and ulcer formation are aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) and infection with Helicobacter pylori.A peptic ulcer affects only a single layer of the stomach or duodenum.Clostridium difficile and Escherichia coli are two types of viral infections that affect the gastrointestinal system.Small-volume diarrhea is usually painless and watery and without blood or pus in the stool. Appendicitis, a condition in which the appendix becomes inflamed, swollen, and gangrenous, is very uncommon.TF
3 Pre lecture Quiz __________ refers to difficulty in swallowing. Crohn disease and ulcerative colitis are two related intestinal disorders that fit under the category of __________ bowel disease.__________ is a condition that occurs primarily in the sigmoid colon, in which the mucosal layer of the colon herniates through the muscular layer.__________ disease is an immune-mediated disorder triggered by ingestion of gluten- containing grains (including wheat, barley, and rye).__________ is a common characteristic of both ulcerative colitis and Crohn disease.CeliacDiarrheaDiverticulosisDysphagiainflammatory
4 The Job of the BowelTo digest food: involves a corrosive solution and potentially pathogenic bacteriaTo absorb the food into the blood while keeping the corrosive substances and the bacteria inside the gutTo keep the solution moving down the bowel at the right rate for digestion and absorption
5 Inflammation and Damage to the Bowel Wall Hemorrhage anemiaPerforation peritonitisDecreased mucosal function malabsorptionDecreased bacterial containment sepsis
6 Hemorrhage Hemorrhage above the stomach: frank hematemesis Hemorrhage into the stomach with partial digestion of blood: coffee-grounds vomitusHemorrhage in the intestine with blood mixing into stools: occult bloodHemorrhage into the intestine with large volumes of blood: melenaHemorrhage in the rectum: red blood coating stools
7 The Vicious Circle: One Kind of Bowel Problem Can Cause Another Reflex paralysisInflammationand cell damageObstructionDistension, ischemiaFood does not pass through bowel at correct rateDecreasedbowelfunctionMalabsorption
8 Which symptom accompanies hemorrhage into the stomach? Hematemesis- QuestionWhich symptom accompanies hemorrhage into the stomach?Hematemesis-Occult blood –Coffee-grounds vomitus –Melena -the vomiting of bloodblood in the stoolblood mixed w/ chimeblack, tarry, bloody stools, usually resulting from a hemorrhage in the alimentary tract.
9 AnswerCoffee-grounds vomitusRationale: Coffee-grounds vomitus is a classic symptom of blood in the stomach (it mixes with chyme to give it the coffee-grounds color and consistency). Hematemesis occurs in hemorrhage above the stomach; occult blood is the result of blood mixing with stool in the small intestine; and melena occurs with large-volume hemorrhages in the intestine.
10 Disorders of the Esophagus Dysphagia -Achalasia -Esophageal diverticulum -Gastroesophageal reflux diseaseCancer of the esophagus -difficulty in swallowinginability of a circular muscle to relax, resulting in widening of the structure above the muscular constrictionmucosal layer herniated through the muscularis layera chronic condition in which acid from the stomach flows back into the lower esophagus, causing pain or tissue damagemalignant neoplasm
11 Disorders of the Stomach Acute gastritisChronic gastritisUlcer diseasePeptic ulcerZollinger-Ellison syndromeStress ulcersCancer of the stomachinflammation of the stomach, especially ofthe mucous membrane of the stomacherosion of the mucous membrane caused in part by the corrosive action of the gastric juicea condition in which a gastrin-secreting tumor of the pancreas or small intestine causes excessive secretion of gastric juice, leading to intractable peptic ulcersAcute peptic ulcers occurring in association with various other pathologic conditions
13 Scenario Mrs. D. has pain in her stomach at night and vomits up blood. She is pale and weakThe doctor finds that her hematocrit is lowHer blood contains large, pale erythrocytes and some reticulocytesBilirubin levels are normalQuestion:Explain her symptoms
14 Helicobacter pylori The major cause of ulcers Second most common cause is NSAIDspyloridamagesstomachliningrepair andULCERhealingincreased risk ofgastric cancer
16 Helicobacter Pylori“In the US: The frequency of HP infection may be linked to race. White persons account for 29% of cases, and Hispanic persons account for 60% of cases.”“Internationally: … At least half of all people are infected … HP may be detected in approximately 90% of individuals with peptic ulcer disease...”(Santacroce, L., and Miragliotta, G Helicobacter pylori infection. eMedicine.Retrieved April 2005 from
17 Inflammations of the Small and Large Intestines Infectious enterocolitisViral infectionsBacterial infectionsInflammatory bowel diseaseCrohn diseaseUlcerative colitisDiverticular diseaseAppendicitisCrohn’s disease – an autoimmune condition-a chronic inflammatory bowel disease that causes scarring and thickening of the intestinal walls and frequently leads to obstruction.
18 Discussion Think back to the last time you had enterocolitis. Questions:List the things that happened to youWhich of them were systemic signs of inflammation?Which of them were caused by your sympathetic system?Which of them helped you get over the disease?Which of them could have caused serious complications?Why?
19 QuestionWhich intestinal disorder is an autoimmune disease?EnterocolitisCrohn diseaseUlcerative colitisDiverticulitis
20 Answerb. Crohn disease Rationale: Crohn disease is an autoimmune disorder that affects the mucous membrane lining of the bowel (it gets thicker and doesn’t function as it should), causing chronic malabsorption.
21 The bowel attempts to get rid of the infectious agent EnterocolitisThe bowel attempts to get rid of the infectious agentExudate to dilute toxinsHypermotilityVomitingDecreased intestinal functionFood not absorbedOsmosis draws water into the bowelOsmotic (or explosive) diarrhea
22 Inflammations That Cannot Be Expelled Pain and sympathetic nervous stimulation cause the bowel to freeze in positionReflex paralysis or paralytic ileusMuscles of the abdominal wall tighten to protect the inflamed bowelBoard-like abdomenDiaphragm and accessory breathing muscle movements decreaseShallow breathing
23 One Kind of Bowel Problem Can Cause Another Reflex paralysisInflammationand cell damageObstructionDistension, ischemia
25 Results of Obstruction Vomiting fluid and electrolyte lossFluids move into intestinal contentsGas accumulatesDistension of bowelCompartment syndrome ischemia, necrosisAnaerobic bacteria produce endotoxin toxemia
26 QuestionTell whether the following statement is true or false. Paralytic intestinal obstruction causes audible paralysis.
27 AnswerFalse Rationale: Mechanical obstruction results in high-pitched peristalsis (bowel sounds); in paralytic obstruction, bowel sounds are inaudible (silent abdomen).
28 Bowel Distension and Compartment Syndrome The blood vessels on the surface of the gut are covered and held in place by the inflexible peritoneumWhen the gut lumen distends, it crushes the blood vessels between the gut wall and the peritoneumPeritoneum = Serosa
29 Compartment SyndromeAn organ expands inside a membrane that will not expandThe blood vessels feeding the organ are crushed between the organ and the membraneBlood supply is cut off
30 Scenario Mrs. K. presents with acute abdominal pain. She has a distended, board-like abdomen with no bowel sounds. Blood pressure is low and heart rate elevated. Her skin is pale and cool with cold sweat. She is very restless and complains of acute abdominal pain.The pain came on over the last 8 hours. WBC count is elevated. Now she complains of nausea and begins throwing up, but there is no blood in her vomitus. She has had no bowel movements or urine production.Question:What adaptive responses and counterattacks are evident?
31 Scenario (cont.) Mrs. K. has begun to run a fever Her skin is now flushed and warm, and her abdomen is further distendedHer blood pressure has decreased furtherThe doctor has ordered nasogastric suction and an isotonic IVQuestion:Why are you taking fluids out of her GI tract and putting them into her veins?