Porth's Essentials of Pathophysiology, 4e

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Gastrointestinal and Hepatobiliary Function

U N I T 8

A. Relate the mucosal protective effects of prostaglandins to the development of peptic ulcer associated with aspirin or NSAID use. B. Explain the apparent suddenness of the bleeding and the fact that the woman did not experience pain as a warning signal. C. Among the results of her initial laboratory tests is an elevated blood urea nitrogen (BUN) level. Explain the reason for the elevated BUN. 3. A 29-year-old woman has been diagnosed with Crohn disease. Her medical history reveals that she began having symptoms of the disease at 24 years of age and that her mother died of complications of the disease at 54 years of age. She complains of diarrhea and chronic cramping abdominal pain. A. Define the term inflammatory bowel disease and compare the pathophysiologic processes and manifestations of Crohn disease and ulcerative colitis. B. Describe the possible association between genetic and environmental factors in the pathogenesis of Crohn disease. C. Relate the use of the monoclonal antibody infliximab to the pathogenesis of the inflammatory lesions that occur in Crohn disease. 1. Everhart JF. The burden of digestive diseases in the United States . 2009. National Institute of Diabetes and Digestive Diseases. NIH publication no. 09-6443. Available at: http://www2. niddk.nih.gov/AboutNIDDK/ReportsAndStrategicPlanning/ BurdenOfDisease/DigestiveDiseases/. Accessed August 19, 2013. 2. Hall JE. Guyton and Hall Textbook of Medical Physiology . 12th ed. Philadelphia, PA: Saunders Elsevier; 2011:753–761, 789–805. 3. Epstein RK, Balaban DH. The esophagogastric junction. N Engl J Med. 1997;336(13):924–932. 4. Saud BM, Szyjkowski R. A diagnostic approach to dysphagia. Gastroenterology 2004;6:525–546. 5. Kuo P, Holloway RH, Nguyen NO. Current and future techniques in the evaluation of dysphagia. J Gastroenterol Hepatol. 2012;27(5):873–881. 6. Turner JR. The gastrointestinal tract. In: Kumar V, Abbas AK, Fausto N, et al., eds. Robbins and Cotran Pathologic Basis of Disease . 8th ed. Philadelphia, PA: Saunders Elsevier; 2010:763–831. 7. Rubin R. The gastrointestinal tract. In: Rubin R, Strayer DS, eds. Rubin’s Pathophysiology: Clinicopathologic Foundations of Medicine . 5th ed. Philadelphia, PA: Wolters Kluwer Health/ Lippincott Williams & Wilkins; 2012:605–675, 727–746. 8. McQuaid KR. Gastrointestinal disorders. In: Papadakis M, McPhee SJ, eds. Current Medical Diagnosis and Treatment . 52nd ed. New York, NY: McGraw-Hill Medical; 2013:564–661. 9. Richter JE. The many manifestations of gastrointestinal reflux disease: Presentation, evaluation, and treatment. Gastroenterol Clin North Am . 2007;37:577–599. 10. Rosemurgy AS, Donn N, Paul H, et al. Gastroesophageal reflux R E F E R E N C E S

SUMMARY CONCEPTS (continued)

■■ Peritonitis is an inflammatory response of the serous membrane that lines the abdominal cavity and covers the visceral organs. It can be caused by bacterial invasion or chemical irritation resulting from perforation of the viscera or abdominal organs. ■■ Malabsorption results from the impaired absorption of nutrients and other dietary constituents. It can involve a single dietary constituent, such as vitamin B 12 , or extend to involve all of the substances absorbed in a particular part of the small intestine. Malabsorption can result from diseases of the small bowel and disorders that impair digestion and, in some cases, obstruction of lymph flow can interfere with the transport of fats into the general circulation. Celiac disease is an immune-mediated disorder triggered by ingestion of gluten-containing grains (including wheat, barley, and rye). ■■ Colorectal cancer, the second most common fatal cancer, is seen most commonly in persons older than 50 years of age. Most, if not all, cancers of the colon and rectum arise in preexisting adenomatous polyps. Programs that provide careful follow-up for persons with adenomatous polyps and removal of all suspect lesions have substantially reduced the incidence of colorectal cancer. R E V I EW E X E R C I S E S 1. A 40-year-old man reports to his health care provider complaining of “heartburn” that occurs after eating and also wakens him at night. He is overweight, admits to enjoying fatty foods, and usually lies down on the sofa and watches TV after dinner. He also complains that lately he has been having a cough and some wheezing. A diagnosis of GERD was made. A. Explain the cause of heartburn and why it becomes worse after eating. B. Persons with GERD are advised to lose weight, avoid eating fatty foods, remain sitting after eating, and sleep with their head slightly elevated. Explain the possible relationship between these situations and the occurrence of reflux. C. Explain the possible relationship between GERD and the respiratory symptoms this man is having. 2. A 36-year-old woman who has been taking aspirin for back pain experiences a sudden episode of tachycardia and feeling faint, accompanied by the vomiting of a coffee-ground emesis and the passing of a tarry stool. She relates that she has not had any signs of a “stomach ulcer” such as pain or heartburn.

disease. Surg Clin North Am . 2011;91:1015–1029. 11. Spechler SJ. Barrett’s esophagus. N Engl J Med . 2002;346:836–842.