SGNA Pathophysiology of GI Disorders 1 — Questions and Answers
Question 1: Barrett's esophagus is characterized by the replacement of normal squamous epithelium with which type of epithelium?
- Columnar intestinal-type epithelium with goblet cells (Correct answer)
- Transitional epithelium
- Pseudostratified columnar epithelium
- Stratified cuboidal epithelium
Correct answer: Columnar intestinal-type epithelium with goblet cells
Barrett's esophagus involves metaplastic replacement of normal squamous epithelium with specialized intestinal-type columnar epithelium containing goblet cells, increasing the risk of esophageal adenocarcinoma.
Question 2: What is the primary pathophysiological mechanism underlying gastroesophageal reflux disease (GERD)?
- Increased basal gastric acid secretion
- Transient lower esophageal sphincter relaxations (TLESRs) (Correct answer)
- Significantly delayed gastric emptying
- Hiatal hernia formation
Correct answer: Transient lower esophageal sphincter relaxations (TLESRs)
Transient lower esophageal sphincter relaxations (TLESRs) are the predominant mechanism allowing gastric contents to reflux into the esophagus, occurring independent of swallowing.
Question 3: Celiac disease is triggered by an immune response to which protein fraction?
- Casein from dairy products
- Gliadin, a fraction of gluten (Correct answer)
- Albumin from eggs
- Beta-lactoglobulin from milk
Correct answer: Gliadin, a fraction of gluten
Celiac disease is an autoimmune condition triggered by gliadin, the alcohol-soluble fraction of gluten, which causes villous atrophy and malabsorption in the small intestine.
Question 4: Which characteristic of Crohn's disease inflammation most distinguishes it pathologically from ulcerative colitis?
- Mucosal inflammation only
- Submucosal involvement only
- Transmural (full-thickness) inflammation (Correct answer)
- Serosal involvement only
Correct answer: Transmural (full-thickness) inflammation
Crohn's disease is characterized by transmural inflammation affecting all layers of the bowel wall, which can lead to fistulas, abscesses, and strictures—complications not typical of ulcerative colitis.
Question 5: Crypt abscesses seen on histopathology are a hallmark finding most characteristic of which condition?
- Crohn's disease
- Ulcerative colitis (Correct answer)
- Celiac disease
- Microscopic colitis
Correct answer: Ulcerative colitis
Crypt abscesses—neutrophilic infiltrates within intestinal crypts—are a hallmark histological finding in active ulcerative colitis, reflecting the mucosal-predominant nature of the disease.
Question 6: Approximately what percentage of peptic ulcers occur in the duodenum rather than the stomach?
- 30–40%
- 50–60%
- 75–80% (Correct answer)
- 90–95%
Correct answer: 75–80%
Approximately 75–80% of peptic ulcers are duodenal ulcers, most commonly located in the duodenal bulb where acid from the stomach directly contacts the duodenal mucosa.
Question 7: Helicobacter pylori preferentially colonizes which region of the stomach, disrupting gastrin regulation?
- Fundus
- Body (corpus)
- Antrum (Correct answer)
- Cardia
Correct answer: Antrum
H. pylori preferentially colonizes the gastric antrum where it disrupts somatostatin-producing D cells and increases gastrin secretion from G cells, leading to excess acid production.
SGNA Pathophysiology of GI Disorders 1
Barrett's esophagus is characterized by the replacement of normal squamous epithelium with which type of epithelium?