Control 5 Flashcards
(6 cards)
What are the key etiological factors in duodenal ulcer development?
High acid-pepsin secretion (hypersecretion, especially at night due to vagal stimulation). Rapid gastric emptying, leading to prolonged exposure of the duodenal mucosa to acid. Helicobacter pylori infection (present in 95-100% of cases), disrupting the protective mucus layer. Genetic predisposition (e.g., blood type O association) may also play a role. Dietary factors and lifestyle can contribute.
What are the key etiological factors in gastric ulcer development?
Impaired gastric mucosal defenses (reduced mucus production or quality). Helicobacter pylori infection (present in 75-80% of cases), further compromising the mucosal barrier. Gastritis (inflammation of the stomach lining). Bile reflux (backflow of bile into the stomach). Smoking. Use of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs). Acid levels can be normal or high (hyperacidity may occur due to increased serum gastrin levels). Genetic factors may also influence susceptibility.
Describe the pathogenesis of duodenal ulcers.
The aggressive action of high acid-pepsin secretion overwhelms the duodenal mucosa’s defensive mechanisms. Rapid gastric emptying exposes the duodenum to this acidic environment for extended periods. H. pylori infection further damages the protective mucus layer, leaving the underlying epithelium vulnerable to acid injury. The combination of these factors leads to ulcer formation.
Describe the pathogenesis of gastric ulcers.
Gastric ulcers result from an imbalance between the aggressive factors (acid-pepsin) and the weakened defensive mechanisms of the gastric mucosa. Reduced mucus production or quality weakens the protective barrier. H. pylori infection damages the mucus layer and promotes inflammation. Other factors, such as gastritis, bile reflux, and smoking, contribute to mucosal injury. Even with normal or low acid levels, these factors can lead to ulcer formation.
What are the pathological changes seen in acute (stress) peptic ulcers?
Grossly: Multiple, small, shallow mucosal erosions (often >3) that can be found anywhere in the stomach or duodenum. Microscopically: Shallow ulcers that do not typically penetrate the muscularis propria; inflammatory reaction is present; healing usually occurs without scarring.
What are the pathological changes seen in chronic peptic ulcers?
Grossly: Usually solitary ulcers; round or oval in shape; 1-2.5 cm in diameter; may penetrate deep into the muscular layers. Microscopically: Four distinct zones are observed: 1. Necrotic zone (necrotic debris and leukocytes). 2. Granulation tissue zone (newly formed tissue). 3. Zone of cicatrization (tissue repair). 4. Fibrous scar tissue (final stage of healing).
