NUR 311 Exam 2 Questions with Correct Answers.

List and explain the 4 defensive factors which protect the stomach and duodenum from self-digestion. Correct Answer Mucus - forms a barrier to protect underlying cells from gastric acid and pepsin. Bicarbonate - neutralizes any acid which penetrates the mucus. Blood flow - maintains integrity or health of the mucosa Prostaglandins - Stimulates mucus and bicarbonate, vasodilates blood vessels, suppresses gastric secretion List and explain 5 aggressive factors which predispose the stomach and duodenum to ulcerations. Correct Answer Helicobacter pylori (H. pylori) - gram-negative bacillus which lives between the mucus layer and the mucosa. Produces CO2 and ammonia from urea which damages the mucosa. NSAIDs - decreases the production of prostaglandins which decreases blood flow, decreases bicarbonate and mucus secretion, and increases gastric acid. Gastric Acid - injures cells of the mucosa and activates pepsin. Pepsin - breaks down protein of the gut wall. Smoking - delays healing of ulcers and increases risk of recurrence. What are three mechanisms of action for antacids? Correct Answer Binds gastric acid and forms a neutral salt, decreases pepsin if pH 5, and stimulates prostaglandins. How are antacids administered in relation to meals, sleep, or other drugs? If not eating, how often are they given? Correct Answer 1 and 3 hrs after meals and at bedtime, 1 hour before another drug, or every 2 hours if not eating Which antacids can cause complications in heart failure and renal disease? Correct Answer Aluminum hydroxide and sodium bicarbonate - heart failure, magnesium hydroxide - CNS toxicity in renal patients How do histamine2 receptor antagonists work? Correct Answer Block H2 receptors on parietal cells which suppress gastric acid secretion and decrease the hydrogen ion concentration in gastric acid. How are histamine2 receptor antagonists administered in relation to meals? Correct Answer May be taken without regard to meals, except take Tagamet with food Which histamine2 receptor antagonist is noted for drug-drug interactions caused by inhibition of hepatic drug-metabolizing enzymes? Correct Answer cimetidine (Tagamet) Which histamine2 receptor antagonist is known for its ability to block androgen effects? Correct Answer cimetidine (Tagamet)