Nokea
All enzymes involved in protein digestion are:
- A. secreted by the pancreas
- B. activated by HCl
- C. present in the stomach
- D. secreted in an inactive form
Correct Answer: D
Rationale: Protein-digesting enzymes like pepsinogen and trypsinogen are secreted in an inactive form and activated later.
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Which of the following would MOST directly affect the operations of the digestive system?
- A. osteoporosis
- B. liver damage
- C. heart attack
- D. kidney failure
Correct Answer: B
Rationale: Liver damage directly impacts digestion by reducing bile production, essential for fat breakdown.
A 55-year-old male presents with a history of recurring episodes of gastric pain, particularly after meals. He describes the pain as a burning sensation in the upper abdomen, which improves with antiacid use. Upper gastrointestinal endoscopy reveals erosions in the duodenal mucosa. Which of the following is the most likely diagnosis?
- A. Gastric ulcer
- B. Duodenal ulcer
- C. Gastroesophageal reflux disease (GERD)
- D. Gastric adenocarcinoma
Correct Answer: B
Rationale: Duodenal ulcers typically present with burning epigastric pain after meals, relieved by antacids, and are associated with mucosal erosions in the duodenum, as seen on endoscopy.
The cells of the epithelial lining in the vertebrate stomach are not damaged by HCl because of
- A. Mucus secretion covering the epithelium
- B. Neutralization of HCl by alkaline gastric juice
- C. HCl being dilute
- D. Epithelium being resistant to HCl
Correct Answer: A
Rationale: Mucus secreted by gastric cells forms a protective barrier against HCl, preventing damage to the stomach lining.
Crypts of Lieberkuhn are found in between the villi. They secrete :
- A. Glucagon
- B. Succus entericus
- C. Insulin
- D. Gastric juice
Correct Answer: B
Rationale: Crypts of Lieberkuhn secrete succus entericus for intestinal digestion.
Saliva contains two enzymes. What are they?
- A. Amylase and pepsin
- B. Amylase and lysozyme
- C. Amylase and lipase
- D. Amylase and renin
Correct Answer: B
Rationale: Saliva contains salivary amylase (ptyalin) for starch digestion and lysozyme for antibacterial action. Pepsin is in the stomach, lipase is mainly pancreatic, and renin is unrelated to saliva.