BDS MODULES E.1 UPDATED EXAM REVIEW
QUESTIONS AND CORRECT ANSWERS
Study-use note: This PDF contains original practice questions designed around common BDS Modules E.1 learning objectives.
They are not presented as leaked, copied, or guaranteed current examination questions. Questions are in blue, choices in dark
gray, correct answers in green, and rationales in orange.
1. Which structure primarily prevents reflux of gastric contents into the esophagus?
A. Lower esophageal sphincter
B. Pyloric sphincter
C. Ileocecal valve
D. Upper esophageal sphincter
Correct Answer: A. Lower esophageal sphincter
Rationale: The lower esophageal sphincter increases resistance at the gastroesophageal junction and helps limit reflux.
2. Which cranial nerve carries the major parasympathetic supply to the thoracic and abdominal
viscera?
A. Facial nerve (CN VII)
B. Vagus nerve (CN X)
C. Accessory nerve (CN XI)
D. Hypoglossal nerve (CN XII)
Correct Answer: B. Vagus nerve (CN X)
Rationale: The vagus nerve provides extensive parasympathetic innervation to thoracic organs and much of the
gastrointestinal tract.
3. The primary site of nutrient absorption in the gastrointestinal tract is the:
A. Stomach
B. Duodenum only
C. Small intestine
D. Large intestine
Correct Answer: C. Small intestine
Rationale: Most digestion and absorption occur in the small intestine, whose folds, villi, and microvilli greatly increase
surface area.
4. Which blood vessel supplies oxygenated blood to most of the small intestine?
A. Superior mesenteric artery
B. Inferior mesenteric artery
C. Splenic artery
D. Internal iliac artery
Correct Answer: A. Superior mesenteric artery
Rationale: The superior mesenteric artery supplies most of the small intestine through its jejunal and ileal branches.
, 5. A patient has a lesion affecting the facial nerve. Which finding is most characteristic?
A. Loss of tongue sensation only
B. Ipsilateral facial muscle weakness
C. Complete loss of hearing
D. Inability to abduct the eye
Correct Answer: B. Ipsilateral facial muscle weakness
Rationale: CN VII innervates the muscles of facial expression, so a peripheral facial nerve lesion produces ipsilateral
facial weakness.
6. Which cells in the stomach secrete hydrochloric acid?
A. Chief cells
B. Parietal cells
C. G cells
D. Goblet cells
Correct Answer: B. Parietal cells
Rationale: Parietal cells secrete hydrochloric acid and intrinsic factor.
7. Which vitamin deficiency is classically associated with impaired DNA synthesis and
megaloblastic anemia?
A. Vitamin C
B. Vitamin B12
C. Vitamin D
D. Vitamin K
Correct Answer: B. Vitamin B12
Rationale: Vitamin B12 deficiency impairs DNA synthesis and can cause megaloblastic anemia and neurologic
manifestations.
8. The principal function of bile salts is to:
A. Digest proteins directly
B. Emulsify dietary fats
C. Convert glucose to glycogen
D. Absorb amino acids
Correct Answer: B. Emulsify dietary fats
Rationale: Bile salts emulsify fats, increasing their surface area for pancreatic lipase and aiding micelle formation.
9. Which pancreatic enzyme is primarily responsible for triglyceride digestion?
A. Pepsin
B. Pancreatic lipase
C. Trypsin
D. Amylase
Correct Answer: B. Pancreatic lipase
Rationale: Pancreatic lipase hydrolyzes dietary triglycerides into absorbable fatty acids and monoglycerides.
QUESTIONS AND CORRECT ANSWERS
Study-use note: This PDF contains original practice questions designed around common BDS Modules E.1 learning objectives.
They are not presented as leaked, copied, or guaranteed current examination questions. Questions are in blue, choices in dark
gray, correct answers in green, and rationales in orange.
1. Which structure primarily prevents reflux of gastric contents into the esophagus?
A. Lower esophageal sphincter
B. Pyloric sphincter
C. Ileocecal valve
D. Upper esophageal sphincter
Correct Answer: A. Lower esophageal sphincter
Rationale: The lower esophageal sphincter increases resistance at the gastroesophageal junction and helps limit reflux.
2. Which cranial nerve carries the major parasympathetic supply to the thoracic and abdominal
viscera?
A. Facial nerve (CN VII)
B. Vagus nerve (CN X)
C. Accessory nerve (CN XI)
D. Hypoglossal nerve (CN XII)
Correct Answer: B. Vagus nerve (CN X)
Rationale: The vagus nerve provides extensive parasympathetic innervation to thoracic organs and much of the
gastrointestinal tract.
3. The primary site of nutrient absorption in the gastrointestinal tract is the:
A. Stomach
B. Duodenum only
C. Small intestine
D. Large intestine
Correct Answer: C. Small intestine
Rationale: Most digestion and absorption occur in the small intestine, whose folds, villi, and microvilli greatly increase
surface area.
4. Which blood vessel supplies oxygenated blood to most of the small intestine?
A. Superior mesenteric artery
B. Inferior mesenteric artery
C. Splenic artery
D. Internal iliac artery
Correct Answer: A. Superior mesenteric artery
Rationale: The superior mesenteric artery supplies most of the small intestine through its jejunal and ileal branches.
, 5. A patient has a lesion affecting the facial nerve. Which finding is most characteristic?
A. Loss of tongue sensation only
B. Ipsilateral facial muscle weakness
C. Complete loss of hearing
D. Inability to abduct the eye
Correct Answer: B. Ipsilateral facial muscle weakness
Rationale: CN VII innervates the muscles of facial expression, so a peripheral facial nerve lesion produces ipsilateral
facial weakness.
6. Which cells in the stomach secrete hydrochloric acid?
A. Chief cells
B. Parietal cells
C. G cells
D. Goblet cells
Correct Answer: B. Parietal cells
Rationale: Parietal cells secrete hydrochloric acid and intrinsic factor.
7. Which vitamin deficiency is classically associated with impaired DNA synthesis and
megaloblastic anemia?
A. Vitamin C
B. Vitamin B12
C. Vitamin D
D. Vitamin K
Correct Answer: B. Vitamin B12
Rationale: Vitamin B12 deficiency impairs DNA synthesis and can cause megaloblastic anemia and neurologic
manifestations.
8. The principal function of bile salts is to:
A. Digest proteins directly
B. Emulsify dietary fats
C. Convert glucose to glycogen
D. Absorb amino acids
Correct Answer: B. Emulsify dietary fats
Rationale: Bile salts emulsify fats, increasing their surface area for pancreatic lipase and aiding micelle formation.
9. Which pancreatic enzyme is primarily responsible for triglyceride digestion?
A. Pepsin
B. Pancreatic lipase
C. Trypsin
D. Amylase
Correct Answer: B. Pancreatic lipase
Rationale: Pancreatic lipase hydrolyzes dietary triglycerides into absorbable fatty acids and monoglycerides.
