Anatomy of GI tract MCQs With Answer

Anatomy of GI tract MCQs With Answer is a targeted study aid for B. Pharm students preparing for anatomy, pharmacology, and clinical exams. This concise, exam-oriented introduction emphasizes GI tract anatomy MCQs with answers covering macroscopic and microscopic structure, arterial and venous supply, lymphatic drainage, enteric and autonomic innervation, and functional zones relevant to drug absorption and first‑pass metabolism. Questions integrate clinical and pharmaceutical relevance — gastric histology, intestinal villi and microvilli, Peyer’s patches, Brunner’s glands, portal circulation, sphincters, and biliary‑pancreatic anatomy — to deepen understanding for prescribing, formulation, and bioavailability considerations. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which three layers compose the mucosa of the gastrointestinal tract?

• Epithelium, lamina propria, muscularis mucosae
• Serosa, submucosa, muscularis externa
• Epithelium, submucosa, serosa
• Muscularis externa, adventitia, serosa

Correct Answer: Epithelium, lamina propria, muscularis mucosae

Q2. Which artery is the primary arterial supply to the stomach’s lesser curvature?

• Left gastric artery
• Right gastro-omental artery
• Left gastro-omental artery
• Splenic artery

Correct Answer: Left gastric artery

Q3. Which cells in the stomach secrete intrinsic factor and hydrochloric acid?

• Parietal (oxyntic) cells
• Chief (peptic) cells
• Mucous neck cells
• G cells (enteroendocrine)

Correct Answer: Parietal (oxyntic) cells

Q4. Where are Brunner’s glands located and what is their main secretion?

• Duodenum; alkaline mucus with bicarbonate
• Jejunum; digestive enzymes
• Ileum; Peyer’s patch secretions
• Stomach; acid

Correct Answer: Duodenum; alkaline mucus with bicarbonate

Q5. Which structural feature most increases small intestinal absorptive surface area?

• Microvilli on enterocytes
• Plicae circulares of the stomach
• Taeniae coli
• Epiploic appendages

Correct Answer: Microvilli on enterocytes

Q6. Peyer’s patches are most abundant in which intestinal segment?

• Ileum
• Duodenum
• Jejunum
• Colon

Correct Answer: Ileum

Q7. The hepatic portal vein carries blood primarily from where to the liver?

• Gastrointestinal tract and spleen
• Kidneys and gonads
• Pulmonary circulation
• Systemic arterial circulation

Correct Answer: Gastrointestinal tract and spleen

Q8. Which histologic cell type synthesizes digestive enzymes like pepsinogen in the stomach?

• Chief (zymogenic) cells
• Parietal cells
• Enterochromaffin cells
• D cells

Correct Answer: Chief (zymogenic) cells

Q9. The myenteric (Auerbach) plexus primarily regulates which function?

• Gastrointestinal motility (muscular contraction)
• Mucosal secretion and blood flow
• Portal venous pressure
• Lymphatic drainage

Correct Answer: Gastrointestinal motility (muscular contraction)

Q10. Which part of the small intestine is the main site for iron absorption?

• Duodenum
• Jejunum
• Ileum
• Colon

Correct Answer: Duodenum

Q11. The pectinate (dentate) line in the anal canal demarcates a change in which of the following?

• Embryologic origin, nerve supply, and epithelial type
• Only blood supply
• Only lymphatic drainage
• Only muscular layers

Correct Answer: Embryologic origin, nerve supply, and epithelial type

Q12. Which structure drains bile and pancreatic juice into the second part of the duodenum?

• Hepatopancreatic ampulla (ampulla of Vater)
• Accessory pancreatic duct
• Pyloric sphincter
• Brunner’s duct

Correct Answer: Hepatopancreatic ampulla (ampulla of Vater)

Q13. Which nerve provides parasympathetic innervation to most of the foregut and midgut structures?

• Vagus nerve (CN X)
• Phrenic nerve
• Pelvic splanchnic nerves (S2–S4)
• Thoracic sympathetic trunk

Correct Answer: Vagus nerve (CN X)

Q14. Which cell type in the stomach secretes gastrin?

• G cells (antral endocrine cells)
• Parietal cells
• Chief cells
• Mucous neck cells

Correct Answer: G cells (antral endocrine cells)

Q15. The taeniae coli are unique features of which organ?

• Colon
• Small intestine
• Stomach
• Esophagus

Correct Answer: Colon

Q16. Which embryologic arterial trunk supplies the midgut derivatives?

• Superior mesenteric artery (SMA)
• Inferior mesenteric artery (IMA)
• Celiac trunk
• Internal iliac artery

Correct Answer: Superior mesenteric artery (SMA)

Q17. Which zone of the liver lobule receives the least oxygenated blood and is most susceptible to ischemia?

• Zone III (centrilobular)
• Zone I (periportal)
• Zone II (intermediate)
• Canalicular zone

Correct Answer: Zone III (centrilobular)

Q18. Kupffer cells in the liver are specialized _____ that perform phagocytosis.

• Macrophages
• Stellate (Ito) cells
• Hepatocytes
• Endothelial cells

Correct Answer: Macrophages

Q19. Which anatomical sphincter separates the esophagus from the stomach and prevents reflux?

• Lower esophageal sphincter (LES)/cardiac sphincter
• Pyloric sphincter
• Upper esophageal sphincter (UES)
• Ileocecal valve

Correct Answer: Lower esophageal sphincter (LES)/cardiac sphincter

Q20. The esophageal mucosa transitions from stratified squamous to columnar epithelium at what landmark?

• Gastroesophageal junction (z-line)
• Pylorus
• Cardiac notch
• Angular incisure

Correct Answer: Gastroesophageal junction (z-line)

Q21. Which structure forms the hepatoduodenal ligament, a part of the lesser omentum?

• Portal triad (portal vein, hepatic artery, bile duct)
• Gastrosplenic vessels
• Gastrocolic vessels
• Phrenicocolic ligament

Correct Answer: Portal triad (portal vein, hepatic artery, bile duct)

Q22. Where are Paneth cells located and what is their primary function?

• Base of small intestinal crypts; antimicrobial secretion (defensins)
• Stomach pits; acid secretion
• Colon surface; mucus secretion
• Gallbladder lumen; bile concentration

Correct Answer: Base of small intestinal crypts; antimicrobial secretion (defensins)

Q23. The ileocecal valve is important because it:

• Prevents colonic backflow into the ileum
• Secretes digestive enzymes
• Controls bile release
• Is a major lymph node

Correct Answer: Prevents colonic backflow into the ileum

Q24. Which cell type in the pancreas produces bicarbonate-rich fluid in pancreatic secretions?

• Centroacinar and ductal epithelial cells
• Acinar cells
• Alpha cells
• Beta cells

Correct Answer: Centroacinar and ductal epithelial cells

Q25. Which anatomical relation allows drugs absorbed in the lower rectum to bypass first-pass hepatic metabolism?

• Inferior rectal veins drain into systemic (internal pudendal) circulation
• Superior rectal vein drains into portal system
• Middle rectal vein drains to portal vein directly
• Rectal lymphatics drain into thoracic duct only

Correct Answer: Inferior rectal veins drain into systemic (internal pudendal) circulation

Q26. Which histologic feature distinguishes the jejunum from the ileum?

• More prominent plicae circulares in jejunum
• Presence of Peyer’s patches in jejunum
• Brunner’s glands only in jejunum
• Villous blunting in jejunum

Correct Answer: More prominent plicae circulares in jejunum

Q27. The portal triad in the hepatoduodenal ligament consists of:

• Portal vein, hepatic artery proper, common bile duct
• Hepatic vein, portal artery, cystic duct
• Proper hepatic artery, hepatic vein, pancreatic duct
• Splenic artery, splenic vein, bile duct

Correct Answer: Portal vein, hepatic artery proper, common bile duct

Q28. The site of water and electrolyte absorption in the large intestine is primarily the:

• Colon
• Stomach
• Duodenum
• Pancreas

Correct Answer: Colon

Q29. Which ligament divides the left and right lobes of the liver anteriorly?

• Falciform ligament
• Round ligament of liver (ligamentum teres) only
• Coronary ligament
• Gastrosplenic ligament

Correct Answer: Falciform ligament

Q30. Which enzyme is responsible for initiating protein digestion in the stomach?

• Pepsin (from pepsinogen)
• Trypsinogen
• Amylase
• Lipase

Correct Answer: Pepsin (from pepsinogen)

Q31. Enterohepatic circulation primarily recycles which molecules relevant to drug disposition?

• Bile salts and some conjugated drugs
• Glucose and amino acids
• Insulin and glucagon
• Chylomicrons

Correct Answer: Bile salts and some conjugated drugs

Q32. Which lymph nodes are the primary regional nodes for the stomach?

• Gastric (left and right) and pyloric nodes along the lesser and greater curvatures
• Mesenteric lymph nodes only
• Inguinal lymph nodes
• Cervical lymph nodes

Correct Answer: Gastric (left and right) and pyloric nodes along the lesser and greater curvatures

Q33. Which structure serves as the major reservoir for bile and concentrates bile by absorption?

• Gallbladder
• Pancreas
• Duodenal bulb
• Hepatic sinusoids

Correct Answer: Gallbladder

Q34. The muscularis externa typically has how many layers in most of the GI tract and what are they?

• Two layers: inner circular and outer longitudinal muscle
• Three layers: circular, longitudinal, oblique everywhere
• One continuous muscular layer only
• Four layers including serosal muscle

Correct Answer: Two layers: inner circular and outer longitudinal muscle

Q35. Which component of bile is critical for lipid emulsification and absorption?

• Bile salts (bile acids conjugated with glycine/taurine)
• Cholesterol crystals
• Albumin
• Pancreatic amylase

Correct Answer: Bile salts (bile acids conjugated with glycine/taurine)

Q36. Which arterial branch supplies the distal transverse colon and descending colon?

• Inferior mesenteric artery (IMA)
• Superior mesenteric artery (SMA)
• Celiac trunk
• Internal iliac artery

Correct Answer: Inferior mesenteric artery (IMA)

Q37. Which features characterize the histology of the colon compared to small intestine?

• Absence of villi; presence of numerous goblet cells and crypts
• Prominent plicae circulares and tall villi
• Brunner’s glands in mucosa
• More Paneth cells and fewer goblet cells

Correct Answer: Absence of villi; presence of numerous goblet cells and crypts

Q38. The hepatic lobule classical model is centered around which structure?

• Central (terminal hepatic) vein
• Portal triad
• Gallbladder neck
• Zone I portal tract

Correct Answer: Central (terminal hepatic) vein

Q39. Which receptor on parietal cells is the target of proton pump inhibitors’ downstream effect?

• H+/K+ ATPase (proton pump)
• H2 histamine receptor
• M3 muscarinic receptor
• Gastrin receptor (CCK-B)

Correct Answer: H+/K+ ATPase (proton pump)

Q40. Which anatomical part of the pancreas lies in the curve of the duodenum?

• Head of pancreas
• Tail of pancreas
• Body of pancreas
• Pancreatic ligament

Correct Answer: Head of pancreas

Q41. Which venous drainage pathway causes colorectal cancers to metastasize primarily to the liver?

• Superior rectal vein → inferior mesenteric → portal vein
• Inferior rectal vein → internal pudendal → systemic IVC
• Middle rectal vein → internal iliac → systemic circulation only
• Superior rectal vein → lumbar veins → azygos system

Correct Answer: Superior rectal vein → inferior mesenteric → portal vein

Q42. The stomach’s protective mucus-bicarbonate layer is mainly produced by which cells?

• Mucous neck cells and surface mucous cells
• Parietal cells
• Chief cells
• Enteroendocrine G cells

Correct Answer: Mucous neck cells and surface mucous cells

Q43. Which ligament contains the splenic vessels and tail of pancreas?

• Splenorenal (lienorenal) ligament
• Falciform ligament
• Hepatogastric ligament
• Coronary ligament

Correct Answer: Splenorenal (lienorenal) ligament

Q44. Which functional zone of the stomach contains parietal and chief cells abundantly?

• Fundus and body (corpus)
• Antrum
• Pyloric canal only
• Cardia only

Correct Answer: Fundus and body (corpus)

Q45. The enteric nervous system’s two major plexuses are:

• Myenteric (Auerbach) and submucosal (Meissner)
• Vagal and sympathetic plexuses
• Celiac and mesenteric nodes
• Hepatic and splenic plexuses

Correct Answer: Myenteric (Auerbach) and submucosal (Meissner)

Q46. Which cell in the pancreas secretes digestive enzymes as zymogens (e.g., trypsinogen)?

• Acinar cells
• Centroacinar cells
• Islets of Langerhans beta cells
• Hepatocytes

Correct Answer: Acinar cells

Q47. In portal hypertension, which superficial abdominal veins become prominent and are known as caput medusae?

• Paraumbilical veins anastomosing with superficial epigastric veins
• Inguinal veins anastomosing with external iliac veins
• Thoracoepigastric veins draining to axillary vein only
• Intercostal veins enlarging with azygos only

Correct Answer: Paraumbilical veins anastomosing with superficial epigastric veins

Q48. Which mucosal change characterizes Barrett’s esophagus relevant to drug absorption and disease risk?

• Metaplasia to columnar epithelium with intestinal-type goblet cells
• Hyperkeratosis of squamous epithelium
• Loss of stratified squamous epithelium replaced by transitional epithelium
• Formation of gastric rugae in the distal esophagus

Correct Answer: Metaplasia to columnar epithelium with intestinal-type goblet cells

Q49. Which structure increases the surface area of hepatocytes for bile collection?

• Bile canaliculi between adjacent hepatocytes
• Central vein lumens
• Portal lymphatics
• Sinusoidal fenestrae only

Correct Answer: Bile canaliculi between adjacent hepatocytes

Q50. Which feature of the small intestinal mucosa is critical for rapid oral drug absorption and is affected by villus atrophy?

• Enterocyte brush border with microvilli (increases surface area)
• Thick muscularis externa
• Crypt only secretions
• Submucosal glands secreting pepsin

Correct Answer: Enterocyte brush border with microvilli (increases surface area)

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

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