GI Digestive System Anatomy 2 — Questions and Answers
Question 1: Which layer of the GI tract wall contains blood vessels, lymphatics, and the submucosal (Meissner's) plexus?
- Mucosa
- Submucosa (Correct answer)
- Muscularis externa
- Serosa
Correct answer: Submucosa
The submucosa contains connective tissue, blood vessels, lymphatics, and Meissner's plexus, which regulates secretion and blood flow.
Question 2: The myenteric (Auerbach's) plexus is located between which two layers of the GI tract?
- Mucosa and submucosa
- Submucosa and circular muscle
- Circular and longitudinal muscle layers (Correct answer)
- Longitudinal muscle and serosa
Correct answer: Circular and longitudinal muscle layers
Auerbach's plexus lies between the inner circular and outer longitudinal smooth muscle layers, coordinating peristalsis.
Question 3: Which structure connects the stomach to the liver and contains the hepatic artery, portal vein, and bile duct?
- Falciform ligament
- Hepatoduodenal ligament (Correct answer)
- Gastrohepatic ligament
- Coronary ligament
Correct answer: Hepatoduodenal ligament
The hepatoduodenal ligament forms the free edge of the lesser omentum and contains the portal triad structures.
Question 4: The hepatic flexure of the colon is located in which abdominal quadrant?
- Left upper quadrant
- Left lower quadrant
- Right upper quadrant (Correct answer)
- Right lower quadrant
Correct answer: Right upper quadrant
The hepatic (right colic) flexure lies beneath the liver in the right upper quadrant, where the ascending colon bends to become the transverse colon.
Question 5: Which portion of the duodenum is retroperitoneal and crosses the vertebral column?
- First (superior) part
- Second (descending) part
- Third (horizontal) part (Correct answer)
- Fourth (ascending) part
Correct answer: Third (horizontal) part
The third part of the duodenum crosses anterior to the aorta and L3 vertebra and is compressed by the superior mesenteric artery in SMA syndrome.
Question 6: Which cells in the gastric mucosa secrete intrinsic factor and hydrochloric acid?
- Chief cells
- G cells
- Parietal (oxyntic) cells (Correct answer)
- Mucous neck cells
Correct answer: Parietal (oxyntic) cells
Parietal cells secrete both HCl (via H+/K+-ATPase) and intrinsic factor, which is essential for vitamin B12 absorption.
Question 7: The splenic flexure of the colon receives its blood supply primarily from which artery?
- Superior mesenteric artery
- Inferior mesenteric artery
- Left colic artery (Correct answer)
- Middle colic artery
Correct answer: Left colic artery
The left colic artery (branch of IMA) supplies the splenic flexure via anastomosis with the middle colic artery, forming the watershed Griffiths' point.
GI Digestive System Anatomy 2
Which layer of the GI tract wall contains blood vessels, lymphatics, and the submucosal (Meissner's) plexus?