A 74-year-old man becomes hypotensive for several hours after cardiac surgery. Next day he has left-sided abdominal pain and passes blood with stools. Colonoscopy shows ischaemic mucosa limited to the region of the splenic flexure. Why is this region most vulnerable?

It is the watershed between SMA and IMA supply

It is the most distal territory of the ileocolic artery

Its veins drain directly into the IVC

It is supplied by the coeliac trunk alone

A 35-year-old thin woman has post-meal epigastric pain. CT angiography shows the coeliac trunk compressed at its origin by the median arcuate ligament, yet the liver, stomach and spleen are well perfused through enlarged arteries around the head of the pancreas. Through which route does blood reach the coeliac territory?

SMA to inferior then superior pancreaticoduodenal arteries

SMA to IMA through the marginal artery

IMA to SMA through the arc of Riolan

Aorta to left gastric through the phrenic arteries

A 19-year-old woman lost 14 kg over 4 months during an illness. She now has bilious vomiting and fullness after meals, eased when she lies prone or in the knee-chest position. A barium meal shows a dilated proximal duodenum with an abrupt vertical cut-off in the third part. What is compressing the duodenum?

Superior mesenteric artery in front, aorta behind

Inferior mesenteric artery in front, aorta behind

Transverse mesocolon in front, right kidney behind

Coeliac trunk in front, aorta behind

GI tract, liver, portal system and peritoneum

12 NEET-PG practice questions on GI tract, liver, portal system and peritoneum, part of Anatomy. The first 12 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 74-year-old man becomes hypotensive for several hours after cardiac surgery. Next day he has left-sided abdominal pain and passes blood with stools. Colonoscopy shows ischaemic mucosa limited to the region of the splenic flexure. Why is this region most vulnerable?
1. AIt is the most distal territory of the ileocolic artery
2. BIts veins drain directly into the IVC
3. CIt is supplied by the coeliac trunk alone
4. DIt is the watershed between SMA and IMA supply
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Answer: D · It is the watershed between SMA and IMA supply
The splenic flexure lies at the junction of the midgut and hindgut, where the territory of the middle colic branch of the SMA meets that of the left colic branch of the IMA. The marginal artery linking them can be thin or interrupted here (Griffiths point), so this watershed area loses perfusion first during low-flow states. Most such ischaemic colitis is non-gangrenous and settles with supportive care, but signs of peritonitis call for surgery.
- A: The ileocolic artery supplies the terminal ileum, caecum and appendix.
- B: Colic veins drain into the portal system, not directly into the IVC.
- C: The coeliac trunk supplies foregut structures, not the colon.
Question 2 · Medium
A 56-year-old man with colorectal liver metastases confined to segments V to VIII is planned for a right hepatectomy. The surgeon marks the plane of resection on the liver surface, from the gallbladder fossa to the inferior vena cava. Which vessel runs in this plane?
1. ALeft hepatic vein
2. BMiddle hepatic vein
3. CLigamentum venosum
4. DRight hepatic vein
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Answer: B · Middle hepatic vein
The functional right and left halves of the liver are separated by a plane (Cantlie line) running from the gallbladder fossa in front to the inferior vena cava behind, not by the falciform ligament. The middle hepatic vein runs in this plane, between the territories of the right and left branches of the hepatic artery, portal vein and bile duct. A right hepatectomy removes segments V to VIII along it. The right hepatic vein divides the right half into anterior and posterior sections, and the left hepatic vein drains the left half.
- A: The left hepatic vein drains the left lateral section.
- C: The ligamentum venosum lies in a fissure separating the caudate lobe from the left lobe.
- D: The right hepatic vein separates the anterior and posterior sections of the right half.
Question 3 · Medium
A 35-year-old thin woman has post-meal epigastric pain. CT angiography shows the coeliac trunk compressed at its origin by the median arcuate ligament, yet the liver, stomach and spleen are well perfused through enlarged arteries around the head of the pancreas. Through which route does blood reach the coeliac territory?
1. ASMA to IMA through the marginal artery
2. BIMA to SMA through the arc of Riolan
3. CSMA to inferior then superior pancreaticoduodenal arteries
4. DAorta to left gastric through the phrenic arteries
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Answer: C · SMA to inferior then superior pancreaticoduodenal arteries
The head of the pancreas and the second part of the duodenum lie at the junction of foregut and midgut and receive both the superior pancreaticoduodenal arteries (from the gastroduodenal, a coeliac branch) and the inferior pancreaticoduodenal arteries (from the SMA). These arcades anastomose, so when the coeliac origin is narrowed, blood flows from the SMA through the inferior and then superior pancreaticoduodenal arteries into the gastroduodenal and common hepatic arteries. The enlarged arcade is a recognised feature of coeliac stenosis.
- A: The marginal artery links the SMA and IMA along the colon, not the coeliac trunk.
- B: The arc of Riolan also joins SMA and IMA territories.
- D: Inferior phrenic branches are too small to perfuse the whole coeliac territory.
Question 4 · Hard
A 49-year-old man with alcohol-related cirrhosis has a haematemesis, bright red bleeding per rectum, dilated veins radiating from the umbilicus and, at a previous laparotomy, large veins in the retroperitoneum. Consider these sites: 1. Lower oesophagus: left gastric vein with oesophageal tributaries of the azygos. 2. Anorectal junction: superior rectal vein with middle and inferior rectal veins. 3. Umbilicus: paraumbilical veins with superficial epigastric veins. 4. Retroperitoneum: colic veins with lumbar and renal veins. Which are correct portocaval anastomoses?
1. A1 and 3 only
2. B1, 2 and 3 only
3. C2 and 4 only
4. D1, 2, 3 and 4
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Answer: D · 1, 2, 3 and 4
All four statements are correct. In portal hypertension, blood is diverted to the systemic veins at sites where portal and systemic tributaries meet: at the lower oesophagus (left gastric vein with azygos tributaries, giving varices), the anorectal junction (superior rectal with middle and inferior rectal veins), the umbilicus (paraumbilical veins along the ligamentum teres with superficial epigastric veins, giving caput medusae) and the retroperitoneum (veins of the colon and bare areas with lumbar, renal and phrenic veins). Oesophageal varices bleed most dangerously and are banded or treated with vasoactive drugs. Anorectal varices are distinct from ordinary haemorrhoids.
- A: Leaves out the anorectal and retroperitoneal sites, both of which are true.
- B: Leaves out the retroperitoneal veins (of Retzius), a true portocaval site.
- C: Leaves out the oesophageal and umbilical sites, both of which are true.
Question 5 · Medium
A 19-year-old woman lost 14 kg over 4 months during an illness. She now has bilious vomiting and fullness after meals, eased when she lies prone or in the knee-chest position. A barium meal shows a dilated proximal duodenum with an abrupt vertical cut-off in the third part. What is compressing the duodenum?
1. ASuperior mesenteric artery in front, aorta behind
2. BInferior mesenteric artery in front, aorta behind
3. CTransverse mesocolon in front, right kidney behind
4. DCoeliac trunk in front, aorta behind
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Answer: A · Superior mesenteric artery in front, aorta behind
The third part of the duodenum crosses from right to left in front of the IVC and aorta, below the origin of the superior mesenteric artery, which descends in front of it. Normally a cushion of mesenteric fat keeps the angle between the SMA and aorta open; rapid weight loss shrinks it, and the duodenum is pinched between the SMA in front and the aorta behind (SMA syndrome). Lying prone or in the knee-chest position lets the mesentery fall forward and relieves it. Nutritional rehabilitation restores the fat pad in most patients.
- B: The inferior mesenteric artery arises below the third part of the duodenum.
- C: The transverse mesocolon and right kidney do not form the vascular pincer that compresses the third part.
- D: The coeliac trunk arises above the pancreas, well above the third part of the duodenum.
Question 6 · Easy
A 25-year-old man is in the operating theatre with a deep liver laceration after a road accident. To slow the bleeding, the surgeon passes a finger through the epiploic foramen and squeezes the free edge of the lesser omentum between finger and thumb. Which structures does this compress?
1. APortal vein, hepatic artery proper and bile duct
2. BInferior vena cava, hepatic artery and bile duct
3. CPortal vein, splenic artery and bile duct
4. DPortal vein, hepatic veins and bile duct
Answer and explanation in LearnFree account
Question 7 · Medium
A 30-year-old man is brought to casualty after a motorcycle crash with abdominal pain and a pulse of 118/min. A FAST scan is done with him lying supine. In which space of the upper abdomen does free blood collect first?
1. ARight subphrenic space
2. BLesser sac
3. CHepatorenal pouch
4. DLeft paracolic gutter
Answer and explanation in LearnFree account
Question 8 · Hard
During laparoscopic cholecystectomy in a 47-year-old woman, a large tortuous artery is seen looping close to the gallbladder neck and cystic duct before entering the liver, and a very short cystic artery arises from the top of the loop. The trainee prepares to clip the large looping vessel as the cystic artery. Which artery is at risk?
1. AProper hepatic artery
2. BGastroduodenal artery
3. CLeft hepatic artery
4. DRight hepatic artery
Answer and explanation in LearnFree account
Question 9 · Medium
A 20-year-old man has had periumbilical pain shifting to the right iliac fossa for 3 days. At operation the appendix is gangrenous and perforated near its tip, though the base looks healthy. Why does gangrene of the appendix develop so readily once it is inflamed and swollen?
1. AThe appendix drains only into the systemic veins
2. BThe appendicular artery is an end artery
3. CThe appendix wall has no submucosal plexus
4. DThe appendicular artery arises from the inferior mesenteric
Answer and explanation in LearnFree account
Question 10 · Easy
During laparoscopic cholecystectomy in a 42-year-old woman, the surgeon dissects the triangle bounded by the cystic duct, the common hepatic duct and the inferior surface of the liver. Which artery normally lies within it?
1. ACystic artery
2. BGastroduodenal artery
3. CRight gastric artery
4. DLeft hepatic artery
Answer and explanation in LearnFree account
Question 11 · Medium
Six weeks after an attack of alcohol-related acute pancreatitis, a 38-year-old man has epigastric fullness and early satiety. CT shows a well-walled fluid collection lying behind the stomach and in front of the pancreas. In which peritoneal space is it?
1. AHepatorenal pouch
2. BLesser sac
3. CRight subphrenic space
4. DLeft paracolic gutter
Answer and explanation in LearnFree account
Question 12 · Medium
A 52-year-old man taking diclofenac for back pain has a massive haematemesis. Endoscopy shows a deep ulcer on the posterior wall of the body of the stomach, away from the lesser curvature, with a visible vessel in its base. Which artery is most likely bleeding?
1. ASplenic artery
2. BRight gastroepiploic artery
3. CLeft gastric artery
4. DGastroduodenal artery
Answer and explanation in LearnFree account

GI tract, liver, portal system and peritoneum

A 74-year-old man becomes hypotensive for several hours after cardiac surgery. Next day he has left-sided abdominal pain and passes blood with stools. Colonoscopy shows ischaemic mucosa limited to the region of the splenic flexure. Why is this region most vulnerable?

A 56-year-old man with colorectal liver metastases confined to segments V to VIII is planned for a right hepatectomy. The surgeon marks the plane of resection on the liver surface, from the gallbladder fossa to the inferior vena cava. Which vessel runs in this plane?

A 25-year-old man is in the operating theatre with a deep liver laceration after a road accident. To slow the bleeding, the surgeon passes a finger through the epiploic foramen and squeezes the free edge of the lesser omentum between finger and thumb. Which structures does this compress?

A 30-year-old man is brought to casualty after a motorcycle crash with abdominal pain and a pulse of 118/min. A FAST scan is done with him lying supine. In which space of the upper abdomen does free blood collect first?

A 20-year-old man has had periumbilical pain shifting to the right iliac fossa for 3 days. At operation the appendix is gangrenous and perforated near its tip, though the base looks healthy. Why does gangrene of the appendix develop so readily once it is inflamed and swollen?

During laparoscopic cholecystectomy in a 42-year-old woman, the surgeon dissects the triangle bounded by the cystic duct, the common hepatic duct and the inferior surface of the liver. Which artery normally lies within it?

Six weeks after an attack of alcohol-related acute pancreatitis, a 38-year-old man has epigastric fullness and early satiety. CT shows a well-walled fluid collection lying behind the stomach and in front of the pancreas. In which peritoneal space is it?

A 52-year-old man taking diclofenac for back pain has a massive haematemesis. Endoscopy shows a deep ulcer on the posterior wall of the body of the stomach, away from the lesser curvature, with a visible vessel in its base. Which artery is most likely bleeding?