Gross Anatomy of GIT (Oesophagus, Stomach)

Question 1

What are the four anatomical/physiological constrictions of the oesophagus, and what are their distances from the upper incisors?

Answer 1

Pharyngo-oesophageal junction (15 cm)

Crossed by the aortic arch (22.5 cm)

Crossed by the left main bronchus (27.5 cm)

Oesophageal hiatus in the diaphragm (38 cm)

Question 2

What is the clinical significance of the oesophageal constrictions?

Answer 2

They are common sites for oesophageal injury during instrumentation, foreign body lodgment, and corrosive stricture formation.

Question 2

Describe the arterial supply of the oesophagus.

Answer 2

Upper third: Inferior thyroid artery

Middle third: Oesophageal branches of aorta and bronchial arteries

Lower third: Left gastric artery and left inferior phrenic artery

Question 3

How does venous drainage of the lower third of the oesophagus contribute to oesophageal varices?

Answer 3

The lower third drains into the left gastric vein (portal system), which anastomoses with the azygos vein (systemic system). In portal hypertension, this porto-systemic anastomosis leads to varices.

Question 3

A 58-year-old alcoholic presents with hematemesis due to ruptured oesophageal varices. Which vein is involved in the porto-systemic anastomosis?

Answer 3

Left gastric vein.

Question 4

What are the anatomical landmarks of the oesophagus?

Answer 4

Begins at C6 (cricoid cartilage)

Passes through diaphragm at T10

Ends at T11 (oesophagogastric junction, 7th costal cartilage)

Question 5

Name the two oesophageal sphincters and their locations.

Answer 5

Upper sphincter: Cricopharyngeus muscle (at pharyngo-oesophageal junction)

Lower sphincter: Near the oesophageal hiatus (physiological, not anatomical)

Question 6

What are the consequences of lower oesophageal sphincter dysfunction?

Answer 6

Failure to close: GERD (gastroesophageal reflux disease)

Failure to relax: Achalasia (dysphagia, proximal dilatation)

Question 7

A perforating ulcer in the posterior stomach wall would likely cause peritonitis in which space?

Answer 7

Omental bursa (lesser sac).

Question 8

What are the nerve supplies to the stomach, and their functions?

Answer 8

Parasympathetic (vagus): Increases motility and secretion

Sympathetic (T6-T9): Vasoconstriction, pain transmission

Question 9

List the parts of the stomach.

Answer 9

Cardia

Fundus

Body

Pyloric part (antrum, canal, sphincter)

Lesser and greater curvatures

Question 10

Which arteries supply the stomach?

Answer 10

Branches of the coeliac trunk:

Left and right gastric arteries

Short gastric arteries (from splenic artery)

Left and right gastroepiploic arteries

Question 10

What structures are posterior to the stomach?

Answer 10

Left kidney, spleen, pancreas, transverse mesocolon, omental bursa, splenic artery.

Question 10

What are the anterior relations of the thoracic oesophagus?

Answer 10

Trachea

Left recurrent laryngeal nerve

Left main bronchus

Pericardial sac and left atrium

Question 11

What structures are posterior to the thoracic oesophagus?

Answer 11

Thoracic vertebrae

Thoracic duct

Azygos vein

Descending thoracic aorta (lower part)

Question 11

Which nerve is at risk during thyroid surgery due to its proximity to the oesophagus in the neck?

Answer 11

Recurrent laryngeal nerve (RLN), which runs anteriorly in the neck.

Question 12

Why is the abdominal oesophagus retroperitoneal?

Answer 12

It lies behind the peritoneum, covered only by the phrenoesophageal ligament, and is 1–2.5 cm long.

Question 13

What is the clinical significance of the oesophageal porto-systemic anastomosis?

Answer 13

In portal hypertension, increased pressure in the left gastric vein (portal) → dilation of oesophageal veins → varices → risk of rupture and hematemesis.

Question 14

Which lymph nodes drain the middle third of the oesophagus?

Answer 14

Superior and posterior mediastinal nodes.

Question 15

What is the function of the stomach’s rugae?

Answer 15

Gastric folds (rugae) allow expansion for food storage and increase surface area for digestion.

Question 16

What structures form the anterior and posterior relations of the abdominal oesophagus?

Answer 16

Anterior: Left lobe of the liver

Posterior: Left crus of the diaphragm

Question 17

Which arteries supply the lesser and greater curvatures of the stomach?

Answer 17

Lesser curvature: Left and right gastric arteries

Greater curvature: Left and right gastroepiploic arteries + short gastric arteries

Question 18

What is the nerve of Latarget, and what is its function?

Answer 18

The anterior vagal trunk (branch of the left vagus) → stimulates gastric motility and secretion.

Question 19

A patient with achalasia has failure of which oesophageal structure?

Answer 19

Lower oesophageal sphincter (LOS) fails to relax, causing proximal dilatation and dysphagia.

Question 20

What is the embryological origin of the stomach’s rotation, and how does it affect its anatomy?

Answer 20

Rotates 90° clockwise during development → vagus nerves reposition: Left vagus → anterior Right vagus → posterior

Question 21

Which vein drains the middle third of the oesophagus, and is it part of the portal or systemic system?

Answer 21

Azygos vein (systemic).

Question 22

What is the significance of the transpyloric plane (L1) in stomach anatomy?

Answer 22

It marks the pyloric-duodenal junction and is a key landmark for abdominal structures (e.g., pancreas, kidneys).

Question 23

Why might gastric cancer metastasize to the left supraclavicular node (Virchow’s node)?

Answer 23

Lymph from the stomach drains to coeliac nodes → thoracic duct → left venous angle → involvement of Virchow’s node.

Question 24

What is the role of the greater omentum in peritonitis?

Answer 24

It can migrate to wall off infections (e.g., from a perforated ulcer)limiting spread.

Question 25

Which spinal cord segments transmit sympathetic fibers to the stomach?

Answer 25

T6–T9 via the greater splanchnic nerve → coeliac plexus.

Question 26

What is the most common site for peptic ulcers, and why?

Answer 26

Lesser curvature (especially posterior wall) due to vulnerability of its arterial supply (end-arteries from left/right gastric arteries).

Question 27

How does vagotomy treat peptic ulcers, and what is a potential side effect?

Answer 27

Cuts vagal trunks → reduces acid secretion; side effect: delayed gastric emptying (loss of motility).

Question 28

What is the "bare area" of the stomach, and why is it clinically relevant?

Answer 28

Posterior stomach wall not covered by peritoneum → ulcers here may perforate into the lesser sac (omental bursa).

Question 29

What is the clinical triad of achalasia?

Answer 29

Dysphagia (difficulty swallowing) Regurgitation Weight loss