Oesophagus, Stomach and Duodenum Part 1

Question 1

Describe the function of the oesophagus

Answer 1

transports food and fluid to the stomach by peristaltic waves

Question 2

Describe the position and relations of the oesophagus

Answer 2

• starts in the midline as continuation of pharynx at C6 inferior border of cricoid)
• descends between trachea and vertebral column
• enters thorax behind trachea with arch of aorta to the left in superior mediastinum
• enters abdominal cavity at T10 slightly left of midline

Question 3

What are the 5 possible constriction of the oesophagus?

Answer 3

4 non-pathological:

• upper oesophageal sphincter C6
• arch of aorta T4
• left main bronchus
• diaphragm T10

1 pathological:
- left atrium if dilated

Question 4

What is the role of the cricophayngeal sphincter?

Answer 4

prevents air from entering the stomach by the oesophagus

Question 5

What are the problems with oesophageal constrictions?

Answer 5

• more likely to cause blockage
• can hinder the passage of instruments
• can slow down the passage of damaging substances which can allow them to cause more harm

Question 6

Describe the neurovascular supply and muscle type of the superior 1/3rd of the oeosphagus

Answer 6

• striated muscle
• arterial: inferior thyroid artery
• venous: BCV
• innervation: vagus (by recurrent laryngeal)
• lymphatic: deep cervical nodes

Question 7

Describe the neurovascular supply and muscle type of the middle 1/3rd of the oesophagus

Answer 7

• mixed muscle
• arterial: aorta and bronchial arteries
• venous: azygos
• innervation: oesophageal plexus
• lymphatic: tracheobronchial nodes

Question 8

Describe the neurovascular supply and muscle type of the inferior 1/3rd of the oesophagus

Answer 8

• smooth muscle
• arterial: left gastric and left inferior phrenic arteries
• venous: left gastric and oesophageal vein
• innervation: oesophageal plexus
• lymphatics: left gastric coeliac nodes

Question 9

What is the abdominal oesophagus?

Answer 9

• shortest part of oesophagus
• from oesophageal hiatus to the cardiac orifice of stomach
• passes through right crus to diaphragm at T10
• tethered to margins of oesophageal hiatus by phrenooesophageal ligament

Question 10

Describe the neurovascular supply of the abdominal oesophagus

Answer 10

• arterial: left gastric artery (from coeliac trunk)
• venous: portal vein (through left and short gastric veins) and azygos system (through oesophageal veins)
• innervation: oesophageal plexus (parasympathetics from vagus, sympathetics from greater splanchnic)

Question 11

What are the anti-reflux mechanisms of the lower oesophgeal sphincter?

Answer 11

Major:

• circular smooth muscle fibres in lower oesophagus
• right crus of diaphragm

Minor:

• clasp fibres
• oblique entry of oesophagus into stomach

Question 12

Achalasia

Answer 12

• when the ganglion cells in the myenteric plexus of the distal oesophagus and gastro-oesophageal junction are reduced or absent
• results in sphincter failing to open during swallowing causing a backup of food

Question 13

What is the Z-line?

Answer 13

• key landmark used in endoscopy
• where the epithelia between the oesophagus and the stomach changes
• pink stratified squamous epithelia changes to red columnar epithelia

Question 14

Barrett’s Oesophagus

Answer 14

• pathological replacement of oesophageal squamous epithelium by gastric columnar epithelium
• pre-cancerous as cells are starting to change

Question 15

Where is the stomach located?

Answer 15

epigastric, left hypogastric and partially umbilical region

Question 16

What is the Labbe triangle and what are its borders?

Answer 16

• where the stomach is in contact with the abdominal wall
• left costal arch
• lower border of liver
• horizontal line connecting tips of left and right 9CC

Question 17

What are the functions of the stomach?

Answer 17

• temporary storage of ingested food
• mechanical breakdown of solid food
• chemical digestion of proteins
• mixes food with gastric secretions forming chyme
• regulation of rate of passage of chyme to duodenum
• secretion of acid to aid digestion and absorb iron
• secretion of intrinsic factor for vitamin B12 absorption
• secretion of gut hormones
• microbial defence

Question 18

What are the anterior relations of the stomach?

Answer 18

• anterior abdo wall
• left costal margin
• diaphragm
• left pleura and lung
• left lobe of liver

Question 19

What are the posterior relations of the stomach?

Answer 19

• lesser sac
• spleen
• upper pole of left kidney
• left suprarenal gland
• pancreas
• splenic artery
• transverse colon
• transverse mesocolon

Question 20

Name the arteries that supply the stomach

Answer 20

• all come from the coeliac trunk
• left gastric artery (direct from coeliac trunk)
• right gastric artery (from common hepatic artery)
• left gastroepiploic artery (of splenic artery)
• right gastroepiploic artery (of gastroduodenal branch of common hepatic)
• short gastric arteries (of splenic artery)

Question 21

Where do the left and right gastric arteries and run and what do they supply?

Answer 21

Left:

• runs along lesser curvature
• supplies abdominal oesophagus, proximal lesser curvature and adjacent body of stomach

Right:

• runs along lesser curvature
• supplies distal lesser curvature and adjacent body of stomach

Question 22

Where do the left and right gastroepiploic arteries run and what do they supply?

Answer 22

Left:

• runs in gastro-splenic ligament
• supplies the left side of greater curvature and adjacent body of stomach

Right:
- supplies the right side of the greater curvature and adjacent body of the stomach

Question 23

Where do the short gastric arteries run and what do they supply?

Answer 23

• runs in gastro-splenic ligament

- supplies the fundus of the stomach

Question 24

Describe the venous drainage of the stomach

Answer 24

• veins run parallel to arteries
• L and R gastric veins to hepatic portal vein
• short gastric and L gastroepiploic veins to splenic vein to hepatic portal vein
• R gastroepiploic vein to superior mesenteric vein to hepatic portal vein