Oesophagus, Stomach and Duodenum

Question 1

Name the 4 oesophageal contrictions

Answer 1

1) Cricopharyngeal sphincter (C6)
2) Arch of aorta (T4),
3) Left main bronchus,
4) Diaphragm (T10)

Question 2

Describe the different muscle types of the oesophagus and their innervation and arterial supply

Answer 2

Superior 1/3 - striated (vagus nerve via recurrent laryngeal and inferior thyroid artery).

Middle 1/3 - Mixed (oesophageal plexus and aorta)

Inferior 1/3 - Smooth (oesophageal plexus and left gastric and inferior phrenic artery)

Question 3

Describe the arterial supply, venous drainage and nerve supply of abdominal oesophagus

Answer 3

Arterial supply via left gastric artery (branch of coeliac trunk). The veins drain to the portal vein (via left and short gastric veins) and to the azygos system via oesophageal veins. Oesophageal plexus. Lymph - celiac and left gastric LNs

Question 4

What are the anti-reflux mechanisms

Answer 4

Circular smooth muscle fibres in lower oesophagus and the right crus of the diaphragm

Question 5

What does the lower oesophageal sphincter control?

Answer 5

Oblique entry of the oesophagus into stomach

Question 6

What is the Z line and where is it located?

Answer 6

It is the gastro-oesophageal junction between oesophagus squamous epithelium and red columnar epithelium below

Question 7

What is Labbe Triangle and its boarders

Answer 7

Location where the stomach is in contact with abdominal wall. Boarders are left costal arch, lower boarder of liver and the horizontal line connecting the tips of the 9th CC

Question 8

Describe the histology of the stomach

Answer 8

• Simples columnar epithelium, Parietal cells that secrete hydrochloric acid, chief cells which produce precursors of pepsin and DNES cells which produce hormones

Question 9

What are the anterior relations of the stomach

Answer 9

Anterior abdo wall, left costal margin, diaphragm, left pleura and lung and the left lobe of the liver.

Question 10

What are the posterior relations of the stomach?

Answer 10

Lesser sac, spleen, upper pole of left kidney, left suprarenal gland, pancreases, splenic artery, transverse colon and transverse mesocolon

Question 11

Name the different parts of the stomach

Answer 11

Cardia - Surrounds the opening of the oesophagus into the stomach,

Fundus - Area above the level of the cardiac orifice,

Body

Pyloric part (atrium and then canal)

Question 12

What forms the pyloric sphincter and what is its role?

Answer 12

Circular fibres of the pyloric region. This controls the outflow of gastric contents into the duodenum.

Question 13

Describe the arterial supply of the stomach that run along the lesser curvature

Answer 13

1) Left gastric artery - branch of coeliac trunk.

2) Right gastric artery - branch of hepatic artery (derived from coeliac trunk)

Question 14

Describe the arterial supply of the stomach which runs along the greater curvature

Answer 14

1) Left gastroepiploic artery - branch of Splenic artery (runs in gastro-splenic ligament)
2) Right gastroepiploic artery - Branch of the gastroduodenal branch of hepatic artery.
3) Short gastric arteries - Branches of splenic artery (supply fundus)

Question 15

Describe the venous drainage of the stomach

Answer 15

Left and right gastric veins drain to hepatic portal vein.

Short gasstric and left gastroepiploic veins drain to splenic vein then to hepatic portal.

Right gastroepiploic vein to superior mesenteric vein then hepatic portal

Question 16

Describe the lymphatic drainage of the stomache

Answer 16

Zone 1 - Subpyloric and omental nodes.

Zone 2 - Pancreaticosplenic nodes,

Zone 3 - Superior gastric nodes,

Zone 4 - Suprapyloric nodes. All drain to celiac nodes

Question 17

Describe the nerve supply of the stomach

Answer 17

Sympathetic from greater splanchnic nerve and control pain and vasomotor..
Parasympathetics from vagal trunks, they increase secretion, motility, relax sphincters and afferents for emesis

Question 18

What forms the stomach bed?

Answer 18

• Left crus of diaphragm,
• Spleen,
• Left suprarenal gland,
• Upper pole of left kidney,
• Body and tail of pancreas,
• Transverse mesocolon,
• Left colic flexure,
• Splenic artery

Question 19

What are hiatus hernia?

Answer 19

Herniation of the stomach through the diaphragm into the mediastinum either sliding or para-oesophageal (rolling)

Question 20

What is the significance of para-oesophageal hernias?

Answer 20

They can causes obstruction and/or ischaemia of the herniated stomach

Question 21

Name the divisions of the small intestine

Answer 21

Duodenum, Jejunum and Ilium.

Question 22

What three structural modifications amplify the absorptive surface of the small intestine?

Answer 22

Circular folds - Transverse ridges of the mucosa and submucosa.
Villi - Contain a network of blood capillaries and lacteals.
Microvilli - These are on the apical surface of the absorptive cells of the villi.

Question 23

What are the 4 parts of the duodenum and the function of the duodenum

Answer 23

Superior (L1), descending (L2-L3), horizontal (L3) and ascending (back to L2). The functions are digestion (especially fats) and absorption.

Question 24

What is the minor duodenal papilla?

Answer 24

Opening of the accessory pancreatic duct into the duodenum.

Question 25

What is the major duodenal papilla?

Answer 25

Common opening of the common bile and pancreatic ducts

Question 26

What is the blood supply of the forgut duodenum?

Answer 26

It is supplied by the supraduodenal and superior pancreaticoduodenal artery which are branches of the gastroduodenal artery which is a branch of the common hepatic artery.

Question 27

What is the blood supply o the midgut duodenum?

Answer 27

The inferior pancreaticoduodenal artery which is a branch of the superior mesenteric artery

Question 28

Describe the lymphatic drainage of the duodenum

Answer 28

Vessels drain to superior mesenteric or pancreoticoduodenal and pyloric nodes

Question 29

Describe the venous drainage of the duodenum

Answer 29

Veins drain to hepatic portal vein through superior mesenteric and splenic veins.

Question 30

Describe the nerve supply of the duodenum

Answer 30

Sympathetics from greater splanchnic nerves and parasympathetics from vagus