General GI tract anatomy Flashcards
What does the peritoneal cavity normally contain?
A small amount of lubricating fluid
What is the relation of ‘intra-peritoneal’ organs to the peritoneal cavity?
They are enveloped in the cavity but not inside of it
What is the relation of ‘retro-peritoneal’ organs to the peritoneal cavity?
Their anterior surfaces are in contact with the cavity but they lie posterior to it
What is pneumo-peritoneum and what can cause it?
When air or gas gets into the peritoneal cavity. This can be a pathological process or as a result of laraposcopy when the cavity is inflated with CO2 so that they can see what they are doing
What significant artery can be damaged if a duodenal ulcer perforates?
gastro-duodenal artery which lies behind the first part of the duodenum
What are the clinical consequences of a damaged gastro-duodenal artery from duodenal ulcer perforation?
Severe bleeding and often massive haematemesis (vomiting up blood)
Blockage of what veins can cause portal hypertension?
Hepatic veins (which drain into the inferior vena cava) as they are distal to the portal vein and so would limit the flow through the portal vein and cause a rise in portal pressure
What forms the anterior border of the lesser sac?
- Posterior surface of stomach
- Lesser omentum
- Part of the greater omentum
What forms part of the posterior border of the lesser sac?
- Diaphragm
2. Pancreas
What is a porto-systemic anastomosis?
A part of the body which normally drains into the portal system but which has the facility to drain blood into the systemic system
In oesophageal varices how does the blood drain into the systemic system?
Systemic drainage - via the azygous vein
Portal drainage - via the left gastric vein
In the porto-systemic varices that present as the caput medusae, which veins are involved?
para-umbilical veins - veins which carry oxygenated blood from the mother to the fetus in utero and are noramally closed within one week of birth but can become re-canalised due to portal hypertension
What branch of the coeliac trunk gives rise to the left gastroepiploic artery (also called gastro-omental artery)
Splenic artery
Where does the left gastroepiploic artery travel after it has branched off of the splenic artery?
It travels along the greater curve of the stomach (about a cm away from it) to anastomise with the right gastroepiploic artery.
What are the three main structures that lie in the free edge of the lesser omentum?
Hepatic artery
Hepatic portal vein
Common bile duct
What is the ligamentum teres?
A remnant of the foetal umbilical vein, found in the falciform ligament
The gastro-duodenal artery branches off which artery to make its way down past the posterior of the first part of the duodenum?
Commonly the common hepatic artery
When does the common hepatic artery become known as the proper hepatic artery?
After the gastro-duodenal artery branches off of the common hepatic artery
The greater sac is divided into supracolic and infracolic compartments. What structure forms the physical divide between these compartments?
Transverse mesocolon (mesentery of the transverse colon)
Where is the gastrocolic ligament attached?
To the greater curve of the stomach and the transverse colon
What divides the infracolic compartment into right and left infracolic spaces?
The mesentery of the small intestine (holding it to the posterior abdominal wall)
The paracolic gutters are channels within the peritoneal cavity which connect the supracolic and infracolic compartments. Where do they lie?
Lateral to the ascending and descending colon (between the lateral aspect of the ascending and descending colon and the lateral abdominal wall)
What two compartments is the greater sac divided into?
Supracolic and infracolic compartments
Where is the pouch of Douglas found?
Beween the rectum and uterus (in females!). It is also called the rectouterine pouch
Below the arcuate line, what is the posterior surface of the rectus abdominis muscle in contact with?
The aponeurosis of the transverse abdominis
At what spinal level does the oesophagus pierce the diaphragm?
T10
NB: there are ten letters in the word ‘oesophagus’
At what spinal level does the vena cava pierce the diaphragm?
T8
NB: there are eight letters in the word ‘vena cava’
At what spinal level does the aorta pierce the diaphragm?
T12
NB: aortic hiatus has 12 letters in it
What structure lies around the oesophageal hiatus (where the oesophagus pierces the diaphragm) and helps prevent reflux of the stomach contents into the oesophagus?
Right crus of the diaphragm (a tendinous structure) which helps prevent reflux by tightening around the lower oesophagus
What structure of the diaphragm does the vena cava pass through?
Central tendon of the diaphragm
Which part of the pancreas does the portal vein originate behind?
Neck - at the confluence of the splenic and superior mesenteric veins
What is the name of the artery that supplies blood to the lesser curve of the stomach?
Left gastric artery - which anastomoses with the right gastric artery (along the lesser curve of the stomach)
What are the three main branches of the coeliac trunk?
Left gastric artery
Splenic artery
Common hepatic artery
What is the name of the small lobe of the liver that lies in close approximation to the gallbladder?
Quadrate lobe
What is the name of the small lobe of the liver that lies very close to the vena cava at the posterior aspect of the liver?
Caudate lobe
What structures lies in the free edge of the lesser omentum?
The hepatic artery, portal vein and common bile duct
What artery does the gastroduodenal artery branch off of?
Common hepatic artery - it then descends down the posterior surface of the duodenum
What are the names of the sphincters which control the input and output of food into the stomach?
Superior sphincter - lower oesophageal sphincter
Inferior sphincter - pyloric sphincter
Where are the subphrenic spaces found?
Recesses in the greater sac between the anterosuperior face of the liver and the diaphragm
What divides the subphrenic spaces into left and right?
Falciform ligament
Where can the lymph nodes be found near the stomach?
the gastric lymphatic vessels travel with the arteries along the greater and lesser curvatures of the stomach. Lymph fluids drain into the gastric and gastroepiploic lymph nodes found at these curvatures. Efferent lymphatic vessels from these nodes connect to the coeliac lymph nodes
What is the anatomical relationship between the duodenum and the pancreas?
The ucinate process, head and neck of the pancreas are nestled in the C shape of the duodenum
What is the relationship between the spenic blood vessel and the tail of the pancreas?
The splenic artery and vein travel along behind the posterior surface of the pancreas’ tail
Where do the superior mesenteric vein and splenic vein meet?
neck of pancreas
What is the relationship between the superior mesenteric vessel (artery and vein) and the third part of the duodenum?
The superior mesenteric vessel pass over the anterior surface of the third part of the duodenum
