Lecture 3 (B) - Liver and spleen Flashcards
What is the liver attached to?
Develops in the ventral mesentery connected the abdominal wall via the falciform ligament and the stomach via the lesser omentum. It is also in direct contact with part of the diaphragm and is mostly under the cover of the rib cage.
What makes the separation of the left and right functional lobes of the liver?
- Falciform ligament
- Gall bladder
- IVC
What marks the separation of the quadrate and caudate lobes?
The porta (which carries the hepatic artery, portal vein, common bile duct and the lymphatics within it)
What are the four lobes of the kidney?
- Right
- Left
- Caudate
- Quadrate
How is blood supplied to the liver?
Via the hepatic artery (highly oxygenated) and the hepatic portal vein coming from the abdominal viscera and spleen (not very well oxygenated but nutrient-rich)
How is blood drained from the liver?
Through three short veins that drain directly into the IVC.
What happens to the portal/systemic blood flow in liver disease?
The portal-systemic anastomoses may become dilated if the portal blood flow through the liver is obstructed.
What forms the ampulla of Vater?
Common bile duct and pancreatic duct, entering the duodenum at the major duodenal papilla.
What controls the movement of pancreatic juice/bile into the duodenum?
Sphincter of Oddi - tonically active so must be relaxed to allow the pancreatic juice to pass through into the duodenum.
What forms the common bile duct?
The common hepatic duct and the cystic duct (from the gall bladder).
How can bile/pancreatic juice flow be obstructed?
In cases of pancreatic neoplasms, tumours can obstruct the ducts and cause pancreatitis, which may lead to the auto-digestion of the pancreatic tissue due to activation of enzymes.
What forms the common hepatic duct?
Left and right hepatic ducts.
What is the spleen?
The largest lymphoid organ in the body - technically not a GI tract organ but its blood flow is similar to that of the GI tract and it drains into the liver via the hepatic portal vein.
Is the spleen within a mesentery?
It is suspended in the dorsal foregut mesentery.
Where is the spleen located?
Lies posteriorly on the left side, under ribs 9, 10 and 11.
What ligaments are part of both the greater omentum and the spleen?
- Gastrosplenic ligament
- Splenorenal ligament
How is blood supplied to the spleen?
Via the splenic artery (a branch off of the coeliac trunk)
How is blood drained from the spleen?
Via the splenic vein, which also drains deoxygenated blood from the stomach (fungus) and parts of the pancreas, forming part of the hepatic portal system.
What regions is the liver found?
Right hypochondrium and epigastric areas and extends into the left hypochondrium.
How is the liver connected to the anterior abdominal wall?
Via the falciform ligament (remnant of the ventral foregut mesentery)
What are the two external surfaces of the liver?
- Diaphragmatic surface
- Visceral surface
What is the diaphragmatic surface of the liver?
The posterior aspect of the liver that is not covered in visceral peritoneum - comes into direct contact with the liver and is called the ‘bare area’ of the liver.
What covers the visceral surface of the liver?
- Covered in visceral peritoneum except for the porta hepatis and gall bladder fossa
- Comes into contact with stomach, duodenum, right kidney and colon
How can the right lobe be further divided?
Into the caudate and quadrate lobe.
What are the locations of the quadrate and caudate lobes?
Caudate - posterior between the IVC and ligaments venousum
Quadrate - anterior, between the gallbladder and ligamentum teres
How is the liver attached to the inferior surface of diaphragm?
Via coronary ligament. Right and left triangular ligaments attach the right and left lobes to the diaphragm also.
What do the ligamentum trees and venousum do?
Separate the caudate and quadrate lobes from the left lobe.
What are the ligaments of the liver?
- Falciform ligament
- Coronary ligament
- Right and left triangular ligaments
- Ligamentum teres and venosum
How are the functional lobes divided and how many segments make up each?
Divided by an imaginary line between the gallbladder and IVC.
Left - segments 1-4
Right - Segments 5-8 (bigger than first four segments)
Functionally, which lobe do the caudate and quadrate lobe belong to?
Left (vascular) lobe
How is blood supplied to the liver?
Hepatic artery proper - 25%
Hepatic portal vein - 75%
What are haemorrhoids?
Rectal varies that often cause itching and bleeding after passing stool.
Where is the gall bladder found?
In a fossa between the quadrate and right love of the liver.
Where is a common place for gallstones to cause an obstruction?
At Hartmann’s pouch - mucosal fold in the neck of the gall bladder.
How is blood supplied to the gall bladder?
Via the cystic artery
What is cholecystitis?
When a gallstone remains in the cystic duct, leading to inflammation and mucosal oedema.
What is ascending cholangitis?
When there is a gallstone in the CBD, causing bacteria from the gut to travel up and enter the system circulation. Causes gram-negative sepsis with a high mortality rate.
What best describes the liver’s relation to the peritoneum?
Intraperitoneal - almost fully covered by visceral peritoneum.
How many anatomical liver lobes are there?
2 main lobes and 2 sublobes.
Is the spleen intra or retro-peritoneal?
Intraperitoneal - forms with dorsal mesentery.