Liver and Biliary Tree Anatomy Flashcards
What is the falciform ligament?
The falciform ligament provides an attachment to the liver with the anterior abdominal wall. It is a fold of the peritoneum (internal lining of abdominal.
What is the lesser omentum?
The double layer of peritoneum that extends from the liver to the lesser curvature of the stomach (hepatogastric ligament) and the first part of the duodenum (hepatoduodenal ligament).
What is the greater omentum?
The greater omentum is a prominent peritoneal fold that hangs down from the stomach anterior to the transverse colon, to which it is attached. The greater omentum is a double fold that connects the stomach to the posterior abdominal wall
What is the portal triad?
The three main structures that enter the liver: hepatic artery proper, hepatic portal vein and the bile duct (in addition to a branch of the vagus nerve and the lymphatics)
What is the porta hepatis?
This region of the liver functions similarly to a hilum and acts as the ‘liver root’. This region contains the portal triad (hepatic artery proper, bile duct and portal vein), lymph nodes and autonomic nerve fibres.
What is the ligament venosum?
The ligamentum venosum is the fibrous remnant of the ductus venosus of the fetal circulation. Usually, it is attached to the left branch of the portal vein within the porta hepatis and it may be continuous with the round ligament of liver
It is invested by the peritoneal folds of the lesser omentum within a fissure on the visceral/posterior surface of the liver between the caudate and main parts of the left lobe.
Name the lobes of the liver
Left, right, quadrate and caudate
What three structure pass into the liver at the porta hepatis?
Hepatic artery proper, bile duct and hepatic portal vein
Name the ligaments of the liver
Right/left coronary ligaments, right/left triangular ligaments, falciform ligament, round ligament, ligamentum venosum
Where are the coronary ligaments of the liver found?
The convex diaphragmatic surface of the liver (anterior, superior and a little posterior) is connected to the concavity of the inferior surface of the diaphragm by reflections of peritoneum. The coronary ligament is the largest of these, having an anterior (frontal) and posterior (back) layers.
Where are the triangular ligaments of the liver found?
The anterior and posterior coronary ligament layers converge on the right and left sides of the liver to form the right triangular ligament and the left triangular ligament, respectively.
What is the omental bursa and where is it found?
This is also known as the lesser sac; the cavity in the abdomen that is formed by the lesser and greater omentum.
What and where is the epiploic/omental foramen?
The passage of communication, or foramen, between the greater sac (general cavity (of the abdomen)), and the lesser sac.
What structures make up the lesser omentum?
Hepatoduodenal and hepatogastric ligaments
What two arteries supply the liver?
Hepatic portal vein (75% of blood supply) and coeliac trunk (25% of blood supply)
What two veins make up the hepatic portal vein?
Splenic and superior mesenteric vein; these meet at the posterior head of the pancreas to form the portal vein
What is liver cirrhosis?
Liver cirrhosis is a consequence of chronic liver disease that is grossly characterised b the replacement of liver tissue by fibrosis, scar tissue and regenerative nodules which eventually leads to the loss of liver function
What are regenerative nodules?
Lumps that occur as a result of damaged tissue being regenerated
What is normal portal pressure?
9mmHg
What is normal inferior vena cava pressure?
2-6mmHg
How is portal hypertension defined?
Portal pressure gradient (portal pressure - IVC pressure) that is greater than 10mmHg
Name the different porto-systemic anastomoses in the body, and why is this clinically relevant?
Oesophageal, rectal, anterior abdominal wall and retroperitoneal; these can all be sites affected by increased portal pressure that can lead to the production of varices
Describe the porto-systemic anastomosis in the oesophagus
Systemic drainage: The superior oesophagus is drained by the oesophageal veins to the azygos vein
Portal drainage: the inferior oesophagus drains into the left gastric veins
Describe the cause of oesophageal varices
At the gastro-oesophageal junction there is anastamosis between the left gastric veins (portal) and oesophageal veins (systemic to azygos); if there is an increase in portal pressure there is blood pooling in the liver so portal drainage is impeded, and therefore the oesophageal blood will preferably drain into the systemic drainage (oesophageal veins) and increase the pressure in these veins which can cause the veins to lengthen and dilate (oesophageal varices)
What is ascites?
Fluid in the peritoneal space
What are the common causes of ascites?
Portal hypertension (increased hydrostatic capillary pressure), hypoalbuminaemia (decreased colloid osmotic pressure) and aldosterone-related renal sodium retention –> increased blood volume
What is caput medusae?
This is where the round ligament (ligamentum teres hepatis), which is the remnant of the umbilical vein, found within the falciform ligament, becomes re-vascularised due to increased portal pressure and this umbilical vein then starts to drain into the paraumbilical veins into the systemic circulation
Describe the blood supply of the ano-rectal junction
Systemic:
The middle rectal and inferior rectal veins which give rise to the internal and external venous plexi respectively drain up into the internal iliac vein
Portal:
The superior rectal vein drains into the inferior mesenteric vein
What is the portal and systemic venous drainage of the oesophagus?
Portal: left gastric vein into the IVC
Systemic: oesophageal veins into the azygos
What is the portal and systemic venous drainage of the rectum?
Portal: superior rectal vein to the internal iliac vein
Systemic: superior rectal vein to the inferior mesenteric vein
What is the portal and systemic venous drainage of the anterior abdominal wall?
Portal: umbilical vein (if the round ligament is revascularised in portal hypertension) which drains into the paraumbilical veins
Systemic: the intercostal and inferior epigastric veins
What is the portal and systemic venous drainage of the retro-peritoneal wall?
Portal: duodenal, pancreatic, right and left colic veins
Systemic: lumbar veins
What is the major duodenal papilla?
It’s the main entry of the bile duct into the duodenum, and this structure is surrounded by the sphincter of Oddi
What is the hepatopancreatic ampulla/ampulla of Vader?
Where the material collects prior to flowing to the major duodenal papilla
Where is the common hepatic duct found?
In the free margin of the lesser omentum
Where is the bile duct found?
In the free margin of the lesser momentum anterior to the hepatic portal vein and to the right of the hepatic artery
Why may gall bladder inflammation (cholecystitis) lead to pain in the upper right quadrant that can be referred to the right flank or scapula?
The gall bladder is related to the hepatic flexure of the colon and duodenum and therefore an inflamed gall bladder (cholecystitis) may herniate into these structures and lead to pain in the upper right quadrant that can be referred to the right flank or scapula, relevant to the innervation of the structures impeded.
What is Calot’s triangle?
An anatomic space bordered by the cystic duct inferiorly, common hepatic duct medially and the inferior (visceral) surface of the liver superiorly.
What’s the blood supply to the gall bladder?
The cystic artery which is branch off of the right hepatic artery
What is the round ligament (ligamentum teres hepatis) of the liver?
Is a degenerative string of tissue that exists in the free edge of the falciform ligament of the liver
