GI 7 - The Liver Flashcards
Name the anatomical lobes of the liver:
- Left lobe
- Right lobe
- Caudate lobe
- Quadrate lobe
Name the ligaments associated with the Liver:
- Falciform ligament (containing ligamentum teres hepatitis)
- Ligamentum venosum
- Coronary ligaments
- Triangular ligaments
What structures enter/leave the Liver at the porta hepatits?
- Hepatic portal vein
- Hepatic artery proper
- Hepatic bile ducts
Name the duct formed when the hepatic bile ducts join the cystic duct:
Common bile duct
Name the duct formed when the common bile duct joins the pancreatic duct:
Ampulla of Vater
How many functional lobes make up the Liver?
8
What is the blood supply to the Liver?
- Hepatic artery proper ~ 30%
- Hepatic portal vein ~ 70%
Describe the breakdown of haem:
Haem
- into biliverdin
- into unconjugated bilirubin
- Liver conjugates bilirubin
- GI breaks it down to Stercobilin + Urobilinogen
What volume of bile is secreted by the Liver per day?
~ 250 - 1000 ml/day
What is the main function of bile?
Emulsifies fats to increase surface area for lipases
List the contents of bile:
- Bile salts ~ 60%
- Fatty acids ~ 12%
- Cholesterol ~ 9%
- Proteins
- Bilirubin
What are bile salts made up of?
- Bile acids (Cholic acid + Chenodeoxycholic acid
- Amino acids (Glycine + Taurine)
Which of bile acids and bile salts are soluble at duodenal pH?
Bile salts
What 3 vessels are present in a hepatic triad?
- Bile duct
- Hepatic arteriole
- Portal venule
What shape is a hepatic lobule?
Hexagonal
Which zone of a hepatic acinus is most susceptible to hypoxic damage? Why?
Zone 3
Furthest from oxygenated blood supply
Which zone of a hepatic acinus is most susceptible to toxic damage? Why?
Zone 1
Closest to blood supply
What is a Kupffer cell, and where are they found?
Phagocytic cell
Lining hepatic sinusoids
What are the 2 mechanisms of bile secretion?
- Bile acid independent
- Bile acid dependent
Name the cells which produce the bile acid independent fraction of bile:
Hepatocytes lining the canaliculi
Name the cells which produce the bile acid dependent fraction of bile:
Intra-hepatic bile duct cells
Describe the circulation of bile salts:
- Secreted by Liver
- Emulsify fats and form micelles in GI tract
- Fats diffuse into epithelia lining GI tract
- Bile salts stay in gut, reabsorbed @ terminal ileum
- Return to Liver via Portal vein
Why does the Liver only need to synthesise very low amounts of bile salts?
Most bile salts are cycled back to the Liver from the GI tract, and re-used, so no need to continuously synthesise more
What is achlorhydria, and what can cause it?
- Low level or absence of HCl in gastric secretions
- Helicobacter pylori
- PPIs
- H2 antagonists
Name the 3 types of jaundice:
- Pre-hepatic
- Hepatic
- Post-hepatic
List some causes of pre-hepatic jaundice:
Haemolytic anaemia:
- Hb abnormalities ie SCA
- Infections
- Drugs
- Burns
List some causes of hepatic jaundice:
Liver failure:
- Alcohol
- Fatty-liver disease
- Drug overdose
- Autoimmune
- Viral
List some causes of post-hepatic jaundice:
Obstruction:
- Gallstones
- Pancreatitis
- Pancreatic cancer
What additional symptom is associated with post-hepatic jaundice, but not pre- or hepatic jaundice?
Steatorrhoea due to blocked bile duct
Liver function tests include measuring AST and ALT levels. What do AST and ALT stand for?
AST = Aspartate transaminase ALT = Alanine transaminase
