hepatobiliary pathology Flashcards
describe the function of liver
- protein synthesis
- metabolism of fat and carbohydrates
- storage
- detoxification of drugs and toxins
what are examples of pathologies of the liver?
- liver failure
- jaundice
- intrahepatic bile duct obstruction
- cirrhosis
- tumours
what are examples of pathologies of the gallbladder?
inflammation
what are examples of pathologies of the extrahepatic bile ducts?
obstruction
what 2 broad categories is liver failure a complication of?
- acute liver injury
- chronic liver injury (such as cirrhosis)
what are examples of acute liver injury?
hepatitis
bile duct obstruction
what can cause hepatitis which causes acute liver injury?
- viruses: hep A, B, C, E, other viruses
- alcohol
- drugs
what is the pathology of virus hepatitis?
- inflammation of the liver
- liver cell damage and death of the individual liver cells
what are the possible outcomes of viral hepatitis
- resolution: liver function returns to normal (hep A &E)
- liver failure: if severe damage to the liver (hep A, B & E)
- progression to chronic hepatitis and cirrhosis (hep B & C)
what is alcohol liver disease?
fatty change of liver to excess alcohol
alcohol hepatitis: acute inflammation, liver cell death, liver failure, progress to cirrhosis
what is jaundice caused by?
increased circulating bilirubin
caused by altered metabolism of bilirubin
what are the pathways of bilirubin metabolism?
- pre-hepatic
- hepatic
- post-hepatic
describe the pre-hepatic pathway of bilirubin metabolism
breakdown of haemoglobin in spleen to form haem and globin
haem is converted into bilirubin
release of bilirubin into circulation
describe the hepatic pathway of bilirubin metabolism
uptake of bilirubin by hepatocytes
conjugation of bilirubin in hepatocytes
excretion of conjugated bilirubin into biliary system
describe the post-hepatic pathway of bilirubin metabolism
transport of conjugated bilirubin in biliary system
breakdown of bilirubin conjugate in small intestine
re-absorption of bilirubin
what are the 3 broad categories of causes of jaundice?
pre-hepatic: increased haemolysis
hepatic: cholestasis, intrahepatic bile duct obstruction
post-hepatic: cholelithiasis, gall bladder diseases, extrahepatic bile duct obstruction
what is haemolysis
increased release of haemoglobin from red cells
what is cholestasis?
accumulation of bile within hepatocytes or bile canaliculi
what are some causes of cholestasis?
- viral hepatitis
- alcoholic hepatitis
- liver failure
- drugs
what are causes of intra-hepatic bile duct obstruction?
- primary biliary cholangitis
- primary sclerosing cholangitis
- tumours of the liver
what is primary biliary cholangitis?
an organ specific autoimmune disease
granulomatous inflammation of bile ducts → loss of intrahepatic bile ducts → cirrhosis
F>M
serum: anti-mitochondrial auto antibodies, alkaline phosphatase is raised
what is primary sclerosing cholangitis?
chronic inflammation and fibrous obliteration of bile ducts → loss of intra-hepatic bile ducts → cirrhosis
increased risk of developing cholangiocarcinoma
what is hepatic cirrhosis?
the response of liver to chronic liver injury → end stage chronic liver disease
liver is replaced by nodules of hepatocytes and fibrous tissue
what causes hepatic cirrhosis?
- alcohol
- hepatitis B and C
- immune mediated liver disease (such as auto-immune hepatitis or PBC)
- metabolic disorders (haemochromatosis, Wilson’s disease)
- obesity (diabetes mellitus)
what are some possible complications of liver cirrhosis?
altered liver function (liver failure)
abnormal blood flow (portal hypertension)
increased risk of hepatocellular carcinoma
what are examples of tumours of the liver?
- hepatocellular carcinoma (tumour of hepatocytes)
- cholangiocarcinoma (tumour of bile duct)
- metastatic tumours
what is cholelithiasis?
gallstones
risk factors: obesity, diabetes
what are examples of diseases of the gallbladder?
acute cholecystitis
chronic cholecystitis
what is cholecystitis
inflammation of the gallbladder
what causes acute cholecystitis?
empyema: pocket of pus collected inside body cavity
- perforation of gallbladder
- biliary peritonitis
what causes of extra-hepatic obstruction?
- gallstones
- bile duct tumours
- benign stricture
- external compression (such as due to tumours)
What are some of the consequences of extra-hepatic bile duct obstruction?
- jaundice
- no bile excreted into duodenum
- ascending cholangitis (infection of bile proximal to obstruction)
- secondary biliary cirrhosis if obstruction prolonged
