Hepato Biliary Pathology Flashcards
What is the pre hepatic metabolism of bilirubin?
Breakdown of haemoglobin in spleen to form haem and globin
Haem converted to bilirubin
Release of bilirubin into circulation
What is the hepatic metabolism of bilirubin?
Uptake of bilirubin by hepatocytes
Conjugation of bilirubin in hepatocytes
Excretion of conjugated bilirubin into biliary system
What is the post hepatic metabolism of bilirubin?
Transport of conjugated bilirubin in biliary system
Breakdown of bilirubin conjugate in intestine
Re-absorption of bilirubin
Entero-hepatic circulation of bilirubin
At what level of bilirubin does jaundice become clinically detectable?
> 50 µmol/L (3 mg/dL)
What is a prehepatic cause of jaundice?
Haemolytic anaemia jaundice)
What are two causes of hepatic jaundice?
Cholestasis
Intra-hepatic bile duct obstruction
What is cholestasis?
Accumulation of bile within hepatocytes or bile canaliculi
What are the differences between intra and extra hepatic cholestasis?
Extrahepatic cholestasis is due to large duct obstruction of bile flow at any point in the biliary tract distal to the bile canaliculi.
Intrahepatic cholestasis occurs because of failure of bile secretion, which may be caused by intrinsic defects in bile secretion or inflammation in the intrahepatic ducts
What are some intra hepatic causes of cholestasis?
Viral hepatitis Alcohol hepatitis Cirrhosis Pregnancy Autoimmune cholangitis
What are some extra hepatic causes of cholestasis?
Gallstones
Liver, bile duct or pancreatic cancer
Primary sclerosing cholangitis
Biliary stricture
What is primary biliary cholangitis?
Organ specific auto-immune disease
Mainly affects females (9:1)
Anti-mitochondrial auto-antibodies in serum
Raised serum alkaline phosphatase
Granulomatous inflammation involving bile ducts
Loss of intra-hepatic bile ducts
Progression to cirrhosis
How is primary biliary cholangitis treated?
Bile acid analogues
What is primary sclerosing cholangitis?
Chronic inflammation and fibrous obliteration of bile ducts
Loss of intra-hepatic bile ducts
Associated with inflammatory bowel disease
Progression to cirrhosis
Increased risk of development of cholangiocarcinoma
What two metabolic disorders can cause liver cirrhosis?
Haemochromatosis (excess iron)
Wilson’s disease (excess copper)
What is Murphy’s sign in cholecystitis?
Palpation of the right subcostal region reveals tenderness. During deep inspiration, the tenderness suddenly becomes worse and produces inspiratory arrest.
