Pathology of the liver Flashcards
what separates the 2 lobes of the liver?
falciform ligament
what is the porta hepatis?
fissure in liver for entry/exit of vessels and ducts into/out of the liver
how can you distinguish the portal vein?
greenish bile ducts surround it
what is contained within a portal area?
hepatic artery
hepatic vein
bile duct
portal areas surround a central vein forming a hexagonal structure, what impact does this have?
hepatocytes closer to central vein have less blood flow
those closer to portal areas have more blood flow
the liver is very resistant to injury, how?
large functional reserve
some insults can produce severe parenchymal necrosis but heal entirely by restitution
Can regenerate after partial resection
what is the pathogenesis of cirrhosis?
insult to hepatocytes (viral, drugs, toxin, antibody etc)
Grading - degree of inflammation
Staging - degree of fibrosis
Cirrhosis (end stage disease)
what is acute liver failure?
acute onset of jaundice
what can cause acute liver failure?
viruses
alcohol
drugs (eg. paracetamol causes acute necrosis)
bile duct obstruction
what are the consequences of acute liver failure?
complete recovery
chronic liver disease
death from liver failure
what are the classifications of jaundice?
pre-hepatic
hepatic
post hepatic
conjugated
unconjugated
- depends on bilirubin
what causes pre-hepatic jaundice?
TOO MUCH HAEM TO BREAK DOWN
haemolysis of any cause
haemolytic anaemia
unconjugated bilirubin
what causes hepatic jaundice?
LIVER CELLS INJURED OR DEAD acute liver failure alcoholic hepatitis cirrhosis bile duct loss pregnancy
what causes post-hepatic jaundice?
BILE CANT ESCAPE INTO BOWEL congenital biliary atresia gallstones block CB duct strictures of CB duct tumours (Ca head of pancreas)
what happens in cirrhosis?
irreversible bands of fibrosis separating non functioning nodules of hepatocytes
micronodular (alcohol) and macronodular
what can cause cirrhosis?
alcohol Hep B/C Iron overload Autoimmune liver disease Gallstones
what is ERCP?
Method of imaging/treatment of biliary and pancreatic issues
what are the possible complications of cirrhosis/liver failure?
portal hypertension - oesophageal varices - caput medusa - haemorrhoids ascites oedema haematamesis spider naevi Purpura and bleeding Coma Infection
what is the mechanism of alcoholic liver disease?
alcohol intake > release/synthesis of fatty acids > acetyaldehyde manifested by formation of Mallory’s hyaline > increased collagen synthesis
what is acetylaldehyde?
product of alcohol metabolism responsible for liver cell injury
which alcoholic liver diseases are reversible?
fatty liver
hepatitis
which alcoholic liver diseases are irreversible?
fibrosis
cirrhosis
what is steatosis?
formation of droplets of fat in the liver
occurs in fatty liver
what can cause fatty liver?
Alcohol (weekend binge) Drugs NASH pregnancy Diabetes Diet HCV
what are the features of alcoholic hepatitis?
Caused by weeks-months of heavy drinking hepatocyte necrosis neutrophils Mallory bodies pericellular fibrosis
what is alcoholic fibrosis?
heavy drinking months-years
collagen is layed down around cells
what is non-alcoholic steatohepatitis (NASH)?
non-drinkers identical to alcoholic liver disease occurs in: - diabetes - obesity - hyperlipidaemia May lead to fibrosis/cirrhosis
