Histopathology - Liver tutorial Flashcards
Why does the liver rarely undergo ischaemia?
It has a dual blood supply (hepatic artery and portal vein)
Which zone of the liver is the portal tract in?
In zone 1 (has the best blood supply)
What is the importance of zone 3?
Contains the most metabolically active hepatocytes but most prone to ischaemia
What is special about the endothelial cels in the liver?
They do not sit on a basement membrane and are discontinuous (fenestrated)
Resident macrophages in liver?
Kuppfer cells
Function of stellate cells when normal and in liver damage
Normal: produce vitamin A
Liver damage: stellate cells become activated to myofibroblasts and lay down collagen
Which cells in the liver are responsible for liver scarring
Stellatecells
Liver injury changes
Hepatocytes lose microvilli
Kuppfer cells become activated
Stellate cells become activated to myofibroblasts
Deposition of scar tissue in space of disse by stellate cells
Loss of fernestration in endothelium
Definition of cirrhosis
Whole liver involved
Fibrosis
Nodules of regenerating hepatocytes
Distortion of liver vasculature: both intra and extrahepatic shunting of blood (due to bridging fibrosis)
What is cirrhosis classification based on?
Aetiological cause of cirrhosis
The patterns of nodular regeneration in alcoholic/ NAFLD hepatitis causing cirrhosis
MICRONODULAR reorganisation
The patterns of nodular regeneration in viral hepatitis causing cirrhosis?
MACRONODULAR reorganisation
Pathological finding in acute hepatitis
Spotty necrosis
Pathoological finding in chronic hepatitis
Interface hepatitis/piecemeal necrosis
Is cirrhosis reversible?
YES
Which hepatitis viruses can casue acute hepatiits?
A and E
3 main causes of chronic hepatitis
Viruses, drugs and autoimmune
Grade and stage of chronic hepatitis
Grade = degree of inflammation Stage = severity of fibrosis/scarring
How is alcohol toxic to the liver?
Alcohol itself is not toxic but the metabolic product of acetaldehyde is
Three histological patterns of alcoholic liver disease
Fatty change, alcoholic hepatitis and cirrhosis
Features of alcoholic hepatitis
Ballooning (+/- mallory denk bodies), apoptosis, pericellular fibrosis
Which zone is affected most in alcoholic hepatiits
Zone 3 as it has the highest concentration of aldehyde dehydrogenase as cells most metabolically active
Histology of NAFLD
Identical to alcoholic liver disease
Pathophysiology of PBC
Bile duct loss due to CHRONIC inflammation with GRANULOMAS
