Lecture 13 Flashcards
What are the 4 main anatomical units of the liver
Hepatocytes Bile duct system Vascular system Kupffer cells
What is the functional organisation of the liver
Blood flows from portal triads around periphery towards the central vein in the centre of the lobule Bile drains from hepatocytes to portal triads at centre
What are periportal hepatocytes affected by
Direct acting toxins
What are periacinar hepatocytes affected by
Activated toxins, hypoxia
What is hepatobiliary injury
Injurious agents may enter liver and biliary system by - Haematogenous - Retrograde biliary entry from GIT - Direct penetration from trauma
What may hepatobiliary injury cause
Inflammation, degeneration (reversible) or apoptosis or necrosis (irreversible)
What are the defence towards hepatobiliary injury
Kupffer cells in sinusoids Biliary tree - Mucosal immunity: IgA - Flow of bile - Sphincter at end of common bile duct
What is seen grossly with acute cellular degeneration: Acute swelling
Liver is pale and swollen
What is seen histologically with acute cellular degeneration: acute swelling
Cells are pale, swollen and finely vacuolated
What do you see grossly with fatty change
Liver is pale, yellowish, large, rounded edges
What do you see histologically with fatty change
Cells have large lipid vacuoles, nuclei pushed to the side
What is the nature and distribution of degeneration, necrosis and inflammatory lesions in the liver affected by
Route of entry Type of injurious agent Predilection for particular cell types Host response
What is the patterns of hepatocellular degeneration and necrosis
Random - no pattern to the damage - e.g. haematogenous infectious agent Zonal patterns - Periaciner/centrolobular - toxins that require activation, anaemia, heart failure - Midzonal - Massive - necrosis of entire lobule
What is cholecystitis
Inflammation of gall bladder
When classifying liver/biliary disease, what should you consider
- Distribution and pattern of involvement - Types of inflammatory cells if present - Evidence of degeneration, necrosis or fibrosis - Evidence of regeneration - Presence of etiologic agent - Severity - Duration
What is seen in acute hepatitis
Often random distribution of inflammation - Often neutrophils esp if bacterial - May be lymphocytes if viral - Hepatocellular necrosis +/- apoptosis
What is seen in chronic hepatitis
Persistence of antigenic stimulus - Accumulation of mononuclear cells - Maybe also be neutrophils present - Fibrosis and biliary hyperplasia - May get regeneration of hepatocytes
What is cholangitis
Inflammation centred on biliary tract