Flashcards in Pathology of the liver Deck (95)
What are the two concepts of microanatomical units in the liver?
The lobular concept and the acinar concept
Which acinar zones are used to describe patterns of liver injury?
Which cells are most vulnerable do injury?
Zone 1: periportal
Zone 2: Mid acinar
Zone 3: Pericentral
Zone 3 cells are most vulnerable to injury
Are all liver cells capable of regeneration?
Do liver cells replicate frequently?
No, they are stable and only replicate infrequently.
However if the liver is injured nearly all surviving hepatocytes can enter the cell cycle and rapidly replace destroyed hepatocytes.
What is the late stage of all chronic liver diseases?
What is cirrhosis defined as?
What effects does it have on the liver?
It is defined anatomically by the presence throughout the liver of fibrous septa that subdivide the parenchyma into nodules.
Perfusion of sinusoids is inefficient, liver cell function is impaired, and intraheptic pressure is increased.
What are the possible outcomes of acute liver failure?
chronic liver disease
death from liver failure
Are all patients with severe liver disease jaundiced?
No, there are many who are not.
The liver has a massive reserve and can handle a build up of bilirubin with just a third of the cells.
How is jaundice classified?
By site and type
What causes pre-hepatic jaundice?
What type of bilirubin causes the jaundice?
Haemolysis of any type.
What causes hepatic jaundice?
Liver cells that are injured or dead.
Bile duct loss (atresia, PBC, PSC)
What causes post hepatic jaundice?
Bile cannot escape into the bowel
Congenital biliary atresia
Gallstones block CBDuct
Strictures of CBDuct
Tumours (Ca head of pancreas)
Is cirrhosis reversible or irreversible?
What are features of cirrhosis?
There is alteration of hepatic microvasculature and many hepatocytes now have a compromised blood supply
There is loss of hepatic function
The liver is nodular, hard and craggy
How is cirrhosis classified?
classified by the average size of the regenerative nodules
micronodular- nodules up to 3mm in diameter
macronodular- nodules greater than 3mm in diameter
What are the major complications of cirrhosis?
Liver cell carcinoma
What are common causes of cirrhosis?
Hep B and C
Is liver failure a manifestation of compensated or decompensated cirrhosis?
What causes hepatic encephalopathy?
Failure of the liver to eliminate toxic nitrogenous products of gut bacteria
What other type of failure may also occur with hepatic failure?
Renal failure (hepato-renal syndrome)
What does failure to eliminate endogenous steroid hormones result in?
Secondary hyperaldosteronism, causing sodium and water retention
In the male, it causes loss of secondary sexual characteristics and gynaecomastia due to hyperoestrogenism.
What are results of portal hypertension?
Is cirrhosis the only cause of portal hypertension?
What is the reason for oedema in chronic liver disease?
Reduced albumin synthesis resulting in hypoalbuminaemia
What is the reason for ascites in chronic liver disease?
What is the cause of haematemesis in chronic liver disease?
Ruptured oesophageal varices due to portal hypertension
What is the cause of spider naevi and gynaecomastia in chronic liver disease?
What is the cause of purpura and bleeding in chronic liver disease?
Reduced clotting factor synthesis
What is the cause of coma in chronic liver disease?
Failure to eliminate toxic gut bacteria metabolites (false neurotransmitters)