Lecture 17: Liver Pathology Flashcards
What is the normal weight of the liver?
1400-1600 grams
What is the porta hepatis?
- Portal vein
- Hepatic artery
- BIle duct
What are the anatomical divisions of the liver?
Lobules
What are the functional divisions of the liver?
Acini
Describe the normal liver architecture?
Portal tract;
- Hepatic art.
- Bile duct
- Portal vein
Parenchyma
- Zone 1 (periportal)
- Zone 2 (Mid-zonal)
- Zone 3 (Centrilobular)
Terminal hepatic vein
What are two common patterns of liver disease?
- Cirrhosis
- Portal hypertension
Both potential consequences of liver pathology.
Describe how liver cirrhosis results;
End stage liver damage
- Death and atrophy
- Inflammation leads to fibrosis = cirrhosis, loss of synthetic function (Hep. damage) (No normal flow from liver to portal vein)
Different sized nodules depending on eitiology.
Describe the change of liver architecture in liver cirrhosis;
- Bridging fibrous septae (Link portal tracts)
- Parenchymal nodules (Proliferating hepatocytes encircled by fibrosis, Micro and macro nodules)
Disruption of entire architecture
- Vascular architecture reorganised with shunts; PV and HA blood bypasses functional liver cells
- Progressive fibrosis
What is portal hypertension and what causes it?
- Increased resistance to portal blood flow
- Prehapatic (obstructive thrombosis)
- Posthepatic (Severe R. sided heart failure)
- Intra hepatic (Cirrhosis)
What is the consequences of portal hypertension?
- Ascites
- Portosystemic shunts; Bypasses develop where systemic and portal circulation share capillary bed.
- Congestive splenomegaly
- Hepatic encephalopathy (Diffuse confusion)
What can cause viral hepatitis?
- Hepatitis A, B, C, D and E virus
- Cytomegalovirus
- Epstein-barr virus
What are some notes on Hepatitis A virus;
- Benign self-limited disease
- Incubation, 2-6 weeks
- Does not cause chronic hepatitis
- Substandard hygiene and sanitation
- Person to person, feacal oral transmission
- Asymptomatic or mild febrile illness +/- jaundice
What are some notes on hepatitis B virus;
- Acute (resolves) or chronic which may lead to cirrhosis
- Fulminant hepatitis leads to massive necrosis
- Associated with hepatitis D infection
- 4-26 weeks infection
- Blood and body fluid born
- Immune response to viral antigens expressed on infected hepatocytes leads to liver cell damage
What are some notes on hepatitis C virus;
- Major cause of liver disease
- Inoculations and blood transfusions
- Acute infection usually undetected
- Chronic disease usually occurs in majority
- 20+% develop cirrhosis 5-20 years post infection
How are drug and toxin induced liver injury classified?
- Predictable hepatotoxins (acting in dose dependant manner and occurring in most individuals) i.e paracetamol
- Unpredictable/idiosyncratic hepatotoxins
