L22 Liver Pathology

Question 1

Functions of the liver

Answer 1

digestion roles
storage of nutrients
metabolism of steroid hormones
drug metabolism

Question 2

How much of liver can be destroyed before it is life threatening

Answer 2

80%

Question 3

Pathogenesis of jaundice

Answer 3

bilirubin binds to plasma albumin which goes to blood and liver then small intestine

Question 4

2 mechanisms of injury of viral hepatitis

Answer 4

1. direct cellular injury + necrosis

2. immune response

Question 5

What is severe fuliminant hepatitis

Answer 5

accelerated immune response (severe necrosis, impaired hepatocyte function)
acute liver failure
main causes are hep A or B, drugs and chemicals, and acute fatty liver of pregnancy

Question 6

What does chronic hepatitis involve

Answer 6

fibrosis (collagen)
3-6 months duration
morphology: 1. mild: inflammation in portal tracts
2. progressive: periportal + bridging necrosis

Question 7

What is cirrhosis

Answer 7

end stage liver disease

Question 8

What is steatosis

Answer 8

fat accumulation in hepatocytes
main causes: alcohol, obesity, diabetes
generally asymptomatic

Question 9

Outcomes of alcohol-induced liver disease

Answer 9

1. steatosis (reversible)
2. alcoholic hepatitis (potentially reversible)
3. cirrhosis

Question 10

`Causes of non-alcoholic liver disease

Answer 10

diabetes, hyperlipidemia, obesity

Question 11

Cirrhosis: treatment

Answer 11

improve lifestyle, transplant

Question 12

Cirrhosis: causes

Answer 12

alcoholic and non alcoholic liver disease, viral hepatitis, biliary cirrhosis, genetic, drugs, autoimmune

Question 13

Cirrhosis: morphology

Answer 13

lobules replaced by fibrous septa
scar tissue
regenerating hepatocytes (red lumps)

Question 14

Cirrhosis: mechanism

Answer 14

progressive hepatocyte injury + death + chronic inflammation
cytokines + toxins activate stellate cells
stellate cells transform to myofibroblasts (fibrosis)
converts synosoids from slow flow to fast flow channels
proliferation of remaining hepatocytes to form nodules

Question 15

Cirrhosis: clinical features

Answer 15

jaundice
ascites
coagulopathy
muscle weakness
hormonal change
impaired blood flow (= portal hypertension)

Question 16

Portal hypertension

Answer 16

tissue fibrosis
increased resistance to blood flow which increases pressure and decreases venous drainage from the GI tract
complications: ascites, portosystemic shunts, splenomegaly, hepatic encephalopathy

Question 17

Possible portosystemic shunts

Answer 17

lower rectal (haemorrhoids)
navel (caput medusae)
esophagus (esophageal varices)