Systems Pathology: Liver Failure Flashcards Preview

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Flashcards in Systems Pathology: Liver Failure Deck (14)
0

Functions of liver

Carb metabolism
Fat metabolism
Protein synthesis and catabolism
Bile synthesis
Storage
Detoxification

1

Hepatocyte location related to function

Centrilobular hepatocytes (acinar zone 3)-> supplied by oxygen depleted blood-> low oxidase activity, high esterase activity -> most vulnerable to damage by hypoxia or poor perfusion
-> esterases make metabolic intermediates-> vulnerable to toxins such as paracetamol
Peripheral hepatocytes (acinar zone1)-> oxygenated blood-> low esterase activity -> resist perfusion damage and toxin damage
Differential susceptibility to toxins

2

Responses of liver to injury

Fatty change-> metabolic stress and alcohol
Choleostasis
Inflammation
Fibrosis
Regeneration
Neoplasia

3

Choleostasis

Bile plugs caliculi
Caused by conditions that cause hyperbilirubinemia
Raised serum alkaline phosphatase
Intra hepatic-> diseases effecting bile secretion
Extra hepatic-> blockage of bile ducts outside the liver

4

Acute liver failure causes

Acute liver damage-> severe necrosis
Systemic shock as part of multi organ failure-> necrosis
Declining chronic liver disease
80% of patients die

5

Liver cell necrosis

Liver necrosis
-> release of Transaminases-> lab test
-> failure of bilirubin metabolism-> jaundice
-> failure to detoxify nitrogenous compounds-> encephalopathy
-> failure to synthesis factors II,VII,IX,X-> bleeding
-> shock with low GFR-> renal failure

6

Chronic liver disease causes

Chronic hepatitis-> inflammation of liver persisting more than 6 months
Hep B,C,D
Autoimmune
Drug metabolic disease
Cirrhosis-> nodules of regeneration separated by fibrosis

7

Chronic hepatitis pathology

Liver cell necrosis and inflammation-> piecemal necrosis-> necrosis of the cells next to the portal tract connective tissue
-> bridging necrosis-> extensive necrosis that bridges between central veins or portal tracts
Fibrosis-> regeneration is distorted by fibrosis-> growth factors produced as part of the inflam response-> portal expansion, periportal, bridges between portal triads

8

Grading of chronic hepatitis

Necrosis and inflammation are given a grade
0-> none or minimal
1-> portal and lobular inflammation
2-> mild periportal necrosis, focal necrotic cells in lobules with acidophilus bodies
3-> moderate necrosis of periportal, lobular severe focal cell damage
4-> severe necrosis of periportal, damage includes necrosis or liver cells that bridge portal tracts

9

Staging of liver fibrosis

0- none
1 enlarged fibrotic portal tracts
2 fibrosis extends to periportal areas
3 fibrosis extends in to septa but no distortion of liver architecture
4 fibrosis associated with architectural distortion corresponding to cirrhosis

10

Cirrhosis

Chronic hepatitis and alcoholic liver disease can progress to cirrhosis
-> long standing liver cell destruction
Also biliary obstruction
Fibrosis
Nodules of regenerate hepatocytes
Distorted liver architecture
Irreversible
-> liver failure and portal hypertension -> ascites
Reduced hepatocyte function-> decreased blood clotting decreased bile etc
Reduced immune competence
Increased risk of carcinoma
Increased risk of portal view thrombosis

11

Alcoholic hepatitis

Fatty change-> fat accumulates in hepatocytes, reversible
Necrosis-> focal reversible intitally
Hyaline
Ballooned cell
Fibrosis-> cirrhosis

12

Portal hypertension

Caused by obstruction of blood flow in the portal system
Back pressure-> Splenomegally, ascites
New Porto-systemic anastomoses-> varicose venous channels
-> oesophageal varices
Cirrhosis, portal tract fibrosis, idiopathic, poly cystic disease

13

Chronic liver disease destabilisation

Alcohol binge
Constipation, dehydration
Infection
GI bleed

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