L16 Liver Flashcards
(20 cards)
What are the cytosolic hepatocellular enzymes checked for hepatocyte integrity?
- AST
- ALT
- LDH
What are the consequences of liver failure?
Within the liver itself
1. Coagulopathy –> impaired hepatic synthetic function
2. Hepatic encephalopathy –> altered level of consciousness due to impaired ammonia metabolism
3. Cholestasis –> impaired bile secretion
Affecting other organs:
4. Hepatorenal, hepatopulmonary syndrome
Generalised:
5, Portal hypertension (chronic»_space;> acute)
Pathophysiology of portal hypertension
- Increased resistance at portal sinusoids
- Scarring –> disrupted blood flow
- Vasoconstriction
- Sinusoidal remodelling - Increased portal venous flow
- Splanchnic vasodilation
Effects of portal hypertension
- Increased pressure in the peritonieal cavity –> ascites
- Formation of collateral vessels to dissipate the pressure, giving rise to varices
- Hepatoencephalopathy
- Splenomegaly –> bleeding
Common terminal events in liver failure
- Hepatic encephalopathy
- Bleeding from esophageal varices
- Sepsis
Chronic: hepatocellular carcinoma
What are the 2 examples of diseases which prove that not all end-stage chronic liver disease is cirrhotic?
- Primary billiary cholangitis
- Primary sclerotic cholangitis
Does hepatitis A cause chronic hepatitis?
NO
What is a risk factor for hepatocellular carcinoma?
- Chronic liver failure
- Hep B viral infection
- NAFLD
What are the inflammatory cell infiltrate that are present in both acute and chronic hepatitis?
Mononuclear T-cells
Drug and toxin induced liver injury can occur through [3]
- Direct toxicity
- Hepatic conversion of xenobiotic to active toxin
- Immune-mediated mechanisms
What are the most common drug / agent that is responsible for the development of ALF and CLF
- ALF: paracetamol
- CLF: alcohol
Pathogenesis of fatty liver disease
- Increase lipid synthesis due to increased NADH
- acetyl induced lipid peroxidation
- Increased hypoxia and oxidative stress (ROS)
Pathophysiology of jaundice
Pre-hepatic (production)
1. Excessive production (hemolysis)
Hepatic
1. Decreased hepatic uptake
2. Impaired bilirubin conjugation
3. Impaired bile flow
Post-hepatic
1. Duct obstruction
What are the most common causes of acute pancreatitis?
- Gallstones
- Alcohol
3 protective mechanism of the pancreas from its own enzymatic secretions
- Secretion of zymogens (inactive enzymez)
- Activation by tripsyn (in duodenum), minimal intra-pancreatic activation
- Acinar and ductal cells secrete trypsin inhibitor –> further prevent the activation of enzymes
What is cirrhosis?
Diffuse transformation of the liver into regenerative parenchymal nodules surrounded by fibrous scarring and variable degrees of vascular shunting
What are the characteristics of liver cirrhosis?
- Diffuse hepatic involvement
- Long-standing necrosis
- Fibrosis
- Nodular parenchymal replacement with disruption in lobular arrangement
What are the risk factors of liver cirrhosis?
- Alcoholic liver disease
- Viral infection (Hep B and C)
- Chronic autoimmune hepatitis
- Chronic billiary obstruction
What happens at the hepatic parenchyma in liver cirrhosis?
- Progressive fibrosis
- Collagen synthesis in chronic inflammatory state
- Release of cytokines
- Toxins
- Shunts production
Gross and microscopic appearance of liver cirrhosis
Gross
1. Firm
2. Shrunken
3. Nodular
4. Irregular surface
Microscopic
1. Disruption of lobar arrangement
2. Fibrosis
