L16 Liver Flashcards
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
