Hepatobiliary System & Pancreas Flashcards
What are the types of jaundice?
- Pre-hepatic: too much bilirubin produced (haemolytic anaemia)
- Hepatic: too few functioning liver cells (acute diffuse liver cell injury, liver disease, inborn errors)
- Post-hepatic: bile duct obstruction (stone, stridor, tumour)
Describe the pathology of different types of jaundice
- Pre-hepatic: unconjugated-bound to albumin, insoluble, not excreted yellow eyes only
- Hepatic: mainly conjugated, soluble, yellow eyes & dark urine
- Post-hepatic: conjugated, soluble, excreted, yellow eyes, pale stools, dark urine
What are the pathological features of obstructive jaundice?
- Bile in liver parenchyma (yellow skin)
- Oedema
- Portal tract expansion
- Itchy- bile salts accumulate in hepatocytes
- Ductular reaction-proliferation
What are causes of acute & chronic hepatitis?
- Damage to hepatocytes
- Viruses
- Drugs
- Alcohol
- Autoimmune
What are the pathological features of acute hepatitis?
- Common asymptomatic
- Malaise
- Jaundice
- Coagulopathy
- Encephalopathy
- Rare death
Describe the underlying pathology of acute hepatitis?
- Mild= lobular disarray, hepatocytes vary is size, inflammatory cells, apoptotic hepatocytes-spotty
- Severe= confluent panacinar necrosis all liver cells die at once, medical emergency
- Bridging necrosis hepatocyte death between vasculature can lead to scarring & inc risk of cirrhosis
What is the pathology of chronic liver disease?
Injury to liver cells, inflammation, formation of scar tissue & regeneration of hepatocytes
What are types of hepatotrophic viruses?
- HepA: P.RNA, faecal-oral route, acute jaundice, no treatment, vaccine
- HepB: H.DNA, acute jaundice, parenteral route, vaccine & IFN
- HepC: F.RNA, acute jaundice, evolves to chronic hepatitis, parenteral route, IFN
- HepD: must have HepB
- HepE: waterborne, pigs, zoonosis
What are the effects of alcohol on the liver?
- Fatty change (steatosis)
- Ballooned hepatocytes w/mallory body
- Inflammatory cells
- Fibrosis in portal tracts & pericellular fibrosis
Describe NAFLD
- non-alcoholic fatty liver disease
- steatosis, HCC, cirrhosis, steatohepatitis
- Metabolic syndrome- DM2, obesity, hyperlipidaemia
What are the types of hepatotoxicity caused by drugs?
- Intrinsic=paracetamol, common, predictable
- Idiosyncratic= metabolic, immuno, rare & unpredictable
How can paracetamol cause liver damage?
-necrosis of a high proportion of hepatocytes in predictable, zonal distribution, no inflammation.
What are the causes of cirrhosis?
- Alcohol
- Chronic viral hepB&C
- Autoimmune
- Metabolic-iron, copper, alpha 1 antitrypsin
- Non alcholic steatohepatitis
What is Cirrhosis?
-Diffuse hepatic process characterised by fibrosis & conversion of normal liver architecture into structurally abnormal nodules
What are the morphological features of cirrhosis?
- Mass of regenerating nodules
- Wrapped in fibrous scar tissue
What are complications of cirrhosis?
- Portal hypertension: stiff liver, inc blood flow, pressure rises in portal vein- varices
- Liver cell failure: unable to maintain homeostasis, oedema, cannot produce clotting factors, hypalbumin
- Excretion: itching & jaundice
- Reticulo-endothelial cells vulnerable to infection
What is the underling defect in alpha-1-antitrypsin?
- Abnormal anti-protease which cannot be exported from hepatocyte
- Accumulates in liver cells and injures them – cirrhosis
- Insufficient in blood, failure to inactivate neutrophil enzymes-emphysema
What is haemochromatosis?
- Inborn error/genetic of iron metabolism- bronzed diabetes
- Venesection to deplete iron stores to normal
- Iron accumulates in liver, pancreas, skin, joints, heart
What is Wilson’s disease?
- Inborn error of copper metabolism
- Treatment to chelate copper and enhance its excretion
- Accumulates in brain(ataxia), eyes(kayser ring), liver
What are systemic signs of liver failure?
- Ascites
- Muscle wasting
- Bruising
- Gynaecomastia
- Spider naevi
- Caput medusae- anastomosis between sup veins & portal veins
What is the mechanism of paracetamol toxicity? Any treatment?
- Enzyme induction
- increased risk of CYP2E1 in alcohol use
- paracetamol metabolised to NAPQI
- Covalently to tissue membrane proteins causing necrosis
