4) The Liver Flashcards
Name the cells of the liver and their basic function:
Hepatocytes - liver function
Endothelial cells - sinusoidal circulation
Kupffer cells - ‘filter’ portal blood
Stellate cells - extracellular matrix
What are the functions of the liver?
Metabolism of glucose, protein and lipids
Protein synthesis
Bile production
Drug and toxin metabolism
How is the liver involved in protein synthesis?
Major site of plasma protein synthesis
Albumin, lipoproteins, coagulation factors, acute phase proteins
What are the functions of albumin?
Oncotic pressure in plasma
Transport of bilirubin
Transport of drugs
What are the function of bile salts?
Solubilise fat
Increase access of lipases
Facilitate absorption
How is bilirubin excreted?
Stercobilin in faeces
Urobilinogen/urobilin by kidneys
What signs are associated with obstructive jaundice?
Dark urine - conjugated bilirubin excreted by kidneys
Pale stools - no stercobilin
How is alcohol metabolised?
Alcohol dehydrogenase
CYP enzymes
How is paracetamol metabolised?
Conjugated by glutathione or sulphate
What can cause toxic injury to the liver?
Drug induced
Industrial/environmental toxins
Alcohol
What inherited condtions can affect the liver?
Haemochromatosis
Alpha-1-antitrypsin deficiency
Wilson’s disease
What is liver cirrhosis?
Nodular regeneration of liver surrounded by scarring
What are some causes of liver cirrhosis?
Alcoholic liver disease
Non-alcoholic fatty liver disease
Chronic hep C
Autoimmune and hereditary causes
How does alcoholic liver disease affect the liver?
Steatosis -> hepatocyte injury -> stellate cell activation -> cirrhosis
What are some systemic effects of liver cirrhosis?
Hepatic encephalopathy
Varices
Ascites
Splenomegaly
What are Mallory Bodies?
Inclusions in cytoplasm of hepatocyte - damaged intermediate filaments
Associated with alcoholic hepatitis and cirrhosis
What is fulminant hepatitis?
Acute liver failure with onset of encephalopathy within 8 weeks
What are the outcomes of hepatitis C infection?
Chronic hepatitis (85%) -> stable disease (80%), cirrhosis (20%)
Resolution (15%)
Fulminant hepatitis
What autoimmune diseases can affects the liver and biliary tract?
Primary biliary cholangitis/cirrhosis
Primary sclerosing cholangitis
Describe the features of primary biliary cholangitis/cirrhosis:
Chronic destruction of bile ducts in liver
More common in females
Fatigue, itching and jaundice
Anti-mitochondrial antibodies often present
Describe the features of primary sclerosing cholangitis: (include associated condition)
Cholangitis with periductal fibrosis
Asscoiated with UC
pANCA often positive
Definitive treatment is transplant
Describe the features of hereditary haemochromatosis:
Autosomal recessive
Abnormal deposition of iron in liver, myocardium and pancreas
Fatigue, malaise, joint pain
Will develop into cirrhosis eventually
How is hereditary haemochromatosis diagnosed?
Transferrin saturation >50%
Genetic testing
