S7 Liver And Pancreas Pathology Flashcards
What are the functions of the liver?
Metabolism of proteins and lipids
Detoxification
Synthesis of bile and albumin
Stores glycogen
Describe bile flow from the gallbladder to the duodenum
From the gallbladder, bile enters the cystic duct, then the common bile duct, then the ampulla of vater
What is found in the portal triad?
Portal vein, hepatic artery, bile duct
What are kupfer cells?
Specialised cells lining sinusoids containing many macrophages, making them an efficient detoxifying system.
Outline the production of bilirubin
Bilirubin is the breakdown product of haem.
Unconjugated bilirubin is bound to albumin and carried to liver where it is conjugated with glucoronic acid.
Conjugated bilirubin then passes into colon where it is metabolised into urobilinogen, then oxidised to stercobillin and urobillin
What is jaundice?
Yellow discolouration of skin due to high levels of bilirubin
Describe the features of pre-hepatic jaundice
Caused by Increased levels of haem/bilirubin (e.g from haemolytic anaemia)
Liver cannot conjugate it so raised levels of unconjugated bilirubin
results in Mild jaundice (pale yellow), only one with normal light urine
Describe the features of intra-hepatic jaundice
Caused by reduced liver function (e.g cholestasis)
Contains both unconjugated and conjugated bilirubin
Moderate jaundice (orange yellow)
High AST and ALT
Describe the features of post-hepatic jaundice?
Caused by obstruction to bile drainage into duodenum (e.g. gallstones)
Raised levels of conjugated bilirubin
Severe jaundice (green yellow)
High ALP
What is the role of liver function tests?
Indicate liver DAMAGE rather than function.
Describe albumin as an LFT
Made by the liver,
Hypoalbuminaemia shows reduced liver function.
Will cause oedema as less oncotic pressure so fluid leaks
Describe prothrombin time (INR) as an LFT
Increased time indicates reduced liver function as fewer clotting factors
Name 3 hepatic enzymes used in LFTs
ALT
AST
ALP
Describe ALT as an LFT
Increased following hepatocyte damage, e.g. toxins, alcohol.
More specific for liver dysfunction than AST
Describe AST as an LFT
Increased following hepatocyte damage, but also found in cardiac and skeletal muscle, so ALT more specific to liver
However in alcoholic liver disease and cirrhosis; AST>ALT
Describe ALP as an LFT
Found in cells lining bile ducts (canaliculi), so increased in bile duct obstruction (cholestasis).
NB also increased in bone disease and pregnancy. Can do Gamma GT to specify if ALP raised from liver damage or other cause.
What imaging method is best for liver disease?
Ultrasonography
What is hepatitis and what is it caused by?
Inflammation of the liver due to hepatocyte inflammation or breakdown.
Caused by alcohol or drug use.
What is the effect of hepatitis on the liver?
Liver fibrosis produces a shrunken hard nodular liver. This leads to replacement of hepatocytes by fibrous tissue causing reduced albumin and clotting factor production.
What are the symptoms of hepatitis?
RUQ pain
Jaundice
Fever