Liver and gall disease Flashcards
The normal liver
Right lobe
Left lobe
The portal circulation ‘the third arm’
Portal vein Umbilical vein Pancreas Spleen Inferior mesenteric vein Superior mesenteric vein -nutrients from gut into liver
Bile flow
Produced in liver as primary bile acids –> bile salts
Helps to digest food
Primary and secondary bile acids
Functions of liver
Approx 500 different functions Detoxification -filters and cleans blood of waste products -drugs, hormones Immune functions -fights infections and diseases -RE system Iinvolved in synthesis of clotting factors, proteins, enzymes, glycogen and fats Production of bile and breakdown of bilirubin Energy storage (glycogen and fats) Regulation of fat metabolism Ability to regenerate
Microanatomy
Organised in lobules with central (hepatic vein)
Hexagon - portal triads in the “corner”
Types of liver injury
Acute
–>viral (A,B, EBV), drugs, alcohol, vascular –> liver failure
–> recovery
Chronic
–>recovery
–>cirrhosis –> liver failure (varices, hepatoma)
–> alcohol, viral (B, C), autoimmune, metabolic (iron, copper) –> liver failure (varices, hepatoma)
Presentation of acute liver injury
Asymptomatic abnormal LFTs Malaise, nausea, anorexia Jaundice Confusion - think ALF *rarer*: Bleeding Liver pain
Presentation of chronic liver injury
Ascites, oedema Haematemesis (varices) Malaise, anorexia, wasting Easy bruising Itching Hepatomegaly, Abnormal LFTs *rarer*: Jaundice Confusion
Serum “liver function tests” (LFTs)
Albumin ALP – Alkaline phosphatase GGT – gamma GT ALT – Alanine Aminotransferase AST – Aspartate Aminotransferase Bilirubin Globulin
Prothrombin time (PT)/ INR Platelet count -normal LFTs and normal PT and platelet count do not exclude liver disease/ cirrhosis, but while normal the function is relatively preserved
Albumin
Bilirubin
Prothrombin time (PT)
Give some index of liver function
-if normal would suggest a “preserved” liver function
ALP – Alkaline phosphatase
GGT – gamma GT
AST – Alanine Aminotransferase
ALT – Aspartate Aminotransferase
Give no index of liver function
Jaundice causes
Pre-hepatic
-haemolysis
Hepatic
-cirrhosis
-acute hepatitis (viral, alcoholic, autoimmune, drug-induced)
-infiltration of the liver by tumours
Post-hepatic (obstruction of biliary outflow)
-gallstones
-external compression: pancreatitis, lymphadenopathy, pancreatic tumour, ampullary tumour
Bilirubin metabolism and excretion
Breakdown product of haemoglobin
Metabolised in liver
Excreted via intestine (and renally)
If bilirubin rises and is not excreted the motion turns pale
Bilirubin metabolism can be interrupted at various points
Cirrhosis of the liver
Scarring of the liver
Result of chronic longstanding damage to the liver
Scar tissue replaces healthy tissue (exceed healing capacity of liver) –> leading to disruption of liver architecture
> resistance to blood flow through the liver, leading to portal hypertension and its complication
Causes of chronic liver disease: most common
Alcohol
Non Alcoholic Steatohepatitis (NASH)
Viral hepatitis (B, C)
Jaundice
Mild can be difficult to spot (light; skin tone)
Scleral jaundice usually first noted
Due to > bilirubin
Less common causes of chronic liver disease
Immune -autoimmune hepatitis -primary biliary cirrhosis -primary sclerosing cholangitis Metabolic -haemochromatosis -Wilson’s -alpha 1 antitrypsin deficiency… Vascular -Budd-Chiari Drugs -amiodarone
Alcoholic liver disease
Commonest cause of cirrhosis in the UK
Deaths from ALD rising dramatically