Hepato-biliary pathology Flashcards
Describe the blood supply to the liver
dual blood supply hepatic artery (high pressure) and portal vein (low pressure)
functions of the liver? (3)
Protein synthesis
Metabolism of fat and carbohydrate
Detoxification of drugs and toxins esp. alcohol
Name some pathologies linked with the liver, gallbladder and extraheptaic bile ducts
liver - failure, jaundice, intrahepatic bile duct obstruction, cirrhosis, tumours
gallbladder - inflammation
extrahepatic bile ducts - obstruction
what can cause hepatitis? (3)
viruses
alcohol
drugs - OTC, prescribed or recreational
which types of hepatitis infection are blood borne?
hepatitis B and C
what are three different outcomes that could come about from acute inflammation due to viral hepatitis? and what types of hepatitis cause each
- resolution - liver returns to normal - hep A, E
- liver failure if severe damage to liver - HEP A, B, E
- progression to chronic hepatitis and cirrhosis - hep B, C
how does alcohol affect the liver?
liver cells accumulate fat cells as the alcohol disrupts normal metabolism of fats within the hepatocytes
progresses to cirrhosis
What is Jaundice and what causes it?
yellowing of the skin - major symptom of liver disease
caused by increased circulating bilirubin
Name the 3 main pathways of bilirubin metabolism ie the 3 classes of jaundice
pre hepatic
hepatic
post hepatic
describe the pre hepatic stage of bilirubin metabolism (3 steps)
Breakdown of haemoglobin in spleen to form haem and globin
Haem converted to bilirubin
Release of bilirubin into circulation
describe the hepatic stage of bilirubin metabolism (3 steps)
Uptake of bilirubin by hepatocytes
Conjugation of bilirubin in hepatocytes (makes it more soluble)
Excretion of conjugated bilirubin into biliary system through bile duct
describe the post-hepatic stage of bilirubin metabolism
Transport of conjugated bilirubin in biliary system
Breakdown of bilirubin conjugate in intestine
Re-absorption of bilirubin
main cause of pre hepatic jaundice
Impaired transport/haemolysis
Main causes of hepatic jaundice? (2)
Cholestasis - decrease in bile flow due to impaired secretion by hepatocytes
Intra-hepatic bile duct obstruction ie the branches off of the left and right hepatic ducts
ie defective uptake, conjugation, excretion
causes of cholestasis (4)
Viral hepatitis
Alcoholic hepatitis
Liver failure – acute/chronic
Drugs - Therapeutic and Recreational
what is cholestasis
accumulation of bile within hepatocytes or bile canaliculi (duct like structures that later form the larger hepatic ducts) which causes obstruction
How can the intra-hepatic bile duct become obstructed
tumour - hepatocellular carcinoma, tumours of intra-hep bile duct, metastatic tumours that compress bile duct (pancreas etc)
primary sclerosing cholangitis
primary biliary cholangitis
what is primary biliary cholangitis?
Organ specific auto-immune disease
Mainly affects females (9:1)
Anti-mitochondrial auto-antibodies in serum
Raised serum alkaline phosphatase
Describe the pathology of primary biliary cholangitis?
Granulomatous inflammation involving bile ducts
Loss of intra-hepatic bile ducts - fibrosis
Progression to cirrhosis - increased risk of developing cholangiocarcinoma
which other disease is primary sclerosing Cholangitis strongly associated with?
inflammatory bowel disease
what is cholangiocarcinoma
cancer of the bile duct
what is the 1 response that all pathologies of the liver result in
hepatic Cirrhosis - response to chronic injury
Causes of cirrhosis (5)
Alcohol
Hepatitis B, C
Immune mediated liver disease eg Auto-immune hepatitis or Primary biliary cholangitis
metabolic disorders - excess iron or copper which are toxic to the liver
obesity - diabetes
Name the disease where there is a real excess of copper in the circulation?
Wilson’s disease
Cirrhosis pathology
loss of normal liver structure as liver tissue is replaced by nodules of hepatocytes and fibrous tissue
a cirrhotic liver is often smaller and much lighter
What are some complications of cirrhosis? (3)
altered liver function - failure
abnormal blood flow - portal hypertension - mucks up the dual blood supply
increased risk of hepatocellular carcinoma
Name 3 liver tumours
hepatocelllular carcinoma - malignant tumour of hepatocytes
cholangiocarcinoma - malignant tumour of bile duct epithelium
metastatic tumours - common site esp tumours of the GI tract
Risk factors for gallstones?
obesity
diabetes - high pain threshold - don’t detect early
acute inflammation of the gallbladder can lead to what within it?
Empyema - pus filled cavity. If the gallbladder then perforates, pus can spill into peritoneal cavity
bile is very toxic outwith the bile duct
what happens if you have chronic cholecystitis
chronic inflammation and fibrosis of the gallbladder
wall thickens and the usual muscular structure is replaced with fibrotic tissue - makes it less mobile
what is the name of the duct that supplies the gallbladder
cystic duct
It connects the top of the gallbladder’s neck to the common hepatic duct.
causes of common bile duct obstruction (5)
Gallstones Bile duct tumours Benign stricture External compression Tumours eg in the pancreas
effects of common bile duct obstruction (4)
Jaundice
No bile excreted into duodenum
Infection of bile proximal to obstruction eg Ascending cholangitis
Secondary biliary cirrhosis if obstruction prolonged
