Liver Pathology Flashcards
Describe the main features of a portosystemic shunt
Anomalous venous connection between the portal system and the venous systemic system.
Allows much of the portal blood to bypass the hepatic parenchymal sinusoids.
State which size of dog breed usually has each type of portosystemic shunt.
Extra-hepatic: Small dog breeds
Intra-hepatic - Large dog breeds
In an intrahepatic congential portosystemic shunt, which vessels are connected?
Left or right portal vein branch with the hepatic vein or directly with the caudal vena cava,
In an extrahepatic congential portosystemic shunt, which vessels are most commonly connected?
Left or right gastric vein or splenic vein and the caudal vena cava or azygous vein
List four functional consequences of congenital portosystemic shunts
Reduced hepatic perfusion
Small liver - microhepatica
Poor growth
Hepatic encephalopathy
List four post-hepatic conditions affecting outflow of blood from the liver
Heart disease - especially right sided congestive heart failure
Obstruction of hepatic veins or caudal vena cava
Hepatic passive venous congestion
Hepatomegaly
List three intra-hepatic and pre-hepatic conditions associated with abnormal portal vein inflow.
Advanced chronic liver disease with fibrosis
Portal vein obstruction
Portal vein hypoplasia (especially in small dog breeds)
List two consequences of portal hypertension
Ascites
Acquired portosystemic shunts
List three substances that may be contained in vacuoles in cases of vacuolar hepatopathy
Lipid (fatty change)
Water (hydropic change)
Glycogen
List three gross changes of the vacuolar hepatopathy
Enlargment
Altered colour
Altered consistency
List two causes of lipid accumulation within the liver
Excess delivery of free fatty acids to hepatocytes
Reduced hepatocellular capacity to metabolise fats often due to hepatocellular injury.
What is glycogen accumulation associated with?
Hyperadrenocortism or corticosteriod administration.
What are the three major patterns of necrosis in the liver?
Focal
Zonal
Massive
Which zone of the liver is most commonly infected in zonal necrosis?
Zone 3
List three typical causes of zonal necrosis of the liver
Hypoxia
Exposure to some toxins
Severe viral infections
State a cause of massive necrosis in the liver
Vitamin E/Selenium deficiency in pigs
How can hepatocellular regeneration of the liver affect function?
Regeneration becomes nodular and with fibrosis distorts the hepatic architecture
Define hepatitis
Inflammation of the liver parenchyma
Define cholangitis
Inflammation of the biliary tree
Define cholangiohepatitis
Inflammation of the biliary tree and hepatic parenchyma
Define cholecystitis
Inflammation of the gall bladder
List three key features of acute hepatitis
Acute inflammation
Necrosis
+/- Regenerative changes
List four of the sequelae to acute bacterial hepatitis
Healing +/- scarring
Persistence of infection and chronic infammation
Abcess
Chronic hepatitis
Explain how fibrosis can affect hepatic function
Fibrosis can interfere with hepatocyte contact with the blood in the sinusoids.
Fibrosis bridging between portal and central regions can contain vascular channels allowing blood to bypass hepatocytes.
