Liver Flashcards
What percentage of cardiac output goes to the liver?
25%
What is the largest visceral organ?
Liver
What percentage of blood flow to the liver comes from the portal vein?
67%
What percentage of blood flow to the liver comes from the hepatic artery?
33%
T/F: Clinical signs of liver disease are variable.
True
The liver of a carnivore is what percentage of its body weight?
3-4%
The liver of an omnivore is what percentage of its body weight?
2%
The liver of a herbivore is what percentage of its body weight?
1%
Portal triads are composed of what 4 components?
- Bile ducts
- Branches of portal vein
- Hepatic artery
- Nerves and lymphatics
What is the name of the extracellular matrix that forms an abrupt border with a circumferential row of hepatocytes that surrounds the portal tract is what?
Limiting Plate
Which hepatic zone surrounds the portal triads?
What is another name for it?
- Zone 1
- Centroacinar
Which hepatic zone is the intermediate or midlobular area?
What is another name for it?
- Zone 2
- Midzone
Which hepatic zone surrounds the central veins?
What is another name for it?
- Zone 3
- Periacinar
What percentage of the liver mass is composed of hepatocytes?
Approximately 80%
What are the macrophages regional to the liver called?
Kupfer cells
Which cells produce and maintain extracellular matrix and store vitamin A?
Stellate cells
What are 7 functions of the liver?
- Bilirubin metabolism
- Bile acid metabolism
- Carbohydrate metabolism
- Lipid metabolism
- Xenobiotic metabolism
- Protein synthesis
- Immune function
What percentage of liver parenchyma is injured before clinical signs appear?
Approximately 75%
What are 5 examples of liver enzymes?
- AST
- ALT
- LDH
- Alkaline phosphate
- Gamma-glutamyl transpeptidase
What are commonly used as biomarkers of liver injury?
Liver enzymes
T/F: Liver lesions are not very common.
False - they are fairly common.
Is a liver lesion usually significant enough to result in hepatic failure?
No
What can help to identify the presence and cause of liver disease?
Interpretation of the location and type of liver lesions.
What can be helpful with making a diagnosis of liver disease?
Histopathology
What are 3 examples of portals of entry of injurious agents?
- Hematogenous
- Retrograde through biliary and pancreatic ducts
- Direct extension through the liver capsule
What are 6 possible mechanisms of liver injury?
- Metabolic bioactivation of chemicals to reactive species
- Stimulation of autoimmunity
- Stimulation of apoptosis
- Disruption of calcium homeostasis
- Canalicular injury
- Mitochondrial injury
What are 5 possible responses to liver injury?
- Atrophy
- Hypertrophy and hyperplasia
- Regeneration of parenchyma
- Replacement by fibrosis
- Biliary hyperplasia
What are 4 possible causes of atrophy of the liver?
- Increased catabolism
- Decreased blood flow
- Decreased bile flow
- Pressure
T/F: The liver has considerable reserve and regenerative capacity.
True
What is liver regeneration stimulated by?
Growth factors
What percentage of the liver can regenerate within a week?
60%
What type of cells can differentiate into hepatocytes or bile duct epithelium?
Oval (stem) cells
What are 3 requisites for liver regeneration?
- Intact framework
- Good blood supply
- Patent bile ducts
What is increased within the liver with fibrosis?
Amount of connective tissue.
With fibrosis within the liver, what cells proliferate?
Ito (stellate) cells
The significance of what is dependent upon effects on normal hepatic function and type of collagen?
Fibrosis
What is a possible cause of fibrosis in the liver?
Parasitic migration
Chronic liver injury can lead to what condition?
Cirrhosis
Regeneration seen with chronic injury can lead to what 3 possible outcomes?
- Hepatocellular nodular proliferation
- Fibrosis
- Impaired blood and bile flow
What is cirrhosis characterized by?
Nodular regeneration and post-necrotic scarring.
What is seen at the end-stage of many chronic liver diseases?
Cirrhosis
T/F: With cirrhosis, the liver is usually larger in size.
False - it is usually reduced in size.
Bile duct proliferation is also known as what?
Biliary hyperplasia
What is another name for capsular hepatic fibrosis?
What species is it common in?
- Perihepatitis filamentosa
- Horses
Can capsular fibrosis in horses be an incidental lesion?
Yes
What are 2 possible causes of capsular fibrosis?
- Resolution of peritonitis
- Parasitic migration
Focal areas of pale discoloration on the liver can be caused by what?
Tension lipidosis
Tension lipidosis can be found where?
Adjacent to mesenteric attachment.
In what species can you find tension lipidosis?
Cattle and horses
Rupture can be seen with what 2 conditions?
- Trauma
- Enlarged liver
T/F: Postmortem changes occur slowly.
False - they occur rapidly.
What are 3 examples of postmortem changes that can be seen in the liver?
- Pale, irregular foci
- Greenish black discoloration near the intestine
- Emphysema
Can autolysis occur in the liver postmortem?
Yes
What postmortem change can be seen on the surface of the liver in contact with the gall bladder?
Bile imbibition
What are 3 examples of patterns of hepatocellular degeneration?
- Random
- Zonal
- Massive