Liver and Pancreas Pathology Flashcards
Repeated injury to the liver leads to what?
Loss of normal tissue and loss of function
Scar tissue/fibrosis (irreversible)
What are the important functions of the liver?
Protein Synthesis - clotting factors and albumin Metabolism - detoxification (ammonia - HE)
Excretion and digestion - bilirubin and bile
Nutrition - regulation of fat and carbohydrate
Is the liver well or poorly oxygenated?
Poorly oxygenated
What % of the liver blood flow is taken up by the portal vein? What about the hepatic artery? What travels through each of those vessels?
- Portal vein (nutrients, 75%)
- Hepatic artery (oxygen, 25%)
How many mm in diameter is a classic lobule?
2mm
What makes up a portal triad?
Portal vein, hepatic artery, bile duct
Where in the liver is bile produced? Which way does bile flow through bile ducts in relation to blood flow?
Bile is produced in canaliculi and flows in opposite direction through bile ducts
Where do hepatocytes converge?
central vein
Label this hepatic lobule
What are these 3 zones of the hepatic lobule? Which is the most poorly oxygenated?
Which hepatic zone is the worst affected in toxic injury? Why?
Centrilobular zone - metabolic enzymes capable of changing toxin into more (or less) toxic molecule are located here
Label this portal triad
What is a portosystemic shunt? Which animals does this commonly occur in?
Portal bloodflow bypasses liver and enters systemic circulation
Dogs and Cats
What are the 2 main causes of portosystemic shunts?
Congenital
Acquired
Describe a congenital portosystemic shunt? What happens to the liver?
- Usually single shunt to vena cava/azygous/renal vein
- Liver is bypassed and does not receive blood supply and cannot grow to normal size (atrophies)
Describe an acquired portosystemic shunt? What does this occur secondary to? How does this differ from congenital shunt?
- Secondary to fibrosis in older animals
- Multiple thin-walled shunts
- Slow development of shunts, fibrosis causes scarring and liver becomes so scarred due to repeated damage that it doesn’t allow new blood to come in (portal hypertension, liver congestion) and blood finds another route by creating thin-walled little veins for blood to travel
What is the end result of a liver shunt?
Hepatic encephalopathy
What is this?
Fatty Liver
List congenital/developmental disorders which lead to liver pathology
Congenital cysts
Displacements
Tension lipidosis
Capsular fibrosis
Telangiectasis
How can you tell if liver is enlarged?
Rounded capsular edges
Cutting through reveals rounded edges
What are some degenerative liver hepatopathies?
Vacuolar hepatopathies
Lipidosis (fatty liver)
Amyloidosis
What does “vacuolar hepatopathies” mean? What are the different types? Which of these is reversible? What are the causes?
Anything which causes swelling and vacuolation of hepatocytes
Can be water (hydropic change), fat (lipidosis), glycogen (glycogenesis)
Hydropic change = reversible
Causes - hypoxia, mild toxic damage, metabolic stress, steroid administration/HAC
What is another name for hepatic lipidosis? How does lipidosis occur? What can cause lipidosis?
Fatty Liver
Can be caused by obesity/starvation, stress, increased energy demand (pregnancy, lactation), Disease (diabetes mellitus, ketosis, pregnancy toxemia)
What is amyloidosis? Which breed of cat is highly susceptible?
Abnormal protein buildup which can accumulate in many organs
Can be primary, secondary or endocrine-associated
Oriental cats - see liver rupture associated with amyloid accumulation
What can cause centrilobular necrosis in the liver?
Ischemia
Anemia
Metabolic/Toxic damage
What causes ZONAL pattern of injury to the liver?
Ischemia/Toxic damage
What causes RANDOM pattern of injury to the liver? Give an example
Viral/Bacterial
Usually an “-itis” - Ex. multifocal random hepatitis
What causes FOCALLY EXTENSIVE pattern of injury to the liver?
Bacterial
What causes MASSIVE pattern of injury to the liver? Give an example
Severe injury/toxicity
Ex. hepatosis dietetica (low selenium, high fat)
How does the liver respond to injury (clinically vs pathologically)?
Clinical - Jaundice, Hemorrhage, Edema, HE
Pathology - Regeneration, Fibrosis (firm)
What has happened to this liver? What is the name for this condition?
Liver cirrhosis
What is the name for this condition? How does this occur? What is usually the cause?
Nutmeg liver usually as a result of right sided heart failure
Hepatic venules and sinusoids congested, centrilobular atrophic hepatocytes (dark red) vs periportal fatty change (pale red)
What are the 3 types of liver inflammation?
Hepatitis
Cholangitis
Cholangiohepatitis
What is hepatitis? What is it often caused by?
Inflammation of liver parenchyma (often caused by infection)
What is cholangitis? How does it occur?
- Inflammation of bile ducts - may be immune mediated (cats) or associated with infection (Ex. salmonellosis in calves)