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170 Cards in this Set
- Front
- Back
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What are the lobes of the canine liver?
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1) Left lateral lobe
2) Caudate lobe: -Papillary process of caudate lobe -Caudate process of caudate lobe 3) Right medial lobe 4) Right lateral lobe 5) Quadrate lobe |
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What are 2 proposed zonal patterns of the liver?
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1) Lobular: Central vein is at the center (blood goes out) and portal triads are at the corners (blood comes in)
2) Acinar: Hepatic artery (portal triad) is at the center of the triangle and central (hepatic) vein is the corners |
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True or false. The liver rarely gets infarction.
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True, has collateral circulation
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What does the portal triad consist of?
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Portal vein
Hepatic artery Bile duct |
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How is the parenchyma of the liver normally arranged?
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In cords that go from portal ---> central
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When 2 hepatocytes meet they form a _____________.
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Canaliculus -drain into bile ducts
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What increases the surface area for hepatocytes to be bathed by the Space of Disse?
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Microvillus border
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What is the function of the liver?
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Synthesizes and accumulates some substances, detoxifies substances and transports others
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What does the liver metabolize and store?
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Fats and carbohydrates
-Glucose--> glycogen -Triglycerides --> phospholipids and cholesterol |
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What 5 substances does the liver metabolize but not store?
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1) Protein and ammonia
-Clotting factors, albumin 2) Vitamins 3) Steroid 4) Drugs 5) Toxins |
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What is the function of the smooth endoplasmic reticulum in the liver?
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Cholesterol, Bile acids, Glycogen, Metabolism of bile pigments, xenobiotics, and ingested substances
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What is the function of the rough ER of the liver produce?
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Plasma proteins
Clotting factors |
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What is the function of the bile canaliculus?
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Bile transport
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What are located in the sinuosoids of the liver?
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Filtration by Kupffer cells
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What are the 3 "zones" of the hepatic parenchyma? List from closest to portal vein to closest to the hepatic vein.
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1) Periportal
2) Mid-zonal 3) Centrilobular |
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What hepatocytes are the most susceptible to anoxic, toxic and nutritional injury?
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Centrilobular hepatocytes
-Lowest O2 and nutrient supplies |
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What is the most common site for bile casts in cholestasis?
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The bile canalicular system farthest from bile ducts- centrilobular
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What hypatocytes perform the most glycogen synthesis?
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Centrilobular hepatocytes (zone III)
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What is the site of earliest fat storage and degenerative lipidosis?
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Centrilobular hepatocytes (zone III)
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What hepatocytes have the highest mixed function oxidase activity (cytochrome p450)?
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Centrilobular hepatocytes (zone III)
-Detoxify most substances so first site of degeneration |
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What type of metabolism is performed in the centrilobular hepatocytes?
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Lipid, steroid and pigment metabolism
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What hepatocytes have the highest concentration of oxygenated blood and blood nutrients?
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Periportal hepatocytes (Zone I)
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What hepatocytes are the first cells to come in contact with direct toxins?
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Periportal hepatocytes (Zone I)
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What hepatocytes are most capable of regeneration? Why?
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Periportal hepatocytes (Zone I)
-Have highest mitotic activity thus more capable of regeneration |
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What hepatocytes have the highest concentration of respiratory enzymes such as succinic dehydrogenase, cytochrome oxidase, and glucose-6-phosphate (mitochondrial enzymes)?
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Periportal hepatocytes
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What do the periportal hepatocytes metabolize?
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Protein and glycogen
-Glycogen synthesis=centrilobular |
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What are 2 functions of Kupffer cells in the dog? What is different about swine, goats and cattle?
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1) Phagocytic-bacterial and particulate material
2) Degrade bacterial endotoxin -Swine goats and cattle have these functions performed by intravascular pulmonary macrophages |
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What happens to the iron from necrotic hepatocytes?
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Taken up by Kupffer cells
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Where are Ito cells (stellate cells) located? 2 functions?
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Reside in Space of Disse
-Vitamin A fat storage -Type IV collagen synthesis |
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What do hepatocytes do to lipophilic substances (how do they protect themselves)?
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Convert lipophilic substances to hydrophilic substances that can be excreted by the kidneys
-SER oxidizing enzyes -Peroxisomes |
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What are 2 types of hepatocellular change that occurs?
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1) Cell swelling
2) Lipidosis -When enough of these changes happen--> liver disease |
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How much of the liver do you have to lose at once in order to trigger regeneration?
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10%
-Can be functional or non-functional |
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What type of cell swelling occurs with hepatocytes?
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Non-specific swelling of mitochondria, ER, and cytoplasm associated with increased content of water (hydropic, vacuolar ballooning of change)
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Why are intracytoplasmic enzymes detected biochemically when hepatocytes are injured?
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Cell swelling causes increased permeability and releases enzymes
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True or false. Non-specific cell swelling is irreversible.
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False, it is reversible
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What is hepatic lipidosis?
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Excess accumulation of cytoplasmic lipid
-Excess of free FAs into hepatocytes |
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What is a common cause of lipidosis in many species?
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Pregnancy
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What are 5 gross lesions of hepatic lipidosis?
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1) Hepatomegaly
2) Friable 3) Greasy 4) Yellow 5) Floats in formalin |
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***What are 2 differentials of a liver that is enlarged, friable, and greasy?
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Hepatic lipidosis
Steroid hepatopathy (only in canids!) |
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What animals get steroid hepatopathy?
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Canids
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***True or false. Steroid hepatopathy is a disease.
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FALSE!!!! Not a disease it's a phenomenom
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What are the clinical signs of fatty liver syndrome in cats?
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-Anorexia, thin, but copious amounts of body fat
-Vomiting, infrequent hard stools +/- icterus (Depends on liver damage) |
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What is the microscopic change of fatty liver syndrome in cats?
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Hepatic lipidosis--> necrosis
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What causes cats to be anorexic with fatty liver syndrome?
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Can't smell because of upper respiratory disease (feline pneumonitis) and if can't smell then won't eat
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What is the pathogenesis for hepatic lipidosis from fatty liver syndrome in cats?
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Anorexia in the presence of abundant fat stores (cat has to be fat) --> hypoglycemia---> lipolysis of body fats, which cannot be processed by the liver due to saturation of plasma transport mechanisms of LDLs---> hepatic lipidosis
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What is the pathogenesis for hepatopathy from fatty liver syndrome in cats?
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Prolonged retention of bowel contents increases absorption of toxic products---> hepatopathy
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Fatty liver syndrome in cattle=________.
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Hepatic lipidosis
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What predisposes (causes) cattle to develop fatty liver syndrome (hepatic lipidosis)?
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Fat dairy cows near parturition and in early lactation are placed on restricted diets to prevent dystocia, retained placenta and metritis.
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What is the pathogenesis of fatty liver syndrome in cattle (hepatic lipidosis)?
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-Fat mobilization from body stores
-Fat transported to liver where there is a decreased removal of triglycerides due to decreased lipoprotein output (saturation of plasma transport mechanisms of LDLs) |
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How does fatty liver syndrome in cattle and cats vary?
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Cattle isn't from not eating like cats, its from management practice
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What causes equine hyperlipemia?
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Pregnant or lactating animals suddenly placed on reduced feed intake
-Shetland ponies, miniature horses |
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True or false. Equine hyperlipemia is not a fatal condition.
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False, fatal because fat vacuoles compress the nucleus of hepatocytes and get hydropic degeneration
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What are 3 causes of large amounts of glycogen in hepatocytes?
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1) Large amounts after feeding
2) Metabolic perturbations 3) Hepatic involvement (manifestation of a systemic disease process) |
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What are 3 metabolic perturbations associated with glycogen accumulation in hepatocytes?
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1) Diabetes mellitus
2) Glycogen storage diseases 3) Glucocorticoid hepatopathy |
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What animal gets glucocorticoid hepatopathy?
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Canids
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How do high corticoid levels cause a hepatopathy?
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Corticoids alter the balance b/w glycogenesis and glycogenolysis in the acinar midzone.
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What do you see on histopathology of a dog with glucocorticoid hepatopathy?
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Diffuse to centrilobular hepatocellular vacuolation (intracellular edema)
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True or false. Steroid hepatopathy is not a disease.
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True, usually an incidental finding
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What are the gross lesions from bile?
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1) Yellow to green liver
2) Extrahepatic or intrahepatic cholestasis |
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What is post mortem imbibition?
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Absorption of a fluid (bile) by a solid or colloid (other tissues)
-e.g. pigment of gallbladder often leaches out and colors the tissues nearby=imbibition |
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True or false. Icterus/jaundice can be a regional condition.
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False, never regional, it's global (affects whole body)
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True or false. Bile is contained within the hepatocytes.
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False, not in the hepatocytes, it's in the cannaliculi.
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What animals naturally have yellow fat?
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Channel breeds of cattle
Warm blooded horses Chickens -If concerned look at sclera & mucous membranes |
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What does it mean if an animal has white feces?
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Biliary blockage
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What are 7 liver parameters that can be measured in a biochemistry panel?
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1) ALT
2) GGT 3) SAP 4) Bile acids 5) Plasma proteins 6) Bilirubin 7) BSP |
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What are 2 ways to evaluate liver function?
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1) Biochemistry panel
2) Biopsy/cytology |
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What are 5 patterns of hepatic necrosis?
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1) Diffuse
2) Multifocal 3) Periportal 4) Midzonal 5) Centrilobular |
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What are 4 causes of diffuse hepatic necrosis?
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1) Vitamin E deficiency-hepatosis dietetica (swine-mulberry heart disease)
2) Some viral infections 3) Some toxins 4) Vascular accidents |
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What is the most common pattern of hepatocellular degeneration & necrosis?
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Centrilobular/periacinar
-Most susceptible to hypoxia -Greatest enzymatic activity |
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What are 4 causes of midzonal hepatocellular degeneration and necrosis?
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1) Yellow fever in primates
2) Pigs & horses w/ aflatoxicosis 3) Cats exposed to hexachlorophene 4) Human eclampsia -Uncommon location |
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What are 2 causes of periportal hepatic necrosis?
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1) Phosphorous poisoning
2) Aflatoxins in some species |
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What are 4 types/locations of hepatic inflammation?
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1) Hepatitis
2) Cholangitis 3) Cholangiohepatitis 4) Pericholangitis |
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What do you call inflammation of the biliary system?
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Cholangitis
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What do you call inflammation of the liver and biliary system?
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Cholangiohepatitis
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What is pericholangitis?
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Inflammation in portal area and not in bile ducts=pericholangitis
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What are 5 broad categories of disease that the liver is susceptible to?
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1) Infectious
2) Parasitic 3) Toxic 4) Etiology unknown 5) Cellular proliferations |
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What do you call inflammation of the biliary system?
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Cholangitis
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What are 7 routes of hepatic infection/damage?
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1) Portal circulation
2) Hepatic artery 3) Umbilican vein 4) Biliary system 5) Hepatic vein 6) Direct extension 7) Parasite migration |
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What do you call inflammation of the liver and biliary system?
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Cholangiohepatitis
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What is pericholangitis?
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Inflammation in portal area and not in bile ducts=pericholangitis
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What are 2 specific viral diseases that affect the liver?
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1) *Infectious canine hepatitis
2) Herpesvirus infections |
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What causes infectious canine hepatitis and how does it spread?
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Canine adenovirus I-spread in urine
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What 3 cells are affected by canine adenovirus-1?
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1) Parenchymal cells
2) Kupffer cells 3) Endothelial cells |
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What are most cases of infectious canine hepatitis characterized by?
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Most cases are subclinical or characterized by pharyngitis and laryngitis
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What is the initial site of replication of canine adenovirus I?
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Tonsils--> tonsillitis
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How do dogs with infectious canine hepatitis present during necropsy? (4)
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1) Hepatic necrosis (pale)
2) Mutlisystem hemorrhage -Sometimes paintbrush hemorrhage in stomach 3) Gallbladder & lymph node edema (gallbladder wall=thick) 4) Blue eye=Arthus-type III hypersensitivity -If have necrosis w/ thick gallbladder=canine hepatitis! |
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Where are intranuclear inclusions found in dogs with infectious canine hepatitis? (4)
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1) Tonsil
2) Liver 3) Kidney 4) Endothelium |
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What animal's livers are affected by other adenoviruses (not CAV-1)? What do you see on necropsy?
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Lambes, calves, kids, crias, foals
-Varying degrees of hepatic necrosis & inflammation as well as damage to other organs |
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What are 6 herpesviruses that are all characterized by multifocal hepatic necrosis with intranuclear inclusions in the fetus and neonate?
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1) Equine rhinopneumonitis
2) Infectious bovine rhinotracheitis 3) Caprine herpesvirus 4) Canine herpesvurs 5) Feline herpesvirus 6) Porcine herpesvirus |
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What are 2 signs that IBR causes?
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Upper respiratory disease & abortion
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What are the pathologies associated with FIP?
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Pyogranulomatous vasculitis/mutlisystemic
-Perivascular accumulations of lymphocytes and plasmacytes |
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How does equine infectious anemia affect the liver?
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Lymphocytic pericholangitis
-Subacute and chronic forms |
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What causes Tyzzer's disease?
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Clostridium piliforme
-Multiple species affected |
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What are 2 pathologies associated with Tyzzer's disease?
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1) Multifocal necrotizing enteritis
-Carnivores, rabbits, rodents, calves 2) Hepatitis |
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What are 3 clinical signs of a foal with Tyzzer's disease?
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1) Depression up to 48 hours prior to death
2) +/- icterus 3) RAndomly scattered foci of acute hepatocellular necrosis |
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Where can you visualize the Clostridium piliforme in an animal suffering from Tyzzer's disease?
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Numerous organisms in hepatocytes at margins of lesions
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What are the peracute clinical signs of bovine bacillary hemoglobinemia ("redwater")?
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Fever, hemoglobinuria, collapse and death
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What causes bovine bacillary hemoglobinemia?
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Clostridium hemolyticum bovin in associated w/ anaerobic liver injury (fasciola hepatica)
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Where is bovine bacillary hemoglobinemia located geographically? What animal other than bovines are susceptible?
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Sheep
Western and southern US |
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What is characteristic of bovine bacillary hemoglobinemia upon necropsy? What causes this lesion?
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Hepatic "infarcts" -not real infarcts
-Bacteria release necrotizing and hemolyzing exotoxin |
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Where are clostridium hemolyticum spores located after ingested?
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-Reside in Kupffer cells
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How do clostridium hemolyticum replicate in an infected host?
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-Proliferate in areas of low oxygen tension such as created with migration of immature liver flukes (fasciola) or other areas of necrotic hepatic parenchyma
-Bacteria spores can germinate -Bacteria can proliferate and release toxins |
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What is the main toxin released by clotridium hemolyticum?
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Phospholipase C
-Necrotizing -Hemolyzing |
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What is the pathogenesis of bovine bacillary hemoglobinemia?
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Hepatocellular necrosis
Intravascular hemolysis -basis for name |
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What animals get Black disease?
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Ruminants-principally sheep
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What agent causes Black disease?
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Clostridium novyi
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The pathogenesis of clostridium novyi is identical to the pathogenesis of _________.
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Bacillary hemoglobinemia, but black disease is usually not associated with hemoglobinuria
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What are the findings of an animal on necropsy with Black disease?
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Multiple foci of liver necrosis, subcutaneous venous congestion (dark coloration of skin)
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What is the characteristic liver lesion associated with salmonellosis?
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"Paratyphoid nodules"
-Macrophages and kupffer cells associated w/ foci of hepatic necrosis -Principally in cattle |
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What agent causes tularemia? What animals are susceptible?
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Francisella tularensis
-Most mammals susceptible |
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How is tularemia transmitted?
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Organisms transmitted across intact mucus membrane and skin
-Also by biting insects, ticks, ingestion and inhalation |
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You find chalky-white foci of necrosis in liver, spleen and lymph nodes in a rabbit, what is at the top of your differentials?
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Tularemia
-Characteristic lesion in rabbits & rodents |
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What is the characteristic lesion of tularemia in humans?
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"Rabbit fever".
Begins as indurated swelling of fever. Progresses to multifocal inflammation, lymphadenopathy and death -ZOONOTIC |
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What animals get leptosporosis?
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Dog and cow
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What will you see during histopathology of a liver from an animal with leptosporosis?
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Dissociation of hepatic cord architecture
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What pattern of hepatic necrosis does leptosporosis cause? Why?
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Centrilobular hepatic necrosis secondary to ischemia from intravascular hemolysis
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Where can you find bacteria in an animal with leptosporosis?
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Liver, but direct affects of bacteria on lier cells is not well defined
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Hepatic abscesses are most common in ________.
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Cattle
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What bacteria are associated with rumen ulcers and cause hepatic abscesses?
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Fusobaceterium necrophorum (Necrobacillosis)
-Causes irregularly shaped hepatic lesions |
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What are the 3 most common causes of hepatic abscesses?
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1) Umbilical vein in neonates
2) Traumatic reticulitis -hardward disease 3) Rumen ulcers |
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What are 5 causes of granulomatous Diseases of the liver?
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1) Tuberculosis
2) Pseudotuberculosis-Corynebacterium spp. 3) Deep mycosis 4) Rhocococus equi 5) Yesiniosis (pseudotuberculosis) |
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What causes the bubonic plague in rodents and man?
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Yersinia pestis
-Lesions in all species |
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What are the acute and chronic signs of yersiniosis?
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-Acute septicemia w/ no lesions
-Chronic infection =pseudotuberculosis-liver, spleen, lymph nodes, lung, GI system |
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Compare an abscess and granuloma.
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Abscess=polymorphonuclear cells
Granuloma=mononuclear cells (not granulocytes) -if also have neutrophils=pyogranulomatous |
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Why does it make sense that the liver is the major organ of detoxification?
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Because most toxins enter the body via the GI tract
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What is bioactivation?
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When the liver is trying to convert lipophilic compounds to hydrophilic compounds for renal excretion the metabolite that's produced is more toxic than the parent compound
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What is the most important factor predisposing animals to hepatotoxicity? Why?
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Anoxia since detoxification reactions increase oxygen requirements
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What are 2 factors that predispose an animal to hepatotoxicity other than anoxia?
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1) Increase in dietary protein increases O2 requirements increasing toxicity & increases urea (toxic
2) Fasting (anorexia) decreases glycogen stores increasing lipid formation. Many toxic free radicals are fat soluble & hence trapped in liver |
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What are 5 ways that hepatotoxins damage hepatocytes?
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1) Altering cellular or organelle membrane transport
2) Interfering w/ energy regulation by mitochondria 3) Disaggregating ribosomes of ER 4) Interfering w/ nucleic acid precursor utilization 5) Blocking or impeding unwanted metabolite removal |
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What are 4 causes of toxic liver disease?
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1) Toxic plants
2) Mycotoxins 3) Hepatotoxic therapeutic drugs 4) Hepatotoxic chemicals |
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What plants cause liver toxicity?
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Pyrrolizidine Alkaloids
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What animals are generally affects by pyrrolizidine alkaloids?
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Growing ruminants
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How are pyrrolizidine alkaloids toxic?
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Are activated by mixed function oxidase system to alkylating agents, which produce cytotoxicity and antimitotic activity
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How long does it take pyrrolizidine alkaloids to cause lesions?
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Can occur up to 2 months post-ingestion
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What kind of liver lesions do pyrrolizidine alkaloids cause?
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Pretty much die of fibrosis
-Hepatocellular necrosis -Bile ductule proliferation -Directly toxic to venules--> occlusive venous lesions -Toxic tubular nephrosis |
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What are the 7 responses of hepatocytes to toxins?
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1) Cellular swelling
2) Fatty change 3) Necrosis 4) Fibrosis 5) Biliary hyperplasia 6) Nodular regeneration 7) Neoplasia |
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What zone of the liver becomes necrotic when aflatoxins are ingested by poultry, cats, rats, rabbits, swine, dogs or cattle?
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-Periportal: poultry, cats, rats
-Midzonal: rabbits -Centrilobular: swine, dogs, cattle |
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What is the pathogenesis of aflatoxin liver damage?
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Metabolites of aflatoxins act on the nucleolus suppressing DNA dependent RNA polymerase depressing protein synthesis
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Why doesn't the liver regenerate when animals ingest pyrrolizidine alkaloids?
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Liver death is slow and regeneration only occurs when animal loses 10% of liver at once
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What is the pathogenesis of carbon tetrachloride poisoning?
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Activated by mixed function oxidase of smooth ER to a toxic trichloromethyl-free radical (CCl3) which damages membrane lipids
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Why are young animals less susceptible to carbon tetrachloride?
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Because have less mixed function oxidase activity (cyt p450)
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What can increase the toxicity of CCl4?
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Phenobarbital increases SER and Mixed function oxidase activity increasing toxicity
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What are the 3 lesions caused by carbon tetrachloride?
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1) Hemorrhagic gastroenteritis
2) Centrilobular fatty change & necrosis of liver which becomes massive 3) Fatty change and necrosis of renal tubule |
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What animals usually ingest Gossypol? What is it in?
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Cottonseed meal-swine
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What is the pathogenesis of Gossypol toxicity? What zone does it occur in and why?
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Interferes w/ Na/K ATP pump & damages mitochondria.
-Centrilobular: hepatocytes have decreased oxygen tension |
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What are the 3 lesions you will find from Gossypol?
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1) Hydrothorax, hydropericardium, ascites, edema
2) Cardiac insufficiency due to necrosis of myofibers 3) Centrilobular necrosis secondary to heart failure(?) |
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Why can drinking out of a stagnant pond cause hepatic dysfunction?
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blue-green algae=cyanobacteria microcystin =poison
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What causes icterohemoglobinuria? What animals are especially susceptible?
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Copper
-Sheep are especially sensitive to dietary levels normal for other ruminants |
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What is the pathogenesis of icterohemoglobinuria?
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Copper causes lipid peroxidation of cell membranes and hemoglobin denaturation.
-Inversely proportional to Mo and Zn in diet |
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What are the 4 pathologies associated with copper toxicity?
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1) Centrilobular fatty change and necrosis
2) Hemolytic anemia 3) Hemoglobinemia nephrosis (sheep) 4) Kayser-Fleischer ring -Brown or gray/green deposit at ocular limbus |
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What is Wilson's disease?
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Inherited disorder of lysosomal copper excretion in Dalmations, cocker spaniels, Bedlington terriers, West highland white terries, Skye terriers, Labs and dobermans.
-Not characterized by hemolysis! |
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What are 3 gross lesions associated with copper accumulation?
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1) Intravascular hemolysis
2) Centrilobular, midzonal to massive hepatocellular necrosis 3) Icterus -Gun medal kidneys |
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What category of drugs cause centrilobular to massive necrosis? How?
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Anticonvulsants:
-Dilantin, primidone etc. can cause severe liver damage over time secondary to cholestasis |
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What is an example of idiosyncratic hepatotoxicity?
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Acetaminophen in cats depletes gutathione--> oxidative damage--> anemia--> death
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True or false. Infarcts of the liver are rare.
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True
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What are 4 diseases of hepatic vasculature?
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1) Thrombosis of vena cava/portal vein
2) Portosystemic anastomoses 3) Passive congestion 4) Veno-occlusive disease -Some hepatotoxins (aflatoxins, pyrrolizidine alkaloids) -Captive cheetahs (high amounts of dietary Vit A) |
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What are 4 predisposing factors to thrombosis of the vena cava/portal vein? What animal is most common?
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Dogs (most common)
1) *Amyloidosis w/ decreased ATIII 2) *Pancreatitis 3) Portal hypertension 4) Steroids |
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What is the normal hepatic blood supply?
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Hepatic artery-25 to 30%
Portal vein-70 to 75% (drains GI and spleen to liver) |
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What are the 2 general types of vascular shunts?
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1) Congenital
2) Acquired |
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What is a congenital portosystemic shunt?
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Persistent patency of fetal ductus venosus
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What are the 6 physiologic sequella to portosystemic anastomosis?
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1) Decreased plasma protein formation
2) Hypoalbuminemia 3) Decreased amino acid utilization 4) Decreased production of bile salts 5) Decreased serum cholesterol and fatty acids 6) Abnormal liver function tests |
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What are the 8 clinical sequella to portosystemic anastomosis?
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1) Depression
2) Poor growth 3) Anorexia 4) Vomiting 5) Seizures 6) Ataxia 7) Diarrhea 8) Ascites |
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What is the pathogenesis of encephalopathy related to a portosystemic anastomosis?
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Decreased amino-acid utilization--> deamination of protein in colon--> increased ammonia ---> liver for conversion to urea--> encephalopathy
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What is the pathogenesis of ascites and edema from portosystemic anastomosis?
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Hypoproteinemia--> ascites & edema
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What is the sequella to ascites an edema from portosystemic anastomoses?
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Decreased colloid osmotic pressure causes shift of intravascular fluid into interstitial space--> hypovolemia--> poor renal perfusion--> increased renin
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What are the sequella from renin release due to portosystemic anastomosis?
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Adrenal increases aldosterone retaining Na+ and excreting K+--> metabolic alkalosis
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Why is the RAAS system a vicious cycle in an animal with liver insufficiency?
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Liver insufficiency decreases degradation of renin and aldosterone prolonging the action of these agents
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Why can there be increased insulin levels in animals with a portosystemic shunt?
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Pancreatic blood may bypass liver increasing insulin in systemic circulation (liver degrades insulin)
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True or false. Ammonium or uric acid calculi can form in dogs with a portosystemic shunt.
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True
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True or false. Portosystemic shunts do not affect bleeding times.
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False, increased bleeding times
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