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98 Cards in this Set
- Front
- Back
What is the main blood supply of the liver?
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Arterial: from *hepatic a.
Venous: from SI via *portal v. Converge in sinusoids and exit into central veins, central veins drain into hepatic vein |
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What cell in the liver are responsible for clearing foreign substances, antigens, bacteria and aged red blood cells?
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Kupffer cells
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There is increased ______ production with Kupffer cell dysfunction.
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IgM-because get immune stimulation
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What do you see on serum protein electrophoresis when there's chronic liver disease?
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Beta-gamma bridging
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Explain the flow of bile.
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Bile--> canaliculi & bile ducts--> cystic duct and gall bladder ---> common bile duct---> SI
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What animals lack a gallbladder?
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Horses & camelids
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What is enterohepatic cycling?
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Substance excreted in bile is resorbed and recirculates in portal blood to the liver
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What can you use to detect issues in enterohepatic cycling?
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-bile acids (extensive- so if increased means issues w/ enterohepatic cycling)
-bilirubin & urobilinogen |
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What is the reserve capacity of the liver?
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60-75%, excellent capacity for regeneration and reserve
-so when signs then large loss of function |
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What are 6 functions of the liver?
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1) Carbohydrate metabolism
2) Protein metabolism -binding proteins, coagulation factors, lipoproteins 3) Fat metabolism -FA and ketone synthesis 4) Urea synthesis 5) Bile acid synthesis 6) Detoxification -bilirubin, urea, aromatic amino acids |
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What happens to urea and ammonia levels with liver disease?
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Decreased BUN, increased ammonia
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Does hypoglycemia indicates acute or chronic liver disease?
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Acute
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What is bilirubin derived from?
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hemoglobin (80%) and non-Hb hemoprotein
-Heme--> biliverdin--> unconjugated bilirubin |
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What happens to unconjugated bilirubin from heme breakdown?
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UCB enters liver--> water soluble conjugated bilirubin (glucuronyl transferase)
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Explain the colors associated with bruising.
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Heme=red------>
Biliverdin= green----> UB=yellow |
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What does it mean if there's no urobilinogen in the urine?
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Means there's a bile duct obstruction e.g. common bile duct obstruction
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What happens to conjugated bilirubin?
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-Excreted into canaliculi (small amount enters blood)
-CB converted to urobilinogen in bowel -some urobilinogen undergoes EH cycling, some enters urine |
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What are 4 causes of hyperbilirubinemia?
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1) Excess production
-hemolysis 2) Hepatocellular disease -decreased uptake into hepatocytes--> disturbed conjugation 3) Disturbed secretion of CB -intra or extra hepatic bile obstruction 4) Congenital syndromes (sheep) |
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What are 2 causes of an increased fraction of unconjugated bilirubin?
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Hemolysis
Hepatocellular disease |
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What does an increase in conjugated bilirubin indicate?
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Obstructive biliary disease
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How do you different the cause of hyperbilirubinemia? (3)
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1) Clinical findings- hisotry & PE
2) Lab findings -CBC, chem panel, SBA 3) Diagnostic tests |
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What are 8 clinical findings of hemolytic disease?
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1) icterus
2) anemia (pale membranes) 3) Weakness 4) Elevated HR/RR 5) Hemoglobinuria 6) Water blood w/ pink serum 7) Low PCV, RBC +/- Hb 8) Normal liver enzymes and SBA's |
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How can you tell how severe hemorrhage is without look at respiratory rate or heart rate?
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Correlate PCV to total protein
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Do you see icterus with acute liver damage?
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No, jaundice takes time to develop
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How do you differentiate b/w myoglobin, hemolgobin and RBCs in urine?
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Myoglobin: look at serum should be clear and CK elevated
Hemoglobin: serum should be pink RBCs: spin down urine and if becomes clear with pellet on bottom |
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*What are 5 infectious causes of hemolytic anemia in horses?
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1) Leptospirosis
2) Babesiosis 3) Eperythrozoon 4) Equine infectious anemia 5)*Clostridium toxins |
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What are 2 toxic causes of hemolytic anemia?
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1) Copper
2) Toxic plants -red maple, onion, brassica, kale, rape |
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What are 3 immune mediated causes of hemolytic anemia?
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1) AIHA
2) Neonatal isoerythrolysis 3) Incompatible blood transfusion |
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What are 5 causes of hepatocellular failure?
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1) Toxins
-pyrrolizidine alkaloids 2) Immune mediated 3) Hypoxia, toxemia, and shock 4) Infectious diseases 5) Lipidosis |
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What are 8 causes of obstructive hepatic disease?
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1) Cholangitis
2) Cholangiohepatitis 3) Fibrosis 4) Cholelithiasis 5) Parasites 6) Hepatic abscesses 7) Neoplasia (all spp) 8) Pancreatitis (dogs) |
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What type of bilirubin causes bilirubinuria?
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CB= soluble bilirubin
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What are 5 clinical findings of obstructive disease? (diagnostics)
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1) Increased serum CB fraction
2) Biliary distension on biopsy or ultrasound 3) Bilirubinuria -excretion increased CB 4) Absence of urine urobilinogen 5) Increased GGT & ALP |
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What are 6 important pieces of history when trying to figure out the cause of hyperbilirubinemia or hemolysis?
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1) Vaccination or transfusion
2) Potential exposure to plant or chemical toxins 3) Fever, colic, weight loss 4) Number of affected/ exposed in herd 5) Behavioral changes 6) Meds |
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What are 2 signs of severe hepatomegaly on clinical exam?
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Percussion dullness
Pain caudal to rib cage on R |
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When do clinical signs of liver failure develop?
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Once ~75% of parenchyma is compromised
-hepatic disease w/o insufficiency shows few signs |
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When is icterus more profound, with acute or chronic liver failure?
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Acute failure or diseases w/ elevated CB
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Is icterus common in ruminants?
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No, so when see it know its very significant
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How do you differentiate icterus from hemolysis or fasting?
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By serum color and liver enzymes
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What are the 9 signs of hepatic failure?
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1) Icterus
2) Hepatic encephalopathy 3) Weight loss 4) Photosensitization 5) Pruritus 6) Ventral edema & ascites 7) Hemorrhage 8) Diarrhea 9) Abdominal pain |
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What are the signs of hepatic encephalopathy?
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Depression, head pressing, aimless walking, circling, mild ataxia, persistent yawning
-eventually recumbency & coma -tenesmus in cattle |
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Why does liver failure cause weight loss?
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Anorexia, chronic inflammation, altered metabolism
-especially in chronic disease |
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Weight loss due to hepatic failure has to be differentiated form what 5 things?
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1) parasitism
2) Malnutrition 3) Neoplasia 4) Other organ failure 5) Other causes chronic inflammation |
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Do animals with hepatic encephalopathy have a menace response?
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No, they don't see you
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Does photosensitization usually develop with acute or chronic liver failure? How does it occur? Clinical signs?
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chronic
Accumulation of phylloerythrin in skin + reacts w/ light Erythemia, crusting and necrosis- lesions of non-pigmented skin |
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Why does edema and ascites develop in animals with liver failure?
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Hypoalbuminemia
Increased portal pressure from hepatic fibrosis -ascites in calves and dogs |
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Why is there hemorrhage w/ liver failure?
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Decreased clotting factors & vit K absorption
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Why do animals with liver failure sometimes develop diarrhea? Which animals do?
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Cattle & small animals w/ chronic disease
-portal hypertension, increased hydrostatic pressure in bowel |
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Why can animals with liver failure develop fever?
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Cholelithiasis, hepatic abscesses
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Why do animals with liver failure have discolored urine?
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bilirubinuria
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What are 2 reasons that hepatocellular and cholestatic disease rarely occur as individual entities?
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-cellular damage results in cell swelling and secondary occlusion of the biliary tract
-biliary dysfunction causes retention of toxic bile products w/ secondary cellular damage |
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What are leakage enzymes?
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Concentrated in liver cells and damages increases serum levels
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What are the 5 hepatic leakage enzymes?
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1) ALT
2) AST 3) GLDH 4) SDH 5) LDH |
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Do leakage enzymes tell you anything about function?
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No, poor correlation to damage and function
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What is ALT? What causes it to increase?
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Alanine aminotransferase
Hepatic necrosis in primates and small animals |
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What is AST? What cell(s) is it present in?
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Aspartate aminotransferase
-liver, muscle, RBCs -interpret with CK |
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What is the specificity and sensitivity of AST for liver disease?
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Sensitive indicator of hepatocellular disease, but not specific can be liver, muscle or RBCs
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When does AST peak? Decrease?
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Peaks in ~24 h
Decreases in 2-3 days |
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What is the best enzyme to detect hepatocellular damage in ruminants?
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GLDH
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What is GLDH? When does it Peak? Decrease?
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Glutamate dehydrogenase
-Peaks in ~24 h -short half life |
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What is the specificity of SDH? What is SDH?
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Sorbitol dehydrogenase
-specific for ACUTE hepatocellular damage -short half life so normalizes rapidly -increases w/ acute GI obstruction or enteritis in horses |
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What does it mean if there's a continuing increase of SDH?
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Continuing disease, because short half life so levels normalize rapidly
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Describe the specificity of LDH?
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Non-specific unless LDH 5
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Why isn't SDH measured very often in the field?
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Very labile, can't keep over night
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What do induced enzymes indicate?
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Active biliary tract disease
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What causes increased induced enzymes?
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Increased de novo syntehsis:
-drugs: corticosteroids, barbiturates -Cholestasis |
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Do induced enzymes indicate acute or chronic biliary tract disease?
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Takes a few days to increase
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What are the induced liver enzymes?
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ALP
GGT |
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What contains ALP in the body? What does ALP stand for?
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Liver, GI and bone isoenzymes
Alkaline phosphatase |
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What liver enzyme is normally elevated in young animals?
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ALP
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When do ALP levels peak?
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5-6 days post insult
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What can cause a massive increase in ALP? What animal(s) is ALP not useful in/
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Bile duct obstruction
Ruminants-wide fluctuations |
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GGT serum levels correspond to_________.
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Cholestasis
-urine GGT used to evaluate renal disease |
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When does GGT peak/
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~7 days and long half life
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What enzyme has the highest sensitivity for liver disease in horses?
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GGT (gamma glutamyltransferase)
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What liver enzyme can be used to assess passive transfer?
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GGT
-Serum GGT elevated for first 2 weeks of life -normal foals commonly have GGT 2 to 3 x normal for 2 weeks |
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What are 4 non-specific tests of liver function?
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1) Bilirubin
2) Total protein and SEP 3) Urinalysis 4) BuN & glucose |
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What are 4 causes of increased bilirubin?
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1) fasting
2) hemolysis 3) hepatocellualr and cholestatic liver disease |
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What will you see on a total protein and serum protein electrophoresis of an animal with liver failure?
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1) Decreased albumin
2) beta-gamma bridging 3) Polyclonal gammopathy |
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What causes bilirubinuria?
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Obstructive disease
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What causes increased urine urobilinogen?
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Hemolysis
Hepatocellular disease |
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What happens to BUN and glucose w/ hepatic failure?
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Altered production and regulation causes a decrease in both
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What are 2 specific tests of liver function/
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1) Serum bile acids
2) Blood ammonia |
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95% of serum bile acids are reabsorbed from ____into the portal vein.
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Ileum, then 90-95% extracted by liver cells on first pass
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How does hepatic disease cause an increase in serum bile acids?
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Decreases extraction and/or causes regurgitation into circulation
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What are 2 downfalls of serum bile acids for evaluating hepatic disease?
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1) Low specificity for type or degree of dysfunction
2) not useful in ruminants |
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What does increased blood ammonia usually indicate?
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Diffuse disease
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What are 2 causes of increased blood ammonia?
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1) Hepatic shunts
-failure to detoxify blood 2) Gut associated hyperammonemia |
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Blood ammonia levels remain normal until > ___% of hepatic function is lost.
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60%
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How should blood be stored to measure blood ammonia?
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Very unstable
-ice samples and analyze immediately |
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What can you visualize with ultrasonography of the liver?
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Hepatic texture & size
Vessels & bile ducts Specific abnormalities -biliary distension, choleliths, hepatic tumors, abscesses |
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When are liver biopsies a help diagnostic tool for diagnosing hepatic disease?
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when diffuse disease
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What is the purpose of performing ultrasound guided liver biopsies?
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assists biopsy site selection and avoids large vessels and other structures
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Do we usually anesthetize animals for liver biopsies?
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no, we use sedation in all species and standing in large animals
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What are 6 abnormalities that a liver biopsy may identify?
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1) Biliary abnormalities
2) Fibrosis 3) Inflammatory cells 4) Neoplasia 5) Necrosis 6) Fat infiltration |
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What is portovenogrpahy good for?
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Small animals and large animal neonates to identify hepatic shunts
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When are exploratory laparotomies helpful to diagnose hepatic issues?
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Suspected portal shunts
Diagnosis of liver disease in cattle |
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Why perform a fecal exam with liver issues/
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Liver fluke eggs in ruminants
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What are 6 indicators of a poor prognosis of liver issues?
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1) Hypoalbuinemia
2) Hyperglobulinemia 3) Prolonged PT 4) High GGT & ALP w/ low or normal SDH 5) Fibrosis 6) HE or hemolytic crisis |