Liver Flashcards
parts of the hepatic lobule - what is in the center vs angels of hexagon?
center = central v.
angels = portal tracts
function of stellate (ito) cells
store vitamin A
role in hepatic fibrosis
function of oval cells
BM origin
liver regeneration
differentiate into hepatocytes and biliary cells
why are liver sinusoids lined by fenestrated endothelial cells
diffusion
what is the gap between endothelial cells and hepatocytes called
space of disse
pale, enlarged, friable, enhanced lobular pattern
zonal degeneration and necrosis
what zone has
- least O2; susceptible to hypoxia
- greatest enzyme activity
-associated with severe anemia or right sided heart failure
centrilobular
zone 3 (peri acinar)
what zone is associated with zonal degeneration/necrosis in pigs/horses with alflatoxicosis
midzonal
zone 2
what zone is associated with toxin exposure lacking requirement of metabolism by oxidases
periportal
zone 1 (centro acinar)
what necrosis can link centrilobular areas or centrilobular to periportal areas and are confluent areas of necrosis
bridging necrosis
what necrosis covers the entire hepatic lobule with NO regeneration due to all hepatocytes in the lobule being affected
replacement occurs through ductular reaction
massive necrosis
what type of hepatic necrosis is caused by infectious agents
random necrosis
causes of pre-hepatic hyperbilirubinemia
problem with uptake
hemolysis
causes of hepatic hyperbillirubinemia
problem with conjugation
liver injury affecting ability of hepatocytes to metabolize/excrete bile
inherited abnormalities of bile synthesis inhibiting excretion
causes of post-hepatic hyperbillirubinemia
problem with secretion
obstruction of extrahepatic bile ducts - calculi, parasites, neoplasia, adjacent inflam (pancreatitis)
type of injury:
individual cell necrosis results in local proliferation and regeneration of hepatocytes
regeneration
4 types of hepatic injury
regeneration
fibrosis
cirrhosis
portal hypertension
causes of periacinal fibrosis
toxins
chronic passive congestion
causes of periportal fibrosis
chronic inflam
some toxins
causes of multifocal fibrosis
migrating nematodes
type of injury:
diffuse process characterized by fibrosis and conversion of normal liver architecture into structurally abnormal lobes
cirrhosis “end stage liver”
type of injury can lead to ascites due to diffuse fibrosis of the liver from chronic injury
portal hypertension
what are the types of circulatory disorders
- disturbances of outflow
- disturbances of inflow
- incidental
- infarction
passive or venous congestion such as from right side heart failure or endocardiosis is an example of what type of hepatic circulatory disorder?
disturbance of outflow
anemia, congenital porto-systemic shunt, portal hypertension are examples of what type of hepatic circulatory disorder?
disturbance of inflow
telangiectasia is an example of what type of hepatic circulatory disorder?
incidental
liver lobe torsion is an example of what type of hepatic circulatory disorder?
infarction
causes of hyper coagulability in dogs
liver disease
hyperadrenocorticism
protein losing disease
neoplasia
immune-mediated diseases
infectious disease
pancreatitis
consequences of vascular disturbances in the liver
portal v thrombosis
portal hypertension
acquired PSS
ascites
what is a consquence of a portosystemic shunt
hepatic encephalopathy
causes of steatosis
diet
toxins
hypoxia
ketosis
species syndromes in equine (ponies, minis, donkeys), sheep/goats, bovine, feline
endocrine diseases - DM or hypothyroidism
clinical characteristics of steroid hepatopathy
excess glycogen/glycogenolysis
what is characterized by a sheep with hepatocellular apoptosis/necrosis
intravascular hemolysis, hemoglobinuria
anorexia, abdominal pain, diarrhea, dehydration, shock
histologically: centrilobular hepatic necrosis and renal tubular necrosis
sheep copper associated hepatitis
what is characterized by a dog with a small liver, accentuated lobular pattern, architectural distortion, coarse nodularity to cirrhosis
canine copper associated hepatitis (chronic-active hepatitis)
what virus causes
gross: multifocal, random, < 1 mm areas of necrosis in several organs
histologic: multifocal random hepatic necrosis, intranuclear inclusion bodies
herpes virus
what virus causes centrilobular necrosis, intranuclear inclusion bodies, immune complex deposition leading to uveitis, corneal clouding and glomerulonephritis
canine adenovirus 1
(infectious canine hepatitis)
what virus causes the liver to look pale, enhanced lobular pattern, limp, friable texture, necrosis is acute and can be periportal to midzonal
rabbit hemorrhagic disease (calicivirus)
what disease would cause lymphocytes and plasma cells in the portal tracts and surrounding bile ducts in a young-middle aged cat?
suppurative chronic cholangitis
what disease would cause lymphocytes and plasma cells in the portal tracts and surrounding bile ducts in a middle aged-older cat?
nonsuppurative cholangitis
what bacteria cause phlebitis, thrombosis, portal hypertension, septic thromboemboli into lungs and sudden death in feedlot cattle
fusobacterium necrophorum
what enteric spp of bacteria can cause hepatitis
Francisella
Nocardia
Actinomyces
what bacteria may cause hepatitis and tuberculosis in dogs in southern US
Mycobacterium
what bacteria will cause pyogranulomas in multiple tissues
Rhodococcus equi
what bacteria will cause abscessation in multiple tissues, often in sheeps
Corynebacterium pseudotuberculosis
what bacteria will cause small area of necrosis in the liver and spleen, often in rabbits
Francisella tularensis
what bacteria has foci of necrosis with macrophages surrounding “paratyphoid nodules”
Salmonellosis
what bacteria will cause pale foci of hepatocellular necrosis with surrounding neutrophilic and mononuclear infiltrate and bacilli within viable hepatocytes at the margins
Clostridium pilliforme “tyzzers disease”
what bacteria will cause intravascular hemolysis causing ischemic injury to centrilobular regions, hepatic dissociation, bile casts, hemosiderin laden Kupffer cells and chronic-active hepatitis
Leptospirosis
what bacteria causes bacillary hemoglobinuria
Clostridium haemolyticum (type D)
pathogenesis of bacillary hemoglobinuria
- caused by C. haemolyticum (type D)
- latent spores in liver
- anaerobic conditions enhanced by F. hepatica (liver fluke)
- germination of spores due to high nitrate diet, liver puncture/biopsy or other necrosis
- beta toxin causes intravascular hemolysis leading to hemoglobinuria - red/purple urine
what bacteria causes “blacks disease” - infectious necrotic hepatitis in sheep/cattle characterized by necrosis surrounded by neutrophils and abundant gram + rods & foci of coagulation necrosis & hemorrhage due to exotoxin
also associated with migration tracts of liver flukes
Clostridium novyi (type B)
what parasite causes “milk spotted liver” in pigs
Ascaris suum
what parasite causes venal caval syndrome (DIC, intravascular hemolysos and acute hepatic failure) in dogs
Dirofilaria immitis
characteristics of equine serum hepatitis
“theiler’s disease”
hepatic failure with hepatic encephalopathy, icterus,
intravascular hemolysis in terminal stages
due to injection of biologic containing equine serum like tetanus antitoxin or gonadotropin
list toxic causes of acute hepatic injury
acetaminophen
carprofen
cyanobacteria such as microcystin LR or blue green algae
alpha-amanitin (amanita mushrooms)
acute aflatoxicosis (mycotoxin from Aspergillus flavus)
xylitol
which hepatotoxin results in methemoglobinemia & hepatotoxicity, renal injury possible
acetominophen
which hepatotoxin results in hemorrhagic gastroenteritis and hemorrhagic liver, centrilobular or massive hepatic necrosis and hemorrhage
cyanobacteria (microcystin LR or blue green algae)
which hepatotoxin results in massive hepatocellular necrosis, ductular reactions, hydropic degeneration
alpha-amanitin (amanita mushrooms)
which hepatotoxin results in centrilobular to midzonal or massive necrosis and vacuolar degeneration
xylitol
what hepatotoxin results in steatosis & cholestasis
subacte aflatoxicosis
what hepatotoxin results in bridging fibrosis & biliary hyperplasia
chronic aflatoxicosis
