Liver Flashcards
The largest visceral organ in the body is the
Liver
The liver takes up __% of cardiac output
25%
The liver is the largest, taking up 3 - 4% of the body weight in these animals
Carnivores
What are the 4 components of the portal tract
that form an abrupt border with a circumferential row
of hepatocytes termed the “Limiting Plate”?
Hepatic artery
Bile duct
Portal vein
Lymphatic vessels
80% of liver mass is comprised of _____
hepatocytes
What is the function of Stellate cells, also known as
“Lipocytes” or “Ito cells”?
Produce and maintain the extracellular matrix
Store vitamin A
The regional macrophages of the liver
that participate in immune and regenerative response
Kupffer cells
______ can be elevated early and are
biomarkers of liver injury
liver enzymes
This zone surrounds the portal triads
and are closest to the portal tract
Zone 1
Centroacinar/Periportal
This zone is the intermediate or midlobular area
Zone 2
Midzonal
This zone surrounds the central veins
Zone 3
Periacinar/Centrilobular
Increased catabolism
Decreased blood flow or bile flow
Pressure
Would cause this liver response
Atrophy
Oval stem cells can differentiate into these two
components
Hepatocytes
Bile duct epithelium
____% of the liver can regenerate in one week
60%
Hepatocellular regeneration is ______
nodular
What is the response by the liver to
Repeated toxic injury
Parasitic Migration
Cirrhosis
Replacement by Fibrosis
Liver is usually _____ in size when affected
by cirrhosis
reduced
Capsular fibrosis in horses
and
Tension lipidosis in horses and cattle are
_______ lesions
incidental
What are the post mortem changes that occur
in the liver?
Pale irregular foci
Greenish-black discoloration near the intestine
Emphysema
Autolysis
What type of liver necrosis is seen in
bacterial, viral, or parasitic infections?
Multifocal liver necrosis
What type of zonal liver necrosis is seen in
toxicity?
Periportal necrosis
Centroacinar, Periacinar, and Centrilobular zonal
necrosis are seen in cases of ______
hypoxia
What is one of the most common causes of
Massive Hepatic Necrosis?
Hepatosis Dietetica of Swine
Hepatosis Dietetica of Swine is one of the
most common causes of Massive Hepatic Necrosis
and is associated with
generation of ________
and
deficiency of _______ and ______
generation of free radicals
and
deficiency of vitamin E and selenium
Congenital Polycystic Liver Disease
is characterized by multiple cysts in the
liver and kidney that may result in mortality due to
______ or ______ failure
Liver or Renal Failure
Ventral hernias and diaphragmatic hernias
are _____________
of the liver
developmental abnormalities
Acute congestion causes slight
_______ of the liver and a
prominent reticular pattern
which is due to ________ congestion
enlargement
centrilobular congestion
Chronic passive congestion causes
“_______ liver”
and a reticulated pattern which is due to
______ congestion
Nutmeg Liver
Zonal Congestion
T/F:
Liver infarcation/ischemia is very rare
TRUE
This syndrome, due to hepatic vein thrombosis
is characterized by
Hepatomegaly, Ascites, and Abdominal Pain
Budd-Chiari Syndrome
When blood within the portal venous system
bypasses the liver and drains into the
posterior vena cava or the azygous vein
Portosystemic shunt
This congenital circulatory disturbance of the liver
is grossly characterized by
Hepatic encephalopathy, Ascites, and Liver Atrophy
and histologically characterized by
small hepatocytes and small portal veins, but
LARGE and PROMINENT hepatic arterioles
Congenital Portosystemic Shunt
What are the 3 portal hepatotropic factors
Insulin
Glucagon
Amino acids
Chronic portal hypertension
characterized by multiple thin walled tortuous blood vessels
can cause this acquired circulatory disturbance
which is indicative of liver disease
Acquired Portosystemic Shunt
Presence of focal areas in which sinusoids are dilated
and filled with blood
Telangiectasis
Telangiectasis, which grossly can be described as
irregular circumscribed dark red foci of the
cavernous ectasia of sinusoids
is common in what two species?
Cattle
Old cats
In order to histologically diagnose
Fat accumulations in the liver
(hepatic lipidosis or steatosis)
What stain must be used?
Oil Red O
or
Osmium tetroxide (stains intracellular triglycerides)
In order to histologically diagnose
Glycogen accumulation in the liver
What stain must be used?
PAS stain
In order to histologically diagnose
Amyloid accumulation in the liver
What stain must be used?
Congo-Red stain
In order to histologically diagnose
Copper accumulation in the liver
What stain must be used?
Rhodanine (Rubeanic acid)
Fat accumulation in the liver
is usually reversible in mild cases, but can lead to
these 4 conditions
Hepatic necrosis
Fatty cysts
Fat embolism
Liver rupture
Fatty livers are more susceptible to
______ damage and ______ injury
toxic damage
and
traumatic injury
Toxic and Anoxic injury to the liver
causes injury to hepatocytes and
_____ _____ can occur due to
decreased formation and exportation of lipoproteins
and
decreased oxidation of fatty acids
Fatty Degeneration
Where is glycogen normally stored?
hepatocytes
Excess storage of glycogen occurs in
which 2 diseases due to excessive levels of glucocorticoids?
Diabetes mellitus
Hyperadrenocorticism (Steroid-induced hepatopathy)
Steroid-induced hepatopathy (glycogen accumulation)
causes enlargement of the liver due to
swollen hepatocytes in the _____ areas
midzonal
Where do amyloids usually accumulate?
The Space of Disse
Amyloid accumulation in the Space of Disse
causes atrophy of
hepatic cords
Abyssian cats
Siamese cats
Sharpei dogs
are predisposed to this accumulation in the liver
Amyloid accumulation
Prolonged antigenic stimulation due to
chronic infection, or repeated inoculations of an
antigen can cause this type of hepatic accumulation
Amyloidosis
Excess copper is toxic and accumulations of copper in the liver can be caused by
Grazing on pastures low in ______
molybdenum
Bedlington terriers, West highland white terriers,
Dalmatians, Cats, and Long Evans Cinnamon rats
are all predisposed to this type of accumulation in the liver
Copper
What is the most common route of hepatitis?
Hematogenous (blood-borne) route
Inflammation of the liver primarily affecting hepatocytes
Hepatitis
Inflammation of the bile ductules and liver parenchyma
Cholangiohepatitis
Multifocal Hepatic Necrosis is caused by this
viral agent which is characterized by
intranuclear inclusion bodies surrounded by inflammatory cells inside the necrotic hepatocytes
Herpesvirus
This viral agent of hepatitis causes
Infectious Canine Hepatitis/ Rubarth’s Disease/
Fox Encephalitis
which is a highly contagious peracute disease
in dogs
Canine Adenovirus 1
Diagnose the disease:
Gross features include an enlarged, congested, friable liver, paint brush hemorrhages, corneal edema “blue eye” in survivors
Histological features include periacinar individual cell necrosis of hepatocytes, and intranuclear basophilic inclusion bodies
Infectious Canine Hepatitis
Canine Adenovirus 1
This hepatitis causing disease is caused by
Pegivirus and occurs 1-2 months after injection with a biological product of equine serum origin.
“Dish Rag” Liver is pathognomonic for this disease
Equine Serum Hepatitis
(Theiler’s Disease)
Which 4 bacterias can cause
multifocal hepatitis in fetuses and neonates especially?
- Salmonellosis*
- Listeriosis*
- Campylobacteriosis*
- Actinobacillosis*
Bacillary hemoglobinuria
affects cattle and sheep and is seen grossly
as a single large area of necrosis in the liver
Clostridium haemolyticum
What toxin is responsible for inducing
hepatocellular necrosis and intravascular hemolysis
in Bacillary Hemoglobinuria
Phospholipase C
Black Disease (Infectious Necrotic Hepatitis)
affects sheep and is grossly seen as
small and numerous areas of necrosis in the liver
is caused by what bacteria?
Clostridium novyi Type B
Tyzzer’s Disease which affects rodents and severely immunocompromised young animals
and causes multifocal necrotic hepatitis
is caused by which bacterial agent?
Clostridium piliforme
What stain is used to demonstrate the
bundles of long bacilli in hepatocytes
termed “Pick Up Sticks” in Tyzzer’s Disease?
Silver (Warthin-Starry) Stain
What is implicated in causing the icterus
in animals infected with Leptospirosis?
Cholestasis
Which 4 bacteria can cause liver abscesses?
- Fusobacterium necrophorum*
- Trueperella pyogenes*
- Streptococcus*
- Staphylococcus*
Which lobe of the liver is more frequently affected
by bacterial liver abscesses?
Left lobe
Which 3 agents can cause Granulomas
of the liver?
Fungi: Blastomycosis and Histoplasmosis
Bacteria: Mycobacterium avium (Tuberculosis)
Which fungi, usually secondary to mycotic rumenitis in cattle, can cause hepatitis?
- Aspergillus fumigatus*
- Histoplasma capsulatum*
- Cryptococcus neoformans*
- Coccidioides immitis*
- Sporothrix schenkii*
Yeasts of Histoplasma are found within the
cytoplasm of
Kupffer cells
Which nematode is implicated in causing
“Milk Spots” or areas of fibrous tissue and eosinophils in the portal units of the liver in a pig?
Ascaris suum
This trematode causes “pipestem” lesions in the liver
Fasciola hepatica
Where do mature Fasciola hepatica flukes reside?
Bile ducts
Where do adult Fascioloides magna flukes reside?
Cysts in the liver parenchyma
Echinococcus granulosus cestodes
form hydatid cysts in the liver. These cysts
are the _______ stage of the disease
intermediate!!
Which protozoal agent causes
Coccidiosis in rabbits
which grossly appears as multiple, raised, off-white nodules scattered throughout the liver
and histologically appears as
proliferative cholangitis with intralesional organisms?
Eimeria stiedae
This protozoal agent causes “target lesions” on the liver which are areas of multifocal granulomatous hepatitis in the disease “Black Head” of Turkeys
Histomonas meleagridis
Blue-green algae is hepatotoxic.
The main preformed toxin of blue-green algae is
Microcystin
Which agent of hepatotoxicity causes
acute centrilobular to massive hepatic necrosis
as well as
acute hemorrhagic gastritis?
Blue-Green Algae
Describe the pathogenesis of
Pyrrolizidine Alkaloid Hepatotoxicity
Alkaloids are converted to toxic pyrrolic esters by
biotransformation via the cytochrome p450 system in the liver
What is the most common form of
Pyrrolizidine Alkaloid Toxicity?
Chronic with fibrosis
What hepatotoxic agent can cause
photodynamic dermatitis in horses?
Alsike Clover
What is the most common and most potent
fungal Aflatoxin?
B1
What type of mycotoxin is converted to a toxic intermediate in the liver, is carcinogenic, and causes
Periacinar to massive hepatocellular necrosis and lipidosis in dogs
and periportal necrosis in ducklings?
Aflatoxins
This mycotoxin is found on dead ryegrass in
warm climates, like Australia or New Zealand
and is toxic to bile duct epithelium?
Sporidesmis
Which mycotoxin causes photosensitization
and facial edema
in sheep?
Sporidesmin
Which mycotoxin grows on lupines and causes
chronic liver damage in herbivores?
Phomopsin
What does mycotoxins of poisonous mushrooms of the Amanita spp. do to the liver in dogs?
Fatal acute periacinar to massive hepatocellular necrosis
Which species is particularly susceptible to copper toxicosis which causes an accumulation of copper within the lysosymes and released during stress
leading to
massive hepatic necrosis?
SHEEP
Trimethoprim-sulfonamide is hepatotoxic to
this breed of dog
Doberman pinschers
In order for hepatic encephalopathy to occurs
a shunting of ____% of portal blood must occur
10 - 15%
What is the main toxic substance in
hepatic encephalopathy?
Ammonia
What type of jaundice is caused by
overproduction of bilirubin
or
hemolysis?
Prehepatic jaundice
What type of jaundice is caused by
decreased uptake, conjugation, or secretion of bilirubin,
severe hepatocellular injury, or
impairment of flow within the canaliculi?
Hepatic Jaundice
What type of jaundice is caused by
reduced outflow of bile in extrahepatic bile ducts and gallbladder due to mechanical obstruction?
Posthepatic Jaundice
Bile pigment is found in these two entities in animals
with hyperbilirubinemia (jaundice)
Canaliculi
Hepatocytes
Mechanical obstruction of bile ducts
Cholestasis
Mechanical obstruction of gallbladder
Cholilithiasis
Hepatocellular Carcinoma is a malignant
solitary, locally extensive (involves entire lobe)
tumor that is most often seen in
DOGS
Cells arranged in a trabecular pattern, 3 or more cells thick is characteristic of this type of hepatic neoplasia
Hepatocellular Carcinoma
This bile duct tumor is multilobulated, firm, raised, and with central areas of depression (umbilicated)
Cholangiocellular Carcinoma
This tumor of mesenchymal origin is rapidly growing and highly invasive. It is almost always in dogs and very rare in cats. It is the most common tumor to cause hemorrhage into the abdomen
Hemangiosarcoma