Lecture 14: Liver pathology I Flashcards
Normal liver is ___% of BW
2-3%
liver receives ___% of cardiac output
25%
The liver is very susceptible to what type of injury
hypoxic injury
what is the most important liver function
synthesis of plasma proteins- albumins, globulins, clotting factors
what makes up the portal triad
- Portal vein
- Hepatic artery
- Bile duct
what is the function of hepatocytes
- Synthesize and secrete plasma proteins- clotting factors, acute phase proteins, and bile acids
- Detoxification
- Store nutrients
what tissue is this, identify 1-4
- Hepatocytes
- Portal vein
- Bile duct
4, hepatic artery
what structure indicated by asterisks
Centrilobular vein
what vessel drains the 02 poor, nutrient rich blood from intestines, stomach, pancreas and spleen
portal vein
what vessel provides 75% of oxygen to liver
hepatic artery
what zone is more susceptible to direct acting toxins
zone 1 or peri portal because gets most blood
what zone is more suspcetible to hypoxia injury
zone 3 or centrilobular-gets less blood
what cell serves as first line of defense of liver
kupffer cells-hepatic macrophages
Is cell swelling a reversible or irreversible response to injury
reversible
what does chronic active injury in liver lead to
fibrosis, bile duct proliferation—> cirrhosis
what liver dysfunction leads to icterus
hyperbilirubinemia due to pre-hepatic, hepatic, or post-hepatic dysfunction
what can cause pre-hepatic dysfunction leading to icterus
hemolysis
what can cause hepatic dysfunction leading to icterus
Decreased conjugation and secretion of bilirubin
what can cause post-hepatic dysfunction leading to icterus
reduction of bile outflow- cholestasis
What is pathogenesis of hemorrhage in liver
hepatocyte damage—> decreased clotting factors produced
horses with acute liver injury can get __, unknown cause
intravascular hemolysis
what does copper toxicity cause and why
hemolysis due to oxidative injury
what are the two mechanisms of ascites from liver injury
- Fibrosis—> portal hypertension—> edema—> ascites
- Decreased albumin—> decreased oncotic pressure—>ascites
what wrong and what pathogenesis n
Photosensitivity
Severe liver disease—> can’t remove phylloerythrin—> accumulates in serum and skin—> UV light activates phylloerythrin in non-pigmented areas of skin—> necrosis of epithelial cells/epidermis
what is hepatic encephalopathy associated with and due to what
ammonia not being cleared due to damage or shunting
what are some clinical signs of hepatic encephalopathy
ataxia, depression, head pressing, behavioral change, convulsions
what is hepatic encephalopathy most commonly associated with
PSS
what wrong and what cause
ammonium urate uroliths due to increased urine acid and ammonium excretion
Associated with PSS
what is the best way to biopsy a liver
wedge, collect from 3 lobes and save some for culture and copper
what wrong
bile accumulation- cholestasis
Note brown material in sinusoids
what wrong and what are some causes
Glycogen accumulation
Causes:
1. Hyperadrenocorticism (most common)
2. DM
what is pathogenesis of hepatic lipidosis
primary disease causing negative energy balance—> increased fat mobilization from fat stores—> lipid accumulation in liver
what are some potential causes of hepatic lipidosis in ruminants
late pregnancy, acute anorexia
what are some causes of feline hepatic lipidosis
DM and DKA, anorexia
What wrong
Hepatic lipidosis
What wrong and what cause
amyloidosis due to overproduction of amyloid A protein
what is a PSS
vascular channel that connects portal vein to systemic circulation (bypasses liver)
intrahepatic shunts are common in who
large breed dogs
extrahepatic shunts common in who
small breed dogs and cats
what are some signs of PSS
poor, shunted growth, behavioral change, collapse, convulsions
what wrong
extrahepatic PSS
what wrong and what zone of liver is affected
Passive congestion due to right sided heart failure
Centrilobular zone most affected because hypoxia injury
when does portal hypertension occur
blood flow in/put of liver gets slowed down
what is most common cause of portal hypertension
hepatic fibrosis
Acquired PSS can develop as a result of __
portal hypertension
what is the likely cause of centrilobular (zone 3) necrosis
hypoxia and toxicity
what is the likely cause of multifocal random hepatic necrosis
infection
what is the likely cause of massive necrosis of majority of liver
toxic
Hepatocellular toxins cause __ and lead to __
lipidosis, centrilobular necrosis
what drugs are hepatocellular toxins
acetominophen, phenobarbital, xylitol
what minerals are hepatocellular toxins
copper, iron
what are some causes of cooper toxicity in sheep
- Increased intake
- Increased availability due to low molybdenum
- Hepatocelllular damage from other toxins
what is the consequence of too much copper
oxidative damage and hepatocellular necrosis
what are some signs of cooper toxicity
icterus, swollen and pale liver, hemoglobinuria
copper storage hepatopathy is common in what breed
bedlington terrier
what causes copper storage hepatopathy
inadequate excretion of bile possibly due to dietary excessive copper in commercial dog food
what causes theiler’s disease (aka equine serum hepatitis)
parvovirus
horse liver- what likely dx and cause
dx: theilers disease
Cause: parvovirus
