#14 Liver 2 Flashcards
what is cirrhosis?
damage to hepatic parenchymal cells
nodular regeneration
fibrosis
Overall disturbance from normal
which cells make the scar?
stellate cells
myofibroblasts
bone marrow derived fibroblasts
maybe hepatocytes and biliary epithelial cells
What does HSP47 immunostaining look for?
fibrillar collagen, therefore it is great to look for cirrhosis.
T/F liver injury alters the hepatocyte-sinusoidal interface?
true
with liver damage/injury, what usually happens within the sinusoids?
1) deposition of a scar
2) loss of fenestrae
what is portal expansion?
infammation/scarring in a localized area such as just around the portal triad.
what is bridging fibrosis?
fibrosis that connects the individual units areas (portal expansion areas)
when you have fibrosis, what happens to the resistance?
your resistance increases
what is the equation for pressure?
pressure=resistance X flow
what is the key initiating event in the development of portal hypertension?
Increased resistance inside the liver
T/F Portal hypertension is the root of all evil in most patients with cirrhosis?
TRUE
What causes the major resistance in cirrhosis?
nodule formation
sinusoidal fibrosis
vasoconstriction (reversible)
what is a pericyte?
Its the same thing as a hepatic stellate cell that causes contraction in capillaries/sinusoids.
what often happens to portal venous flow during liver fibrosis?
Flow can actually increase. This is because the body tries to compensate by vasodilating the splanchnic arteries/veins supplying the hepatic portal vein.
How do collaterals work?
THey allow blood under high pressure to be shunted to an area of lesser resistance. There are four main ones we should know:
1) gastro-esophageal
2) umbilical
3) rectal
4) retroperitoneal
what is the most common cause of esophageal varicies?
portal hypertension. This is very common with chronic alcoholics because of a failing liver.
what is the number one cause of portal hypertension in the USA?
Cirrhosis
what can cause a prehepatic blockage?
portal vein thrombosis (for our purposes)
What can often happen with schistosomiasis?
pre sinusoidal blockage
what often causes blockage of the hepatic sinuses?
cirrhosis
where would veno-occlusive disease affect the liver?
post sinusoidal
Give an example of post hepatic portal flow blockage?
congestive heart failure
How do you calculate HVPG?
HVPG= (wedge - free)
what is a normal portal vein pressure?
6mmHg
