Hepatic pathophysiology Flashcards
(20 cards)
What is the basic functional unit of the liver?
lobule
About how many lobules are in the liver?
50,000-100,000
What 2 blood vessels bring blood to the liver?
portal vein and hepatic artery
What blood vessel brings blood out of the liver and where does that blood go?
hepatic vein, goes into IVC and returns to the heart
How much of the liver’s O2 requirement does the portal vein supply?
50-55%
What is the SaO2 of the portal vein?
85%
How much of the liver’ O2 requirement doe the hepatic artery supply?
45-50%
What is normal hepatic blood flow?
1,500 mL/min
How much of the body’s CO goes to the liver?
25-30%
About how many mL/min is delivered to the liver from the portal vein?
1100 mL/min
About how many mL/min is delivered to the liver from the hepatic artery?
400 mL
What is the portal vein pressure as blood enters the liver?
9 mmHg
What is the pressure in the hepatic vein as blood leaves the liver?
0 mmHg
The liver has (high/low) blood flow and (high/low) vascular resistance.
high blood flow, low vascular resistance
About how long does it take for blood to traverse from the portal vein to the central vein and why is this important?
8-9 seconds, allows sufficient time for the blood to be in contact with hepatocytes and Kupffer cells
What controls hepatic artery blood flow?
autoregulation based on metabolic demand
What controls portal vein blood flow?
blood flow to the GI tract and the spleen
What happens if there is a decrease in blood flow in one of the vessels that supplies blood to the liver?
change in blood flow from one source will produce a reciprocal (but somewhat limited) compensatory change in the blood flow from the other source Ex: dec. in hepatic artery blood flow produces an increase in portal venous blood flow
What organs supply blood to the portal vein?
stomach spleen pancreas small intestines colon
How does cirrhosis affect blood flow through the liver?
greatly increases resistance to blood flow, destruction of liver parenchymal cells results in replacement with fibrous tissue that contracts around the blood vessels
