Physiology of Liver

Question 1

blood supply to liver

Answer 1

oxygenated, nutrient poor blood from hepatic artery
deoxygenated, nutrient rich blood from hepatic portal vein (can increase after eating)
hepatic portal is low pressure system
can increase its capacity for blood

Question 2

liver lobules

Answer 2

functional units of liver
hexagon shape and has central vein
at corners has portal triad made up of hepatic artery, hepatic portal vein and bile duct
blood from here drains into sinusoid and then central vein
there are gaps in sinusoid where proteins are filtered through
these pass into hepatocytes which produced substances that pass into central vein which then connects to main hepatic vein

Question 3

hepatocytes

Answer 3

after leaving sinusoid and entering heaptocytes substances are either metabolised and secrete their productfrom hepatocyte or hepatocyte secrete makes their own substances and sends them down the central vein
hepatocytes also secrete bile which drains in the opposite direction

Question 4

stellate (ito) cells

Answer 4

found under endothelial cells of hepatic portal vein
store vitamin A and can be antigen presenting cells
in diseased livers they lose their lipid droplets and express RER and golgi body more
they can leave their space and secrete metalloproteases which causes fibrosis