liver tissue architecture Flashcards
functional unit of liver: shape?
hexagonal (6) lobules
surrounding a central vein
what are on the edge of each hexagonal lobule surrounding a central vein?
portal triad
portal triad constists of what?
portal vein, hepatic artery, bile duct
also lymphatics
portal vein, hepatic artery, bile duct
what is this?
portal triad
how many portal triads surrounding a central vein?
6 (hexagonal)
apical surface of hepatocytes face what?
bile canaliculi
basolateral surface of hepatocytes face what?
sinusoids
what are kupffer cells?
specialized macrophages in sinusoids of liver
what are specialized macrophages in sinusoids of liver called?
Kupffer
what is a liver sinusoid?
vessels that receive blood from terminal branches from
- hepatic artery
- portal vein
located the periphery of lobules
deliver blood into central veins
kupffer cells: role?
clear bacteria and damaged/senescent RBCs
which cells clear bacteria and damaged RBCs in the liver?
Kupffer cells
what are hepatic stellate cells also called?
Ito cells
what are Ito cells?
hepatic stellate cells
store Vitamin A
Hepatic stellate (Ito) cells: role when quiescent?
vitamin A storage
Hepatic stellate (Ito) cells: role when active?
make ECM
what are the 2 roles of Ito cells?
vitamin A storage, ECM production
which cells are responsible for hepatic fibrosis?
Ito cells
where are stellate hepatic cells (ito cells) located?
in the space of Disse
which Vit A storing cell type does the space of Disse contain?
Ito cells
what is the space of Disse?
space between hepatocyte and sinusoid
where are Kupffer cells located?
in the sinusoids of the liver
what are the 3 zones of the hepatic hexagon?
Zone I: periportal (near portal triad)
Zone II: intermediate
Zone III: pericentral (centrilobular) zone
Which hepatic zone is first affected by viral hepatitis?
Zone I: periportal zone
which hepatic zone is most oxygenated?
Zone I: periportal zone
which hepatic zone is most resistant to circulatory compromise?
Zone I: periportal zone
what is zone I in the liver hexagon called?
periportal zone
which zone is affected in yellow fever?
zone II: intermediate zone
what is yellow fever?
infection of yellow fever virus, spread via mosquitoes. symptoms include fever, muscle pain, headache, loss of appetite, nausea or vomiting. normally symptoms disappear in 3-4 days
sometimes second, more toxic phase within 24 hrs from recovering from initial symptoms
what is zone II called?
intermediate zone
what characterizes the second, toxic phase of yellow fever?
High fever returns. liver and the kidneys affected. jaundice, dark urine, abdominal pain with vomiting, bleeding.
50% dies
what is zone III called?
pericentral (centrilobular) zone
which zone is first affected by ischemia?
zone III
zone III has a high concentration of which enzyme?
cytochrome P-450
cytochrome P-450, high concentration in which zone?
zone III pericentral
which zone is most sensitive to metabolic toxins?
zone III
what are examples of metabolic toxins to which zone III is sensitive?
ethanol, CCl4, halothane, rifampin, acetominophen
what is rifampin?
antibiotics to treat TB
what is halothane?
inhalation anesthetic
what is CCl4?
very hepatotoxic chemical compound (used in cleaning supplies, no longer permitted)
where is the site (zone) of alcoholic hepatitis?
zone III, pericentral
