liver microanatomy Flashcards
What are the main structures of the liver?
Major vessels include:
* Portal vein
* Hepatic artery
* Hepatic veins
* Lymphatics
* Hepatic ducts
These vessels enter and leave at the porta.
What is the concept of liver lobule?
The liver lobule is a structural unit where hepatocytes are arranged in perforated plates with sinusoidal blood channels in between.
Define the portal triad.
The portal triad consists of:
* Branch of portal vein
* Hepatic artery
* Bile duct
The lymphatics are typically ignored in this naming.
Describe the flow of blood within liver sinusoids.
Blood flows from the periphery of the lobule towards the central vein, passing through the sinusoids lined by endothelial cells.
What is the liver acinus?
The liver acinus is a functional unit comprising parts of three lobules, reflecting differences in blood supply exposure and metabolic function.
List the main cell types in the liver parenchyma.
Main cell types include:
* Hepatocytes
* Kupffer cells
* Stellate cells of Ito
Each type has distinct functions in liver metabolism and immune response.
What are the main functions of the hepatocyte?
Functions include:
* Metabolism
* Storage
* Transformation
* Synthesis
* Regulation of plasma concentrations
* Detoxification
* Production of bile
* Defense by producing acute-phase proteins.
Describe the flow of bile.
Bile flows from the center of the lobule towards the peripheral bile ducts, running between liver cells in bile canaliculi.
What is the blood supply distribution in the liver?
Blood supply is:
* Hepatic artery 25%
* Portal vein 75%.
True or False: Hepatic veins take away processed blood into the vena cava.
True.
Fill in the blank: The hepatic lobular blood flow is from branches of the ______ and hepatic artery towards the center.
portal vein.
What are sinusoids?
Low pressure vascular channels that receive blood from terminal branches of the hepatic artery and portal vein.
What type of cells line the liver sinusoids?
Fenestrated endothelial cells.
What is the role of Kupffer cells?
They are phagocytic cells that help cleanse blood and provide immune defense.
What is the space of Disse?
A space between the sinusoidal lining cells and hepatocytes that allows plasma to interact with liver cells.
What do stellate cells of Ito store?
Vitamin A.
What does the hepatic architecture concept of metabolic zonation describe?
It describes the differences in exposure to blood supply and varying functional activities of hepatocytes within the acinus.
What changes occur in bile ducts as they move outside the liver?
The epithelium changes to columnar mucous cells and acquires smooth muscle and collagen tissue.
Where is lymph formed in the liver?
Lymph is formed by filtration of plasma into the spaces of Disse.
What anatomical structures run along the portal vessels and biliary ducts?
Lymphatics.
