13- The anatomy of the liver Flashcards
What is the function of the glissons capsule
Connective tissue that surrounds the liver.
How many surfaces do hepatocytes have
2 basal surfaces on opposite ends of the cell and each surface faces the blood
Where in the hepatocyte is bile secreted from
Bile is secreted from the apical surface around the hepatocytes middle
What connects neighbouring hepatocytes
The lateral surface
What is the arrangement of hepatocytes and what are they separated by
They are arranged into cords separated by vascular sinusoids
What vessels take blood to the liver
Hepatic artery and portal vein
What vessels take processed blood
Hepatic Veins
Where does blood mix in the liver and where does it drain
Mixes in the sinusoids and drains in the central vein
What is a sinusoid and how do they achieve their function
A small blood vessel found in the liver that functions similarly to a capillary
They have increased permeability compared to capillaries and allow larger molecules to leave the blood stream
What allows the passage of large molecules out of sinusoids
endothelial layer contains large intracellular gaps.
a further leak is allowed by fenestrations that penetrate endothelial cells.
What is different about the basement membrane in sinusoids
They are absent or discontinuous
Where does blood enter sinusoids
Enters via the portal vein and hepatic artery
What is the space called between endothelium and hepatocytes
Space of Disse
Where does the space of disse drain to
Drain into lymph nodes
What are the function of kupffer cells
Of the macrophage lineage found in the sinusoid
They are phagocytic and important in removing particulate material, including bacteria from portal blood
Where are ito cells found and what are their function
Found in the space of disse and are the primary storage site for hepatic fat and vitamin A
What is the fate of vitamin A found in ito cells
Transported from the liver to the retina to form rhodopsin
What happens to ito cells in the liver is continuously exposed to harm
Ito cells become myofibroblasts and produce collaged leading to fibrosis
What do dendritic cells do in the liver
They play important roles in liver immunity, auto immunity and regulation of hepatic allograft acceptance
What is the function of biliary ducts
A series of channels and ducts that convey bile from the liver to the small intestine
What do apical faces form in biliary system
They are held together to form canniculi
What is the hierarchy of cells in the bile duct
Hepatocytes-Bile canaliculi-Canal of herring-Interlobar bile duct-bileduct
Where is the portal triad found and what does it consist of
At each of the six corners of the lobule
Comprises of hepatic artery, portal vein and bile duct
What do liver lobules comprise of
Hexagonal structures composing of hepatocytes which radiate outward from a central vein
What are liver acinus
Oblong shaped and defined as the functional unit in the liver
How many zones are found in the liver acinus
3 zones
What is zone 1 of the liver acinus
Periportal Zone
First to receive oxygen, nutrients and toxins to blood
First to show morphologic changes after bile duct occlusion
Last cells to die if circulation is impaired
First cells to regenerate
Closest to the short axis
What is zone 2 of the liver acinus
Intermediate zone
Have functional and morphological characteristics and responses that are
lies between zone 1 and 3
What is zone 3 of the liver acinus
Perivenous zone
Most sensitive to hypoxia
First to show ischaemic necrosis
First to show fat accumulation
Last to respond to toxic substances
furthest from the short axis and closest to the central vein
What processes does zone 1 carry out
oxidative metabolism
Gluconeogenesis
Ureagenesis
Bile formationW
What processes does zone 3 carry out
Glycogen synthesis
Glycolysis
Xenobiotic Metabolism
