Liver microanatomy Flashcards
What are liver cells called?
Hepatocytes
What are the 5 functions of hepatocytes?
- Creation and storage of energy (glycogen & fats)
- Synthesis + secretion of plasma proteins
- Deamination of amino acids & production of urea
- Uptake, synthesis & excretion of bilirubin and bile acids
- Detoxification and inactivation of drugs & toxins by oxidation, methylation or conjugation
Describe how the hepatocytes are organised?
Organised into polygonal lobules separated by septa (made of connective tissue)
Each lobule contains cords of tightly joined hepatocytes that radiate from a central vein.
Between the cords are sinusoids
What shape is a lobule? And what is found at each corner?
Hexagonal/polygonal
Portal triad at each corner
What is a portal triad made up of?
Small muscular arteriole (branch of hepatic artery)
Thin walled vein branch of portal vein (deoxygenated nutrient rich blood from intestine)
Bile ductile (takes bile from hepatocytes to main bile duct & gall bladder)
What is a sinusoid?
A wide, thin walled, fenestrated capillary that bathe hepatocytes in blood from arteriole and vein of portal triad
What cells make up the sinusoidal lining?
Endothelial
Macrophages (Kupffer cells)
Ito cells/hepatic stellate cells - store fat
What type of collagen makes up the network that sinusoids sit on?
Reticulin
Collagen III
Where exactly do Ito cells reside?
In space of Disse
Between sinusoids and cords made up of hepatocytes
What do Kupffer cells do?
Phagocytose blood borne pathogens and toxins that go through the liver
Also involved in bilirubin production
What does the sinusoidal membrane of hepatocytes do?
Uptake of nutrients from blood (transport proteins)
Release of macromolecules (by pinocytosis)
What does the canalicular membrane of hepatocytes do?
Backs on to bile canaliculi
What are the bile canaliculi?
Tubes that collect bile produced by hepatocytes and transport it to bile ductules at portal triad
