Liver, Pancreas and Biliary Tract Flashcards
What are sinusoids
Specialised blood vessels
What are the principle cells of the liver
Hepatocytes
Describe the liver
Portal tract
Hepatocytes arranged in cords with intervening sinusoids
Central veins
What does the portal tract contain
Portal veins
Arteries
Bile ducts
What are classic lobule
Area drained by one central hepatic lobule
Artificial construct
Roughly hexagonal
What is the acinus
Architectural concept based around the blood supply rather than drainage - diamond
Why are all hepatocytes not equal
Closest to edge of lobule and central artery receive greater flow of blood as blood veins out in
Describe hepatocytes
Principle functional cells of liver
Polyhedral epithelial cells
Abundant mitochondria
Larger central spherical nucleus
Prominent nucleoli
May be binucleate
What are the surfaces of the hepatocytes
3
Sinusoidal 70%
- permits exchange of material with blood (space of Disse)
Canalicular 15%
- permits excretion of bile
Intercellular 15%
Describe the space of Disse
Contains stem cells - etocells
Contains reticulin fibres
Describe sinusoids
Highly specialised blood vessels
Thin discontinuous fenestrated endothelium
No basement membrane
Contains scattered Kupffer cells
Describe Kupffer cells
Phagocytic cells
Derived from blood monocytes
Describe the intrahepatic biliary tree
Canaliculi (lie between individual hepatocytes)
Bile ductules
Trabecular ducts
Bile ducts
What are the bile ducts lined by
Simple cuboidal-columnar epithelium resting on a basement membrane
What is the epithelium of the gallbladder
Simple columnar epithelium
Beneath is a specialised mucosa
Describe the specialised mucosa of the gallbladder
Increase SA - adapted for water and salt absorption
Microvilli - thrown into folds
Describe the exocrine pancreas
Synthesise and secrete enzymes bicarbonate-rich fluid into the duodenum
Surrounded by poorly defined capsule with septa dividing gland into lobules
Epithelial cells arranged in acini
Describe acinar cells
Epithelial
Pyramidal shape
Basally - rich in RER
Apically - zymogen granules - precursors for enzymes
What do acinar cells drain into
Centroacinar cells
Intercalated ducts
Interlobular ducts
Main pancreatic ducts
What is the interlobular duct epithelium
Cuboidal
What is the pancreatic duct epithelium
