Liver, Gall Bladder and Exocrine Pancreas Flashcards
How are hepatocytes arranged in the live?
In cords with intervening sinusoids
Describe the classic lobule arrangement
1) Hexagonal shape, with portal tract in each angle
2) Area drained by one hepatic venule
3) Some hepatocytes more richly oxygenated (nearer tract)
Describe the acinus arrangement
Diamond shaped, with central veins at end of long axis and portal tracts at end of short axis
Describe appearance of hepatocytes and their features (3)
Polyhedral epithelial cell
1) Abundant in mitochondria
2) Large central spherical nuclei
3) Some are binucleate
What are the 3 surfaces of a Hepatocyte?
1) Sinusoidal (70%): Permits exchange of material with blood
2) Canalicular (15%) Excretion of Bile
3) Intercellular (15%)
Describe a sinusoid capillary
Specialised fenestrated capillary
Describe microscopy of Hepatocyte? (4)
1) Large prominent nucleus
2) Active Golgi
3) Prominent ER
4) Lots of mitochondria and peroxisomes
Describe sinusoidal microscopy (2)
1) No BM, but scattered Kupffer
2) Highly specialised BV with thin discontinuous endothelium
Describe structures and epithelia of Biliary Tree
S: Canaliculi -> B Ductules -> Trabecular Ducts –> Bile Ducts
(Simple Cuboidal –> Columnar)
What type of Epithelia does the Gall Bladder have?
Simple Columnar Epithelium (Specialised mucosa and loose fibrous CT)
How is Gall Bladder surface adapted?
SC Epithelium thrown into folds
Microvilli on surface
Increase mucosa SA for water and salt absorption
Describe appearance and feature of Acinar cells?
App: Epithelial pyramidal cells
Feature: Apically Zymogen granules, basally RER
Describe ducts system of Pancreas and Epithelia
D: Centroacinar cells -> Intercalated ducts -> Interlobular ducts -> Main pancreatic duct
Epithelia: Cuboidal –> Low Cuboidal –> Columnar
Describe 2 functions of Exocrine Pancreas
1) Synthesise and secrete enzymes
2) Secrete bicarbonate rich fluid into duodenum for digestion
Where does exocrine pancreas receive PS nerve fibres from?
Vagus Nerve
