Flashcards in Pancreas and Liver Microanatomy Deck (41)
How is the pancreas structured
lobules with ducts
Appearance and structure of exocrine pancreatic cells
Dark staining (due to zymogen granules). Granular appearance
Arranged as pancreatic acini
Appearance and structure of endocrine pancreatic cells
Light/pale staining cells, arranged in clusters, embedded among exocrine cells.
Form Islets of Langerhans
Function of Ductule cells
To produce HCO3-
Function of exocrine pancreatic cells
to produce digestive enzymes, fluids and electrolytes
Function of the endocrine pancreatic cells
Produce hormones to control blood sugar
exocrine pancreatic gland?
tubulo-acinar gland with highly branched ducts
What is the exocrine pancreatic gland similar to?
parotid gland (serous)
contain 5-8 pyramid-shaped cells surrounding a tiny lumen.
Large spherical nucleus in the basal position
Mitochondria perpendicular to the basal surface.
How tiny is the pancreatic acinar lumens?
Too small to see with a light microscope
where are protein secretory products (enzymes) synthesised in the pancreas
Basal rER, packaged in the golgi, and accumulated as zymogen granules in the apical cytoplasm of exocrine acinar cells.
A small volume of enzyme rich fluid.
Duct cells produce
Bicarbonate and a large volume of alkaline fluid ~1L/day
What is the path of product drainage from the acini to the duodenum?
intercalated ducts > intralobular ducts > interlobular ducts > pancreatic duct > Ampulla of Vater > duodenum
Intercalated duct cells that penetrate the lumen of acini are called?
Some Liver functions
synthesis (albumin, prothrombin, bile)
What runs between the radiating columns of hepatocytes, and what is their function
Sinusoids. (special capillary)
Carry the mixed blood flow from branches of the portal vein/ hepatic artery to drain into the central vein.
As blood flows through sinusoids oxygen and nutrients are diffused into adjacent hepatocytes down their concentration gradient.
What lines the sinusoids?
The central veins position, purpose and journey.
Position: Centre of liver lobule
Purpose: collects blood from the lobule sinusoids
Journey: Central veins collect > hepatic veins > IVC
Why are the sinusoids arranged the way they are?
To ensure maximal exposure of the hepatocytes to a blood supply.
Ensure a good supply of nutrients, keeps them nourished
What encases the liver lobules?
made of CT
-with collagen, BV's and nerves
What are liver lobules meant to look like?
a hexogonal shape, but this often isn't the reality
Classical anatomical shape within the liver
hexagonal shape. Formed by the hepatic lobule. Each edge has a portal space
Functional unit of the liver?
Diamond that radiates from the branches interlobular septa/portal triad out to the central veins.
Portal lobule looks like?
Triangle (points are the central veins). The bile drains through canaliculi in the hepatocytes to the bile duct.
Portal space contains
CT and a portal triad
Branch of the Hepatic portal vein under the microscope looks?
-large lumen (therefore low pressure)
Branch of the Hepatic artery proper looks like
thicker muscular wall
relatively smaller lumen (therefore higher systemic pressure)
Contribution of blood to the liver?
75% From hepatic portal vein (nutrient rich)
25% from Hepatic artery Proper (oxygen rich)