Digestive glands and Liver Flashcards
What is the major component that helps form the pancreas?
-loose CT with blood vessel, lymph, nerve, excretory duct to the duodenum
What are the four ducts that leave the pancreas?
Duct of Wirsung
- Duct of Santorini
- Interlobular duct
- Intercalated ducts
What do the interlobular ducts of the pancreas look like?
-simple columnar epithelium with gobleet cells
What secretions come from the intercalated duct of the pancreas?
- secrete water and bicarbonate in response to secretin.
- contain low cuboidal cells
Where are the centroacinar cells found in the pancreas?
-in the pancreatic acinus
What type of gland are the acini of the pancreas?
- pyramidal serous cells that secrete zymogen granules and give rise to precursors of trypsin, chymotrypsin, amyalse, lipase
- responds to cholecystokinin
What are centroacinar cells?
truncated cuboidal epithelium in the lumen of acini that is continuous wit intercalated cells of the epithelium
What area of the acinar cells allows for the synthesis of zymogens?
-RER of duodenal enteroendocrine cells
What does the pancreas look like histologically?
lobulated, compound, tubulo-alveolar gland with exocrine and endocrine secretions
The islets of langerhans are the pancreatic islets that consist of what cells?
alpha (A) cells: form glucagon
Beta (B) cells: form insulin
Delta (D) cells: form somatostatin to regulate insulin and glucagon
What do the alpha and beta cells look like in the islets of the pancreas?
- alpha cells are fine granules
- beta cells are coarse granules
How are the islets of the pancreas stained?
-immunochemical staining that is specific to staining insulin bright red.
What are the space of disse in the liver?
- separates the hepatic cells form endothelial cells
- active transfer between blood and parenchyma
What type of tissue of the liver is arranged around the central vein?
epithelial parenchyma forms an irregular arrangement of plates arranged as cords
What helps drain into the lymphatics?
Space of Mall is continuous with the space of disse, and connects to the lymphatics
At what point does Glisson’s thin capsule not cover with FECT?
the diaphragmatic attachment.
What components does the hepatic lobule (classic) contain?
- consists of a hexagonal lobule with 1 central venule, and the angled edge contain parts of the portal triad
What is the best way to identify the portal lobule of the liver?
- these lobules contain a bile canaliculi which drains into the same bile duct. (center of lobule)
- the edges of the lobule are formed by the central vein of 3 classic lobules
How is the best way to histologically identify the liver acinus?
- the branch that receives blood from hepatic arteries and conducts to opposite central veins.
- arterial flow establishes metabolic gradients from zone 1 to zone 3
Zone 3 hepatocytes which are closely associated with the venules are most susceptible to what?
- ischemia, and damage as they have the highest level of detoxification and lowest amount of oxygen available to them.
What components form the portal triad?
hepatic artery
portal vein (venule)
bile duct
What does the basolateral domain of the hepatocyte contain and what do they contribute to?
- microvilli
- oriented towards space of disse
- help with absorption from blood and secretion of plasma proteins
What type of lining forms the hepatic sinusoids?
- fenestrated endothelial cells with a discontinuous basal lamina
The perisinusoidal cells located in the space of Disse and contribute to cirrhosis, contain what?
- store Vit A
- produce collagen and other components
-stimulate cytokines and kupffer cells and myofibroblasts to produce collagen 1
What is significant about the subendothelial space of Disse?
- contains interstitial fluid that drains into space of mall and into the lymphatics
The bile canaliculus is not truly its own space but rather invaginations on the extracellular surface of the hepatocytes
Use of canal of hering to carry bile to bile ductule.
