6.1 Pancreas and Liver Flashcards
Describe the chyme leaving the stomach
Hypertonic, acidic, partially digested
Why is chyme leaving the stomach hypertonic?
Solutes from food are dissolved in gastric juice. The stomach is impermeable to water so water cannot move into the stomach to dilute the solutes
What type of cells make up the endocrine pancreas?
Acinar cells- release enzymes
Duct cells- modify secretion
What innervates the pancreas to release secretions?
Parasympathetic system- vagus nerve
CCK
When are acinar cells stimulated to release secretions?
When hypertonicity or fats are detected in the duodenum
What enzymes do acinar cells produce?
Amylases
Lipases
Proteases- trypsin, chymotrypsin, elastase, carboxypeptidase (all zymogens)
What is a zymogen granule?
A membrane-bound vesicle containing zymogens- so that the zymogens cannot be activated and cause damage to tissues
What do duct cells release?
HCO3- to raise the pH
What stimulates pancreatic duct cells to release HCO3-?
Secretin
What are the main functions of the liver?
Energy metabolism, detoxification, plasma protein production, bile secretion
What are the main cells in the liver?
Hepatocytes
What is a liver lobule?
A structural unit of the liver
What is a liver acinus?
A functional unit of the liver
Where does the blood draining into the liver come from?
Portal venous system- from the gut
Hepatic arteries
What is ‘bile acid dependent’ bile?
Bile from the hepatocytes which is secreted into the canalculi. It contains bile acids and bile pigments