Pancreatic Enzymes and Gastric Motility Flashcards
Name the two types of Ganglia involved in the ENS
Myenteric and Submucosal plexus
Where is the myenteric plexus located?
Between the inner and outer layers of the muscularis externa
Where is the submucosal plexus located?
In the submucosa
What do Brunner’s glands secrete?
Bicarbonate
What is the function of Bicarbonate in the GI tract?
To neutralise acid in the duodenum
What occurs when there is acid in the duodenum?
It triggers both vagal and enteric nervous system reflexes which triggers bicarbonate secretion
Where is secretin released from?
S Cells of pancreas
What is the response when secretin is released?
Bicarbonate secretion
When is secretin inhibited?
When acid is neutralised
Where does gastric motility occur?
The antrum of the stomach as the muscle is thick and permits for powerful contraction
What occurs when the pyloric sphincter contracts?
A small amount of chyme enters the duodenum
What occurs after the pyloric sphincter contracts?
Further mixing forces antral contents back up towards the body of the stomach where the muscle is thin and contraction is weak
What is the function of the pancreas?
To secrete hormones, pancreatic polypeptide, pancreatic juice and digestive enzymes
Describe the action of secretin on pancreatic and bile secretion?
An increase in acid in the duodenum =SECRETIN RELEASE = decrease in gastric emptying and gastric acid secretion and increases in duodenal, bile duct and pancreatic HCO3- secretion = NEUTRALISATION
Describe the action of CCK on pancreatic and bile secretion?
Increasing intestinal FA’s and Amino Acids will increase CCK secretion in the small intestine which increases plasma CCK .CCK contracts the Sphincter of Oddi and causes bile release. This increases enzyme secretion in the pancreas which increases the flow of enzymes in the small intestines which increases digestion of fat and protein
What is the role of zymogens?
To prevent the autodigestion of the pancreas
What are zymogens?
Inactive forms of enzymes stored in acinar cells
What activates zymogens?
Trypsin
How is tripsinogen converted into trypsin?
Via enterokinase
Name the parts of the pancreas?
Head, neck, body and tail
What makes up the endocrine portion of the pancreas?
Islets of langerhans which produce insulin, glucagon and somatostatin
What makes up the exocrine portion of the pancreas?
Acinar cells which secrete digestive enzymes and duct cells which secrete bicarbonate
