Gastric Motility And Pancreatic Function Flashcards
Where does the mixing and grinding in stomach occur
Antrum
What is the effect of gastrin on contraction
Increased contraction
Effect of distension of stomach wall on contraction
Increased contraction
Effect of fat/acid/amino acid/hypertonicity in duodenum on motility
Inhibition of motility (negative feedback on stomach peristalsis when food products detected in duodenum)
What glands secrete bicarbonate to neutralise acid in duodenum
Brunner’s glands (submucosal glands)
Which systems control bicarbonate secretions
Nervous system:
Long - vagal & short - ENS reflexes
Both innervate Brunners gland stimulating bicarbonate secretion
What hormone is released when acid arrives in duodenum (what cells release this + what do they act on)
Secretin from S cells (which stimulate Brunners Glands - once acid neutralised this is inhibited)
Where are duct cells found
Pancreas (contain the Brunners gland which release bicarbonate)
What are the endocrine functions of pancreas (where are these located)
(Endocrine = secrete to circulation)
Located in pancreatic islets
Islets produce and secrete hormones controlling metabolism (insulin and glucagon)
What are the exocrine functions of pancreas (where are these located)
(Secrete outside body e.g. gut)
Acinar cells which form lobules
Secrete bicarbonate by duct cells & digestive enzymes by acinar cells
What is the route from lobules to duodenum
Lobules connected by intercalated ducts —> intralobular ducts —> main pancreatic duct —> common bile duct —> sphincter of oddi —> duodenum
What enzyme controls the conversion of zymogens to their active forms
Enterokinase
What zymogen do enterokinases convert into its active form
Trypsinogen into trypsin (which converts all other zymogens to active form)
Where is trypsinogen bound
Brush border bound enzyme (membranes of micro villi poking out into lumen of small intestine)
What stimulates secretin release
Acid in duodenum
