Gastric Motility and Pancreatic Function Flashcards
why does little mixing occur in the body of the stomach
because the muscle is thin hence a weak contraction
which part of the stomach has thick muscle for strong contractions
antrum
what causes the pyloric sphincter to contract
antrum contraction
what name is given to food in the gut tube
chyme
frequency of peristaltic waves
about 3/min
where are the pacemaker cells of the stomach
longitudinal muscle layer
how are slow waves generated
by spontaneous de and repolarisation
what is the basic electrical rhythm
the slow wave rhythm
how do slow waves move from cell to cell
through tight junctions
when do slow waves create a contraction
when they reach threshold from further depolarisation by gastrin release and stomach wall distension
what triggers will inhibit stomach motility
fat, acid, amino acid and hypertonicity in the duodenum. Indicate the stomach is emptying
what happens to stomach acid once it reaches the duonenum
it is neutralised to prevent damage to the rest of the gut tube like ulcers
what neutralises stomach acid in duodenum
bicarbonate
where does duodenum bicarbonate come from
mucus secreted by brunner’s gland in the submucosa
nervous control of bicarbonate secretion
vagal and enteric nervous system reflexes
what is a long reflex
one which goes to the brain or spinal cord
what is a short reflex
one which stays within the enteric plexus
effect of secretin on bicarbonate
secretion of bicarbonate from pancreas and liver
what kind of feedback system is secretin release
negative feedback
location of pancreas
curvature of duodenum to spleen
insulin production in pancreas
islet of langerhans
enzyme production in pancreas
acini cells of lobule –> pancreatic duct
pathway from lobules to duodenum
intercalated ducts –> intralobular ducts –> interlobular ducts –> pancreatic duct –> common bile duct –> hepatopancreatic ampulla – duodenum
duct cell secretion
bicarbonate
hepatopancreatic ampulla also called
sphincter of oddi
where are duct cells
along the sides of intercalated etc ducts
how do the zymogens secreted by the pancreas become activated in the duodenum
trypsinogen is converted to trypsin by membrane bound enterkinsa found on the wall on the duodenum.
Trypsin then converts all other zymogens to active enzymes
