Gastric Motility & Pancreatic Function Flashcards
Body of the stomach has
thin muscle wall - weak contraction
No mixing
Antrum of stomach has
thick muscle wall - powerful contraction
mixing, & forcing chyme into duodenum
What is chyme?
gastric content
What produces gastric peristaltic waves?
Peristaltic rhythm
Peristaltic rhythm
(~3/min) generated by pacemaker cells (longitudinal muscle layer)
slow wave rhythm =
basic electrical rhythm
slow waves -
spontaneous depolarisation/repolarisation
slow waves conducted through
gap junctions along longitudinal muscle layer
Slow wave depolarisation sub-threshold require further depolarisation to induce
action potentials for contraction
More AP waves means stronger
contraction
Gastrin & stretching of stomach walls increases
contraction
Fat/acid/increase tonicity in duodenum inhibits
motility
Bicarbonate secreted in submucosal gland of duodenum to
neutralise acid
Control of HCO3 secretion in duodenum:
- Vagus nerve & enteric nervous system
- S cells release secretin
what is secretin?
hormone that activates HCO3 release from pancreas & liver