Gastric Motility and Secretions Flashcards
What are the 3 basic movemnts of the stomach
storing
churning
emptying
Receptive relaxation
vasovagal reflex
initiated by swallowing
mediated by NO
gastric accommination
stomach relaxation in response to gastric filling
what is gastric accommodation reglatued by
ENS
What hormones impaire gastric emptying
secretin, CCK, gastrin
what NT impair gastric emptying
Ach, 5-HT
what NT promote gastric empything
NO, VIP
what are key neurotransmitters involved in emetic resposne
serotonin, dopamine, Ach, histamine
Pyloric stneosis
narrowing of pyloric sphincter
what does pyloric stenosis cause
impaired motility of stomach which can cause GERD and vomiting
Secretions of parietal cell
HCl, intrinsic factor
function of Hcl
protein digestion, sterilization, absorption, prevent bacterial/fungal growth, promote bile and pancreatic enzyme flow
function of intrinsic factor
B12 absorption
secretion of chief cell
pepsinogen
function of pepsinogen
protein digestion
secretion of ECL
histamine
function of histamine
promote HCl secretion
secretion of G cell
gastrin
funciton of gastrin
promote HCl secretion
secretion of D cell
somatostatin
functino of somatostatin
suppress HCl secretion
secretion of nerve cell
ACH
functino of Ach
promote mucus, bicarb, and HCl secretion
secretion of superficial epithelial cell
mucus, bicarb
how does the paracrine pathway regulate acid secretion ins tomach
histamine promote acid secretion
prostglandin and somatostatin decrease acid secretion
how does endocrine pathway regulate acid secretion in stomach
gastrin promotes acid secretion
how does neuronal pathway regulate acid secretion in stomach
Ach promotes acid secretion
what negative feedback affect does somatostatin have
inhibits release of gastrin from G cells
what indiirectly acts on ECL cells
gastrin, Ach
what acts on neighboring parietal celsl
histamine
regulators of interdigestive phase
of pariteal cells, body weight, presence of food in stomach
what is pH in interdigestive phase
3-6
what happens during cephalic phase
30% of acid secretion
regulators of cephalic phase
sigh/smell of food triggers vagal response
what happens during gastric phase
50-60% of gastric secretion
regulation of gastric phase
distension of stomach, protein products in stomach trigger vagal response
what is hapepning during intestinal phase
10% of gastric secertion
regulators of intestinal phase
presence of peptide in duodenum,
absorption of amino acids in duodenum
role of mucus in stomach
protective factor
lowers pH when you get closer to lumen
forms protective barrier
what are 2 key stimuli for mucus secretion
Ach, Prostaglandin both increase secretion
components of mucus
mucin, phosphlipid, electrolyte, water, bicarb
Role of secretin
decreases acid release from parietal cells
increases pepsinogen release from chief cells
delay gastric emptying
What is gastrisis
infiltration of inflammatory cells without break in mucosal barrier
what can gastritis be caused by
NSAIDS, H. pylori
H pylori infection
bacteria colonize luminal surface of gastric epithelium causing inflammation and ulceration
damage done because of immune system putting up response to H. pylori
how is H. pylori protected from stomach acid
urease
peptic ulcers
inflammation that breaks through mucosal lining
can lead to perforation of GI tissue, hemorrhage, cancer
zollinger-ellison syndrome
high serum gastrin lvels
causes tumor in duodenum/pancreas
