-
mucous neck cells
produce a sticky alkaline substance that coats the stomach mucosa
-
parietal cells
- secrete HCl and intrinsic factor
- HCl makes stomach acidic, which is necessary for activation of pepsinogen
- acidity also helps in food digestion by denaturing proteins
-
chief cells
produce pepsinogen
-
enteroendocrine cells
releases histamine, serotonin, somatostatin, and gastrin
-
rennin
- produced in infants
- breaks down the milk protein (casein)
-
hormone ghrelin
- produced by the stomach
- stimulates hunger
-
cholecystokinin (CCK)
- produced in duodenum
- stimulus: fatty chyme
- targets pancreas & gallbladder to increase output of pancreatic juice and bile
-
Gastric inhibitory peptide (GIP)
- produced in duodenum
- stimulus: glucose, fatty acids, amino acids
- targets stomach (inhibits HCl release) and pancreas (stimulates insulin release)
-
gastrin
- produced in stomach G cells
- stimulus: food in stomach
- targets stomach (increase HCl secretion) and causes relaxation of ileocecal valve
-
histamine
- produced in stomach mucosa
- stimulus: food in stomach
- targets stomach and makes parietal cells release HCl
-
secretin
- produced in duodenum
- stimulus: acidic chyme
- inhibits gastric gland secretion and increases output of pancreatic juice
-
serotonin
- produced in stomachÂ
- stimulus: food in stomach
- causes contraction of stomach muscle
-
somatostatin
- produced in stomach and duodenum
- stimulus: food in stomach
- inhibits gastric secretion, GI blood flow (inhibiting intestinal absorption) and bile release
-
vasoactive intestinal peptide (VIP)
- produced in enteric neurons
- stimulus: chyme containing partially digested food
- induces smooth muscle relaxation in the stomach and inhibits acid secretion
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