Hormones and Paracrines that Act in Digestion
Vasoactive intestinal peptide VIP
Duodenal hormone that stimulates buffer secretion, inhibits acid production, and dilates intestinal capillaries.
somatostatin
Produced by Pancreatic Islets. Targets insulin-secreting cells to inhibit digestion of nutrients, hence their absorption from gut.
MOTILIN
duodenal mucosa is site of production; Stimulated by fasting Target organ is proximal duodenun Motilin stimulates migrating motor complex
SECRETIN
hormone produced on duodenum wall that stimulates pancreas to release bicarbonate to neutralized acid in duodenum increases bile output
GIP
produced in duodenal mucosa Stimulus: fatty chyme target organs: stomach, pancreas (beta cells) STIMULATES INSULIN RELEASE AND INHIBITS HCL PRODUCTION
Intestinal Gastrin
produced in duodenal mucosa, and is stimulus for production of acidic and partially digested food in duodenum. The target organ is stomach and it stimulates gastric glands and motility
Histamine
produced in stomach mucosa; stimulus for production is food in stomach; target organ is stomach; Histamine activates parietal cells to release HCL
Gastrin
site of production is g cells in stomach mucosa; stimulus for production: food, particularly partially digested proteins in stomach, chemically stimulated by acetylcholine released by nerve fibers. Gastrin increases HCL secretion, stimulates gastric emptying, stimulates contraction of intestinal muscle, relaxes iliocecal valve, stimulates mass movements
CHOLECYSTOKININ (CCK)
site: duodenal mucosa Stimulus: fatty chyme target organs: stomach, liver, pancreas, gallbladder activity: inhibits stomach secretory activity potentiates secretin's actions on liver and pancreas increases output of enzyme rich pancreatic juice stimulates gallblader to store and expel bile
SEROTONIN
stimulates other neurons to release enkephalins; causes contraction of stomach muscle and is produced in stomach mucosa; food in stomach stimulates production.