Increases H+ secretion by parietal cells

Stimulates growth of gastric mucosa by stimulating synthesis of RNA and new protein

small peptides and amino acids in stomach lumen - phenylalanine and tryptophan

Distention of the stomach

Vagal stimulation by gastrin-releasing peptide (GRP)

stimulates contraction of bladder and relaxation of sphincter of Oddi

stimulates pancreatic enzyme secretion

potentiates secretin-induced stimulation of pancreatic HCO3- secretion

Stimulates growth of the exocrine pancreas

Inhibits gastric emptying to allow more time for intestinal digestion and absorption

released from I cells of the duodenal and jejunal mucosa

Small peptides and amino acids

Fatty acids and monoglycerides

Triglycerides DO NOT stimulate secretion

actions are coordinated to reduce the amount of H+ in the lumen of the small intestine

Stimulates pancreatic HCO3- secretion and increases growth of exocrine pancreas

Stimulates HCO3- and H2O secretion by the liver, and increases bile production

Inhibits H+ secretion by gastric parietal cells

released by S cells of the Duodenum in response to:

H+ in the lumen of the duodenum

Fatty acids in the lumen of the duodenum

Stimulates insulin release from pancreas

Inhibits H+ secretion by gastric parietal cells

secreted by duodenum and jejunum

only GI hormone that is released in response to fat, protein, and carbohydrate

stimulated by fatty acids, amino acids, and orally administered glucose

released from endocrine cells 

diffuse over short distances to act on target cells located in the GI tract

Somatostatin and Histamine

secreted by cells throught GI tract in response to H+ in lumen. 

Inhibited by vagal stimulation

inhibits the release of all GI hormones

inhibits gastric H+ secretion

secreted by mast (ECL) cells 

increases gastric H+ secretion

synthesized in neurons of the GI tract, moved by axonal transport down the axon and released by action potentials in the nerves

diffuse across synaptic cleft to target cell

vasoactive intestinal peptide (VIP), GRP (bombesin), and enkephalins

produces relaxation of the GI smooth muscle, including LES

stimulates pancreatic HCO3- secretion and inhibits gastric H+ secretion

released from vagus nerves that innervate the G cells

stimulates gastrin release from G cells

secreted from nerves in the mucosa and smooth muscle 

stimulate contraction of GI smooth muscle

inhibit intestinal secretion of fluid and electrolytes

Body (fundus)

Secrete HCl and Intrinsic Factor

Gastrin

Vagal stimulation (ACh)

Histamine

Body (fundus)

Secrete Pepsinogen (converted to pepsin at low pH)

Antrum

Secrete Gastrin

Vagal stimulation (via GRP)

Small peptides

Inhibited by somatostatin

Inhibited by H+ in stomach

Antrum

Secrete mucous and pepsinogen

M3

Blocked by atropine

CCKb

second messenger is IP3/Ca2+

H2

coupled to adenylyl cyclase via Gs protein

second messenger is cAMP

Cimetidine inhibits binding to H2 receptor

direct pathway binds to receptor on parietal cell coupled with adenylyl cyclase via Gi protein decreasing cAMP levels antagonizing histamine

indirect pathway inhibits release of histamine and gastrin

Atropine - muscarinic receptors blocked

Cimetidine - blocks H2 receptors

Omeprazole - proton pump inhibitor

Isotonic

High flow rates Na+ and HCO3-

low flow rates Na+ and Cl-

disorder of pancreatic secretion

defect in CFTR channels

associated with a deficiency in pancreatic enzyme causing malabsorption and steatorrhea

Cholic acid

chenodeoxycholic acid

Deoxycholic acid

Lithocholic acid

converts chymotrypsinogen

proelastase

procaboxypeptidase A and B

Trypsinogen to trypsin

cholesterol ester hydrolase

phospholipase A2

pancreatic diseas

hypersecretion of gastrin

ileal resection

bacterial overgrowth

decreased number of intestinal cells

failure to synthesize apoprotein B