ABSITE Review - GI Hormones Flashcards
Mention the cells that produce the following hormones.
Mention the cells that produce the following hormones.
Gastrin
G cells in antrum
Somatostatin
D cells in antrum
Gastric inhibitory peptide (GIP)
K cells in duodenum
CCK
I cells of duodenum and jejunum
Secretin
S cells of duodenum
Insulin
Beta-cells of the pancreas
Glucagon
Alpha-cells of the pancreas
Pancreatic polypeptide
Islet cells in pancreas
Motilin
Intestinal cells of gut
What stimulates the secretion of GASTRIN?
AAs, vagal input (Ach), Ca, ETOH, antral distention, pH >3.0
What inhibits the secretion of GASTRIN?
pH < 3.0, somatostatin, secretin, CCK, VIP, GIP
What are the target cells of GASTRIN? What is the response?
Target cells - parietal cells and chief cells
Response - increase HCl, IF and pepsinogen secretion
What stimulates the secretion of SOMATOSTATIN?
Acid in the duodenum
What are the target cells of SOMATOSTATIN? What is the response?
Target cells - many; it is the great inhibitor
Response - inhibits gastrin and HCl release; inhibits release of insulin, glucagons, secretin, GIP, motilin, neurotensin, enteroglucagon; decrease pancreatic and biliary outoput
What stimulates the secretion of GIP?
AAs, glucose, long-chain FAs, decrease pH
What are the target cells of GIP? What is the response?
Target cells - parietal cells of the stomach and beta cells of the pancreas
Response - decrease HCl secretion and pepsin; increase insulin release
What stimulates the secretion of CCK?
AAs, fatty acids chains
What are the response to CCK?
Response - GB contraction, relaxation of sphincter of Oddi, increase pancreatic enzyme secretion, some increase intestinal motility
What stimulates the secretion of SECRETIN?
Fat, bile, pH < 4.0
What inhibits the secretion of SECRETIN?
pH > 4.0, gastrin
What are the responses to SECRETIN?
Response - increase pancreatic bicarbonate release, increase bile flow, inhibits gastrin release (this is reverse on patients with gastrinoma) and inhibits HCl release
How varies the composition of a high vs slow pancreatic duct output?
High pancreatic duct output - increase HCO3, decrease Cl
Slow pancreatic duct output - increase Cl, decrease HCO3 (carbonic anhydrase in duct exchange HCO3 for Cl)
What stimulates the secretion of VIP?
Fat, ACh
What are the response to VIP?
Response - increase intestinal secretion (water and electrolytes) and motility. Inhibits gastrin release.
What stimulates the secretion of INSULIN?
Glucose, glucagons, CCK
What inhibits the secretion of INSULIN?
Somatostatin, pancreatostatin
What are the responses to INSULIN?
Response - cellular glucose uptake; promotes protein synthesis
What stimulates the secretion of GLUCAGON?
Decrease glucose, increase AAs, ACh, gastrin releasing peptide
What inhibits the secretion of GLUCAGON?
Increase glucose, increase insulin, somatostatin
What are the responses to GLUCAGON?
Response - glycogenolysis, gluconeogenesis, lipolysis, ketogenesis, decrease gastric acid secretion, decrease pancreatic secretion, decrease intestinal motility, decrease stomach motility, increase LES pressure, decrease MMCs
What stimulates the secretion of Pancreatic Polypeptide?
Food, vagal stimulation, other GI hormones
What are the response to Pancreatic polypeptide?
Response - decrease pancreatic and gallbladder secretion
What stimulates the secretion of MOTILIN?
Duodenal acid, food, vagus input, gastrin-releasing peptide
What inhibits the secretion of MOTILIN?
Somatostatin, secretin, pancreatic polypeptide, duodenal fat
What are the responses to MOTILIN?
Response - increase intestinal (small bowel) motility –> erythromycin acts on this receptor
What are the responses to Bombesin (gastric releasing peptide)?
Increase intestinal motor activity, increase pancreatic enzyme secretion, increase gastric acid secretion
What are the responses to peptide YY?
Inhibits acid secretion and stomach contraction; inhibits gallbladder contraction and pancreatic secretion
What is the usual recovery time of small bowel?
24 hours
What is the usual recovery time of stomach?
48 hours
What is the usual recovery time of colon?
3-5 days