GI: Hormones and Peptides Flashcards
What secretes Gastrin?
G cells (Gastric Antrum and Duodenum)
What secretes CCK?
I cells (Duodenum and Jejunum)
What secretes Secretin?
S cells (Duodenum)
What secretes Somatostatin?
D cells (Duodenum) Delta cells (Pancreatic islets)
What secretes GIP (Gastric-inhibitory polypeptide)?
K cells (Duodenum and Jejunum)
What secretes Pancreatic polypeptide?
F cells (PP cells; Pancreas and Small Intestines)
What secretes GLP-1 (Glucagon-like peptide)?
L cells (Small Intestine)
What secretes Motilin?
ECL cells (Duodenum and Jejunum, Enterochromaffin-like cells)
What secretes Histamine?
ECL cells (Duodenum and Jejunum, Enterochromaffin-like cells)
What secretes VIP (Vasoactive Intestinal Peptide)?
Enteric neurons and Pancreas
What secretes GRP, or Bombesin?
Neurons of Gastric mucosa (Vagus)
What does Gastrin do?
Stimulates Parietal cells (H+), Chief cells (Pepsinogen), ECL cells (Histamine)
Trophic on Gastric mucosa
Increases gastric motility
What does CCK do?
Stimulates Pancreatic enzyme secretion (Amylase, Lipase, Proteases) and Gallbladder contraction
Relaxes sphincter of Oddi
Trophic on Exocrine Pancreas and Gallbladder
Inhibits Gastric H+ secretion
What does Secretin do?
Stimulates Pancreatic and Biliary HCO3- secretion (neutralizes Gastric acid to Facilitate Pancreatic enzymes) and Production of Bile
Trophic on Exocrine Pancreas
Ihibits Gastric H+ secretion
What does Somatostatin do?
Inhibits Gastric acid and Pepsinogen secretion, Pancreatic and Small Intestine secretion,
Gallbladder contraction
Insulin and Glucagon release
What does GIP (Gastric-inhibitory polypeptide) do?
Stimulates Insulin release (Endocrine)
Inhibits Gastric H+ secretion (Exocrine)
What does Pancreatic polypeptide do?
Inhibits pancreatic enzyme and HCO3- secretion
What does GLP-1 (Glucagon-like peptide-1) do?
Stimulates Insulin release
Inhibits Gastric acid and Glucagon secretion
Decreased Gastric motility
What does Motilin do?
Stimulates MMC (Migrating motility complex) in the Stomach and Small Intestine Stimulates the production of Pepsin
What does Histamine do?
Stimulates Gastric acid secretion
What does VIP (Vasoactive Intestinal Peptide) do?
Stimulates receptive relaxation of the Stomach
Relaxation of Intestinal Smooth muscle, Intestinal Secretion of Water and Electrolytes
Increased release of Pancreatic HCO3-
What does GRP (Gastrin-releasing peptide) or Bombesin do?
Increases secretion of Gastrin from G cells
Regulation of Gastrin?
Stimulus: Small peptides, AA, Ca2+ in Gastric lumen, Gastric distention, Vagal stimulation
Inhibits: Low gastric pH
Regulation of CCK?
Stimulus: Fatty acids and AA in the Small Intestine
Inhibits: Secretin
Regulation of Secretin?
Stimulus: Decreased Gastric pH, Fatty acids in Duodenum
Inhibits: None
Regulation of Somatostatin?
Stimulus: Decreased luminal pH
Inhibits: Vagal stimulation
Regulation of GIP?
Stimulus: AA, FA, Oral glucose
Inhibits: None
Regulation of Pancreatic polypeptide?
Stimulus: Ingestion of Carbohydrates, Proteins, or Lipids
Inhibits: None
Regulation of GLP-1?
Stimulus: Oral Glucose load
Inhibits: None
Regulation of Motilin?
Stimulus: Released by Absence of Food for > 2 hours
Inhibits: None
Regulation of Histamine?
Stimulus: Gastrin, ACh (Vagus)
Inhibits: None
Regulation of VIP?
Stimulus: Intestinal Distention and Vagal Activation
Inhibits: None
Regulation of GRP, or Bombesin?
Stimulus: Cephalic phase, Gastric distention
Inhibits: None
