GI-Hormones Flashcards
Which Gastrin is released between meals?
Big Gastrin
Which Gastrin hormone is produced during a meal?
Little Gastrin
Gastrin is released in response to luminal contact of products of …
protein digestion; small peptides, AAs, physical distention, and secretagogues (Ca, coffee, wine)
What is Gastrin mediated by?
GRP; Bombesin
What is the action of Gastrin?
stimulate gastric acid secretion (by parietal cells) and growth of gastric oxyntic gland mucosa
Where is CCK released from?
I-cells of the Duodenal and Jejunal Mucosae
CCK is released in response to chemoreception of …
peptides, AAs, FFAs, and to a lesser extent H+
CCK produces contraction of the …, and relaxation of the …
Gall Bladder; Sphincter of Oddi
CCK potentiates the actions of …
Secretin
What does CCK inhibit?
Gastric Emptying
What elicits Secretin release?
pH
What does Secretin stimulate?
Pancreatic, Liver, and Intestinal water and bicarb secretion; increases the secretion of Pepsinogen from Chief Cells of the Stomach
What does Secretin Inhibit?
Gastric acid secretion and reduces the effects of Gastrin
Where is GIP released from?
K-Cells in duodenum and jejunum
What is the releasing stimuli of GIP?
Oral glucose, FFA, AAs, and acid
What is the action of GIP?
insulin release from beta cells of the Pancreas
What does GIP inhibit?
gastric acid secretions
What GI Hormone will not be found during or within 5 hours of a meal?
Motilin
Pancreatic Polypeptide is released from the pancreas in response to …
protein-rich chyme (major stimulus), fat and carbohydrates
What is the action of Pancreatic Polypeptide?
Inhibits the release of Pancreatic enzymes and bicarb secretion
Enteroglucagon is released in response to…
glucose and/or fat in the chyme (last ditch effort to absorb glucose)
What does Enteroglucagon stimulate?
Hepatic Bile Flow
What does Enteroglucagon inhibit?
Acid secretion and motility
Somatostatin is released in response to …
Acid
What does Somatostatin inhibit?
Gastrin release, other peptide hormones, and Gastric acid secretion
In what cells is Histamine synthesized and stored in?
ECL-cells of the gastric mucosa
What is the action of Histamine?
Gastric Acid Secretion (HCl)
What are the releasing stimuli of Histamine?
Gastrin, ACh, inflammation
What are the actions of VIP?
Relaxes sphincters and gut circular muscle, Stimulates intestinal mucosa to release pancreatic fluid, bicarb, water, and electrolytes
What produces NO?
neuronal nitric oxide synthase (nNOS)
What is the function of NO?
relaxation of the LES during deglutition (swallowing)
