GI Flashcards
Cholecystokinin source
I cells (duodenum, jejunum)
Gastrin source
G cells (antrum of stomach)
Glucose-dependent Insulinotropic peptide source
K cells (duodenum, jejunum)
Motilin source
Small intestine
Secretin source
S cells (duodenum)
Somatostatin source
D cells (pancreatic islets, GI mucosa)
VIP source
Parasympathetic ganglia in sphincters, gallbladder and small intestine
Intrinsic factor source
Parietal cells (stomach)
Gastric acid source
Parietal cells (stomach)
Pepsin source
Chief cells (stomach)
HCO3- source
Mucosal cells (stomach, duodenum, salivary glands, pancreas) Brunner glands (duodenum)
Cholecystokinin action
- Increase pancreatic secretion
- Increase gallbladder contraction
- Delay gastric emptying
- Increase sphincter of Oddi relaxation
Gastrin action
- Increase gastric H+ secretion
- Increase growth of gastric mucosa
- Increase gastric motility
- Stimulate ECL cells to release Histamine (which also stimulates parietal cells to release H+)
Glucose-dependent insulinotropic peptide action
Exocrine: decrease H+ secretion
Endocrine: increase insulin release
Motilin action
Produces migrating motor complexes (MMCs)
Secretin action
- Increase pancreatic HCO3- secretion
- Decrease gastric acid secretion
- Increase bile secretion
Somatostatin action
- Decrease gastric acid and pepsin secretion
- Decrease fluid secretion from pancreas and small intestine
- Decrease gall bladder contraction
- Decrease insulin and glucagon release
Nitric oxide action (in GI)
-Increase SM relaxation (including LED)
VIP action
- Increase intestinal water and electrolyte secretion
- Increase relaxation of intestinal smooth muscle and sphincters
Intrinsic factor action
Binds Vitamin B12 so that it can be taken up in the terminal ileum
Gastric acid action
Decrease stomach pH
Pepsin action
Protein digestion
HCO3- action
neutralize action
What is increased with fatty acids and amino acids ONLY?
Cholecystokinin
What is increased with fatty acids, amino acids, and oral glucose?
Glucose-dependent insulinotropic peptide
What is increased with stomach distention/alkalinization, amino acids (phenylalanine and tryptophan), peptides, and vagal stimulation but decreased by stomach pH <1.5?
Gastrin
What is increased in fasting state?
motilin
Name a motilin receptor agonist used to stimulate intestinal peristalsis?
Erythromcin
What is increased by acid and fatty acids in lumen of duodenum?
Secretin
What is increased by acid but decreased by vagal stimulation?
somatostatin
What is increased by distention and vagal stimulation and decreased by vagal input?
VIP
What are the symptoms of a VIPoma?
- Watery diarrhea
- Hypokalemia
- Achlorhydria
What is increased by histamine, Ach, and gastrin but decreased by somatostatin, GIP, prostaglandin and secretin?
gastric acid
What is increased by vagal stimulation and local acid?
pepsin
What is increased by pancreatic and biliary secretion with secretin?
HCO3-
What are two pathological things that can lead to increased gastrin?
- Zollinger-Ellison syndrome
- Chronic PPI use
What is glucose-dependent insulinotropic peptide known as?
GIP
Why is GIP significant for oral v. IV glucose?
Oral glucose load used more rapidly than IV due to GIP
Why is secretin important?
Increases HCO3- to allow pancreatic enzymes to function in duodenum
What is one of the underlying causes of achlasia?
Loss of NO secretion leading to increased LES tone
Why does atropine not block G cells?
vagal stimulation of G cells is through GRP not Ach (like with parietal cells)
Where is gastrin released?
into circulation (NOT into stomach)
What does falciform ligament connect?
Liver to anterior abdominal wall
What is contained in falciform ligament?
Ligamentum teres hepatis (fetal umbilical vein)
What does the hepatoduodenal ligament connect?
liver to duodenum
What does the hepatoduodenal ligament contain?
Portal triad (proper hepatic artery, portal vein, common bile duct)
What does the gastroheptic ligament connect?
liver to lesser curvature of stomach
What does the gastroheptic ligament contain?
gastric arteries
What separates greater and lesser omental sacs on the left?
gastrosplenic ligament
What separates greater and lesser sacs on the right?
gastrohepatic ligament
What does the gastrocolic ligament connect?
greater curvature and transverse colon
What does the gastrocolic ligament contain?
gastroepiploic arteries
What does the gastrosplenic ligament connect?
greater curvature and spleen
What does the gastrosplenic ligament contain?
Short gastrics
Left gastroepiploic vessels
What does the splenorenal ligament connect?
Spleen to posterior abdominal wall
What does the splenorenal ligament contain?
Splenic artery and vein; tail of pancreas
Part of GI with plicae circulares and crypts of Lieberkuhn
jejunum
Part of GI with crypts of Lieberkuhn, no villi and numerous goblet cells
colon
Part of GI with nonkeratinized stratified squamous epithelium
esophagus
Part of GI with villi and microvilli, Brunner glands, and crypts of Lieberkuhn
Duodenum
Part of GI with tons of goblet cells, Peyer patches, plicae circulares (proximally) and crypts of Lieberkuhn
Ileum
