Stomach Flashcards
What is the blood supply of the stomach?
Greater curvature: R and L gastroepiploic arteries (from gastroduodenal, splenic, resp.).
Lesser curvature: R and L gastric arteries (from proper hepatic, celiac, resp.).
Pylorus: gastroduodenal artery (from common hepatic).
Fundus: short gastric arteries (from splenic).
What is the innervation of the stomach?
Motor: L vagus (ant. gastric wall), R vagus (post. gastric wall)
Pain sensation: symp. afferents from T5-10.
What are the major cells found in the stomach?
Parietal cells (fundus and body). Chief cells (fundus and body). G cells (antrum).
What do gastric parietal cells do?
Secrete intrinsic factor (vitamin B12 absorption).
Secrete HCl.
What do gastric chief cells do?
Secrete pepsinogen.
What do G cells do?
Secrete gastrin.
How can parietal cells be stimulated or inhibited?
Stimulation: Gastrin, Vagus nerve, Histamine.
How can G cells be stimulated or inhibited?
Stimulation: Gastrin-releasing peptide.
Inhibition: Somatostatin.
How can gastric bicarbonate secretion into mucous gel be inhibited?
NSAIDs.
Acetazolamide.
Alpha blockers.
EtOH.
How can the thickness of gastric gel be increased or decreased?
Increased: PGE.
Reduced: Steroids, NSAIDs.
How does H. pylori contribute to ulcer formation?
Produce urease which breaks down the protective mucous lining of the stomach.
How do NSAIDs contribute to ulcer formation?
Inhibit production of PGE, which stimulates mucosal barrier production.
What is the urease breath test?
1) C13/14 labeled urea is ingested.
2) If H. pylori is present, carbon isotope can be detected in breath.
What are the most common PPIs?
Omeprazole (Prilosec).
Lansoprazole (Prevacid).
Pantoprazole (Protonix).
What are the most common H2 blockers?
Cimetidine (Tagamet).
Ranitidine (Zantac).
Famotidine (Pepcid).
Nizatidine (Tazac).