gastric secretion Flashcards
What do parietal cells in the stomach produce
Hydrochloric acid and intrinsic factors
What do G cells in the antrum of the stomach produce
Gastrin
What increases production of HCL
gastrin
Histamine
acetylcholine
What is the function of gastrin
Increases the motility of the stomach by increasing secretion of HCL
What inhibits HCL production
Prostaglandins - inhibit conversion of ATP into cAMP
What do chief cells produce
Pepsinogens
What is the affect ofHow does food present increase HCL production
Vagus nerve becomes activated which increases acetylcholine production which leads to increased HCL
How does the cephalic phase stop gastric acid secretion
Decreased vagal acting due to cephalic phase beinbg stopping eating
How does the gastric phase inhibit gastric acid secretion
Decreased pH due to the excess HCL being produced which leads to decreased gastric acid secretion through inhibition of G cell
How does the intestinal phase inhibit gastrin secretion
Acid in duodenum stimulates secretin which decreases release of G cells so less gastrin is produced which prevents HCL stimulation
What is a pepsinogen
Zymogen - proenzyme which is inactive but can be activated later - in PH < 3, the pepsinogen is converted into pepsin - breaks down protein
Pepsin is inactive at neutral pH
What is the role of gastric mucus
Protects from HCL and pepsins since the mucosal wall would be digested without it
What is the only essential function of the stomach
intrinsic factor production
What is pernicious anaemia
Decrease in red blood cells caused by the malfunction of B 12 absorption in the intestines
