Gastric physiology Flashcards
What are the four regions of the stomach?
Cardia, fundus, body and antrum
Which two regions of the stomach are histologically identical?
Fundus and body
Which chemicals are secreted by the oxyntic mucosa (fundus and body)?
Intrinsic factor
Pepsinogen
Hydrochloric acid
Histamine
Which chemicals are secreted around the pyloric gland area?
Somatostatin
Gastrin
What action do locally produced prostaglandins take to protect the mucosa from attack by HCl and pepsin?
Stimulate secretion of mucus
Why do NSAIDs such as aspirin predispose patients to development of peptic ulcers?
Protective effect of prostaglandin is lost as NSAIDs are COX inhibitors - the production of prostaglandin is inhibited
Which bacterium can cause peptic ulcer formation?
H. pylori
How does H. pylori cause peptic ulcer formation?
H. pylori sits protected in the mucous layer, and continually secretes agents causing persistent inflammation and weakening of the mucous barrier - this is eventually eroded away leaving the mucosa exposed to attack from HCl and pepsin
Which three factors are the pharmacological targets for prevention of peptic ulcer formation?
Increasing mucosal resistance
Eradicating H. pylori
Reducing acid secretion
Which nerves stimulate salivary production by the parasympathetic system?
Facial and glossopharyngeal (7 and 9)
Mediated by M3 muscarinic receptors
Where is the swallowing centre in the brain?
Medulla
Which cells secrete pepsinogen?
Chief cells
What does pepsinogen do?
Initiates proteolysis
Which cells secrete hydrochloric acid?
Parietal cells
Where are parietal cells and chief cells found in the stomach?
Upper 2/3
