MP322 - PEPTIC ULCER DISEASE AND GORD Flashcards
Peptic ulcers?
sores that develop in the lining of the stomach, lower oesophagus, or small intestine
duodenum ulcers more common than gastric ulcers
Causes of peptic ulcers
- stress
- alcohol
- diet
- use of NSAIDs
- presence of H. Pylori
Treatment of peptic ulcers
anti-ulcer therapy
drugs - H2 antagonists and Proton pump inhibitors (PPIs)
current treatment of H. Pylori peptic ulcer
triple therapy -
PPI
amoxicillin
clarithromycin or metronidazole
(penicillin allergic)
PPI
clarithromycin
metronidazole
Dyspepsia
range of symptoms arising from the upper GI tract, not a diagnosis itself
symptoms of dyspepsia
- upper abdominal pain/discomfort
- heartburn
- gastric reflux
- nausea/vomiting
symptoms typically last 4 weeks or more
How the stomach doesn’t digest itself
(1) surface of mucosa is lined with cells that secrete slightly alkaline mucus that forms a thin layer over the luminal surface. both the protein content of mucus and its alkalinity neutralise H+ in the epithelium.
(2) tight junctions between the epithelial cells lining the stomach limit the diffusion of H+ into the underlying tissues
(3) damaged epithelial cells are replaced every few days by new cells by cell division in gastric pits
consequences of NSAIDs use
- inhibition of endogenous prostaglandin synthesis
- decrease in epithelial mucus, bicarbonate secretion, mucosal blood flow, epithelial proliferation, mucosal resistance to injury
- lower mucosal resistance increases the incidence of injury by endogenous factors such as acid, pepsin, and bile salts as well as exogenous factors such as NSAIDs, ethanol and other noxious agents
peptic ulcer symptoms
- abdominal discomfort, pain or nausea
- pain is located in the epigastrium and usually does not radiate
- pain aggravated by meals, whereas that of a duodenal ulcer is relived
H. Pylori mechanism of action
- avoids acidic environment of the interior stomach (lumen) by using the flagella to burrow into mucus lining of the stomach to reach epithelial cells, where the pH is more neutral
- can sense the pH gradient in the mucus and move towards the less acidic region (chemotaxis)
- can neutralise the acid in its environment by producing large amounts of urease
why does H. Pylori produce urease
- breaks down the urea in the stomach into carbon dioxide and ammonia
- the basic ammonia then neutralises the stomach acid
non-invasive diagnostic testing for H. Pylori
- evaluation of presence of H. Pylori antibodies
- urea breath test
- stool antigen test
gastric gland regions in the stomach
body, antrum, fundus
body region in the stomach
thin-walled upper portion secretes mucus, pepsinogen and HCL
antrum region in the stomach
- lower portion
- thicker layer of smooth muscle
- responsible for mixing and grinding stomach contents
- secretes mucus, pepsinogen and gastrin