Stomach (GIT) Flashcards
What are common causes of gastritis?
Drugs (NSAIDs)
Cocaine
Bacterial infection (H. pylori)
Alcohol
Gastritis can be classed as acute, chronic and active chronic.
How can you diffferentiate these microscopically?
Acute = neutrophils present
Chronic = plasma cells present
Active chronic = both neutrophils and plasma cells present.
What macroscopic features might you see in gastritis?
Eryhtema
Oedema
Intestinal metaplasia
Enlarged folds
What anatomical sites do you find different types of gastritis?
H. pylori is often found in the antrum.
Reactive / chemical gastritis involves the greater curvature of the stomach due to gastric contents settling there.
What are the two causes of atrophic gastritis?
What is the effect on acid production in these?
H pylori infection - acid production can be increased or decreased
Autoimmune gastritis (AIG) - acid production is decreased.
Why can Vitamin B12 deficiency arise from atrophic gastritis?
Chronic inflammation of gastric mucosa causes loss of gastric glands (parietal cells) responsible for creating intrinsic factor.
Without IF we cannot absorb B12.
What is the pathophysiology of H. pylori associated ulcer formation?
What is the relationship between H. pylori infection location and ulcer formation?
Antral gastritis from H pylori results in increased gastric acid production, creating environment for ulcer formation.
Antral inflammation causes release of gastrin, causing parietal cells to secrete acid.
H. pylori infection of fundus/body only has modest increase in gastric acid production due to atrophy to gastric glands in this area, and thus are relatively protected from antral/duodenal ulcers.
What are the two anatomical sites that peptic ulcer disease forms ulcers/
Stomach (gastric ulcer) or duodenum (duodenal ulcer)>
What are the common presentations of P.U.D and complications?
Present with burning after meals and at night.
Complications: Bleeding, perforation, dysplasia –> carcinoma.
Additionally, can casuse lymphoid hyperplasia and MALT lymphoma.
What are the three types of benign gastric tumours, with commonality, dysplastic potential and neoplasm/not neoplasm
Hyperplastic polyp - most common, can become dysplastic, not neoplasm
Fundic gland polyp - rarely become dysplastic, not neoplasm
Gastric adenoma - neoplastic polyp with low/high grade dysplasia. Can become gastric carcinoma
What type of carcinoma are most gastric carcinomas?
WHat are some risk factors?
Adenocarcinoma.
Risk factors:
Smoked/salted food (dietary carcinogens - Japan = capital of gastric cancer)
H pylori causing intestinal metaplasia
What are the two classifications of gastric carcinoma?
Intestinal type adenocarcinoma - forms solitary mass, caused by chronic inflammation that leads to dysplasia/adenoma that develops into adenocarcinoma (e.g. H pylori)
Diffuse adenocarcinoma - infiiltrative, no precursor lesions, due to mutations in genes. Cells have characteristic signet ring shape.
Can gastric carcinoma be ulcerative?
Yes
What is the main cause of MALT lymphoma?
Chronic inflammation from H pylori infection.
What is the name given to mesenchymal tumours of teh stomach?
From what cells do they arise?
Gastrointestinal Stromal Tumours (GISTs)
Cells of Cajal
