Stomach Flashcards
(37 cards)
What do parietal cells secrete, what do chief cells secrete, what do G cells secrete
P = Acid, Intrinsic Factor
C = Pepsin
G = Gastrin
WHat are 2 congenital diseases of the stomach?
Diaphragmatic Hernia
Congenital Pyloric STenosis
What are 6 acquired diseases of the stomach
- Gastropathy
- Acute Gastritis
- Chronic Gastritis
- Peptic Ulcer
- Special forms of Gastritis
- Neoplasms
What is the difference between acute gastritis and gastropathy?
Acute gastritis is when neutrophils are present, while in gastropathy inflammatory cells are rare/absent
How does acute gastritis present?
- Asymptomatic
- Epigastric Pain
- Indigestion
- Nausea & Vomitting
- Bleeding
What two things can result from acute gastritis?
Superficial Erosions
Acute Ulcers
What can be seen on an endoscope in acute gastritis?
- Petechial Hemorrhages
- Erosions
What are 5 causes of gastropathy/gastritis?
Reactive Gastritis
- Chemical/reflux (alcohol, bile, corrosives)
- NSAIDs
- CIgarette smoking
Chemotherapy/radian
Vascular gastropathy
- portal hypertension
Stress-induced mucosal injury (local ischemia)
- shock, sepsis, post MI, trauma
- severe burns
- intracranial disease
Uremia
How does uremia causes gastric injury?
Inhibition of gastric bicarbonate transporters by ammonium ions
How do NSAIDs cause gastric injury
Inhibit COX, no PGs, PGs needed for bicarbonate production, mucus production, regulation of acid secretion
Why are elderly more susceptible to gastric injjury?
Reduced mucin and bicarbonate secretion
How do people get acute gastritis at high altitudes?
Decreased oxygen delivery
How does chemotherapy/radiation cause gastric injury?
Direct Injury
pathogenesis of stress associated gastric injury
Local Ischemia
pathogenesis of intracranial injury related gastritis
Direct stimulation of vagal nuclei, hypersecretion of acid
What can chronic gastritis lead to?
Mucosal atrophy, intestinal metaplasia, dysplastic, development of carcinoma
What are 2 main causes of chronic gastritis?
- H. pylori
- Autoimmune gastritis
4 disease a/w H. Pylori
- Chronic Gastritis
- Peptic Ulcer
- Gastric Carcinoma
- Gastric Lymphoma
Mechanism of injury of H. Pylori
- Urease generates free ammonia from endogenous area
- Protease breaks don glycoprotein in mucus
- Phospholipase damages epithelial cells, release leukotrienes
- Neutrophils attracted by H. pylori release MPO
- H Pylori colonisation damages epithelial and endothelial cells; thrombotic occlusion of capillaries promoted by bacterial platelet-activating factor
- Recruitment of more inflammatory cells to mucosa
- Chronically inflamed mucosa more susceptible to acid injury
- damaged mucosa permits leakage of tissue nutrients into surface microenvironment, sustaining bacillus
4 features relating H. Pylori virulence
- Flagella
- Urease
- Adhesin
- Toxin (CAG-A)
Progression of H. Pylori in Chronic Gastritis
Active Inflammation –> Regenerative Changes (mitoses in epithelium, loss of mucus vacuoles) –> Metaplasia (intestinal type) –> Atrophy (loss of glandular structures and specialised cells) –> Dysplasia –> Invasive adenocarcinoma
How to diagnose H .Pylori
- Urea Breath Test
- Serology
- Histology
- CUlture
What happens in autoimmune gastritis?
Diffuse gastritis of oxynitic mucosa in the body and fundus with extensive intestinal metaplasia and pseudopyloric metaplasia and severe gastric body-fundal atrophy
What antibodies can be detected in autoimmune gastritis?
Ab to Gastric Parietal Cells & IF
