Chronic gastritis Flashcards
Definition
It’s a chronic disease of the stomach characterised by inflammation of the gastric mucosa
Layers of the stomach
The stomach wall is composed of four distinct layers, each with a specialized function in digestion:
* Mucosa: This is the innermost layer, in direct contact with the stomach contents. It’s a delicate layer of epithelial tissue that contains specialized cells responsible for secreting digestive enzymes, hydrochloric acid, and mucus. The mucus layer protects the stomach lining from the harsh acidic environment.
* Submucosa: This layer lies beneath the mucosa and is made up of connective tissue, blood vessels, lymphatic vessels, and nerves. It provides support and nourishment to the mucosa.
* Muscularis Externa: This is the muscle layer responsible for the stomach’s churning and mixing motions. It consists of three layers of smooth muscle: longitudinal, circular, and oblique. This unique arrangement allows the stomach to contract in various directions, aiding in the breakdown of food.
* Serosa: This is the outermost layer of the stomach, composed of connective tissue. It provides a smooth surface that reduces friction between the stomach and other organs in the abdominal cavity.
These four layers work together to ensure the efficient digestion of food in the stomach.
Risk factors of chronic gastritis
To protect itself from damage, the stomach has a delicate balance of aggressive and defensive factors.
Aggressive factors
These are substances that can damage the stomach lining:
* Gastric acid: This strong acid helps to break down food and kill bacteria, but it can also damage the stomach lining if it comes into contact with it.
* Pepsin: This enzyme breaks down proteins, but it can also damage the stomach lining if it is not properly regulated.
* Bile salts: These substances are produced in the liver and help to digest fats. Irritate stomach lining
*diet- spicy food coffee spam of vessels stimulate HCL extremely cold or hot food
* Helicobacter pylori: This bacteria can infect the stomach lining and cause inflammation, which can lead to ulcers.
*Age-older weaken immune system,atrophy decrease regenerating
*Disease-diabetes,atherosclerosis
* Non-steroidal anti-inflammatory drugs (NSAIDs): These medications can irritate the stomach lining and increase the risk of ulcers.
* Alcohol: Alcohol can damage the stomach lining and increase the risk of ulcers,increase acid production risk of atrophic gastritis increase inflammation
* Smoking: Smoking can damage the stomach lining and increase the acid production reduced blood flow
Defensive factors
These are substances that help to protect the stomach lining from damage:
* Mucus: This thick, sticky substance coats the stomach lining and protects it from acid and pepsin.
* Bicarbonate: This substance neutralizes acid and helps to protect the stomach lining.
* Prostaglandins: These substances stimulate the production of mucus and bicarbonate, and they also help to heal any damage to the stomach lining.
* Blood flow: Good blood flow to the stomach lining helps to deliver nutrients and remove waste products, which helps to keep the lining healthy.
* Cellular renewal: The stomach lining is constantly being renewed, which helps to repair any damage.
Balance is key
The stomach lining is normally able to withstand the aggressive factors that are present, but if the balance between aggressive and defensive factors is disrupted, ulcers can develop. For example, if there is too much acid or pepsin, or if the defensive factors are weakened, the stomach lining can become damaged.
Factors that can disrupt the balance
Several factors can disrupt the balance between aggressive and defensive factors, including:
* Infection with H. pylori: This bacteria can damage the stomach lining and increase the risk of ulcers.
* Use of NSAIDs: These medications can irritate the stomach lining and increase the risk of ulcers.
* Excessive alcohol consumption: Alcohol can damage the stomach lining and increase the risk of ulcers.
* Smoking: Smoking can damage the stomach lining and increase the risk of ulcers.
* Stress: Stress can increase the production of acid in the stomach, which can increase the risk of ulcers.
Classification of chronic
gastritis
Non-atrophic (caused by Helicobacter pylori), type B
Atrophic (autoimmune type and multifocal atrophic type), type A
Special forms
Chemical irritants, type C
Radiation type
Lymphocytic
Non-infectious granulomatous
Eosinophilic
Infectious gastritis
Mechanism of C.G
Imbalance between aggressive and defensive factors
H pylori–associated chronic gastritis
H. pylori has several ulcerogenic factors that contribute to the development of ulcers:
- Urease Production: H. pylori produces an enzyme called urease, which breaks down urea into ammonia. This ammonia neutralizes stomach acid, allowing the bacteria to survive in the acidic environment of the stomach. However, this process can also damage the stomach lining.
- Adhesion Factors: H. pylori has specific adhesion molecules that allow it to attach to the gastric epithelium. This attachment can disrupt the protective mucus layer of the stomach, making it more susceptible to acid damage.
- Cytotoxins: Some strains of H. pylori produce cytotoxins, such as cytotoxin-associated gene A (CagA), which can induce inflammation and damage to the gastric cells, leading to ulcer formation.
VagA-destroys stomach cells - Inflammatory Response: The presence of H. pylori triggers an immune response, leading to chronic inflammation (chronic gastritis) in the stomach lining. This inflammation can weaken the protective barriers of the stomach and promote ulcer formation.
- Disruption of Gastric Secretion: H. pylori infection can lead to altered gastric acid secretion, which can result in increased acid production in some individuals, further contributing to ulcer development.
Indication for eradication gastritis
Peptic ulcer
Gastric Mucosa Associated Lymphoid tissue
Easily gastric cancer
H. pylori is a spiral-shaped bacterium with flagella that help it move. It also produces enzymes that help it survive in the acidic environment of the stomach.
Diagnosis of helicobacter pylori
Endoscopy with biopsy
• Rapid urease test (RUT). It is performed by placing a gastric biopsy specimen, obtained
on endoscopy, onto a gel- or membrane-containing urea and a pH-sensitive indicator. If H
pylori is present, the bacterial urease hydrolyzes urea and changes the color of the
media.
• Bacterial culture H pylori. It is highly specific but is not widely used because of the degree
of expertise required. It is used when antibiotic susceptibilities are necessary.
• Histologic detection of H pylori in the biopsy specimen is another endoscopy-based test
Breath tests- Urea breath test. H pylori metabolizes the urea and liberates labeled carbon dioxide that
is exhaled. This, in turn, can be quantified in breath sample
Blood tests
Stool tests(antigen)
Treatment for h.p type B
Eradication of H. pylori (when present) First-line eradication therapy: one of the following one-week triple
therapy regimens is used.
• A ‘PAC’ regimen (a PPI (Proton pump inhibitor) plus Amoxicillin 1 g and
Clarithromycin 500 mg, all given twice a day)
• Or (for people with penicillin hypersensitivity) a ‘PCM’ regimen (a PPI
plus Metronidazole 400 mg and Clarithromycin 250 mg, all given twice
2nd line eradication
Bismuth amoxicillin
Tetracycline four times a day
Acid-suppressive drugs
Smoking should be stopped, and alcohol consumption
stopped or limited to small amounts of dnilute alcohol.
Auto immune G type A
Autoimmune atrophic gastritis is associated with serum anti-parietal and anti–intrinsic factor (IF)
antibodies. The gastric corpus undergoes progressive atrophy, IF deficiency occurs, and
patients may develop pernicious anemia. This is for informational purposes only. For medical advice or diagnosis, consult a professional.
Parietal cells and intrinsic factor are essential components of the stomach that play a crucial role in digestion and nutrient absorption.
Parietal Cells
Parietal cells are specialized cells located in the lining of the stomach. They are responsible for producing two vital substances:
* Hydrochloric acid: This strong acid helps to break down food in the stomach, activate digestive enzymes, and kill harmful bacteria.
* Intrinsic factor: This protein is essential for the absorption of vitamin B12 in the small intestine.
Intrinsic Factor
Intrinsic factor is a glycoprotein produced by parietal cells. It binds to vitamin B12 in the stomach, forming a complex that protects the vitamin from degradation by stomach acid and enzymes. This complex then travels to the small intestine, where intrinsic factor facilitates the absorption of vitamin B12 into the bloodstream.
Importance of Parietal Cells and Intrinsic Factor
Parietal cells and intrinsic factor are essential for maintaining health. Hydrochloric acid is crucial for digestion and nutrient absorption, while intrinsic factor is necessary for preventing vitamin B12 deficiency. Vitamin B12 is essential for red blood cell production, nerve function, and DNA synthesis.
Conditions Affecting Parietal Cells and Intrinsic Factor
Certain conditions can affect the function of parietal cells and the production of intrinsic factor, leading to vitamin B12 deficiency. These conditions include:
* Autoimmune gastritis: This condition occurs when the body’s immune system attacks parietal cells, leading to their destruction and a decrease in intrinsic factor production.
* Atrophic gastritis: This condition is characterized by chronic inflammation of the stomach lining, which can damage parietal cells and reduce intrinsic factor production.
* Gastrectomy: Surgical removal of part or all of the stomach can reduce the number of parietal cells and decrease intrinsic factor production.
* Certain medications: Some medications, such as proton pump inhibitors, can interfere with the production of hydrochloric acid and intrinsic factor.
Vitamin B12 Deficiency
Vitamin B12 deficiency can lead to a variety of symptoms, including fatigue, weakness, numbness or tingling in the hands and feet, memory problems, and depression. In severe cases, it can cause irreversible neurological damage.
Diagnosis and Treatment
Vitamin B12 deficiency can be diagnosed with a blood test. Treatment typically involves vitamin B12 supplementation, either orally or through injections. In some cases, treatment for the underlying condition affecting parietal cells or intrinsic factor may be necessary.
If you have any concerns about parietal cells, intrinsic factor, or vitamin B12 deficiency, please consult a healthcare professional for personalized advice and management.
Autoimmune disorder
Decrease HCL
Decrease digestion atrophy gastritis
B12 deficiency (lack of intrinsic factor )
Anemia pericinous
Type C
Ethology
Reflux of bile
Diet
Smoking
Drugs
Clinical symptoms
Pain in the epigastric region
Dull boring pain 20-1hour after meal
Pyloric part-1hour after
Fundus -20 minutes after meal
Vomiting meteorism
Dyspepsia
Loss of appetite
Bloating
