Objective 3: Describe the Pathophysiology, Clinical Manifestations, Major Causes, and Potential Complications of Acute and Chronic Gastritis

Gastritis

Inflammation of the gastric mucosa caused by damage or weakening of the stomach's protective mechanisms.

Acute Gastritis

A sudden, generally temporary inflammation of the gastric mucosa caused by disruption of the protective barrier.

Chronic Gastritis

Persistent inflammation of the gastric mucosa that can progressively destroy gastric glands and produce long-term structural changes.

Acute Gastritis Pathophysiology

Disruption of mucus, bicarbonate, prostaglandins, or blood flow allows acid and pepsin to irritate the gastric epithelium.

Chronic Gastritis Pathophysiology

Long-term inflammation causes inflammatory cell infiltration, erosion, and progressive gastric gland atrophy.

NSAIDs as a Cause of Gastritis

Medications that inhibit prostaglandin production, decreasing mucus and bicarbonate secretion and reducing mucosal blood flow.

Alcohol as a Cause of Gastritis

An irritant that directly damages gastric epithelial cells and weakens the protective mucosal barrier.

Bacterial Toxins

Toxins from contaminated food that irritate the gastric lining and trigger acute inflammation.

H. pylori

A bacterium that survives in the acidic stomach environment and is the most common cause of chronic gastritis.

Urease

An enzyme produced by H. pylori that breaks down urea into ammonia and carbon dioxide.

Ammonia

A product of urease activity that helps H. pylori survive in the acidic gastric environment but contributes to mucosal injury.

Gastric Gland Atrophy

Progressive destruction of normal gastric glands caused by chronic inflammation.

Atrophic Gastritis

Chronic inflammation associated with loss of gastric glands and reduced gastric secretory function.

Vitamin B12 Deficiency

A deficiency that can occur when destruction of parietal cells decreases intrinsic factor production.

Pernicious Anemia

An anemia associated with impaired vitamin B12 absorption caused by insufficient intrinsic factor.

Iron Deficiency Anemia

Anemia that can develop as a complication of chronic gastritis.

Gastric Adenocarcinoma

A malignant tumor of the stomach whose risk increases with extensive chronic atrophy and intestinal metaplasia.

Urea Breath Test

A diagnostic test for H. pylori that detects labeled carbon dioxide in exhaled breath after the patient ingests labeled urea.

What is gastritis?

Inflammation of the gastric mucosa caused by damage to the stomach's protective mechanisms.

What is the difference between acute and chronic gastritis?

Acute gastritis develops suddenly and is generally temporary, while chronic gastritis involves persistent inflammation and progressive tissue damage.

What happens during acute gastritis?

The protective barrier becomes disrupted, allowing hydrochloric acid and pepsin to irritate the gastric lining and produce inflammation.

What happens in severe acute gastritis?

Damage to gastric mucosal blood vessels can cause hemorrhage and gastrointestinal bleeding.

What are the major causes of acute gastritis?

NSAIDs, aspirin, excessive alcohol consumption, and bacterial toxins from contaminated food.

How do NSAIDs cause acute gastritis?

They decrease prostaglandin production, reducing mucus, bicarbonate, and mucosal blood flow.

How does excessive alcohol consumption cause gastritis?

It directly irritates and damages gastric epithelial cells and weakens the protective barrier.

What are common clinical manifestations of acute gastritis?

Nausea, vomiting, epigastric pain, and abdominal discomfort, sometimes accompanied by gastrointestinal bleeding.

What is the most common cause of chronic gastritis?

Helicobacter pylori infection.

How does H. pylori survive in the acidic stomach?

It produces urease, which breaks down urea into ammonia and carbon dioxide.

What is the function of urease in H. pylori infection?

It produces ammonia, helping the bacteria survive in the acidic gastric environment.

How does chronic H. pylori infection damage the stomach?

It produces persistent inflammation that weakens the mucosal barrier and progressively destroys gastric glands.

What is gastric gland atrophy?

The progressive destruction of normal gastric glands, which can reduce hydrochloric acid and other gastric secretions.

How can chronic gastritis cause vitamin B12 deficiency?

Destruction of parietal cells decreases intrinsic factor production, impairing vitamin B12 absorption in the terminal ileum.

What is pernicious anemia associated with?

Vitamin B12 deficiency caused by inadequate intrinsic factor production and impaired absorption.

What types of anemia can occur with chronic gastritis?

Vitamin B12 deficiency-related pernicious anemia and iron deficiency anemia.

What is a potential cancer complication of chronic gastritis?

Increased risk of gastric adenocarcinoma, particularly with extensive atrophy and intestinal metaplasia.

What are other potential complications of chronic gastritis?

Gastric gland atrophy, reduced acid production, nutrient deficiencies, and peptic ulcer disease.

How does the urea breath test detect H. pylori?

The patient ingests labeled urea; bacterial urease breaks it down, producing labeled carbon dioxide that is detected in exhaled breath.

What does detection of labeled carbon dioxide in a urea breath test indicate?

The presence of urease-producing H. pylori bacteria.