📍 What Is the Stomach?
The stomach is a muscular, hollow organ located in the upper left side of your abdomen, just under the ribs. It’s part of the digestive system and plays a crucial role in breaking down food and preparing it for absorption in the intestines.
🧱 Structure of the Stomach
The stomach has four main parts:
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Cardia – where food enters from the esophagus
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Fundus – upper curved part that stores undigested food
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Body (Corpus) – the main section for digestion
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Pylorus – connects the stomach to the small intestine
The stomach wall has 3 layers of muscle that help mix and churn food, and it is lined with mucosa (protective layer).
🔬 Main Functions of the Stomach
| Function | Description |
|---|---|
| Food storage | Holds food temporarily (up to 2–6 hours) |
| Mechanical digestion | Muscular contractions mix and break food down |
| Chemical digestion | Releases acid and enzymes to break down proteins |
| Defense | Kills bacteria with stomach acid |
| Controlled release | Gradually pushes food into the small intestine (duodenum) |
⚙️ Step-by-Step: How the Stomach Works
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Food Entry
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After chewing and swallowing, food travels down the esophagus
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Enters the stomach via the lower esophageal sphincter
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Storage Phase
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The stomach temporarily stores food in the fundus and body
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It can stretch to hold up to 1.5 liters
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Mechanical Mixing
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Strong muscle contractions (peristalsis) churn the food
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This creates a semi-liquid mixture called chyme
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Chemical Digestion
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Gastric glands release:
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Hydrochloric acid (HCl) → kills bacteria, activates enzymes
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Pepsinogen → becomes pepsin, which digests proteins
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Mucus → protects the stomach lining from acid
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Regulated Emptying
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Chyme is gradually released into the duodenum (first part of the small intestine)
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This is controlled by the pyloric sphincter
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🧪 Important Chemicals in the Stomach
| Chemical | Role |
|---|---|
| Hydrochloric acid (HCl) | Lowers pH, kills pathogens, activates enzymes |
| Pepsin | Enzyme that digests proteins |
| Gastrin | Hormone that stimulates acid production |
| Mucus | Protects stomach lining from acid |
🦠 Common Stomach Disorders
| Condition | Description |
|---|---|
| Gastritis | Inflammation of the stomach lining |
| Ulcers | Sores in the lining, often due to H. pylori or NSAIDs |
| GERD | Acid reflux when stomach acid moves into the esophagus |
| Indigestion | Discomfort after eating due to improper digestion |
| Stomach cancer | Rare, but serious—often linked to chronic inflammation or infection |
🧠 Interesting Facts About the Stomach
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The stomach's acid is strong enough to dissolve metal
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A new layer of stomach lining is produced every 3–5 days
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Your stomach "growling" is caused by contractions of the empty stomach
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The stomach does not absorb most nutrients — absorption mostly happens in the small intestine
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Despite all that acid, the stomach doesn’t digest itself thanks to mucus
💬 Medical Terms Related to the Stomach
| Term | Meaning |
|---|---|
| Gastric | Related to the stomach |
| Gastroenterology | The branch of medicine focused on the digestive system |
| Peptic | Related to digestion (e.g., peptic ulcer) |
| Chyme | The semi-liquid mixture of food and digestive juices |
| Sphincter | A ring of muscle that controls the opening/closing of a passage |