Digestive system
Stomach
The stomach is a muscular, stretchy bag that stores food and begins digestion. It churns food with strong acid and enzymes into a paste before passing it to the intestines.
What it is
The stomach is a J-shaped, expandable organ that connects the food pipe to the small intestine.
Where it is
The upper left abdomen, below the ribs, between the oesophagus and the small intestine.
What it does
Stores swallowed food, mixes it with acid and enzymes to start breaking down proteins, kills many germs, and releases the food gradually into the small intestine.
How it works
The stomach wall produces hydrochloric acid and enzymes, and its muscular walls churn the food into a semi-liquid called chyme. A protective mucus layer stops the acid from digesting the stomach itself. The chyme then passes into the small intestine.
When things go wrong
Common conditions affecting the stomach
- Indigestion and acid reflux
- Stomach ulcers
- Gastritis (inflammation)
- Stomach cancer
Education and reference only. This explains the anatomy in plain terms and is not a diagnosis. Sudden severe symptoms — such as severe chest pain, breathlessness or collapse — are an emergency; call 999.
Looking after it
Keeping your stomach healthy
Eating regularly, limiting very fatty or spicy foods and alcohol if they cause symptoms, not smoking, and treating H. pylori infection where present all help.
Did you know?
An interesting fact
The stomach's acid is strong enough to dissolve metal, yet a mucus lining renewed every few days stops it from digesting the stomach itself.
Answers
Stomach: frequently asked questions
What does the stomach do?
The stomach stores food and begins digestion, churning it with acid and enzymes into a paste before passing it on to the small intestine.
What causes stomach ulcers?
Most stomach ulcers are caused by a bacterial infection (Helicobacter pylori) or by anti-inflammatory painkillers, rather than by spicy food or stress alone.
The digestive system
Related organs
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students
- TeachMeAnatomy / TeachMePhysiology
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