Respiratory system
Lungs
The lungs are two spongy organs in the chest that take oxygen into the body and remove carbon dioxide. Together they contain hundreds of millions of tiny air sacs where this exchange happens.
What it is
The lungs are a pair of soft, elastic organs filling most of the chest. The right lung has three lobes and the slightly smaller left lung has two, making room for the heart.
Where it is
In the chest, one on each side of the heart, protected by the rib cage.
What it does
Bring oxygen into the bloodstream and remove carbon dioxide — the waste gas of the body's cells — every time you breathe.
How it works
Air travels down the windpipe into branching airways that end in tiny air sacs (alveoli). Oxygen passes from the air sacs into the blood, while carbon dioxide passes the other way to be breathed out. The diaphragm and rib muscles drive the bellows-like movement of breathing.
When things go wrong
Common conditions affecting the lungs
- Asthma
- Chronic obstructive pulmonary disease (COPD)
- Chest infections and pneumonia
- Lung 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 lungs healthy
Not smoking is by far the most important step; avoiding air pollution and workplace dusts, staying active, and having recommended vaccinations also protect the lungs.
Did you know?
An interesting fact
If the air sacs of both lungs were flattened out, they would cover an area roughly the size of a tennis court.
Answers
Lungs: frequently asked questions
What do the lungs do?
The lungs take oxygen from the air into the blood and remove carbon dioxide, the waste gas produced by the body's cells.
How can I keep my lungs healthy?
Not smoking is the single most important thing. Avoiding pollution and dusts, staying active, and getting recommended vaccinations (like flu and pneumococcal) also help.
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students
- TeachMeAnatomy / TeachMePhysiology
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