The airways into the lungs
Main bronchi · bronchi principales
The two tubes that split off the windpipe and lead into each lung.
What it does
The windpipe splits into the left and right main bronchi behind the breastbone. Each one enters a lung and keeps dividing into smaller and smaller branches, like an upside-down tree. Rings of cartilage hold the larger airways open, and a lining of tiny hairs sweeps mucus and dirt up and out.
Surprising fact
The right main bronchus is wider, shorter and more upright than the left, so an inhaled peanut or toy is more likely to end up in the right lung.
Why it matters
In asthma, the muscle around the smaller airways tightens and their lining swells, narrowing the passages and making breathing difficult.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.