Bronchi (singular: bronchus) are the large, branching airways that lead from the trachea (windpipe) into the lungs. The trachea divides into two primary bronchi, one leading to each lung, and these primary bronchi then divide into smaller and smaller bronchi, eventually becoming bronchioles, which end in clusters of tiny air sacs called alveoli.
The bronchi, along with the trachea and other parts of the respiratory system, are responsible for delivering air to the lungs and exchanging oxygen and carbon dioxide with the blood. They are lined with a layer of mucus and hair-like projections called cilia, which help to trap and remove particles and other debris from the air before it reaches the delicate tissues of the lungs.
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