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Respiratory system

When you breathe in, air first travels through your nose or mouth, and then through the trachea (windpipe), which further divides into bronchi, then smaller bronchioles, finally ending in the tiny air sacs (alveoli) in the lungs.

Respiratory system

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Review Date: 7/2/2011

Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital.

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