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Your Air Passages

Air is brought into your lungs through passages from your nose and mouth. The process of warming, moistening and filtering inspired air is continued throughout the respiratory system.

• Air is warmed as it passes over the surface of your airways.
• The air is moistened by contact with mucus and filtered by cilia (tiny hair–like projections) which waft any particles of dust or debris (caught in the mucus) towards your throat to be either expectorated (coughed up) or swallowed.
• There are protective cells within your air passages that fight any infection or foreign particles that have not been trapped in the mucus.
• There is a layer of muscle in the walls of your air passages that controls the width of the passageway and so controls the amount of air that can enter your lungs.

The path for air to enter your body starts at your nose and travels through your larynx and trachea to divide into two branches to supply your left and right lungs. These are called the left bronchus and the right bronchus.

The bronchi further subdivide and branch out into smaller and smaller air passages to form an intricate system of tiny air passages throughout the lungs, called bronchioles.

These tiny passages end in millions of tiny air sacs called alveoli. These special structures contain tiny blood vessels or capillaries, which allow gases (oxygen and carbon dioxide) to pass in and out of the bloodstream.

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