Inhaled air is primarily filtered in the nasal passages through a combination of nasal hairs and mucus.
Here's a more detailed breakdown of the process:
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Nasal Hairs (Cilia): The nostrils are lined with tiny hairs called cilia. These hairs act as a first line of defense, trapping larger particles like dust, pollen, and debris before they can enter the respiratory system.
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Mucus Membrane: The nasal passages are also lined with a mucus membrane. This membrane secretes a sticky fluid called mucus. This mucus traps smaller particles that bypass the nasal hairs, as well as pathogens like bacteria and viruses.
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The Combined Action: The nasal hairs and mucus work together to effectively filter the inhaled air. The particles trapped by the mucus are eventually moved towards the back of the throat by the cilia, where they are swallowed. This process, called the mucociliary escalator, helps prevent these particles from reaching the lungs.
In summary, the inhaled air undergoes filtration in the nostrils through a combination of physical trapping by nasal hairs (cilia) and adhesion to the sticky mucus lining. This coordinated action removes particulate matter and pathogens, protecting the delicate tissues of the respiratory system.
