The nasal cavity performs several vital functions. Three key roles are:
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Respiration: The nose is the primary entry point for air into the respiratory system. It filters, warms, and humidifies the air before it reaches the lungs, protecting the delicate lung tissue from irritants and temperature extremes. As noted by Cleveland Clinic, the nose "warms, conditions and filters the air you breathe."
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Olfaction (Sense of Smell): The nasal cavity houses the olfactory receptors, responsible for our sense of smell. These specialized cells detect odor molecules in the air, sending signals to the brain for interpretation. Verywell Health explicitly states that olfaction is one of the three main functions of the nasal cavity.
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Immune Defense: The nasal lining contains immune cells that protect against inhaled pathogens. The nasal cavity's mucous membranes trap bacteria and viruses, preventing them from entering the lower respiratory tract. This is a crucial aspect of the body's overall defense system. The nasal cavity's role in immune defense is highlighted by its large humidified surface area and its ability to condition inhaled air.
