Nasal Cavity: The Entry Point for Respiration and Air Conditioning

The nasal cavity is the initial segment of the respiratory tract. As air enters, it is:

• Filtered by nasal hairs (vibrissae) and mucus trapping particles.
• Warmed to near body temperature by rich vascular mucosa.
• Humidified to near 100% relative humidity.

The cavity also houses the olfactory epithelium (smell receptors) and resonates speech. Proper nasal breathing optimizes gas exchange and protects lower airways.