||The nasal cavity, the most proximal part of the respiratory system, has two important functions: the conditioning of inspired air and olfaction. The inspired air is filtered of its larger particulate contaminants by the vibrissae of the nasal vestibule while the finer particles are trapped in the mucociliary blanket. This blanket of mucus which is constantly produced by the respiratory epithelium lining the nasal cavity, is continuously swept posteriorly by the action of the cilia until it reaches the nasopharynx.
The inspired air is warmed almost to body temperature by the nose before it enters the lungs, and at the same time it is humidified to near saturation.
Olfaction is performed by the highly specialized nerve endings of the olfactory nerve which are located in the most superior regions of the nasal cavity.