Anatomy, Head and Neck, Nasal Cavity

The role of the nasal cavity is to humidify and warm the inspired air. Also, as the air passes through, the nasal cavity removes minute airborne particles and other debris before the air reaches the lower airways. Columnar epithelium lines the nasal cavity. This type of epithelial lining also secretes mucus that coats the lining and helps with the mucociliary clearance of minute aerosolized particles that become trapped in the nasal mucosa. The nasal cavity also functions to facilitate drainage for the secretions from the adjacent paranasal sinuses. It also captures the odor bearing particles and transmits them to the olfactory recesses, that are in the superior portion of the nasal cavity, just medial to the superior turbinates. Air containing mucosal lined sinuses surround the nasal cavity, which includes the frontal, paired maxillary, sphenoid, and ethmoid sinuses. These cavities directly communicate with the nasal cavity. The secretions from these sinuses drain into the nasal cavity via the thin-walled ostia. Like the nasal cavity, the wall lining of the sinuses also secretes mucus. The cilia on the surface sweep the mucus in a carpet like fashion and move them towards the nasal ostia. The hard palate lines the floor of the nasal cavity. The lateral walls are spiral shaped mucosal folds that overlie the turbinates and sinus ducts draining into the ostia. The spiral shape of the turbinates is designed to increase the surface area for the inspired air.