Nose and Nasal Cavity

About the Nose and Nasal Cavity

The nose and nasal cavity warm, humidify, and filter inspired air and provide the sense of smell. The external nose has bone nasal and frontal processes of maxilla and cartilage upper lateral, lower lateral alar, septal. The nasal septum divides the cavity into two halves, deviated in approximately 80 percent of people. Three turbinates conchae superior, middle, inferior create turbulent airflow, increasing contact with the mucosal surface for warming, humidifying, and filtering. The nasal mucosa has ciliated pseudostratified columnar epithelium with goblet cells producing mucus trapping particles. Cilia beat toward the pharynx at 10 to 15 beats per second, moving the mucociliary blanket in 10 to 20 minutes. The paranasal sinuses maxillary, frontal, ethmoid, sphenoid lighten the skull and resonate the voice. Olfaction occurs in the olfactory epithelium at the roof of the nasal cavity, containing approximately 350 functional olfactory receptor genes the largest gene family in humans. Each olfactory neuron expresses one receptor type, and axons pass through the cribriform plate to the olfactory bulb. Anosmia loss of smell affects taste and is an early sign of Parkinson disease and a common symptom of COVID-19.