The paranasal sinuses are connected to the nasal cavity through small orifices called ostia.

Most of these ostia communicate with the nose through the lateral nasal wall, via a semi-lunar depression in it known as the semilunar hiatus.

[4] The vestibule is enclosed by the nasal cartilages and lined by the same epithelium of the skin (stratified squamous, keratinized).

The named arteries of the nose are: Innervation of the nasal cavity responsible for the sense of smell is via the olfactory nerve, which sends microscopic fibers from the olfactory bulb through the cribriform plate to reach the top of the nasal cavity.

In addition, the air is humidified, and dust and other particulate matter is removed by nasal hair in the nostrils.

The entire mucosa of the nasal cavity is covered by a blanket of mucus, which lies superficial to the microscopic cilia and also filters inspired air.

The cilia of the respiratory epithelium move the secreted mucus and particulate matter posteriorly towards the pharynx where it passes into the esophagus and is digested in the stomach.

The nasal cavity also houses the sense of smell and contributes greatly to taste sensation through its posterior communication with the mouth via the choanae.