The nose is an external facial feature that is supported by the skull and hyaline cartilage. Hyaline cartilage forms the nasal septum, a midline dividing wall that separates the nose into the right and left sides.

The external openings of the nose are the nostrils or external nares. They lead air directly into and out of a small space within the nose, called the nasal vestibule. The nasal vestibule contains vestibular hairs, which act as a coarse filter that prevents dust, bugs, and other unwanted debris from entering the respiratory tract.

The nasal vestibule opens into a larger space called the nasal cavity which continues to be divided into right and left sides by the nasal septum. The lateral walls of the nasal cavity have three ridge-like elevations formed by the underlying bone structure of the nasal conchae. The nasal conchae, also known as the nasal turbinates, create turbulence in the air. This turbulent air movement forces the air to swirl around the nasal cavity, contacting the posterior superior region where olfactory receptors are housed. It additionally functions to warm and humidify the incoming air.

Figure 1: The structures of the nasal cavity, the oral cavity and the tongue. Olfactory receptors housed in the nasal cavity connect to the olfactory bulb in the forebrain.