The respiratory section of each nostril contains four conchae (protrusions or bumps) which are also referred to as turbinate bones or lobes and are covered by the nasal mucosa. Underlying these conchae are meatuses (passages to interior body structures). The meatuses of the nasal cavity connect to the paranasal sinuses.

Projecting out of the lateral walls of the nasal cavity are curved shelves of bone. They are called conchae (or turbinates). The are three conchae – inferior, middle and superior. They project into the nasal cavity, creating four pathways for the air to flow. These pathways are called meatuses:

Inside the nasal cavity are three curved shelves of bone called turbinates or nasal conchae. They project from the lateral walls of the cavity and are called the superior, middle, and inferior turbinates. The space between the turbinates is called the meatus.

The lateral wall of the nasal cavity is of great significance in respect to the paranasal sinuses. Three large shelf-like protrusions, called nasal conchae (also known as turbinates) serve as landmarks for locating drainage of each of the sinuses (more details in the subsequent sections). Inferior to each concha is an air space called meatus.

The lateral wall presents three or four medial projections termed nasal conchae, which overlie passages (meatuses). The inferior concha is a separate bone; the others are portions of the ethmoid bone. The conchae were formerly known as turbinates. It should be noted that the plural of meatus is meatus in Latin and meatuses in English (cf fetus).