The nasal conchae or turbinates are long, narrow curled shelves of bone that protrude into the nasal cavity. The superior, middle and inferior conchae divide the nasal cavity into four groove-like air passages. Their position and relationship to other important anatomic landmarks are extremely important especially in skull base and ENT surgical procedures.
Each inferior nasal concha is a separate facial bone articulating with its respective maxilla and palatine bone. Conversely, both the middle and superior conchae are part of the ethmoid bone .
The conchae are located laterally in the nasal cavity and covered by pseudostratified columnar, ciliated respiratory epithelium with a thick, vascular and erectile glandular tissue layer. Each pair is composed of one concha that curls medially and downwards on either side of the nasal cavity, separated by the septum :
- inferior conchae: these are the largest conchae and may be as long as the index finger; they are responsible for the majority of airflow direction, humidification, heating and filtering of air inhaled through the nose
- middle conchae: small and usually as long as the 5th finger; they project downwards over the openings of the maxillary and ethmoid sinuses and act as buffers to protect the sinuses from pressurised nasal airflow
- superior conchae: the smallest of the conchae, connected to the middle conchae by nerve-endings and serves to protect the olfactory bulb
- supreme conchae: variably present, it is usually very small and is the highest of all conchae