noun, plural: ethmoidal labyrinths
The ethmoidal labyrinth is one of the three parts of the ethmoid bone. The other parts include the cribriform plate and the perpendicular plate. But the ethmoidal labyrinth is the one that forms the bulk of the ethmoid bone. It consists of lateral series of tiny air chambers called ethmoid air cells. The ethmoid air cells are fluid-filled thin-walled cavities that are arranged into anterior, middle, and posterior clusters. They are involved in the warming and moistening of the inspired air. They are also associated with voice resonance such that with age they grow resulting, in the resonance of the voice to increase with age, particularly until puberty.
There are also long, narrow, curved bone shelves projecting from the medial surface of the ethmoid labyrinth. They are the middle nasal concha and the superior nasal concha. The conchae (together with the independent bone inferior nasal concha) provide support to the mucous membrane that line the nasal cavity.