ethmoid sinus

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Related to Ethmoidal air sinuses: ethmoid sinus

ethmoid sinus

An air cavity or space within the ethmoid bone, opening into the nasal cavity.

ethmoid sinus

Any of the 3-18 paranasal sinuses on each side of the skull in and adjacent to the ethmoid bone. The ethmoid sinuses can be categorized as anterior, middle, or posterior, with each group usually draining into a different part of the nasal cavity. Ethmoid sinuses have very thin walls and are interconnected via openings in the septa between the sinuses.
See also: sinus

ethmoid sinus,

n one of the facial cavities, located beneath the nasal bridge, through which air flows.


1. sievelike; cribriform.
2. the ethmoid bone.

ethmoid bone
the sievelike bone that forms a roof for the nasal fossae and part of the floor of the rostral cranial fossa. See also Table 10.
ethmoid sinus
see concha.