Floor of the cranium, inferior to the frontal bone and anterior to the sphenoid. Non-technically: Centre of the face, behind the nose. Forms part of the nasal cavity and the orbits. Main support structure of the nasal cavity
Gr. ethmos = a sieve, and eidos = resemblance. A term describing the structure of the ethmoid bone of the skull, the most anterior of the four principal braincase regions. It is associated with the nasal capsules and chemosensation. Frequently it fuses with the sphenoid region and is referred to as the sphenethmoid. In mammals, the ethmoid is reduced to a series of turbinals: very thin bones in the nasal passage that help recover respiratory water vapor.