Ethmoid bone
Os ethmoidale
SkeletalSkeletonHead
- What it is
- Light, box-like bone between the orbits: the sieve-like cribriform plate and crista galli above, a midline perpendicular plate (upper nasal septum) and air-cell labyrinths forming the medial orbital walls.
- Function
- Separates the nasal cavity from the brain and orbits; olfactory nerve fibres pass through its cribriform plate.
- Size
- ≈ 2.5 cm wide, 4 cm deep
- Clinical note
- A fracture of the cribriform plate can cause loss of smell and CSF leaking from the nose.