Ethmoid bone – perpendicular plate

Ethmoid bone - perpendicular plate


Projects down from body of ethmoid (unpaired bone inside skull, between orbits, forming part cranial floor and part roof nasal cavity), forms part of nasal septum. Thin, flat, polygonal, usually deviated a little left or right. Septal cartilage attached below. Articulates with frontal, sphenoid, nasals.


Ethmoid made up of perpendicular plate, cribriform plate and ethmoidal labyrinth. Forms part of roof of nose and eye sockets. Fragile (spongy) and direct trauma to nose can fracture ethmoid. Can lead to temporary exophthalmos (eye bulging out of socket) on sneezing (eg) if fracture causes connection between nasal cavity and orbit.

Olfactory fibres course through cribriform plate, fracture of which can lead to anosmia (loss of smell and associated taste). Fracture can breach blood brain barrier, leading to central nervous system (CNS) infection.

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