Perpendicular plate

The perpendicular plate is a thin sagittal bony wall located in the median plane of the ethmoid bone. It divides the ethmoid bone into two symmetrical, cylindrical parts. The perpendicular plate projects dorsally and extends as a continuation of the crista galli into the cranial cavity, participating in the formation of the bony nasal septum.

Its lateral surfaces serve as the point of origin for the ethmoidal labyrinths, whose medial walls attach directly to this plate. The perpendicular plate connects with the cribriform plate and is related to the ethmoid fossae.

Its bony composition acts as support for the ethmoid bone. Its shape and thickness vary according to the species; however, its main characteristic as a median divider of the ethmoid bone remains.