=====Ethmoid bone=====

{{ http://img.tfd.com/MosbyMD/thumb/ethmoid_bone.jpg}}

(/ˈɛθmɔɪd/; from Greek ethmos, "sieve") A bone in the [[skull]] that separates the [[nasal cavity]] from the [[brain]]. It is located at the roof of the nose, between the two [[orbit]]s. The cubical bone is lightweight due to a spongy construction. The ethmoid bone is one of the bones that make up the orbit of the eye and makes up a portion of the anterior cranial floor, forms  part of the medial wall of the orbits but mainly participates in the anatomy of the medial and lateral walls of the nasal cavity. 

It consists of four parts: a horizontal plate or [[cribriform plate]], a perpendicular plate, constituting part of the [[nasal septum]]; and two lateral masses or ethmoidal labyrinths.