Ethmoid Bone, Superior View

Description

Arising in the midline of the anterior cranial base, the ethmoid bone is presented from a superior aspect, centering the cribriform plate and its perforations for fila olfactoria. Anteriorly, the crista galli projects upward for attachment of the falx cerebri, while laterally the ethmoidal labyrinths expand as paired masses that house the ethmoidal air cells. Posteriorly and laterally, the ethmoid articulates with the sphenoid and frontal bones, and the orbital plates (laminae papyraceae) form the medial walls of the orbits. Small bone. Dense anatomy. A superior view is the clearest way to teach the relationship between the anterior cranial fossa floor and the nasal cavity, because the cribriform plate is the thin barrier between them. Traumatic shearing of olfactory nerve filaments at the cribriform plate can produce anosmia, and fractures here also create a pathway for cerebrospinal fluid rhinorrhea and ascending meningitis. Endoscopic sinus surgery and anterior skull base approaches rely on these landmarks, with the anterior and posterior ethmoidal foramina marking the course of the ethmoidal arteries near the roof of the ethmoid. Medical educators can place this plate into a cranial osteology lab to orient students to the ethmoid’s contribution to the orbit, nasal septum, and paranasal sinus complex, and authors can pair it with coronal CT or endoscopic views when discussing ethmoiditis, mucoceles, or skull base defects. Neurosurgical and ENT texts will also find it useful when illustrating crista galli and falx cerebri attachment, or when mapping safe dissection planes along the fovea ethmoidalis. Anatomical accuracy verified by SciePro's Medical Advisory Board.