Ethmoid Bone, Superior View

Description

Centered in the anterior cranial base, the ethmoid bone is presented from a superior aspect, with the cribriform plate forming the perforated roof of the nasal cavity and the crista galli projecting superiorly in the midline. Lateral to the cribriform plate, the ethmoidal labyrinths (lateral masses) expand toward the medial orbital walls, where the lamina papyracea would lie immediately medial to the orbital contents. Inferiorly in the midline, the perpendicular plate descends to contribute to the nasal septum, aligning anteriorly with the region of the nasal bones and posteriorly toward the sphenoid body. Orientation matters here because a superior view best clarifies the relationship between the cribriform plate and the anterior cranial fossa, the exact interface implicated in cerebrospinal fluid rhinorrhea after anterior skull base trauma or endoscopic sinus surgery. Olfactory fila traverse the cribriform foramina from the olfactory mucosa to the olfactory bulb, so even small fractures can produce anosmia. Clean landmarks. The crista galli also anchors the falx cerebri, a point surgeons keep in mind during anterior cranial fossa and planum sphenoidale approaches. Use this illustration for gross anatomy teaching of the skull base and nasal cavity (especially when pairing with coronal CT anatomy), for otolaryngology and neurosurgery course material on endoscopic endonasal corridors, and for publisher figures explaining cribriform plate fractures and CSF leak pathways. Anatomical accuracy verified by SciePro's Medical Advisory Board.