Ethmoid Bone Labeling Practice (Axial Skeleton)

Ethmoid Bone Anatomy

• Crista Galli: A vertical, triangular projection located in the midline of the cribriform plate; serves as an attachment point for the falx cerebri, a dural membrane in the brain.

• Cribriform Plate: A perforated horizontal structure that forms the roof of the nasal cavity; contains olfactory foramina through which olfactory nerves pass to reach the nasal epithelium.

• Left Ethmoidal Labyrinth: A complex, maze-like structure containing the ethmoidal air cells; contributes to the formation of the lateral walls of the nasal cavity.

• Middle Nasal Concha: A curved bony structure that extends from the lateral wall of the nasal cavity; it helps to increase surface area for airflow and is involved in conditioning inhaled air.

• Perpendicular Plate: A thin bony structure that descends from the cribriform plate and forms part of the nasal septum, thereby separating the left and right nasal cavities.

• Ethmoidal Air Cells: Small air-filled spaces located within the ethmoidal labyrinth; these cells are involved in the drainage of mucus and connected to the nasal cavity, playing a role in sinus function.

• Orbital Plate: A horizontal, thin bony layer that forms part of the eye socket; it separates the orbits from the nasal cavity and is critical for protecting the eyes.