Quick Facts
The cribriform plate is the horizontal plate of the ethmoid bone that forms the roof of the nasal cavity; it is perforated by many foramina for the passage of the olfactory nerves. On its superior surface is a projection called the crista galli (Dorland, 2011).
Structure and/or Key Features
The cribriform plate is the horizontal, sieve-like plate of bone found along the superior aspect of the ethmoid bone. It is situated between the anterior cranial fossa and the nasal cavity and occupies the ethmoidal notch of the frontal bone, forming a significant portion of the roof of the nasal cavity.
The cribriform plate is one of the three parts of the ethmoid bone that provides support to the olfactory bulb in the olfactory fossa. The ethmoid bone is made up of three components, the horizontal cribriform plate, the vertical perpendicular plate, and the two ethmoid labyrinths.
The cribriform plate possesses a number of perforations or foramina, through which the branches of the olfactory nerve (cranial nerve I) and their corresponding meninges (dura and arachnoid mater) pass through.
The perpendicular plate is a thin, quadrilateral, midline bony projection that descends from the undersurface of the cribriform plate and constitutes a majority of the superior aspect of the nasal septum. The perpendicular plate continues superiorly as the crista galli. The pair of ethmoid labyrinths, which harbor the ethmoidal air cells, is situated on either side of the perpendicular plate.
The crista galli is a thick, triangular part of the ethmoid bone, essentially a median ridge situated posterior to the foramen cecum, which projects superiorly from the cribriform plate. It aids the attachment of the falx cerebri to the ethmoid bone via its posterior edge. The cribriform plate is narrowed and indented on either side of the crista galli and is situated inferior to the gyrus rectus and the olfactory bulb. A small aperture, which is occupied by dura mater, is located on either side of the crista galli anteriorly. Anterolateral to this aperture is a foramen through which the anterior ethmoidal nerve and blood vessels pass on their way to the nasal cavity.
Anatomical Relations
The cribriform plate is one of the three parts of the ethmoid bone. The ethmoid bone is among one of the eight bones that make up the cranium, along with the frontal, sphenoidal, occipital, and symmetric pairs of the temporal and parietal bones. It forms a part of the viscerocranium and is situated in the midfacial aspect of the cranium, centered among the sinonasal structures.
Function
The main function of the cribriform plate is to provide support for the olfactory bulb, which sits superior to it. The cribriform plate possesses a number of perforations or foramina, through which the branches of the olfactory nerve, which is concerned with the sense of smell, and their corresponding meninges pass through.
Clinical Correlates
—Head trauma (blunt force trauma to the head)
—Neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease
—Congenital anosmia
—Chronic sinus infection or inflammation
References
Dorland, W. (2011) Dorland's Illustrated Medical Dictionary. 32nd edn. Philadelphia, USA: Elsevier Saunders.
