Anatomy of the Anterior Cranial Fossa

Anterior Cranial Fossa

• Located superiorly over the nasal and orbital cavities
• Lodges the frontal lobes of the cerebral hemispheres
• Formed by the orbital plates of the frontal bone, cribriform plate of the ethmoid bone, lesser wing of the sphenoid bone, and the anterior part of the body of the sphenoid
• Bounded anteriorly by the inner surface of the frontal bone, marked by the frontal crest in the midline
• Posterior boundary formed by the sharp lesser wing of the sphenoid
• Median part of the anterior cranial fossa limited posteriorly by the groove for the optic chiasma
• Floor of the fossa formed laterally by the orbital plates of the frontal bone and medially by the cribriform plate of the ethmoid
• Crista galli is a sharp upward projection of the ethmoid bone, acting as a point of attachment of the falx cerebri
• Small perforations in the cribriform plate are for the olfactory nerves

Middle Cranial Fossa

• Bounded anteriorly by the lesser wings of the sphenoid bone
• Bounded posteriorly and laterally by the superior border of the petrous part of the temporal bone
• Bounded posteriorly and medially by the dorsum sellae of the sphenoid bone
• Floor formed by the body and greater wing of the sphenoid, and the squamous and petrous parts of the temporal bone