196. Basis cranii - anterior, middle and posterior cerebral fossae

Borders

• Anterior cranial fossa: Formed mainly by the frontal bone, cribriform plate of ethmoid, and lesser wings of sphenoid.

• Middle cranial fossa: Formed by the body and greater wings of the sphenoid and parts of temporal bones.

• Posterior cranial fossa: Formed by the occipital bone and parts of temporal and sphenoid bones.

Contents

• Anterior fossa: frontal lobes of brain, olfactory bulbs and tracts.

• Middle fossa: temporal lobes, pituitary gland (in sella turcica), cavernous sinus.

• Posterior fossa: cerebellum, brainstem (pons, medulla), cranial nerves IX–XII.

Relations

• The fossae are separated by bony ridges: anterior clinoid processes, sphenoid ridges, petrous ridges, and grooves for dural venous sinuses.