General Medical Information

Cranial Fossae

Susan D. John
Michael D. Maves

The intracranial cavity is roughly divided into three fossae. The anterior or frontal cranial fossa contains the paired frontal lobes and provides access to the nasal cavity for the olfactory nerves through the cribriform plate. The crista galli provides superior midline extension of the nasal septum. The middle cranial fossa contains the temporal lobes. In this important junction of the cranial cavity, the middle meningeal artery arises from the foramen spinosum, and the trigeminal nerve enters through the superior orbital fissure (V1), the foramen rotundum (V2), and the foramen ovale (V3). Cranial nerves II, III, IV, and VI, which traverse the cavernous sinus and enter the orbit, also course through the middle cranial fossa. The internal carotid artery is in its place in the carotid siphon as it traverses the cavernous sinus in this region. The posterior cranial fossa contains the paired cerebellar hemispheres and the brainstem. In this location, the internal auditory meatus is associated with the seventh and eighth cranial nerve complex. The jugular foramen, transverse sinus, and foramen magnum are the major landmarks of the posterior cranial fossa.