The middle cranial fossa (fossa cranii media) is the butterfly-shaped central depression of the internal cranial base, positioned posterior-inferior to the anterior cranial fossa and anterior-superior to the posterior cranial fossa. Bound anteriorly by the lesser wings and chiasmatic sulcus of the sphenoid bone, laterally by the temporal squama and greater sphenoid wings, and posteriorly by the petrous ridges of the temporal bones and dorsum sellae, its primary physiological functions include cradling the temporal lobes, housing the pituitary gland in the sella turcica, supporting the cavernous sinus complexes, and transmitting cranial nerves II through VI alongside the internal carotid arteries. Bordering regions include the Anterior Cranial Fossa, Posterior Cranial Fossa, Infratemporal Fossa, Orbit, and Neurocranium.
Anatomical Terminology · Internal Cranial Base
Term Spotlight: Middle Cranial Fossa
A vital central compartment of the skull base. Explore the butterfly-shaped architecture, neurovascular passageways, sella turcica, temporal lobe support, and surrounding anatomical borders of the middle cranial fossa.
Located on the interior aspect of the skull floor, the middle cranial fossa (fossa cranii media) is a deep, complex, butterfly-shaped basin situated between the higher anterior cranial fossa and the lower posterior cranial fossa. Anatomically, it consists of a narrow median portion—dominated by the hypophyseal fossa—and expansive, concave lateral portions that accommodate the prominent temporal lobes of the cerebral hemispheres.
Two primary cranial bones form the osseous framework of the middle cranial fossa floor and walls:
Sphenoid Bone: Forms the central bridge and anterior-medial walls. The central body features the sella turcica ("Turkish saddle"), which includes the tuberculum sellae anteriorly, the deep hypophyseal fossa (cradling the pituitary gland), and the upright dorsum sellae posteriorly (flanked by the posterior clinoid processes). Radiating laterally from the sphenoid body are the expansive greater wings, forming the anterior-lateral floor of the fossa.
Temporal Bones: Complete the posterior and lateral expanses of the fossa. The vertical squamous part forms the lower lateral cranial wall, while the robust, pyramidal petrous part forms the prominent posterior boundary separating the middle fossa from the posterior cranial fossa. The anterior surface of the petrous apex exhibits the trigeminal impression (lodging the trigeminal ganglion) and the arcuate eminence.
Topographically, the middle cranial fossa floor is perforated by a series of critical neurovascular apertures arranged along the crescentic line of the sphenoid bone.
2. Anatomical Position & Spatial Boundaries
The middle cranial fossa occupies the central floor of the neurocranium, situated lower than the anterior fossa and higher than the posterior fossa. Its spatial boundaries are clearly demarcated:
Anterior Boundary
Marked by the sharp posterior borders of the lesser wings of the sphenoid bone, the anterior clinoid processes, and the chiasmatic sulcus.
Posterior Boundary
Delineated by the superior borders of the petrous parts of the temporal bones and the dorsum sellae of the sphenoid.
Lateral Boundaries
Formed by the squamous parts of the temporal bones, the sphenoidal angles of the parietal bones, and the greater wings of the sphenoid.
Inferior Boundary (Floor)
Rests over the infratemporal fossa, pterygopalatine fossa, middle ear cavity, and sphenoid sinus.
3. Primary Functions & Key Foramina
The middle cranial fossa acts as a major hub for neural transmission, endocrine housing, and vascular routing. Its essential apertures and contents include:
Endocrine Support: The hypophyseal fossa securely cradles the master pituitary gland, capped by the dural diaphragma sellae.
Temporal Lobe Housing: The deep lateral concavities support the basal surfaces of the cerebral temporal lobes.
Superior Orbital Fissure: Transmits Cranial Nerves III (oculomotor), IV (trochlear), V1 (ophthalmic division of trigeminal), and VI (abducens), along with ophthalmic veins into the orbit.
Foramen Rotundum: Routes Cranial Nerve V2 (maxillary nerve) forward into the pterygopalatine fossa.
Foramen Ovale: Transmits Cranial Nerve V3 (mandibular nerve) and the accessory meningeal artery down into the infratemporal fossa.
Foramen Spinosum: Transmits the middle meningeal artery and vein into the cranial vault to supply the dura mater.
Carotid Canal & Foramen Lacerum: Routes the internal carotid artery through the petrous apex, emerging adjacent to the cavernous sinus.
Anatomical Boundaries
5 Bordering Areas Surrounding the Middle Cranial Fossa
Understanding the middle cranial fossa requires examining the five contiguous anatomical spaces sharing its borders:
Located directly posterior and inferior, separated by the petrous temporal ridge and dorsum sellae, containing the cerebellum and brainstem.
3. Orbital Cavities
Positioned anteriorly, communicating directly with the middle fossa via the optic canal and superior orbital fissure.
4. Infratemporal Fossa
Located directly beneath the greater wing of the sphenoid bone, communicating via the foramen ovale and foramen spinosum.
5. Middle Ear & Tympanic Cavity
Embedded directly within the petrous temporal floor, separated from the fossa by a thin roof of bone called the tegmen tympani.
Clinical & Surgical Relevance
Clinical Significance & Surgical Considerations
In neurosurgery and neurology, the middle cranial fossa is of critical importance. Fractures across the pterion (where the frontal, parietal, temporal, and sphenoid bones meet) risk lacerating the underlying middle meningeal artery, leading to rapid arterial bleeding and life-threatening epidural hematoma. Pituitary adenomas expanding within the sella turcica compress the optic chiasm directly superior to it, causing classic bitemporal hemianopsia (tunnel vision). Furthermore, infections of the middle ear can erode through the thin tegmen tympani floor, giving rise to temporal lobe abscesses or meningitis.
Frequently Asked Questions
Middle Cranial Fossa FAQ
What structure lodges the pituitary gland in the middle cranial fossa?
The hypophyseal fossa, a deep central depression in the sella turcica of the sphenoid bone, houses the pituitary gland.
What passes through the foramen spinosum?
The middle meningeal artery and vein pass through the foramen spinosum to enter the middle cranial fossa and supply the dura mater.
