middle cranial fossa(redirected from fossa cranii media [NA])
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mid·dle cra·ni·al fos·sa[TA]
a butterfly-shaped portion of the internal base of the skull posterior to the sphenoidal ridges and limbus and anterior to the crests of the petrous part of the temporal bones and dorsum sellae; it lodges the temporal lobes of the brain in the lateral portions, and the hypophysis centrally.
Synonym(s): fossa cranii media [TA]
middle cranial fossaAn irregular depression in the middle of the inner surface of the base of the skull. which houses the temporal lobe of the brain laterally and the hypophysis at its centre. It consists of a central and two lateral portions. The middle cranial fossa is bounded anteriorly by the posterior margin of the lesser wings of the sphenoid bones and the anterior margin of the sulcus chiasmatis, and posteriorly by the superior margins of the petrous parts of the temporal bones and dorsum sellae of the sphenoid bone; laterally, the middle cranial fossa merges with the lateral wall of the skull on either side. The floor of the middle cranial fossa is comprised of the body and greater wings of the sphenoid bone and the anterior surfaces of the petrous parts of the temporal bones.
middle cranial fossa
The middle one-third of the floor of the cranial cavity; it is deeper and wider than the anterior cranial fossa. The middle cranial fossa is formed from the posterior two thirds of the sphenoid bones (the greater wings, the dorsum sella, and the clinoid processes) and the petrous and squamous portions of the temporal bones. The middle cranial fossa contains the superior orbital fissures, optic canals, foramina rotundum, foramina ovale, foramina spinosum, and foramina lacerum. The temporal lobes of the cerebral hemispheres, the optic chiasm, the hypophysis (pituitary), internal carotid arteries, circle of Willis, and cavernous sinuses lie in the middle cranial fossa.
See also: fossa