Final answer:
The cranial fossae are three spaces within the cranial cavity that house different brain regions. The anterior cranial fossa contains the frontal lobes, the middle cranial fossa houses the temporal lobes and pituitary gland, and the posterior cranial fossa encloses the cerebellum.
Step-by-step explanation:
The fossa of the cranial cavity are spaces on the floor of the skull that house different parts of the brain. The cranial fossae consist of the shallow anterior cranial fossa, the middle cranial fossa, and the deep posterior cranial fossa. From anterior to posterior, these fossae increase in depth corresponding to the shape and size of the brain regions they contain.
The anterior cranial fossa is the most anterior and shallow, and it houses the frontal lobes of the brain. It is bordered by the frontal bone and contains a small area of the ethmoid bone, including the crista galli and cribriform plates. The middle cranial fossa, ranging from the lesser wing of the sphenoid bone to the petrous ridge, contains the temporal lobes and the pituitary gland nestled in the sella turcica. The posterior cranial fossa is the deepest, housing the cerebellum, and is bordered by the petrous ridges and the occipital bone. This section of the skull also contains the large foramen magnum, which provides passage for the spinal cord.