Question

The ridge-like bone or bones that separate(s) the posterior from the middle cranial fossa is

(are) the
A) occipital bone.
B) sphenoid bone.
C) frontal bone.
D) temporal bones.

Answer 1

The petrous portion of the temporal bone is the ridge-like structure that separates the posterior from the middle cranial fossa.

Step-by-step explanation:

The ridge-like bone that separates the posterior from the middle cranial fossa is the petrous portion of the temporal bone. This large, triangular structure forms a significant part of the floor of the cranial cavity and serves not only as a physical divide but also houses important structures like the middle and inner ear.

The petrous ridge is crucial in demarcating the boundary between the posterior cranial fossa, which contains the cerebellum, and the middle cranial fossa, which houses the temporal lobes of the brain.