Which of the following cavities are separated from the middle cranial fossa by a thin layer of bone?
The middle ear cavity is separated from the middle cranial fossa by the tegmen tympani, a thin plate of the petrous pa of the temporal bone. A pa of the roof of the sphenoid bone forms the floor of the hypophyseal fossa. The other pairs of sinuses or bony cavities are not separated from the middle cranial cavity.
Auditory tube and bony orbit
Middle ear cavity and sphenoid sinus
Sigmoid sinus and frontal sinus
Sphenoid sinus and ethmoid sinus
Cranial cavity