This cavity just beyond the drum, which forms the greater part of its outer wall, is an irregular cavity, compressed from without inward and situated in the petrous bone.
In some of these it has come on without assignable cause, in others it has been the consequence of pyæmia, of tubercles, or of the extension of inflammation from the petrous portion of the temporal bone.
Occasionally, however, the affection of the middle ear gives rise to perforation of the tympanum or to caries of the petrous portion of the temporal bone.
Her intentionally looking aplomb into the rosary saleswoman's petrous countenance as she paid the money to her was a feigned attempt to project composure and went unnoticed.
Defn: Of or pertaining to the petrous and mastoid parts of the temporal bone, periotic.
Like stone; hard; stony; rocky; as, the petrous part of the temporal bone.
It forms the highest point of the labyrinth, becoming fused with the innermost portion of the tegmen tympani, and is in such close relationship with the upper surface of the petrous bone as to cause a smooth elevation on its surface.
Sometimes, however, the necrosis is very extensive, involving a large area of the petrous bone, including the labyrinth.
It is at this point in the operation of removal of the semicircular canal that the greatest risk is encountered of breaking through the petrous bone and of injuring the dura mater.
If it be certain that internal-ear suppuration exists, or if the operation be secondary to opening of the labyrinth, the posterior wall of the petrous bone may be removed until the internal auditory meatus is almost reached.
By this means the posterior surface of the petrous bone can be exposed as far inwards as the internal auditory meatus.
If it be not discovered at the first attempt, the instrument should be directed forwards, upwards, and inwards towards the posterior surface of the petrous bone.
The =petrous portion= lies dorsally and anteriorly, and is much the more important of the two, as it encloses the essential part of the auditory organ.
This small muscle arises from the apex of the petrous temporal and the cartilage of the Eustachian tube, enters the tympanum at its anterior wall, and is inserted into the malleus near its root.
The osseous labyrinth may be regarded as an osseous mould in the petrous portion of the temporal bone, lined by tesselated endothelium, and containing a small quantity of fluid called the perilymph.
The petrous or hard portion of the temporal bone, in which the parts of the middle and internal ear are situated.
It is bounded externally by the membrana tympani; internally by its inner wall; and in its circumference by the petrous portion of the temporal bone and mastoid cells.
The bony labyrinth presents a series of cavities which are channelled through the substance of the petrous bone.
The internal ear or labyrinth lies in the petrous part of the temporal bone, its outer boundary being the inner wall of the middle ear.
With bone forceps or a fine saw, split open the petrous portion of the temporal bone and observe the cochlea and the semicircular canals.
The Internal Ear*, or labyrinth, occupies a series of irregular channels in the petrous process of the temporal bone.
The inner projection of the temporal bone is known as the petrous process.
In its course each lateral sinus receives two petrosal sinuses, which pass from the cavernous sinus backwards along the upper and lower borders of the petrous part of the temporal bone.
If the petrous portion of the temporal bone be the part struck by the ball and struck squarely at the base, that portion of the bone is crumbled or broken in such exceedingly fine pieces as to defy restoration.
That if the ball struck any part of the skull the petrous portion will be broken, but can be usually recognized and generally put together again.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "petrous" in a variety of sentences. We hope that you will now be able to make sentences using this word.
