A practical treatise on the diseases of the ear including the anatomy of the organ . aqueducts open by one ex*tremity into the labyrinth, and by the other on the surface ofthe petrous portion of the temporal bone. One opens into 470 COCHLEA. the vestibule, and has already been alluded to, and is calledthe aqueductus vestibuli; the other enters into the tympanicscala of the cochlea, and is called the aqueductus length of the aqueduct of the vestibule is about one-thirdof an inch ; that of the aqueduct of the cochlea is about one-quarter of an inch. The aqueduct of the vestibule beg
A practical treatise on the diseases of the ear including the anatomy of the organ . aqueducts open by one ex*tremity into the labyrinth, and by the other on the surface ofthe petrous portion of the temporal bone. One opens into 470 COCHLEA. the vestibule, and has already been alluded to, and is calledthe aqueductus vestibuli; the other enters into the tympanicscala of the cochlea, and is called the aqueductus length of the aqueduct of the vestibule is about one-thirdof an inch ; that of the aqueduct of the cochlea is about one-quarter of an inch. The aqueduct of the vestibule begins bya groove immediately below and in front of the opening com-mon to the two vertical semicircular canals. From this the aque-duct turns itself around the inner wall of the common canal,and runs downwards and backwards. It gradually widensand opens under a thin osseous projection, seen a little be-hind the middle of the posterior and inner surface of the pe-trous bone, just above the jugular fossa. From the fossa thereis a narrow groove running to the opening of the Apex of the Left Osseous Cochlea opened to shore the End of the Lamina Spiralis. AfterEenle. The aqueduct of the cochlea begins by a very small open-ing in the lower wall of the scala tympani, immediately abovethe fenestra rotunda. It passes downwards, inwards, andforwards in the inner wall of the jugular fossa, and opens atthe bottom of a triangular depression, situated towards themiddle of the edge which limits the inner and inferior surfacesof the petrous bone, and below the internal auditory canal. THE MEMBRANOUS LABYRINTH. TJie Auditory Nerve (Nervus acusticus).—The auditorynerve, or portio mollis (soft part of the 7th nerve), is the COCHLEA. 471 nerve of the sense of hearing, and is distributed exclusivelyto the internal ear. The auditory nerve arises from numer-ous white lines, or striae (linse transversa), which come fromthe posterior median fissure in the anterior wall, or floorof the fourth
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Keywords: ., bookcentury1800, bookdeca, booksubjectear, booksubjecteardiseases
