| orifice of external acoustic meatus | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
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| orifice of internal acoustic meatus | The inner opening of the internal acoustic meatus on the posterior surface of the petrous part of the temporal bone. Synonym: porus acusticus internus, internal acoustic foramen, internal acoustic pore, auditory pore, internal auditory foramen, orifice of internal acoustic meatus. (05 Mar 2000) |
| transverse crest of internal acoustic meatus | A horizontal ridge that divides the fundus of the internal acoustic meatus into a superior and an inferior area. In the former are the introitus of the facial canal and openings for the branches of the vestibular nerve to the utricle and to the ampullae of the anterior and lateral saemicircular canals. In the latter are openings for the cochlear nerve, and for branches of the vestibular nerve to the saccule and to the ampulla of the posterior saemicircular canal. Synonym: crista transversa, falciform crest, transverse crest. (05 Mar 2000) |
| external acoustic foramen | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| external acoustic meatus | The passage leading inward through the tympanic portion of the temporal bone, from the auricle to the tympanic membrane; it consists of a bony (inner) portion and a fibrocartilaginous (outer) portion, the cartilaginous external acoustic meatus. Synonym: meatus acusticus externus, acoustic meatus, antrum auris, auditory canal, external auditory meatus. (05 Mar 2000) |
| external acoustic pore | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| fundus of internal acoustic meatus | The thin cribriform plate of bone separating the cochlea and vestibule from the internal acoustic meatus; a transverse crest divides it into two regions; in the superior region are located the area nervi facialis and the area vestibularis superior; in the inferior region are located the area cochleae, area vestibularis inferior, and foramen singulare. Synonym: fundus meatus acustici interni, fundus of internal auditory meatus. (05 Mar 2000) |