| cochlear ganglion | An elongated ganglion of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of the modiolus; each ganglion cell gives rise to a peripheral process that passes between the layers of the bony spiral lamina to the organ of Corti, and a central axon that enters the hindbrain as a component of the inferior (cochlear) root of the eighth nerve. Synonym: ganglion spirale cochleae, auditory ganglion, cochlear ganglion, Corti's ganglion, spiral cochlear ganglion. (05 Mar 2000) |
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| cochlear hair cell | <anatomy> The sound sensing cell of the inner ear. The cells have modified ciliary structures (hairs), that enable them to produce an electrical (neural) response to mechanical motion caused by the effect of sound waves on the cochlea. Frequency is detected by the position of the cell in the cochlea and amplitude by the magnitude of the disturbance. (18 Nov 1997) |
| cochlear hair cells | Sensory cell's in the organ of Corti in synaptic contact with sensory as well as efferent fibres of the cochlear (auditory) nerve; from the apical end of each cell about 100 stereocilia extend from the surface and make contact with the tectorial membrane. Synonym: Corti's cells. (05 Mar 2000) |
| cochlear implant | An electronic device implanted under the skin with electrodes in the middle ear on the promontory or cochlear window or in the inner ear in the cochlea to create sound sensation in total sensory deafness. A microphone behind the ear feeds sound waves into a microprocessor carried on the body, which analyzes the data and sends information back to a radio transmitter that triggers the electrodes in the middle or inner ear to produce the appropriate electrical pulses. This does not enable the patient actually to hear, but rather to distinguish different sounds according to the neural sensation they produce. The first successful cochlear implant was performed in 1978 in Melbourne, Australia. Such devices are among many implanted aids which have been made possible by the advent of microchip technology. Synonym: cochlear prosthesis. (05 Mar 2000) |
| cochlear implantation | Surgical insertion of an electronic device implanted beneath the skin with electrodes to the cochlear nerve to create sound sensation in persons with sensorineural deafness. (12 Dec 1998) |
| cochlear implants | Electronic devices implanted beneath the skin with electrodes to the cochlear nerve to create sound sensation in persons with sensorineural deafness. (12 Dec 1998) |
| cochlear joint | A variety of hinge joint in which the elevation and depression, respectively, on the opposing articular surfaces form part of a spiral, flexion being then accompanied by a certain amount of lateral deviation. Synonym: screw joint, spiral joint. (05 Mar 2000) |
| cochlear labyrinth | The content of the cochlea including the portion of the membranous labyrinth containing the spiral organ (cochlear duct) and the perilymphatic channels (scalae) which lie on either side. Synonym: labyrinthus cochlearis, organ of hearing. (05 Mar 2000) |
| cochlear microphonic potentials | The electric response of the cochlear hair cells to acoustic stimulation. (12 Dec 1998) |
| cochlear nerve | <anatomy, nerve> The cochlear part of the acoustic (8th cranial) nerve. The cochlear nerve fibres originate from neurons of the spiral ganglion and project peripherally to cochlear hair cells and centrally to the cochlear nuclei of the brainstem. They mediate the sense of hearing. (12 Dec 1998) |
| cochlear nuclei | The nucleus cochlearis dorsalis and nucleus cochlearis ventralis, located on the dorsal and lateral surface of the inferior cerebellar peduncle, in the floor of the lateral recess of the rhomboid fossa. They receive the incoming fibres of the cochlear part of the vestibulocochlear nerve and are the major source of origin of the lateral lemniscus or central auditory pathway. Synonym: cochlear nuclei, nuclei nervi cochlearis. (05 Mar 2000) |
| cochlear nucleus | The brainstem nucleus that receives the central input from the cochlear nerve. The cochlear nucleus is located lateral and dorsolateral to the inferior cerebellar peduncles and is functionally divided into dorsal and ventral parts. It is tonotopically organised, performs the first stage of central auditory processing, and projects (directly or indirectly) to higher auditory areas including the superior olivary nuclei, the medial geniculi, the inferior colliculi, and the auditory cortex. (12 Dec 1998) |
| cochlear part of vestibulocochlear nerve | <anatomy, nerve> The cochlear part of the acoustic (8th cranial) nerve. The cochlear nerve fibres originate from neurons of the spiral ganglion and project peripherally to cochlear hair cells and centrally to the cochlear nuclei of the brainstem. They mediate the sense of hearing. (12 Dec 1998) |
| cochlear prosthesis | An electronic device implanted under the skin with electrodes in the middle ear on the promontory or cochlear window or in the inner ear in the cochlea to create sound sensation in total sensory deafness. A microphone behind the ear feeds sound waves into a microprocessor carried on the body, which analyzes the data and sends information back to a radio transmitter that triggers the electrodes in the middle or inner ear to produce the appropriate electrical pulses. This does not enable the patient actually to hear, but rather to distinguish different sounds according to the neural sensation they produce. The first successful cochlear implant was performed in 1978 in Melbourne, Australia. Such devices are among many implanted aids which have been made possible by the advent of microchip technology. Synonym: cochlear prosthesis. (05 Mar 2000) |
| cochlear recess | A small depression on the inner wall of the vestibule of the labyrinth at the portion of the pyramid of vestibule, between the two limbs into which the vestibular crest divides posteriorly; it is perforated by foramina giving passage to fibres which the cochlear branch of the vestibulocochlear nerve sends to the posterior extremity of the cochlear duct. Synonym: recessus cochlearis, Reichert's cochlear recess. (05 Mar 2000) |