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21-499: [REDACTED] Look up cupula in Wiktionary, the free dictionary. A cupula is a small, inverted cup or dome-shaped cap over a structure, including: Ampullary cupula , a structure in the vestibular system, providing the sense of spatial orientation Cochlear cupula , a structure in the cochlea Cupula of the pleura , related to the lungs The cervical parietal pleura in

42-404: A result, the cupula is deflected opposite the direction of head movement. As the endolymph pushes the cupula, the stereocilia is bent as well, stimulating the hair cells within the crista ampullaris. After a short time of continual rotation however, the endolymph's acceleration normalizes with the rate of rotation of the semicircular ducts. As a result, the cupula returns to its resting position and

63-458: Is commonly referred to as "the spins" . [REDACTED] This article incorporates text in the public domain from page 1051 of the 20th edition of Gray's Anatomy (1918) Vestibulocochlear nerve The vestibulocochlear nerve or auditory vestibular nerve , also known as the eighth cranial nerve , cranial nerve VIII , or simply CN VIII , is a cranial nerve that transmits sound and equilibrium (balance) information from

84-410: Is equal in both ears. If bone conduction (BC) is more than air conduction (AC) (BC>AC) indicates Rinne Test is negative or abnormal. If AC>BC Rinne test is normal or positive. If BC>AC and Weber's test lateralizes to abnormal side then it is Conductive hearing loss. If AC>BC and Weber's test lateralizes to normal side then it concludes Sensorineural hearing loss. After pure-tone testing, if

105-457: Is located within the ampullae of each of the three semicircular canals . Part of the crista ampullaris , the cupula has embedded within it hair cells that have several stereocilia associated with each kinocilium. The cupula itself is the gelatinous component of the crista ampullaris that extends from the crista to the roof of the ampullae. When the head rotates, the endolymph filling the semicircular ducts initially lags behind due to inertia. As

126-451: Is neutrally buoyant. The Buoyancy Hypothesis assumes that alcohol, with a different specific gravity from that of the cupula/endolymph, diffuses at different rates into the cupula and the surrounding endolymph. The result is a temporary density gradient between the cupula and endolymph, and a consequent (erroneous) sensitivity to linear accelerations such as that of gravity by a system normally signalling rotational accelerations. This sensation

147-399: The anterior inferior cerebellar artery at the cerebellopontine angle, and then goes with the 7th nerve through the internal acoustic meatus to the internal ear. The cochlear nerve travels away from the cochlea of the inner ear where it starts as the spiral ganglia . Processes from the organ of Corti conduct afferent transmission to the spiral ganglia. It is the inner hair cells of

168-452: The brainstem called the pons (which then is largely composed of fibers going to the cerebellum ). The 8th cranial nerve runs between the base of the pons and medulla oblongata (the lower portion of the brainstem). This junction between the pons, medulla, and cerebellum that contains the 8th nerve is called the cerebellopontine angle . The vestibulocochlear nerve is accompanied by the labyrinthine artery , which usually branches off from

189-417: The inner ear to the brain . Through olivocochlear fibers , it also transmits motor and modulatory information from the superior olivary complex in the brainstem to the cochlea . The vestibulocochlear nerve consists mostly of bipolar neurons and splits into two large divisions: the cochlear nerve and the vestibular nerve . Cranial nerve 8, the vestibulocochlear nerve, goes to the middle portion of

210-477: The AC and BC responses at all frequencies 500–8000 Hz are better than 25 dB HL, meaning 0-24 dB HL, the results are considered normal hearing sensitivity. If the AC and BC are worse than 25 dB HL at any one or more frequency between 500 and 8000 Hz, meaning 25+, and there is a no bigger difference between AC and BC beyond 10 dB at any frequency, there is a sensori-neural hearing loss present. If

231-461: The BC responses are normal, 0-24 dB HL, and the AC are worse than 25 dB HL, as well as a 10 dB gap between the air and bone responses, a conductive hearing loss is present. {updated March 2019} The modified Hughson–Westlake method is used by many audiologists during testing. A battery of (1) otoscopy, to view the ear canal and tympanic membrane, (2) tympanometry, to assess the immittance of

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252-421: The endolymph moves them toward or away from their adjacent kinocilia , respectively. When the endolymph moves in the opposite direction, the direction of stimulation is reversed accordingly, from depolarization to hyperpolarization or vice versa. The corresponding signal is transmitted to the brain by the vestibulocochlear nerve (CN VIII). In their natural orientation within the head, the cupulae are located on

273-443: The hair cells cease to be stimulated. This continues until the head stops rotating which simultaneously halts semicircular duct rotation. Due to inertia, however, the endolymph continues on. As the endolymph continues to move, the cupula is once again deflected resulting in the compensatory movements of the body when spun. With each rotation, the hair cells undergo either depolarization or hyperpolarization , depending on whether

294-441: The inner ear. The vestibular ganglion houses the cell bodies of the bipolar neurons and extends processes to five sensory organs. Three of these are the cristae located in the ampullae of the semicircular canals . Hair cells of the cristae activate afferent receptors in response to rotational acceleration. The other two sensory organs supplied by the vestibular neurons are the maculae of the saccule and utricle . Hair cells of

315-456: The maculae in the utricle activate afferent receptors in response to linear acceleration, while hair cells of the maculae in the saccule respond to vertically directed linear force. The vestibulocochlear nerve is derived from the embryonic otic placode . This is the nerve along which the sensory cells (the hair cells) of the inner ear transmit information to the brain . It consists of the cochlear nerve, carrying details about hearing , and

336-400: The medial aspect of the semicircular canals. In this orientation, the kinocilia rest on the posterior aspect of the cupula. The Buoyancy Hypothesis posits that alcohol causes vertigo by affecting the neutral buoyancy of the cupula within the surrounding fluid called the endolymph . Linear accelerations (such as that of gravity) should not in theory effect a movement of the cupula when it

357-408: The organ of Corti that are responsible for activation of afferent receptors in response to pressure waves reaching the basilar membrane through the transduction of sound. The exact mechanism by which sound is transmitted by the neurons of the cochlear nerve is uncertain; the two competing theories are place theory and temporal theory . The vestibular nerve travels from the vestibular system of

378-461: The thorax A layer in the otolith organs The cupula optica , or optic cup , in embryological development of the eye Cup-like structure fitted over the eye during electrophysiology study Suprapleural membrane See also [ edit ] Cupola (disambiguation) Copula (disambiguation) Cupule (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

399-457: The title Cupula . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Cupula&oldid=999289149 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Ampullary cupula The cupula

420-420: The tympanic membrane and how well it moves, (3) otoacoustic emissions, to measure the response of the outer hair cells located in the cochlea, (4) audiobooth pure-tone testing, to obtain thresholds to determine the type, severity, and pathology of the hearing loss present, and (5) speech tests, to measure the patients recognition and ability to repeat the speech heard, is all taken into consideration when diagnosing

441-542: The vestibular nerve, carrying information about balance . It emerges from the pontomedullary junction and exits the inner skull via the internal acoustic meatus in the temporal bone . The vestibulocochlear nerve carries axons of type special somatic afferent . Damage to the vestibulocochlear nerve may cause the following symptoms: Examinations that can be done include the Rinne and Weber tests . Rinne's test involves Rinne's Right and Left Test, since auditory acuity

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