hearing and balance Flashcards
what connects the vestibular system to the cortex and what is its function
meidal lemniscus through thalamus
conscious awareness of position and movements of head
what are the rows of hair cells in the organ of corti
includes three rows of outer hair cells and one row of inner hair cells.
what is the function of the superior olivary nucleus
This nucleus is the site of origin of olivary cochlear fibres which leave the brain stem in the vestibulocochlear nerve and end in the organ of corti.
where are the vestibular nuclei
pons and medulla
where do utricle nerve fibres terminate
lateral vestibular nucleus
describe the path of the ventral cranial nerve of the cochlear nerve
superior olivary nucleus to lateral lemniscus which runs through the pontine tegmentum to end in the inferior colliculus of the midbrain.
The inferior colliculus in turn sends axons to the medial geniculate nucleus of the thalamus.
Axons that originate in the medial geniculate nucleus and pass through the internal capsule to the primary auditory cortex of the temporal lobe
(SLIM -Superior olivary nucleus, Lateral lemniscus, inferior colliculus, Medial geniculate nucleus)
where do saccule nerve fibres terminate
lateral and inferior vestibular nucleus
where do vestibular nerve fibres bifurcate
in the vestibular nuclear cortex
where do cochlear nuclei second order neurons ascend
into the pons, some of them crossing to the other side of the pontine tegmentum as the trapezoid body.
what creates vestibular nerve action potenials
endolymph passing the crista ampularis which contains hair cells
what is the nerve supply of the hair cells in the inner ear
the peripheral process of bipolar spiral ganglion cells
what is the function of the crista
organ that senses movements of endolymph in the ampulla
senses rotaion and rotational acceleration
what are the spiral ganglion
the cell bodies of the cochlear nerve fibres which lie within the cochlea
what is the receptor for sound in the organ of corti
is the neuroepithelial cell
what is the function of the utriculosaccule duct
gives rise to the endolymphatic duct
where do semicircular canal nerve fibres terminate
superior vestibular nucleus and medial vestibular nucleus
what connects the vestibular system to the spinal cord and what is its function
vestibulospinal tract
to control posture in balance
describe the path of the cochlear nerve
- The cochlear nerve fibres make dendritic contact with hair cells of the organ of corti within the cochlear duct
- Its fibres bifurcate and end in the dorsal and ventral cochlear nuclei which lie close to the inferior cerebellar peduncle.
where do the vestibular and cochlear nerves attach to the brainstem
at the junction of the medulla and pons in the cerebellopontine angle.
what connects the vestibular system to the CN nuclei in brainstem and what is its function
medial longitundinal fisciculus to abducens, trochlear and oculomotor nerve
visual fixation
what connects the vestibular system to the cerebellum and what is its function
the vestibulocerebellar pathway
maintaining equilibrium
fibres connected at the base of the cochlea will respond best to ______
high frequency sound
what is in the static labyrinth
utricle and saccule
where does the vestibular nuclei enter the brain stem
at the junction of the medulla and pons
what is the membranous labyrinth
a group of ducts (cochlear and semicircular ducts) and chambers (utricle and saccule) filled withendolymphatic fluid.
what neural pathways are associated with the vestibular system
those that respond to afferent input from the peripheral vestibular system in the inner ear and provide efferent signals that make these reflexes possible.
where is the primary auditory coretx
in Heschl’s gyri which are situated on the dorsal surface of the superior temporal gyrus
what is the function of hair cells in organ of corti
Vibrations caused by sound waves bend the stereocilia on these hair cells via an electromechanical force.
The hair cells convert mechanical energy into electrical energy that is transmitted to the central nervous system via the cochlear nerve
what is the auditory association cortex
The region of the temporal lobes surrounding the primary auditory cortex and contains the Wernicke’s area.
fibres connected at the apex of the cochlea will respond best to ______
low frequency sounds
what is a clinical perspective for vestibular nerve
vestibular neuronitis
what is the function of the auditory association cortex
is concerned with the memory and classification of sound
what is in the kinetic labyrinth
semicircular canals
what is the function of the macula
specialised otolyth organs that respond to gravity -head tilting
The macula of the saccule detects linear acceleration in the vertical/sagittal plane (up and down).
The macula of the utricle detects linear acceleration in the horizontal plane
what is the function of the vestibular system
sense of proprioception and equilibrium
what parts of the ear are controlled by the vestibular system
semicircular canals
utricle and saccule
