Vestibular System Flashcards
The ________ network controls eye movements to maintain gaze while head is in motion, while the ______ network influences postural adjustments of the head and body
vestibuloocular network, vestibulospinal network
The ______ network provides conscious perception of motion and spatial orientation
vestibulothalamocortical network
The _____ and the _____ merge to form the vestibulocohlear nerve, CN VIII
vestibular nerve, cochlear nerve
The vestibule of the bony labyrinth contains the _____ and the _____
utricle, saccule
The sensory organ of the semicircular ducts is the _______ contained in the ______
crista ampullaris, ampullae
The otolith organs, utricle and saccule, in vestibule contain ______ as their sensory organ
macula
The ______ transduce linear acceleration and tilt
otolith organs (utricle and saccule)
The ______ is found between the bony labyrinth and membranous labyrinth and has a high ______ concentration and low _____ concentration
perilymph, Na+, K+
The perilymph is continuous with the subarachnoid space via the _______
cochlear aqueduct
The _______ is within the membranous labyrinth and is high in ________ and low in ______
endolymph, K+, Na+
The ampullae of the semicircular ducts and the utricle and saccule are located in the _______
membranous labyrinth
The stereocilia of hair cells of the crista ampullaris are embeded in _________
gelatinous cupula
The stereocilia of hair cells in crista ampullaris are deflected by ___________
endolymph movement of cupula
________ or _____ displaces otolith membrane and causes deflection of stereocilia
linear acceleration, tilt
The otoconia of the macula of the utricle and saccule are _____ dense than the surrounding endolymph
more dense
The ______ forms a thickening of the surface ectoderm and invaginates to form otic pit
otic placode
The otic placode is a thickening of the _______
surface ectoderm
The ________ closes off to form otic vessicle
otic pit
The ________ ganglion will eventually split into vestibular (scarpa’s) ganglion and cochlear (spiral ganglion)
statoacoustic ganglion
The vestibular ganglion is also called the ________ ganglion
Scarpa’s ganglion
The ________ forms the membranous labyrinth. The dorsal portion forms the _______, ________, and _________
otic vesicle, utricle, endolymphatic duct, semicircular ducts
The ventral component of the otic vessicle forms the _____ and ______
saccule, cochlear duct
The ________ begin as flattened outpocketings of the dorsal otic vesicle
semicircular ducts
The blood supply to the membranous labyrinth is via the ________ which is typically a branch of ______
labyrinthine artery, AICA
The _________ artery courses with VIII through the internal acoustic meatus
labyrinthine artery
_______ and _______ are embedded in cupula or otolith membrane and are surrounded by endolymph (high K+)
stereocilia, kinocilium
________ are contained in support cells of the crista ampullaris and maculae and is surrounded by perilymph (low K+)
vestibular hair cell bodies
displacement of stereocilia toward the kinocilium of a vestibular hair cell promotes _______ and influx of ____ from endolymph
channel to open, K+
Influx of K+ after hair cell channels are opened causes _________ channels to open leading to the release of _______ and _______
Ca2+ channels, aspartate, glutamate
The semicircular ducts are oriented ________ to the utricle and saccule
orthogonal
The semicircular ducts are _____
yoked to each other
orientation of hair cells in yoked semicircular ducts are _________ in relation to each other
complementary (reversed)
A head turn to the left will excite hair cells in the __________ and inhibit hair cells in the _______
left horizontal crista ampullaris, right crista ampullaris
The kinocillium in the left horizontal semicircular ampulla is closest to the ______ head
posterior
The _______ of the otolith membrane of each macula is what all macular hair cells are oriented relative to
striola
_______ hair cells are oriented toward the striola, _______ hair cells are oriented away from the striola
utricular, saccular
The _______ make it possible for head tilt or linear acceleration to deflect hair cells in this sensory organ
otoconia
biplolar neurons of CN VIII form a ____ which synapses with type I vestibular hair cells, and forms a ______ on type II vestibular hair cells
calyx, synaptic bouton
Cells bodies in the ________ ganglion are within the internal acoustic meatus
vestibular (Scarpa’s) ganglion
The vestibular nuclei found in the caudal pons are the:
superior, medial, and lateral vestibular nuclei
The vestibular nuclei found in the rostral medulla are the:
medial and inferior vestibular nuclei
The vestibular nuclei of the caudal pons are supplied by the ________ and _______ arteries
circumferential branches of basilar, AICA
The vestibular nuclei in the rostral medulla are supplied by the ______ artery
PICA
Saccular primary afferent neurons project to _______ which influences _______ via projections to _______
cell group Y, vertical eye movements, oculomotor nucleus
The ______ is the only sensory organ to send direct projections to the cerebellum
vestibular labyrinth
The ________ nucleus projects bilaterally to vestibular nuclei
fastigial nucleus
The ________ influences eye movements, head movements, and posture
vestibulocerebellar module
The fastigial nucleus receives input from the vestibular nuclei via the ________ and ________
fastigiovestibular fibers, juxtarestiform body
The fastigial nucleus projects to the ________ and ______
flocculonodular lobe, medial part of vermis
The _______ are pathways by which pairs of yoked semicircular ducts and maculae are compared
commissural fibers
reflexes and postural control impaired by unilateral lesion of peripheral structures can be restored by ________ through commissural fibers
central adjustment
________ axons provide proprioceptive input to the vestibular nuclei and arise from ______
spinovestibular axons, all levels of spinal cord
The ________ provide input from visual environment to vestibular nuclei
accessory optic system (small visual system nuclei)
________ axons are afferents from the thalamus and cortical regions to the vestibular nuclei
corticovestibular and thalamovestibular axons
The vestibulospinal network produces reflexive postural adjustments of the head and body via the _______ and the _______
lateral vestibulospinal tract, medial vestibulospinal tract
The lateral vestibulospinal tract of the vestibulospinal network projects to the ________ nucleus
lateral vestibular nucleus
The medial vestibulospinal tract of the vestibulospinal network receives projections from the ______ and _______
medial vestibular nucleus, inferior vestibular nucleus
The UMN cell bodies in the vestibular nucleus are ipsilateral and responsible for reflexive control of ________ and _______ muscles related to balance and posture
paravertebral muscles, proximal limb extensor muscles
The _______ receives no input from the cerebral cortex
vestibulospinal network
All 4 vestibular nuclei contralaterally project to the ______
thalamus
Primarily the ______ thalamus, especially the _____ receive vestibular nuclei input
posterior, VPL
The function of the vestibuloocular network is to:
maintain a fixed gaze on an object while the head is moving
VOR:
vestibuloocular reflex (moving eyes to maintain gaze on object during head movement)
The 3 nuclei involved in the vestibuloocular network are the:
abducens, trochelar, oculomotor
The _______ provides connections between abducens, trochlear, and oculomotor nuclei
MLF
The bipolar primary afferent neurons of CN VIII within the vestibuloocular network project to the vestibular nuclei and then to ____________ and ________
contralateral abducens nucleus and MLF
