10 Flashcards
auditory system receptors
hair cells
integrates the information from both ears
inferior colliculus
movement of the eyes and head towards the sound
superior colliculus
relay to the primary auditory cortex
medial geniculate body: thalamus
cochlea (organ of corti) signal pathway
coclear n via CN VIII superior olivary n inferior colliculus MGN primary auditory cortex
What does the inferior colliculus also branch to
superior colliculus
muscles of neck to reflexively turn head via tectospinal pathway
What does the coclear n also branch to
reticular formation
general movement/postural muscles via the reticulospinal pathway
comprehension of sound
Wernickes area
provides sensory input about both angular and linear acceleration. orients the head with respect to gravity
peripheral sensory apparatus
sensitive to angular change in acceleration in yaw, pitch, and roll planes
Oriented at right angles to one another
semicircular canals
horizontal canal sits at
30 degrees
ampulla contains
crista ampullaris and hair cells
Biological sensors which convert head motion into neural firing
present in the ampulla and otolith organs
hair cell
the coplanar pairing of canals is associated with ____________ change in the quantity of semicircular canals output
push pull
info from semicircular canals are used to
stabilize vision
otoliths
utricle and saccule
Sensitive to linear acceleration and gravity
otoliths
Oriented in the horizontal plane
utricle
when is the utricle maximally stimulated
with sideways movement
oriented in the vertical plane
saccule
when is the saccule maximally stimulated
with up/down movements
the macula of the utricle is oriented in the
horizontal plane
macula of the saccule is oriented in the
vertical plane
head movements cause change in
firing rates of both vestibular nerves but in opposite directions
_____ and _____ work in conjunction with other motor systems to control _______ and _________ during head movements and posture movements and locomotion
VOR and VSR
gaze stability and whole body equilibrium
flocculonodular lobe of the cerebellum
central vestibular system
vestibular nucleii
4 medial, lateral, inferior and superior
____ connects to extraocular muscles
medial longitudinal fasciculus and superior colliculus
stabilize eyes when head moves
vestibulo-occular reflex
balance control
vestibulo-spinal reflex
connection between vestibular system and stability muscles of the torso and lower extremities (below the neck)
lateral vestibulospinal tract
head position
medial vestibulospinal tract
detects movement and postural sway and corrective signal sent to muscles to maintain balance and coordinate movement
vestibular system
maintain gaze stability during head motion
allows disired object to stay on fovea, even when walking/running or moving head
vestibulo-ocular reflex
oscillopsia
deficit of the vestibulo-ocular reflex
what is the VOR regulated by
afferent input from semicircular canals
VOR gain
as the head moves in one direction, the eyes move in the opposite direction with equal velocity
what is VOR gain regulated by
semicircular canals
in a nystagmus fast beat always
toward the more active side
Nystagmus; slow phase is driven by
ears
nystagmus: fast phase is driven by
CNS
Nystagmus beats towards a
stimulated ear
Acute inflammation of the vestibular nerve
Vestibular neuritis
Bacterial infection of the labyrinth
can cause hearing loss
Vestibular labyrinthitis
fistulas occur at the round or oval window - separates middle ear and the inner ear
Perilymphatic fistula
symptoms of perilymphatic fistula
vertigo
oscillopsia
imbalance induced by auditory stimuli or straining
malabsoption of endolymph in the endolymphatic duct and sac
devastating vestibular and hearing loss
Meniere’s Disease
symptoms of minieres
fullness in ear reduced hearing rotational vertigo nausea increased prevalence of migraine
apparent movement of a stationary visual environment
oscillopsia
