auditory and vestibular anatomy Flashcards
auditory symptoms: lesion to cochlear nerve (aside from tinnitus)
- unilateral hearing loss
- facial weakness
- vestibular disorder
auditory symptoms: lesion to cochlea (aside from tinnitus)
- hearing loss
- hyperacusis
- aural fullness
auditory symptoms: middle ear lesion (aside from tinnitus)
- hearing loss
auditory symptoms: lesion to cerebellopontine angle (aside from tinnitus)
- unilateral hearing loss
- poor word discrimination
- vestibular disorder
- facial weakness
- facial numbness
Three signs/symptoms of vestibular lesion
- quick spins
- vertigo
- ataxia
two brainstem neurons for auditory system
- cochlear nuclei
- superior olivary nuclei
___ is connected to the oval window
scala vestibuli
photoreceptors are to the eye as ___ are to the ear
inner hair cells: primary sound TRANSDUCTION
olivocochlear bundle
affects the outer hair cells for the MODULATION of sound
basilar membrane changes in __ and __ from the apex to the base. which part is for high pitches?
it changes in thickness and stiffness; the stiff part is for high pitches
can you regenerate hair cells?
NO
does he care about type I vs type II hair cells? medial vs lateral olivocochelar?
NO. just call them hair and olivocochlear
endolymph is made by __ important for?
striavascularis; it has ion pumps for manipulating the ions in perilymph/endolymph
when hairs bend toward the kinocilium what happens?
depolarize
pathway for cell bodies of auditory system
KNOW THIS!!
1= spiral ganglion and send to brain and bifurcate to 2= dorsal cochlear nucleus and and ventral cochelar 3= superior olive (some cross to other side via trapezoid body) 4= inferior colliculus to brachium 5= mgn 6= auditory cortex (heschels area 41)
first place that you get info from both ears
superior olive
where else does auditory info go
reticular formation for the auditory startle reflex
CN8 ==> CN 5, CN 7 (stapedial reflex)
amygdala (for emotions)
cochlear nerve cells go to
both dorsal and ventral cochlear nuclei
lateral lemniscus
connection of auditory pathways from superior olive to inferior colliculus
superior olivary complex
RIGHT NEXT TO FACIAL MOTOR NUCLEUS
where do you compare R and L sound?
begins in SUPERIOR OLIVE. Remember this is the first location for BIAURALinfo. it compares which sound ARRIVES first, and which one is LOUDER; this tells you where the sound is coming from
middle ear reflex
related to both tensor tympani and facial motor nucleus
turning your head toward sound … what parts do you need
inferior colliculss
MGN
area 42
tectospinal tract
rinne test
tuning fork on mastoid prcess, because of bone conduction, sound goes to CNVIII; when you can’t hear the bone, they move it in front of the ear to see if you can still hear it. (AIR conduction)
tests for conduction hearing loss
weber test
you put tuning fork on midline of skull; which side is louder? the ear that hears it louder is plugged
localizes sound to the BAD ear if it is conductive deafness
localizes to GOOD ear if its a nerve damage
lean with it, rock with it. if you lean to the right you….
stimulate right utricle, right leg stiffens (via medial and lateral vestibulopinal tract) and pushes back toward center
location of otoconia in BPPV
utricle
loss of function in right utricle
lean to the right. (I would like to call this the “lean with it rock with it” syndrome)
vestibulo-occular reflex (VOR)? which CNS
the ballerina reflex so that you can “foveate” and fix gaze while you spin
CN III, VI, VIII
lateral vestibular nucleus is
IPSILATERAL and LONGER; goes to cbellum, limb motor neurons
medial vestibular nucleus
vestibulocolic reflex: if you fall on sidewalk, then you pull your head back so you don’t hit it on the sidewalk; this nucleus is BILATERAL
medial and lateral vestibulospinal tract
affect the axial muscles
VOR pathway
Ms. Scarpa is a MiLF. She likes 3, 4, or 6 things to go in her vestibular complex
- scarpa ganglion (aka vestibular ganglion)
- vestibular nuclear complex
- MLF
- CN 3, 4, 6
vestibulo-thalamo-cortical path
vestibular nuclei
VPL,
area 3a and posterior insula
vestibular system gets input from?
hair cells, cBellum
location of plantum temporale
posterior to heschel’s gyrus
remember “COWS”
Cold Opposite; Warm Same
always named by the FAST component of nystagmus
what is the endolymphatic aqueduct
its a little connection between the utricle, saccule, endolymphatic sac; we aren’t really sure what the function is… its a tube that dead ends at the dura.
where does blood to inner ear drain?
the veins follow the course of the artery (labyrinthine) then it collects in the superior petrosal sinus
what happens at the modiolus?
this is the point where the cochlear canal turns around and comes back toward the round window.
