Karius - Auditory & Vestibular System Flashcards
where is perilymph found?
scala vestibuli and scala tympani
what is perilymph composition? similar to?
high Na, low K; ECF/CSF
where is endolymph found?
scala media
what is the composition of endolymph? similar to?
high K, low Na; ICF
what do the middle ear ossicles do?
impedence matching
What does vibration of the basilar membrane is determined by?
frequency of the sound
where does high frequency sound vibrate basilar membrane?
near base
where does low frequency sound vibrate basilar membrane?
near helicotrema
what does the vibration of the membrane cause?
bending of hair cells–> depolarization
what does the ventral path of the cochlear nuclei detect?
the nature of the sound (high or low)
what does the dorsal path of the cochlear nuclei detect?
the location of the sound
what does the medial superior olive detect?
differences in time of arrival to the ears
what does the medial superior olive detect?
differences in intensity
what does the inferior colliculus detect?
spatial map of sound (where is it coming from)
what does the primary auditory cortex detect?
tonotopic map, beginning to know what the sound is
what 3 things does the associated auditory cortical area do?
- processing of complex sounds (music)
- ID of sound (naming)
- speech
what movement is linear acceleration?
moving along a line, horizontally or vertically
what movement is angular acceleration?
rotation; fall forward, backward
what detects forward falls?
anterior semicircular canal
what detects spinning?
horizontal semicircular canal
what detects backward falls?
posterior semicircular canal
what detects forward walking?
utricle
what detects jumping up and down?
saccule
what is the process of vestibular detection?
moving of endolymph, bending of hair cells, initiation of action potentials
what is the goal of vestibule-optic reflex?
maintain focus on point on horizon in front of us until impossible to do so
what extra ocular m. is activated in forward falls?
eyes go up: superior rectus
what extra ocular m. is activated in backward falls?
eyes go down: superior oblique m.
what extra ocular m. are involved in spins?
medial and lateral rectus m.
what is the majority of cortical and cerebellar involvement in the vestibulooptic reflexes?
suppress the reflex to allow for voluntary motion
