Auditory and Vestibular System Flashcards
- collects and focuses/ localizes sounds (monaural localization)
- directs frequencies in a direction dependent fashion
external ear
Monaural localization = location of sound
external ear
middle ear
- transmits vibrations cross a chain of ossicles
- transmits waves in the air to waves into fluid
tympanic membrane and ossicles are what part of the ear
middle ear
amplification occurs where?
middle ear
occurs between the oval window and tympanic membrane (22 to 1 ratio)
amplification
- transduction
- has fluid filled chambers
- codes sounds into action potentials by frequency and volume
inner ear
sound waves are converted to action potentials for processing in the NS
transduction
membranous labyrinth that has the primary sensory transducer of sound
cochlea
organ of corti
hair cells (long microvilli)
auditory and vestibular sensory detectors
hair cells
localized within space in the temporal bone
labyrinth
Sound waves enter the fluid causing the tectorial membrane to rub against the organ of corti (hair cells)
sound transduction
high frequencies activate hair cells near?
the base of the cochlea
lower frequencies activate hair cells near?
near the apex
continuous rang of sound carried in the cochlear nerve that contains an organized distribution of sound frequency
tonotopic organization
frequency is measure in?
hertz (cycles per second) and volume
volume of sound is measure in?
decibeles (dB)
20 Hz - 20,000 Hz is what rang of frequency?
audible range
150Hz or more is what rang of frequency?
rapid damage
2 primary apartments of filled fluids in the auditory system?
- lumen of membranous labyrinth
- between the bone and membrane
lumen of membranous labyrinth is filled with what fluid?
endolymph
endolymph
high in potassium and similar to intercellular fluid
between the bone and membrane what is the filled?
perilymph
perilymph
is smilier to CSF and flows within the subarachnoid space of the cranial cavity
- Helps with motor control in the cerebellum
- Helps with the visual motor system for the control of eye movements while the head is in motion
- Helps with the thalamus and cortex for the conscious perception of movement and orientation in space
Peripheral vestibular apparatus connecting to the vestibular nuclei of the brainstem
- the peripheral receptor apparatus in the inner ear
- the central vestibular nuclei in the brainstem
- the vestibulo-ocular network: controls eye movement
- the vestibulospinal network: controls position and balance
- the vestibulo-thalamo-cortical network: conscious perception of information
primary components of vestibular system
orientation relative to gravity
static labryinth
staying upright without moving & responsive to the pull of gravity
static
sensory detectors are located here
in the saccule and utricle of vestibule
detects dynamic movement in space
kinetic labyrinth
dynamic standing is what?
moving and staying upright
kinetic receptors are in
the ampulla
controls eye movement & keeps eyes fixated upon an object when moving the head
vestibulo-ocular network
CN 3, 4, 5 connect to this network
vestibulo-ocular network
controls positon and balance
vestibulospinal network
head and neck posture
medial part of the vestibulospinal network
control balance and extensor bias
lateral part of the vestibulospinal network
conscious perception of information
vestibulo-thalamo-cortical network
