Lecture 17: Hearing and Balance Flashcards
(25 cards)
what is the human range of hearing?
20Hz-20kHz
What cranial nerve innervates to hearing?
Vestibulocochlear nerve
The 3 bones in the inner ear are:
- Malleus
- Incus
- Stapes
The cochlea
the spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations.
First Stage
Sound waves are collected in ____ and ____ ear. Pressure is _____ so that air can be transmitted to ____ -____ ______.
outer and middle
amplified; fluid-filled cochlea
The middle ear:
boosts pressure of air to overcome higher impedance of inner fluid ear
The Inner Ear
Most ____ structure. Where pressure waves are transformed into :
critical
neural impulses
The cochlea is also:
decomposes complex waveforms
Hair cells:
transform mechanical movements into electrical impulses for the brain
Transformation: Step 01
Displacement of fluid in ____ and ____ windows move the ____ membrane. This movement _____ the hair cells
round and oval
basilar
deflects
Deflection of Hair Cells: Step 02
Deflection causes a channel to ____, releasing _____, _____ hair cells. _____ is pumped ___ the cell
open, potassium, depolarizing
Calcium; into
Neuron (auditory) Nerve
Influx of _____ triggers the release of a _________.
calcium; neurotransmitter
The basilar membrane movement:
deflects hair cells
Properties of Basilar Membrane
Maximum _____ will occur at ____ points depending on _____ of sound waves
deflection; different
frequency
Base = ____ resonant frequency. this ____ and ___ region near the ____ window
high
narrow and stiff
oval
Apex= _____ resonant frequency. this ____ and ____ region is _____.
low
wide and floppy
flexible
As the sound travels from the base of the cochlea to the apex, the ____ the frequency, the _____ it travels
lower/longer or higher/shorter
Cochlear Implants
The _____ ____ is attached to the ____.
electrode array; cochlea
Balance
Ability to balance is due to:
the brain changes in direction and making motor corrections
The semicircular canal:
response to rotation acceleration of the head
The otolith organs:
respond to linear acceleration and static position
- sense linear acceleration
Canals filled with fluid
allows the brain to ____ ______. Important function is to adjust the _____ during locomotion
sense movements
eyes
Motion sickness is due to :
mismatch between information from your eyes and vestibular system
Features of the Vestibular System
Large radius =
lower sensitvity
