Sensory Systems: Auditory Flashcards
Amplitude is measured in _____ and determines _____.
decibels
loudness
Frequency is measured in _____ and determines _____.
hertz
pitch
Humans hear frequency range between _____ and _____.
20 Hz
20 kHz
The _____ and _____ collect sound waves and amplify pressure.
external ear
middle ear
Sound waves are transmitted to fluid filled _____ in the _____.
cochlea (hair cells)
inner ear
The cochlea breaks down complex sound waves in _____.
simple sinusoidal components
Hair cells encode _____, _____, and _____.
frequency
amplitude
phase
Hair cells transmit to _____.
auditory fibers
The _____ is the softest part of the outer ear.
pinna
the _____ is the harder entrance to the ear.
concha
the _____ leads from the concha to the tympanic membrane.
external auditory meatus
The ear bones (osciclles) are the _____, _____, and _____.
Malleus
Incus
Stapes
Sound waves enter the external auditory meatus and vibrate the _____.
tympanic membrane
The stapes vibrates against the _____.
oval window
Hair cells reside in the _____.
inner ear
The middle ear boosts _____ 200 fold.
air pressure
The large tympanic membrane funnels sound onto the small _____.
oval window
Ear bone breakage results in _____.
conductive hearing loss
The two small muscles _____ and _____ are activated automatically to protect the ear.
tensor tympani
stapedius
The tympanic membrane is _____ shaped.
cone
The stapes moves with a _____ action.
piston-like
Hair cells send impulses to the _____.
spiral ganglion
Hearing loss due to receptor damage is called _____.
sensorineural hearing loss
The _____ vibrates opposite to the oval window, allowing fluids in the cochlea to move
round window
The oval window leads to the _____.
scala vestibuli
The scala vestibuli leads to the _____ where it becomes the _____.
helicotrema (cochlear apex)
scala tympani
Tonotopy
Topographical mapping of frequencies along the basilar membrane.
The basal end of the cochlea is _____ and responds well to _____.
narrow and stiff
high frequencies
The apical end of the cochlea is _____ and responds well to _____.
wide and flexible
low frequencies
The _____ transforms pressure waves into action potentials.
organ of corti
The organ of corti sits inside the _____, between the _____ and _____.
cochlear duct
scala vestibuli
scala tympani
The _____ pushes the hair cells against the _____ as perilymphatic pressure waves pass.
basilar membrane
tectorial membrane
Vertical motion of the traveling wave along the basilar membane induces a _____ between the _____ and _____.
shearing motion
basilar membrane
tectorial membrane
The shearing motion between the basilar membrane and the tectorial membrane bends _____ on the _____, causing hyper- or depolarization
stereocilia (hair-like structures)
hair cells
_____ are receptors for _hearing and constitute __% of auditory nerve.
Inner hair cells (3,500)
95
_____ receive efferents from the brain and amplify the _____.
Outer hair cells (12,000)
traveling wave
Inner hair cells send info via the _____.
auditory nerve
Outer hair cells get _____ in response to changes in membrane potential.
longer and shorter
Outer hair cells receive strong innervation from the _____ (modulation of sensitivity).
superior olive
There are ~_____ hair cells in each ear.
15,000
There are _____ stereocilia per hair cell, arrange in height and are _____.
30-100+
bilaterally symmetrical
_____ connect 2 adjacent stereocilia, transforming shearing motion into receptor potential.
Tip links
Pull on tip links opens _____, leading to _____.
cation channels
depolarization
Depolarization of hair cells triggers _____ release, creating an action potential which travels to the _____.
glutamate
spiral ganglion
Hair cells are _____ when inactive.
hyperpolarized
Opening and closing of channels results in a _____, enabling receptor potential to follow signals up to _____.
bi-phasic receptor potential
3 kHz
_____ enables hearing up to 20 kHz.
“labeled-line” coding
Auditory fibers are specifically tuned to _____.
characteristic frequencies
The auditory nerve enters the cochlear nucleus in the _____.
brainstem
From the _____, there are bilateral projects to the _____ and _____.
cochlear nucleus
medial
lateral superior olive
The _____ acts as a coincidence detector.
medial superior olive
The _____ uses intensity differences.
lateral superior olive
The _____ uses timing differences.
medial superior olive
The _____ is used to locate a sound source.
medial superior olive
Above _____, the head acts as an obstacle for short, high-frequency waves resulting in lower intensity signals in the distant ear.
2 kHz
Differences in intensity are used by the _____ and the _____ to locate sound.
lateral superior olive
medial nucleus of the trapezoid body
The inferior colliculus resides in the _____.
midbrain
In the _____, the _____ integrates combinations of frequencies.
auditory thalamus
medial geniculate complex
The primary auditory cortex is located in the _____.
temporal lobe
The primary auditory cortex A1 has a _____ organization (low in _____, high in _____).
tonotopic
front
back
The belt areas adjacent to A1 receive _____.
diffuse inputs
