Auditory System Flashcards
What are the four steps of sound transduction?
- Sound wave ->
- Mechanical force ->
- Fluid wave ->
- Action potentials of sensory neurons
What are considered parts of the external ear? (2)
- pinna (auricle)
- external auditory meatus (canal)
What are considered parts of the middle ear? (4)
- tympanic membrane (ear drum)
- malleus
- incus
- stapes
What is the word for the malleus, incus, and stapes all together?
ossicles
What are considered parts of the inner ear? (5)
- semicircular canals
- cochlea
- vestibule
- round window
- oval window
What cranial nerves branch out from the inner ear?
Facial nerve (CN 7), Vestibular nerve (CN 8), and Cochlear nerve (CN 8)
The middle ear contains structures that convert ________________ into ___________________.
sound vibration into mechanical input.
The (INNER/MIDDLE/OUTER) ear’s anatomical structures convert mechanical input into electrical signals by amplifying and sorting out auditory information
inner
The ____________ is attached to
the tympanic membrane and to the incus.
malleus
The ____________ is further attached to the stapes.
incus
What sits in an oval shaped window that connects to the inner ear.
stapes
When the ___________________ vibrates, the _____________ moves, causing the ___________ to move and the __________ is pushed into the inner ear, setting up a concomitant vibration within the inner ear
tympanic membrane
malleus
incus
stapes
The __________ ear is a hollow space within the temporal bone.
inner
The inner ear is known as the ____________________.
osseous labyrinth
The inner ear is filled with a fluid called:
perilymph
In the osseous labyrinth (inner ear) there is a membranous division called the _____________ and this is filled with _____________.
membranous labyrinth, filled with endolymph
The inner ear communicates with the middle ear through the _________________ (in contact with the stapes) and the __________________.
oval window and the round window
The labyrinth is divided in three cavities:
- Scala vestibuli
- Scala tympani
- Scala media
The scala vestibuli and scala tympani are known as:
Perilymph
The scala media is known as:
endolymph
The scala media contains the sensory organ of _____________ with hair cells that project fibers to spiral ganglia and cochlear nerve.
Corti
The endolymph has HIGH/LOW K+ and ___ mV.
HIGH
80 mV
The perilymph has HIGH/LOW K+ and ___ mV.
LOW
0 mV
The inner hair cells have ___ mV.
-45 mV
When sound waves produce a vibration of the tympanic membrane, the ossicles move and the _____________ hits the oval window, compressing its ____________.
stapes
perilymph
What is “tuned” for high frequencies?
the base of the basilar membrane
What is “tuned” for low frequencies?
The apex
A fluid wave is transferred through the scala _____________ and the scala _______________.
scala tympani and the scala vestibuli
The _____________ membrane contains the organ of Corti.
basilar
As the wave of fluid displaces the basilar membrane, the ______________________________ are ___________because of their resistance against the tectorial membrane.
This produces a change in _________________ which stimulates the firing of __________ neurons that project into the brain.
stereocilia of hair cells
deflected
ionic conductance
bipolar
bipolar neurons’ somata are found are referred to as ________________.
spiral ganglia
The auditory pathway is ___________________!
BILATERAL
The major auditory pathway is ______________. And the minor auditory pathway is ________________.
CONTRALATERAL
IPSILATERAL
What is the auditory pathway? (7 steps)
1.) Bipolar neurons in the cochlea
2.) CN VIII
3.) Cochlear nuclei
4.) Superior olive
5.) Inferior colliculus
6.) Medial geniculate nucleus
7.) Primary auditory cortex
Auditory information perceived by one ear can be processed by _______________ of the brain
both sides
The point of fiber decussation occurs at the _________before synapsing in the ____________.
pons
olive
Both ipsilateral and contralateral fibers ASCEND/DESCEND to the ____________ in the _____________-.
ascend
inferior colliculus
lateral lemniscus
_________ frequencies (pitch) stimulate hair cells near the apex of the cochlea. While, _________ frequencies stimulate hair cells near the base of the cochlea
Lower
Higher
Neurons responding to higher and lower frequencies extend axons to different regions of the ____________________, ________________________, and _____________________.
cochlear nucleus, medial geniculate nucleus, and auditory cortex.
