Auditory System

Question 1

What are the four steps of sound transduction?

Answer 1

1. Sound wave ->
2. Mechanical force ->
3. Fluid wave ->
4. Action potentials of sensory neurons

Question 2

What are considered parts of the external ear? (2)

Answer 2

1. pinna (auricle)
2. external auditory meatus (canal)

Question 3

What are considered parts of the middle ear? (4)

Answer 3

1. tympanic membrane (ear drum)
2. malleus
3. incus
4. stapes

Question 4

What is the word for the malleus, incus, and stapes all together?

Answer 4

ossicles

Question 5

What are considered parts of the inner ear? (5)

Answer 5

1. semicircular canals
2. cochlea
3. vestibule
4. round window
5. oval window

Question 6

What cranial nerves branch out from the inner ear?

Answer 6

Facial nerve (CN 7), Vestibular nerve (CN 8), and Cochlear nerve (CN 8)

Question 7

The middle ear contains structures that convert ________________ into ___________________.

Answer 7

sound vibration into mechanical input.

Question 8

The (INNER/MIDDLE/OUTER) ear’s anatomical structures convert mechanical input into electrical signals by amplifying and sorting out auditory information

Answer 8

inner

Question 9

The ____________ is attached to
the tympanic membrane and to the incus.

Answer 9

malleus

Question 10

The ____________ is further attached to the stapes.

Answer 10

incus

Question 11

What sits in an oval shaped window that connects to the inner ear.

Answer 11

stapes

Question 12

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

Answer 12

tympanic membrane
malleus
incus
stapes

Question 13

The __________ ear is a hollow space within the temporal bone.

Answer 13

inner

Question 14

The inner ear is known as the ____________________.

Answer 14

osseous labyrinth

Question 15

The inner ear is filled with a fluid called:

Answer 15

perilymph

Question 16

In the osseous labyrinth (inner ear) there is a membranous division called the _____________ and this is filled with _____________.

Answer 16

membranous labyrinth, filled with endolymph

Question 17

The inner ear communicates with the middle ear through the _________________ (in contact with the stapes) and the __________________.

Answer 17

oval window and the round window

Question 18

The labyrinth is divided in three cavities:

Answer 18

1. Scala vestibuli
2. Scala tympani
3. Scala media

Question 19

The scala vestibuli and scala tympani are known as:

Answer 19

Perilymph

Question 20

The scala media is known as:

Answer 20

endolymph

Question 21

The scala media contains the sensory organ of _____________ with hair cells that project fibers to spiral ganglia and cochlear nerve.

Answer 21

Corti

Question 22

The endolymph has HIGH/LOW K+ and ___ mV.

Answer 22

HIGH
80 mV

Question 23

The perilymph has HIGH/LOW K+ and ___ mV.

Answer 23

LOW
0 mV

Question 24

The inner hair cells have ___ mV.

Answer 24

-45 mV

Question 25

When sound waves produce a vibration of the tympanic membrane, the ossicles move and the _____________ hits the oval window, compressing its ____________.

Answer 25

stapes
perilymph

Question 26

What is “tuned” for high frequencies?

Answer 26

the base of the basilar membrane

Question 27

What is “tuned” for low frequencies?

Answer 27

The apex

Question 28

A fluid wave is transferred through the scala _____________ and the scala _______________.

Answer 28

scala tympani and the scala vestibuli

Question 29

The _____________ membrane contains the organ of Corti.

Answer 29

basilar

Question 30

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.

Answer 30

stereocilia of hair cells
deflected

ionic conductance
bipolar

Question 31

bipolar neurons’ somata are found are referred to as ________________.

Answer 31

spiral ganglia

Question 32

The auditory pathway is ___________________!

Answer 32

BILATERAL

Question 33

The major auditory pathway is ______________. And the minor auditory pathway is ________________.

Answer 33

CONTRALATERAL
IPSILATERAL

Question 34

What is the auditory pathway? (7 steps)

Answer 34

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

Question 35

Auditory information perceived by one ear can be processed by _______________ of the brain

Answer 35

both sides

Question 36

The point of fiber decussation occurs at the _________before synapsing in the ____________.

Answer 36

pons
olive

Question 37

Both ipsilateral and contralateral fibers ASCEND/DESCEND to the ____________ in the _____________-.

Answer 37

ascend
inferior colliculus
lateral lemniscus

Question 38

_________ frequencies (pitch) stimulate hair cells near the apex of the cochlea. While, _________ frequencies stimulate hair cells near the base of the cochlea

Answer 38

Lower
Higher

Question 39

Neurons responding to higher and lower frequencies extend axons to different regions of the ____________________, ________________________, and _____________________.

Answer 39

cochlear nucleus, medial geniculate nucleus, and auditory cortex.