Auditory System

Question 1

What are the three parts of the ear?

Answer 1

external, middle, and inner

Question 2

What are the parts of the external ear?

Answer 2

the external canal

Question 3

What are the parts of the middle ear?

Answer 3

auditory ossicles and auditory tube

Question 4

What are the parts of the inner ear?

Answer 4

cochlea and cochlear duct

Question 5

What are the auditory ossicles of the ear?

Answer 5

the malleus, incus, and stapes

Question 6

What is the function of the auditory ossicles?

Answer 6

to transfer vibration of tympanic membrane to inner ear, increase force, and decrease amplitude

Question 7

What is the inner ear lined with?

Answer 7

membranous structure that divides into chambers

Question 8

Where is the vestibular window (oval) located?

Answer 8

between the stapes and the upper chamber of the inner ear

Question 9

Where is the cochlear (round) window?

Answer 9

between the middle ear and the lower chamber

Question 10

What is the function of the auditory tube?

Answer 10

to connect the middle ear with the oropharynx

Question 11

What are the tensor tympani muscle and the stapedeus muscle important for?

Answer 11

keeping the auditory ossicles in place

Question 12

What is the tympanic membrane also known as?

Answer 12

the ear drum

Question 13

What is the scale vestibuli?

Answer 13

the upper chamber of the cochlea

Question 14

What is the scale tympani?

Answer 14

the lower chamber of the cochlea

Question 15

What is the basilar membrane?

Answer 15

the seperation between the scale tympani and the cochlear duct

Question 16

What is the cochlear duct?

Answer 16

the middle chamber of the cochlea

Question 17

What is the osseous labyrnth?

Answer 17

the bony part of the cochlea

Question 18

What is the membranous labyrinth?

Answer 18

the part that divides the cochlea into its three parts

Question 19

What is the scale vestibuli and scale tympani filled with?

Answer 19

perilymph

Question 20

What is the cochlear duct filled with?

Answer 20

endolymph

Question 21

Where is the organ of corti?

Answer 21

in the cochlear duct on top of the basilar membrane

Question 22

What is the organ of corti made up of?

Answer 22

stereocilia and supporting cells

Question 23

Where are the stereocilia imbedded?

Answer 23

in the tectorial membrane

Question 24

What are the spiral ganglia?

Answer 24

the axons that make up the auditory nerve that send axons into the stereo cilia

Question 25

When the wave caused by sound reaches the scale tympani, what happens?

Answer 25

the basilar membrane moves up and down to move the tectorial membrane

Question 26

What is the size of the base of the basilar membrane?

Answer 26

narrow and taut

Question 27

When does the base of the basilar membrane move?

Answer 27

when high frequency sounds reach it

Question 28

What is the size of the apex of the basilar membrane?

Answer 28

wide and floppy

Question 29

When does the apex of the basilar membrane move?

Answer 29

when low frequency sounds reach it

Question 30

What happens when hair cells bend?

Answer 30

K channels open, depolarization opens Ca channels, and a neurotransmitter is released

Question 31

What is the function of the cochlear nerve?

Answer 31

take information from the sensory hair cell to the cochlear nuclei

Question 32

What is the first stop for all auditory info?

Answer 32

the cochlear nuclei

Question 33

Is the cochlear nuclei unilateral or bilateral?

Answer 33

receives information unilaterally (ipsilateral) but sends information contralaterally

Question 34

What does the cochlear nuclei send information to?

Answer 34

the dorsal nucleus of the trapezoid body on both sides and to the acoustic stria (which ascends on the contralateral side of the body)

Question 35

What sides does the dorsal nucleus of the trapezoid body get information from?

Answer 35

both sides

Question 36

What sides does the caudal colliculus get information from and from what structures?

Answer 36

both sides: the acoustic stria of the contralateral side and the dorsal nucleus of the trapezoid body of the ipsilateral side

Question 37

Why is there bilateral auditory input?

Answer 37

so that we can localize sound

Question 38

What is the acoustic startle reflex?

Answer 38

the reflexive head towards sound

Question 39

What structures are involved in the acoustic startle reflex?

Answer 39

caudal colliculus, rostral colliculus, tectospinal tract, and spinal lower motor neurons

Question 40

What type of information goes to the caudal colliculus?

Answer 40

auditory information

Question 41

What type of information goes to the rostral colliculus?

Answer 41

visual information

Question 42

How does the rostral colliculus work in the acoustic startle reflex?

Answer 42

it coordinates with the eyes to move towards the sound

Question 43

What is the middle ear reflex?

Answer 43

protection of the inner ear from loud sound by limiting movement of the auditory ossicles

Question 44

What structures are involved in the middle ear reflex?

Answer 44

cochlear nuclei, dorsal nuclei of the trapezoid body, and the stapedius muscle

Question 45

What is the pathway of the middle ear reflex?

Answer 45

sound causes the stereocilia to send information to the cochlear nuclei, the cochlear nuclei transmits information to the dorsal nucleus of the trapezoid body, the trapezoid body sends information to the motor nucleus of the facial nerve, the facial nerve then tells the stapedius to either contract or relax depending on the sound