Neuro Auditory System

Question 1

What are the three gross anatomical regions of the ear?

Answer 1

External, Middle, Inner

Question 2

What are the three components of the external ear?

Answer 2

1) pinna
2) external auditory canal
3) tympanic membrane

Question 3

What are the three bones of the middle ear?

Answer 3

1) malleus (tensor tympani muscle with its trigeminal nerve)
2) Incus
3) stapes (stapedius muscle with its facial nerve)

Question 4

What are the two labyrinths of the inner ear?

Answer 4

1) osseous labyrinth (cavity within the temporal bone)
2) membranous labyrinth (contains the neuroepithelium of the ear, the cochlear duct, the organ of Corti, and the vestibular labyrinth)

Question 5

From what bone is the osseous labyrinth derived?

Answer 5

It is derived from a hollowed-out region of the petrous portion of the temporal bone filled with a fluid called perilymph

Question 6

The osseous labyrinth is filled with _____ and the membranous labyrinth is filled with _____

Answer 6

perilymph

endolymph

Question 7

Where is the sensory neuroepithelium of the inner ear located?

Answer 7

in the membranous labyrinth

Question 8

Be able to point out the scala media, scala tympani, and scala vestibuli

Answer 8

1) scala vestibuli is filled with perilymph
2) scala media is filled with endolymph
3) scala tympani is filled with perilymph

Question 9

Where does the footplate of the stapes sit?

Answer 9

in the oval window

Question 10

What is the other window besides the oval window?

Answer 10

round window

Question 11

Be able to identify basic structures within the organ of corti including the scala vestibuli (filled with perilymph), the vestibular (Reissner’s) membrane, scala media (filled with endolymph), basilar membrane, scala tympani (filled with perilymph), tectorial membrane with its hair cells in contact with the periphreal processes of the statoacoustic nerve (VIII) and the basilar membrane

Answer 11

Question 12

Describe the basics of the “what” and “where” components of the auditory system

Answer 12

“What” : language processing, located in the dorsal cochlear nucleus

“Where” : responsible for locating sound stimuli, located in the ventral cochlear nucleus (focused in the accessory auditory nuclei… superior olivary nucleus & nucleus of lateral lemniscus)

Question 13

What are the responsibilities of the superior olivary complex?

Answer 13

The superior olivary complex is responsible for sound location including the time delay and intensity difference components of sound location

Question 14

Where does the olivocochloear system terminate?

Answer 14

the outer hair cells of the cochlea

Question 15

What is the role of the olivocochlear system?

Answer 15

It plays a role in postnatal development of hearing, protection from loud sounds, and suppression of constant background noise

Question 16

What higher brain areas deal with the “what” aspect of audation?

Answer 16

superior and middle temporal gyri

Question 17

What higher brain area deals with the “where” aspect of audation?

Answer 17

inferior colliculus, superior colliculus (reflex response to sound stimulus)

superior parietal lobule (planned motor response to stimulus location)

Question 18

What part of the brain handles the “what” component of audation?

Answer 18

superior temporal gyrus

Question 19

Where in the brain does word processing occur?

Answer 19

anterior superior temporal gyrus

Question 20

Where in the brain does sentence processing occur?

Answer 20

posterior superior temporal gyrus to inferior parietal lobule

Question 21

What part of the outer brain does the “where” aspect of audation occur?

Answer 21

the superior temporal gyrus to superior parietal lobe