Chapter 22: Auditory Pathways

Question 1

VIII was once called the auditory nerve because it is the nerve of _____.

Answer 1

• Hearing

Question 2

Many anatomists objected to calling VIII the auditory nerve because it serves the function of hearing as well as the function of _____.

Answer 2

• Balance

Question 3

The central processes of _____ in the vestibular ganglion and the spiral ganglion of the cochlea synapse on neurons in the nuclei of VIII.

Answer 3

• Primary sensory neurons

Question 4

VIII is now called the vestibulocochlear nerve because it carries information from the _____ ganglion and the spiral ganglion of the _____.

Answer 4

• Vestibular

- Cochlea

Question 5

Although some mnemonics still refer to VIII as the _____ nerve, VIII is formally called the _____ nerve.

Answer 5

• Auditory

- Vestibulocochlear nerve

Question 6

The vestibulocochlear nerve enters the _____ at the border between the medulla and the pons.

Answer 6

• Brainstem

Question 7

The vestibulocochlear nerve is assigned to the medulla although 1/3 of its nuclei are in the lower _____.

Answer 7

• Pons

Question 8

Four nuclei of VIII are in the upper _____, and 2 nuclei of VIII are in the lower _____.

Answer 8

• Medulla

- Pons

Question 9

Most of the nuclei of the vestibulocochlear nerve that are assigned to the upper medulla extend a short distance into the _____, and one nucleus assigned to the lower pons extends a short distance into the _____.

Answer 9

• Lower pons

- Upper medulla

Question 10

The dorsal and ventral cochlear nuclei and the inferior and medial vestibular nuclei of VIII are in the upper medulla; the lateral and superior vestibular nuclei of VIII are in the _____.

Answer 10

• Lower pons

Question 11

The dorsal cochlear nucleus is in the _____ dorsolateral to the inferior cerebellar peduncle.

Answer 11

• Upper medulla

Question 12

The dorsal cochlear nucleus is _____ to the inferior cerebellar peduncle.

Answer 12

• Dorsolateral

Question 13

The dorsal cochlear nucleus is in the _____ between the _____ and the lateral aperture of the 4th ventricle.

Answer 13

• Upper medulla

- Inferior cerebellar peduncle

Question 14

The ventral cochlear nucleus is in the _____ anterior to the dorsal cochlear nucleus.

Answer 14

• Upper medulla

Question 15

Auditory information reaches the ipsilateral ventral (anterior) and dorsal (posterior) cochlear nuclei of the medulla in the cochlear division of the _____ nerve.

Answer 15

• Vestibulocochlear

Question 16

The spiral ganglion of the cochlea sends auditory information to the ipsilateral _____ and _____ nuclei.

Answer 16

• Ventral

- Dorsal

Question 17

The central processes of the axons of spiral ganglion cells branch with the ventral branch synapsing in the ipsilateral _____ and the dorsal branch synapsing in the ipsilateral _____.

Answer 17

• Ventral cochlear nucleus

- Dorsal cochlear nucleus

Question 18

Each sound frequency is detected in a specific spot in the cochlea, and each sound frequency synapses in a specific spot in the _____ dorsal cochlear nucleus, and each sound frequency synapsing in 3 specific spots in the _____ ventral cochlear nucleus.

Answer 18

• Ipsilateral

- Ipsilateral

Question 19

The dedication of a linear array of places to specific sound _____ is called tonotopic organization.

Answer 19

• Frequency (pitch)

Question 20

The dorsal cochlear nucleus and each of the 3 parts of the ventral cochlear nucleus have independent _____ organizations.

Answer 20

• Tonotopic

Question 21

Tonotopic organization is preserved in the projections of the _____ and _____.

Answer 21

• Dorsal

- Ventral cochlear nuclei

Question 22

_____ is preserved in all pathways from the cochlea to the nucleus of the inferior colliculus in the lower midbrain.

Answer 22

• Tonotopic organization

Question 23

The nucleus of the inferior colliculus is inside the _____ in the _____.

Answer 23

• Inferior colliculus

- Lower midbrain

Question 24

Directly or indirectly, each nucleus of the _____ receives tonotopically organized information from both dorsal cochlear nuclei and both ventral cochlear nuclei.

Answer 24

• Inferior colliculus

Question 25

Auditory information from the dorsal and ventral cochlear nuclei reaches the _____ of the _____ through the lateral lemniscus.

Answer 25

• Nucleus

- Inferior colliculus

Question 26

Some projections of the dorsal and ventral cochlear nuclei to the _____ of the _____ are direct.

Answer 26

• Nucleus

- Inferior colliculus

Question 27

Indirect projections of the dorsal and ventral cochlear nuclei to the _____ are relayed by the superior olivary complex in the lower pons and the nucleus of the lateral lemniscus at the mid-pontine level.

Answer 27

• Nucleus of the inferior colliculus

Question 28

Some auditory information relayed to the _____ from the dorsal and ventral cochlear nuclei crosses from left to right and vice-versa one to four times.

Answer 28

• Nucleus of the inferior colliculus

Question 29

The first crossing of auditory information is between the ventral cochlear nucleus and the superior olivary complex of the _____.

Answer 29

• Lower pons

Question 30

The second crossing of auditory information is between the _____ of the lower pons and nucleus of the lateral lemniscus in the mid-pons.

Answer 30

• Superior olivary nucleus

Question 31

The third crossing of auditory information is between the _____ of the _____ in the mid-pons and the nucleus of the inferior colliculus.

Answer 31

• Nuclei

- Lateral lemniscus

Question 32

Some auditory information crosses from the nucleus of the lateral lemniscus to the _____ nucleus of the inferior colliculus and some information crosses from one nucleus of the lateral lemniscus to the _____ nucleus of the lateral lemniscus.

Answer 32

• Contralateral

- Contralateral

Question 33

Because the nuclei of the lateral lemniscus are at the same level, their projections to each other are called a _____.

Answer 33

• Commissure

Question 34

The _____ of the _____ is at the mid-pontine level.

Answer 34

• Commissure

- Lateral lemnisci

Question 35

The final crossing of auditory information is the _____ in which the nuclei of the inferior colliculi project to each other.

Answer 35

• Commissure of the inferior colliculi

Question 36

The nuclei of the auditory system can detect the direction to the source of a sound by comparing the time delay between the arrival of information from the _____.

Answer 36

• Right and left ears

Question 37

Because the _____, the nuclei of the _____, and the nuclei of the _____ receive both crossed and uncrossed auditory information, all can participate in detecting the source of a sound.

Answer 37

• Superior olivary complex
• Lateral lemniscus
• Inferior colliculus

Question 38

The nucleus of the inferior colliculus receives information directly or indirectly from both nuclei of the _____, both _____, and both _____, but it projects to only the ipsilateral medial geniculate nucleus of the thalamus.

Answer 38

• Lateral lemniscus
• Superior olivary complexes
• Cochlear nuclei

Question 39

The nucleus of the inferior colliculus projects to the ipsilateral _____ of the thalamus through the brachium of the inferior colliculus.

Answer 39

• Medial geniculate nucleus

Question 40

The medial geniculate nucleus of the _____ receives information from the _____ nucleus of the inferior colliculus through the _____ of the inferior colliculus.

Answer 40

• Thalamus
• Ipsilateral
• Brachium

Question 41

Due to the many crossings of auditory information in the brainstem, each _____ is conscious of _____.

Answer 41

• Medial geniculate nucleus

- Sound in both ears

Question 42

Each medial geniculate nucleus is conscious of sound in both ears even ‘though it receives projections from only the ipsilateral _____ of the _____.

Answer 42

• Nucleus

- Inferior colliculus

Question 43

The medial geniculate nucleus receives projections from the _____ nucleus of the inferior colliculus through the _____ of the _____.

Answer 43

• Ipsilateral
• Brachium
• Inferior colliculus