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 ___________ nerve because it serves the function of hearing as well as the function of ____________.

Answer 2

auditory

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

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 ___________, and 2 nuclei of VIII are in the ______.

Answer 8

upp medulla

lower pons

Question 9

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

Answer 9

pons

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

dorsal

ventral cochlear

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 frequency/pitch is called

Answer 19

tonotopic organization (Greek: tono=tone, topos=place)

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 __________ ___________ nuclei.

Answer 21

dorsal
ventral
cochlear

Question 22

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

Answer 22

tonotopic

Question 23

The nucleus of the inferior colliculus is inside the ____________ ______________ in the ________ midbrain.

Answer 23

inferior colliculus

lower

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 nucleus of the inferior colliculus through the

Answer 25

lateral lemniscus.

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 nucleus of the inferior colliculus are relayed by the ____ in the lower pons and the ___ at the mid-pontine level.

Answer 27

lower: superior olivary complex mid: nucleus of the lateral lemniscus

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 ______ and the ____ of the lower pons.

Answer 29

ventral cochlear nucleus | superior olivary complex

Question 30

The second crossing of auditory information is between the ____________ __________ ____________ of the lower pons and _____ in the mid-pons

Answer 30

superior olivary nucleus | nucleus of the lateral lemniscus

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 leminiscus

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 leminisci

Question 35

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

Answer 35

commissure

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 __________ and the ________.

Answer 36

right | left ears

Question 37

Because the _____________ _____________ ____________, the ____________ of the ___________ _______________, and the ___________ of the _____________ _______________ receive both crossed and uncrossed auditory information, all can participate in detecting the source of a sound.

Answer 37

superior olivary complex nuclei lateral lemniscus nuclei inferior colliculus

Question 38

The nucleus of the inferior colliculus receives information directly or indirectly from both _________ of the ___________ ____________, both __________ ___________ ______________, and both _____________ ___________, but it projects to only the ipsilateral medial geniculate nucleus of the thalamus.

Answer 38

nuclei 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 ipsilateral ____________ of the ___________ _______________ through the ____________ of the ___________ _____________.

Answer 40

thalamus nucleus inferior colliculus brachium inferior colliculus

Question 41

Due to the many crossings of auditory information in the brainstem, each medial geniculate nucleus is conscious of sound in _________ ears.

Answer 41

both

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