auditory system 2

Question 1

neurotransmitters for auditory pathways

Answer 1

glutamate and aspartate.

Question 2

tonotopy of afferent axons of auditory system

Answer 2

maintained throughout the central auditory pathways.

Question 3

dorsal and ventral cochlear nuclei

Answer 3

recieve all nerve info from ipsilateral ear
near restiform body in upper medulla by exit of CN9, only part of auditory pathway where lesion can cause monoaural deafness.

Question 4

spiral ganglion incoming axons

Answer 4

ascending bundle goes to post cochlear nuc
descending go to anterior coch nuc
have tonotopy, laterally synapsing neurons have low tones, medially synapsing neurons have high tones.

Question 5

monoaural information

Answer 5

routed to contralateral side

project from both cochlear nuclei, termed direct and indirect

Question 6

binaural information

Answer 6

used to compare differences in sounds that reach both ears.

Question 7

direct monoaral projections

Answer 7

direct projection to the inf colliculus

Question 8

indirect monoaural projections

Answer 8

multisynaptic through brainstem nuclei

Question 9

superior olivary nucleus

Answer 9

first area of convergence of binaural information, first level of processing of sound localization
medial and lateral divisions (tonotopically organized.)

Question 10

medial superior olivary nuclei

Answer 10

organized so that input from ipsi and contr ears can be compared in time to localize a sound

Question 11

lateral superior olivary nuclei

Answer 11

function in sound localization and sound intensity processing.

Question 12

lateral lemniscus

Answer 12

binaural and monoaural neurons join to form the lateral lemniscus that projects to the inferior colliculus.

Question 13

inf colliculus

Answer 13

recieve all ascending auditory pathways, highly organized for sound frequency, has areas for processing of binaural localization of sound and monoaural frequency information

Question 14

frequency organization of the inf colliculus

Answer 14

low frequencies are lateral and posterior, high are anterior and medial.

Question 15

inf projection

Answer 15

to the medial geniculate body via the inf brachium

Question 16

anterior division of med geniculate nucleus

Answer 16

projects to the prim audit cortex, responds to complex sound patterns

Question 17

post div of med gen nuc

Answer 17

projects to secondary auditory cortex, has cells that rapidly adapt to sound stimuli, conveys information about moving or novel stimuli

Question 18

medial div of med gen nuc

Answer 18

responds to wide range of frequencies and other stimuli, has many projections and may act as a part of the reticular formation.

Question 19

med div of med gen nuc projection

Answer 19

to auditory cortex via the retrolenticular portion of the posterior lim of the internal capsule.

Question 20

prim auditory complex

Answer 20

BA 41, tonotopically organized low-lat high-med in a series of columns that respond tothe same frequency.

Question 21

olivocochlear efferent system

Answer 21

descending projections from the superior olivary complex to the cochlea specifically hair cells with a majority of innervation to outer. involved in auditory sharpening.

Question 22

middle ear reflex

Answer 22

high intensity sounds cause restriction of middle ear ossicle movement, cochlear nuclei of superior olive provied afferent arm that project to the motor nuclei of
CN 5 and 7