Auditory System II

Question 1

Connections of the auditory nerve fibers

Answer 1

many collaterals and various decussations throughout all levels

Question 2

Tonotopic organization

Answer 2

auditory neurons are responsive to a specific tonal frequency, this information is mapped throughout the auditory system

Question 3

Reflexes

Answer 3

auditory system is involved in certain reflexes

Question 4

spiral ganglion neurons are

Answer 4

bipolar

Question 5

Cochlear neuron begins

Answer 5

as the fibers exit the modiolus

Question 6

CN8 enters the brainstem at the

Answer 6

pontocerebellar angle

Question 7

Before synapsing at the cochlear nuclei the cochlear nerve

Answer 7

bifurcates and sends one branch to the ventral cochlear nucleus and the other bifurcates again sending a collateral to the ventral cochlear nucleus and 1 to the dorsal cochlear nucleus

Question 8

Dorsal cochlear nucleus gives off dorsal acoustic stria that project to

Answer 8

the contralateral lateral lemniscus

Question 9

Posterior portion of the ventral cochlear nucleus gives off intermediate acoustic stria that project to

Answer 9

the contralateral lateral lemniscus primarily, or bilaterally to the superior olive –> Lateral lemniscus

Question 10

Anterior portion of the ventral cochlear nucleus gives off ventral acoustic stria that project to

Answer 10

ipsilateral superior olive or to the trapezoid body and to the contralateral superior olive –> Lateral lemniscus

Question 11

Superior olivary complex is composed of

Answer 11

medial and lateral superior olivary nucleus and the nucleus of the trapezoid body

Question 12

What is the first point where auditory information first converges from both sides

Answer 12

SUPERIOR OLIVARY COMPLEX

Question 13

Superior Olivary Complex’s function

Answer 13

to analyze the timing and intensity of the auditory stimuli from both ears to LOCALIZE sounds (auditory cortex interprets this info)

Question 14

Superior Olivary Complex projects

Answer 14

bilaterally to the lateral lemniscus

Question 15

Nuclei of the Lateral Lemniscus

Answer 15

communicate via commissures and project to the ipsilateral Inferior colliculus

Question 16

Inferior colliculus receives input from

Answer 16

IPSILATERAL lateral lemniscus and nuclei of lateral lemniscus and BILATERAL superior olivary nuclei

Question 17

Inferior Colliculus projects to

Answer 17

Medial Geniculate Nucleus in the thalamus

Question 18

Medial Geniculate Nucleus projects to

Answer 18

Primary Auditory Cortex

Question 19

The Primary Auditory Cortex is located

Answer 19

within the lateral fissure, Brodman’s 41, 42 (tonotopic organization)

Question 20

Wernicke’s Area

Answer 20

Auditory Association Cortex 42, 22 part of temporal gyri

Question 21

Olivocochlear bundle

Answer 21

feedback to the Organ of Corti

Question 22

Auditory Sharpening

Answer 22

(pre- and post-synaptic inhibition) suppression of background noise via olivocochlear bundle

Question 23

Conduction Deafness

Answer 23

sound vibrations do not reach the oval window

Question 24

Bone or air conduction during conduction deafness is better

Answer 24

BONE - vibration still travels through temporal bone to activate HCs

Question 25

Causes of Conduction Deafness

Answer 25

otosclerosis, otitis media, inflammation to middle ear, ear wax, foreign object

Question 26

Otosclerosis

Answer 26

conduction deafness due to fixation of the foot plate of the stapes

Question 27

Sensorineural deafness

Answer 27

caused by disease of the cochlea, cochlear nerve or nuclei

Question 28

Causes of Sensorineural deafness

Answer 28

prolonged exposure to loud noise, aminoglycosides, aspirin, quinine, streptomycin side effects, acoustic neuroma, diabetes, syphilis, Meniere's

Question 29

Anacusis

Answer 29

absent hearing

Question 30

Hypacusis

Answer 30

reduced hearing

Question 31

presbycusis

Answer 31

hearing loss associated with aging (bilateral loss of high-frequency tones)

Question 32

Ipsilateral hearing loss

Answer 32

damage to CN8 or cochlear nuclei

Question 33

Bilateral hearing loss

Answer 33

CNS lesion after synapse within the cochlear nuclei

Question 34

Lesion of primary auditory cortex

Answer 34

affected ability to localize sounds in space (difficult to detect)

Question 35

Hearing loss of air conduction

Answer 35

damage to outer, middle, or inner ear

Question 36

Hearing loss of bone conduction

Answer 36

damage to inner ear indicating a sensorineural deficit

Question 37

Rinne test conduction deafness

Answer 37

Bone conduction > Air Conduction

Question 38

Rinne test sensorineural deafness

Answer 38

Air conduction > Air conduction

Question 39

Rinne

Answer 39

compares air and bone conduction

Question 40

Weber

Answer 40

hearing loss between ears

Question 41

Weber Conduction deafness

Answer 41

sound is louder in abnormal ear

Question 42

Weber Sensorineural deafness

Answer 42

sound is louder in normal ear

Question 43

Audiogram

Answer 43

device for measuring tones and frequencies heard by patient