Test 2 - CENTRAL AUDITORY SYSTEM

Question 1

VIII cranial nerve (Auditory portion) is ______ neuron and is part of the ______________.

Answer 1

1. 1st order

2. peripheral auditory system

Question 2

Nerve fibers pass from the cochlea through the ___________.

Answer 2

Internal Auditory Canal

Question 3

The Internal auditory canal begins at the ____________ and terminates at the _______________.

Answer 3

1. cochlear modiolus

2. base of the brain

Question 4

The fibers of the 8th nerve are innervated by the ______, ______, and the _____________

Answer 4

1. Utricle
2. Saccule
3. Semicircular canals

Question 5

[In the 8th nerve] There are approximately ________ nerve fibers in the cochlear portion and __________ in the vestibular portion.

Answer 5

1. 30 Thousand

2. 20 Thousand

Question 6

The auditory portion of the VIIIth nerve spirals through the _____________.

Answer 6

Internal Auditory Canal

Question 7

The Internal Auditory Canal carries what 3 things?

Answer 7

1. VIIIth Nerve
2. VII Facial Nerve
3. Internal Auditory Artery

Question 8

The VIIIth nerve attaches to the brain at the__________.

Answer 8

cerebellopontine angle (CPA)

Question 9

Ascending central auditory pathway involves these 5 nuclei:

Answer 9

1. Cochlear nucleus
2. Superior olivary complex
3. Lateral lemniscus
4. Inferior colliculus
5. Medial geniculate body

Question 10

From the cochlear nucleus there are two ascending pathways:

Answer 10

1. Ipsilateral

2. Contralateral

Question 11

______of fibers from Cochlear nucleus are Ipsilateral (remain on the same side) to ascend the ___________.

Answer 11

1. 1/3

2. Superior olivary complex

Question 12

_______ of fibers cross over/decussate the brainstem to the other _____________.

Answer 12

1. 2/3

2. superior olivary complex

Question 13

What are decussations?

Answer 13

crossover points in the brain that unite symmetrical portions of it’s two halves.

Question 14

The first decussation in the auditory pathways occurs after the _________ at the level of the ___________.

Answer 14

1. cochlear nucleus

2 trapezoid body

Question 15

All neurons will synapse at the ___________ before going toward primary auditory cortex in the temporal lobe.

Answer 15

1. medial geniculate body

Question 16

_____________ are specialized nerve-fiber bundles that unite similar structures on both sides of the brain.

Answer 16

Commissures

Question 17

The _____________ receives input from both the ipsilateral and contralateral cochlear nuclei.

Answer 17

Superior Olivary Complex

Question 18

The _____________ provides a major pathway for the transmission of impulses from the ipsilateral lower brain stem.

Answer 18

Lateral Lemniscus

Question 19

The ______________ receives afferent stimulation from both superior olivary complexes.

Answer 19

Inferior Colliculus

Question 20

What is the Medial Geniculate Body?

Answer 20

The final subcortical auditory relay station, found in the thalamus on each side of the brain.

Question 21

From the medial geniculate body neurons proceed to the ipsilateral temporal lobe via ______________.

Answer 21

Auditory Radiations

Question 22

Ascending/afferent pathway terminates in the primary auditory cortex reception area: AKA

Answer 22

Heschel’s gyrus

Question 23

The efferent pathway is comprised of what two main segments?

Answer 23

1. Cortex and rostral Brainstem system

2. The Olivocochlear system

Question 24

The Olivocochlear system

Answer 24

Made up of neurons which make up medial and lateral superior olivary complex nuclei on both sides of the brainstem.

Question 25

Each nucleus along ascending pathway is ________ organized

Answer 25

tonotopically

Question 26

Neurons in the primary auditory cortex also maintain a representation of the ___________.

Answer 26

tonotopic organization (frequency map) of the basilar membrane.

Question 27

From the cochlear nuclei, small fibers connect with the __________ where the auditory message joins all other sensory messages.

Answer 27

reticular formation

Question 28

The ____________ is where the auditory message joins all other sensory messages.

Answer 28

reticular formation

Question 29

The main function of the reticular formation is…

Answer 29

To select the type of sensory message to be treated first.

Question 30

Conscious perception requires the integrity of both the ______________ and the ______________.

Answer 30

1. Central Auditory System (primary auditory)

2. Reticular Formation (secondary auditory)