Clh&n And Fns Test Iv Fns 20: Auditory And Vestibular Pathways

Front 1

What are the three compartments of the cochlea?

Back 1

Scala vestibuli, scali tympani, and cochlear duct

Front 2

What two membranes of the cochlea separate the three compartments of the cochlea?

Back 2

Vestibular and basilar membranes

Front 3

On which membrane is the organ of corti located in the cochlea?

Back 3

Basilar membrane

Front 4

What are the three basic components of the organ of corti?

Back 4

Hair cells, supporting cells and tectorial membrane

Front 5

What contains cell bodies of bipolar afferents that innervate hair cells?

Back 5

Spiral ganglion

Front 6

What produces a wave that travels through the scala vestibuli and the scala tympani?

Back 6

Movement of the oval window produced by the stapes

Front 7

What determines the amount of displacement of the basilar membrane?

Back 7

The amplitude of the sound

Front 8

What sound property determines the area of maximal basilar membrane displacement?

Back 8

The frequency of the sound (High frequencies at base, low at apex)

Front 9

What nerve is formed by axons of the spiral ganglion?

Back 9

Cochlear nerve

Front 10

Where does the cochlear nerve terminate after origination at the spiral ganglion?

Back 10

dorsal and ventral cochlear nuclei

Front 11

On what structure are the two cochlear nuclei located?

Back 11

Lateral surface of the Inferior cerebellar peduncle

Front 12

How is the cochlear nerve organized?

Back 12

Tonotopically (higher frequencies are spatial separated dorsally from lower frequencies)

Front 13

What are the two main pathways through the pontine tegmentum for acoustic axons?

Back 13

Dorsal acoustic stria and ventral acoustic stria

Front 14

Which of the two acoustic stria is larger?

Back 14

Ventral acoustic stria

Front 15

Where do the fibers for both the ventral and the dorsal acoustic stria ascend?

Back 15

They cross in the midline and ascend as the CONTRALATERAL lateral lemniscus

Front 16

What forms the trapezoid body?

Back 16

Crossing fibers from the ventral acoustic stria

Front 17

Besides sending axons up through the contralateral lateral lemniscus (via the trapezoid body) where else do acoustic axons go (collaterals)?

Back 17

Superior olivary complex

Front 18

True/False: Individual neurons in the superior olivary complex receive neuronal cell input from both ears.

Back 18

TRUE

Front 19

True/False: Axons from the Superior Olivary complex enter both the contralateral and ipsilateral lateral lemniscus

Back 19

TRUE

Front 20

What structure functions in the spatial localization of sounds?

Back 20

Superior olivary complex

Front 21

What two structures contribute fibers for the lateral lemniscus?

Back 21

Ipsilateral/Contralateral SOC, CONTRALATERAL dorsal/ventral cochlear nuclei (via acoustic stria)

Front 22

True/False: Acoustic information carried in the lateral lemniscus is monoaural.

Back 22

False. The information ascending in each lateral lemniscus is binaural since the SOC receives binaural input and sends axons bilaterally to the lateral lemniscus

Front 23

Where is the site of termination of the lateral lemniscus?

Back 23

Inferior colliculus

Front 24

Where do axons of the brachium of the inferior colliculus terminate?

Back 24

Ipsilaterally in the medial geniculate body of the thalamus

Front 25

Where do fibers from the MGB (medial geniculate body) terminate?

Back 25

In the primary auditory cortex

Front 26

Trace the pathway of auditory information starting with the lateral lemniscus (four steps).

Back 26

1. Lateral lemniscus 2. Inferior colliculus 3. Medial Geniculate Body (via brachium of inferior colliculus) 4. Primary Auditory Cortex (via auditory radiations)

Front 27

What is a descending pathway from auditory cortex to superior olivary complex, that parallels the ascending pathway

Back 27

Efferent auditory pathway

Front 28

In the Efferent auditory pathway, what name is given to efferent fibers which arise from the SOC and terminate around the hair Corti cells?

Back 28

Olivocochlear bundle

Front 29

What is the clinical name for rining in the ears?

Back 29

Tinnitus

Front 30

What are defects in conductive mechanisms in external or middle earcalled?

Back 30

Conductive deafness

Front 31

What is the name for defects in the production or transmission of neural auditory information?

Back 31

Sensorineural deafness

Front 32

What is the name for the sensory receptor region in the utricle and saccule called?

Back 32

Macula

Front 33

What is the collective name for the utricle and saccule?

Back 33

The otolithic organs

Front 34

What is the name of the dilated portion of the semicircular canals called?

Back 34

Ampulla

Front 35

What is the sensory region of the semicircular canal's ampulla called?

Back 35

crista ampullaris

Front 36

What is the gelatinous 'roof' of the hair cells of the crista ampullaris called?

Back 36

cupula

Front 37

What are the four vestibular nuclei associated with the vestibular nerve?

Back 37

Superior, inferior, lateral and medial

Front 38

Describe the location of the vestibular nuclei?

Back 38

Located in the floor of the IV ventricle lateral to the sulcus limitans

Front 39

Superior is adjacent with ____________ (vestibular nuclei).

Back 39

Lateral

Front 40

List the three projections of the vestibular nuclei.

Back 40

Spinal cord, extraocular nuclei, vestibulo-cerebellar

Front 41

What are the two components of the vestibular nuclei's projection of the spinal cord?

Back 41

Lateral vestibulospinal tract, and medial vestibulospinal tract

Front 42

Which (lateral/medial) vestibulospinal tract is responsible for the "righting reflex" (upper/lower limb extensors) and projects ipsilaterally to all levels of the spinal cord?

Back 42

Lateral vestibulospinal tract

Front 43

Which (lateral/medial) vestibulospinal tract is responsible for controlling neck and head movements and projects bilaterally to the cervical spinal cord?

Back 43

Medial vestibulospinal tract

Front 44

Describe the pathway of the vestibulo-ocular projection.

Back 44

Originate from the four vestibular nuclei, travel up the MLF and terminate on the extraocular nuclei (III, IV and VI)

Front 45

What cranial nerves arise from extraocular nuclei?

Back 45

III, IV and VI

Front 46

What vestibular projection mediates the vestibular-ocular reflex?

Back 46

Extraocular projection

Front 47

What is the purpose of the vestibular-ocular reflex?

Back 47

Stabilize images on the retina

Front 48

What are three clinical signs of vestibular dysfunction?

Back 48

Nystagmus, vertigo, and disequillibrium/unsteadiness

Front 49

Name the disease: Characterized by abnormal production of endolymph in the membraneous labyrinth, affects vestibular and auditory functions.

Back 49

Meniere's disease

Front 50

What is the effect of cold or warm water on the vestibular system?

Back 50

It alters the density of the endolymph resulting in nystagmus

Front 51

Which direction will the nystagmus be when cold water affects the vestibular system?

Back 51

Direction of nystagmus is to the side opposite the affected ear (Cold Opposite Warm Same COWS)

Front 52

Which direction will the nystagmus be when warm water affects the vestibular system?

Back 52

Direction of nystagmus will be to the same side of the affected ear (Cold Opposite Warm Same COWS)

Front 53

What is the doll's eye reflex?

Back 53

rotating the head to one side results in opposite eye movement.

Front 54

What is the absence of the doll's eye reflex indicate?

Back 54

Brainstem lesion.