M2-C2-L42 --> Auditory & Vestibular Pathways

Front 1

Where does the majority of auditory input end up?

Contralateral or Ipsilateral?

Back 1

Contralateral (80%)

Front 2

The apical tip of the cochlea is for what type of tones?

Back 2

Low tones

Front 3

The base of the cochlea is for what type of tones?

Back 3

High tones

Front 4

Where do you first discern sound?

Back 4

Primary auditory cortex

Front 5

What type of cell bodies are in the spinal ganglia?

Back 5

Bipolar

Front 6

Describe the auditory DIRECT pathway (aka - simple pathway)

Back 6

Hair Cells
Spinal Ganglion
Dorsal Cochlear nucleus (synapse)

Crosses over the
Dorsal Auditory Stria

Lateral Lemniscus
Inferior Colliculus nucleus (synapse)
Medial Geniculate Body (synapse)

Goes underneath Lentiform nucleus,
(thus sublentiform radiation)

Transverse Temporal Gyri of Hescl (synapse)

Front 7

Describe the auditory INDIRECT pathway.

Back 7

Hair cells
Spinal Ganglion
Ventral Cochlear nucleus (synapse)

Crossover via Trapezoid body
(aka - inferior + intermediate acoustic striae)

Superior Olivary nucleus (synapse)

(goes contralateral or ipsilateral)

Lateral Lemniscus
Inferior Colliculus nucleus (synapse)
Medial Geniculate Body (synapse)
Transverse Temporal Gyri of Hescl (synapse)

Front 8

Continuation of the lateral lemniscus occurs where?

Back 8

Brachium of the Inferior Colliculus

Front 9

Sympathetic reflex responses to noise occur via what pathway and nucleus?

Back 9

Tectospinal pathway

Superior Colliculus

Reticular Formation (Brainstem)

Front 10

The pathway for the sublenticular portion of the Internal canal which carries info to the Hescl is called what?

Back 10

Geniculocortical tract.

Front 11

In the auditory pathways, what is unique about the MGB?

Back 11

Only nucleus of the auditory pathway in which you don't have communication from one side to the other.

Front 12

Describe the crossovers for the DIRECT auditory pathway.

Back 12

Occurs from the Dorsal Cochlear Nucleus to the Inferior Colliculus nucleus on the Lateral Lemniscus tract

via Dorsal Auditory Striae

Front 13

Describe the crossovers for the INDIRECT auditory pathway.

Back 13

Occurs from the Ventral Cochlear Nucleus to the Superior Olivary Nucleus

via Trapezoid Body Striae

May also crossover at....

From Superior Olivary Nucleus to Inferior colliculus

via Lateral Lemniscus

Front 14

Describe the Weber test.
- What makes it positive/negative on which side?

Back 14

Place active tuning fork on forehead.

The side with greater hearing is infected side b/c brain will focus on bone conduction on the ear that has air conduction problems.

Front 15

Describe the Rinnes test.
- What makes it positive/negative on which side?

Back 15

Put active tuning fork on mastoid, then besides ear.

If AC > BC, then normal ear.

If BC > AC, then the ear on that side is infected.

Front 16

In terms of auditory, lesions of the primary afferent fibers would cause what?

Back 16

Complete deafness in that side of ear.

Front 17

Lesions of the Ventral or Dorsal Cochlear nucleus would cause what?

Back 17

Total deafness in that side of ear.

Front 18

Lesions to the lateral lemniscus tract would cause what?

Back 18

70% to 85% hearing loss on that ear.

Not complete b/c of ipsilateral and contralateral properties.

Front 19

When you hear from your right ear, which part of the cortex are you using to "hear?"

Back 19

Left side (majority)

Front 20

How does hair cells get promote excitation?

Back 20

Fluid moves Stereocilia towards Kinocilium

Front 21

How does hair cells promote inhibition?

Back 21

Fluid moves Kinocilium towards Stereocilia.

Front 22

Actions of the vestibular system can be described how?

Back 22

Subconscious reflex

Front 23

Components of the vestibular nucleus complex.

Back 23

Pairs of:

- Superior vestibular nu.
- Lateral vestibular nu.
- Inferior vestibular nu.
- Medial vestibular nu.

Front 24

The vestibular system is intimately associated with what brain part?

Back 24

Flocculonodular lobe of cerebellum

Front 25

Afferents from hair cells go to where in the vestibular system?

Back 25

Each component of the vestibule system

AND

Cerebellum

Front 26

Describe the ascending pathway of the vestibular system from the vestibular nu. and what is its purpose?

Back 26

From superior and middle vestibular nu.

Ascends bilaterally through the MLF contralaterally to the Lateral Gaze Center.

Front 27

Describe the descending pathway of the vestibular system from the LATERAL vestibular nu. and what is its purpose?

Back 27

Will stay on the ipsilateral side along the

lateral vestibulospinal tract

along the ventral horn of the spinal cord.

Will affect lower motor neurons associated with

ANTI-GRAVITY

Front 28

Describe the descending pathway of the vestibular system from the MEDIAL vestibular nu. and what is its purpose?

Back 28

Will travel bilaterally along the

medial vestibulospinal tract

along the ventral horn of the spinal cord.

Will affect lower motor neurons associated with

ANTI-GRAVITY

Front 29

When you turn your head left, describe the EXCITATION process on the oculomotor nu. and the lateral gaze center.

Back 29

Fluid of LEFT semicircular duct lags behind and goes toward the crista ampullaris.

Ascending pathway (via Sup. and Medial ventricular nu.) will cross over to contralateral Lateral Gaze Center and Oculomotor nu.

via MLF

This will excite eye to opposite direction of head turn.

Front 30

Describe the physiological process and result of putting cold water in someone's LEFT ear.

Back 30

Will change density of the air,

causes fluid in the semicircular ducts to move DOWNWARD

Will cause right eye nystagmus

Front 31

Describe the physiological process and result of putting warm water in someone's LEFT ear.

Back 31

Will change density of the air,

causes fluid in the semicircular ducts to move UPWARD

Will cause LEFT eye nystagmus