Special Senses Hearing And Vestibular - 4/11 Karius

Question 1

Fx of middle ear?

Answer 1

Impedance matching

Question 2

Fx of inner ear?

Answer 2

Cochlea converts sound waves to APs (neural mechanism)

Question 3

What is the fluid in the Scala vestibule and tympani?

Answer 3

Perilymph

Question 4

Properties of Perilymph?

Answer 4

Similar to ECF

High Na, low K

Question 5

Endolymph composition?

Located where?

Answer 5

High K, low Na

Scala media

Question 6

How does the basilar membrane move during compression w/ the stapes?

During Rarefaction?

Answer 6

Down

Up

Question 7

High frequency sounds have what kind of wavelength?

Pitch?

Answer 7

Low

High

Question 8

At low frequency where does the maximum vibration of the basilar membrane occur?

Answer 8

Near the helicotrema

Furthest away from oval window

Question 9

Hair cells are composed of what?

They are connected to each other by what protein filament?

Answer 9

Stereocilia

Tip link

Question 10

What is the single true cilium called?

Answer 10

Kinocilium, it is tall

Question 11

What happens if the cilia bend TOWARD the kinocilium?

AWAY?

Answer 11

Depolarization

Hyperpolarize

Question 12

Bending hair cells towards the kinocilium opens what?

Answer 12

potassium channels that depolarize the cell

Potassium moves into cell

Question 13

The hearing pathway splits into 2 parallel paths in the cochlear nucleus, where does the ventral path process?

Dorsal?

Answer 13

Temporal and spectral features of the sound (timing and pitch)

Integrates acoustic info w/somatosensory info for localizing the sound

Question 14

What does the medial superior olive generate?

Mostly related to which pathway?

Answer 14

Intramural time differences

Dorsal

Question 15

What does the lateral superior olive generate?

Answer 15

Map of intral-aural INTENSITY differences

Question 16

What does the inferior colliculus do?

Answer 16

Suppresses info related to echoes and arrives at a final estimation of the sound on the horizon

Question 17

What does the superior colliculus do with the location data from the inf colliculus?

Answer 17

Adds 3rd dimension (vertically) to create spatial map

Question 18

In the primary auditory cortex (A1), what is activated by low frequency sounds?

High frequency?

Answer 18

Rostral

Caudal

Question 19

The association cortex is activated by what?

Answer 19

Has more neurons and is activated by complex sounds

Question 20

Fx of outer ear?

Answer 20

Funnel sound waves into ear

Question 21

What does angular acceleration require?

Answer 21

Rotation around 1 or more planes

Question 22

What is the utricle best situated to detect?

Answer 22

Linear motion occurring on the horizontal plane

Ex. Walking

Question 23

What is the saccule best position for?

Answer 23

Vertical acceleration

Question 24

Turning motion is best detected by what?

Answer 24

Horizontal/lateral canals

Question 25

Falling or being thrown backwards maximally activates what?

Answer 25

Posterior semicircular canal

Question 26

Falling forward activates what?

Answer 26

Anterior semicircular canal

Question 27

In the semicircular canals, what is used to detect sound?

Answer 27

Ampulla

Question 28

What is used in the utricle and saccule to detect sound? What other organ is here?

Answer 28

Macula Otolith organ

Question 29

If you are falling forward what is activated? What muscle is activated? Inhibited? How do your eyes move?

Answer 29

Anterior semicircular canal Superior rectus m. Activated Inferior rectus m. Inhibited EYES move UP

Question 30

If you are falling backward what is activated? What muscle is activated? Inhibited? How do your eyes move?

Answer 30

Posterior semicircular canal Superior oblique active Inferior oblique inhibited EYES move DOWN

Question 31

If you are spinning to the RIGHT what is activated? Ipsilateral eye: What muscle is activated? Inhibited? Contralateral eye? How do your eyes move?

Answer 31

Horizontal (lateral) semicircular canal Medial rectus activated Lateral rectus inhibited Lateral rectus activated Medial rectus inhibited Eyes move LEFT

Question 32

Fx of the cortex/cerebellar involvement in the vestibulooptic reflex?

Answer 32

Suppress the reflex to allow for voluntary motion