Sfs - Auditory

Front 1

Function of superior olivary nucleus

Back 1

Localizaiton of sound

Front 2

Inferior colliculus function

Back 2

localization of sound

Front 3

Medial geniculate function

Back 3

main thalamic-relay point

Front 4

Heschl's gyrus function

Back 4

auditory cortex

Front 5

What kind of wave is sound?

Back 5

Sinusoidal, involving pressure increases and decreases. Fluctuating between compression and rarefaction in an elastic medium.

Front 6

Normal frequency range in humans.

Back 6

20 Hz to 20 kHz

Front 7

With respect to loudness, there is approximately an equal increment between a ___ fold increase in pressure.

Back 7

Ten

Front 8

a. Most sensitive frequency.
b. Damage occurs at what loudness?

Back 8

a. 1 kHz
b. 120 dB

Front 9

What is the central auditory pathway (step-by-step)?

Back 9

Cochlea > cochlear nerve > cochlear nucleus. From here, some fibers cross in trapezoidal body, or go straight to inferior colliculus > medial geniculate > cortex. This is a bilateral system.

Front 10

Function of outer ear.

Back 10

Collection of sound, focusing sound on eardrum

Front 11

Functions of middle ear.

Back 11

Air-filled, 3 bones. Transmission of sound from eardrum to oval window. AMPLIFICATION!!!

Front 12

Cochlea function.

Back 12

Convert mechanical energy to electrical.

Front 13

What goes on in middle and inner ear?

Back 13

Vibrations cause ossicles to oscillate, sending pressure waves into perilymph chambers. Pressure eventually released at round window. Scala media has endolymph.

Front 14

Main transduction organ sitting on the basilar membrane and semi encapsulated by the tectorial membrane.

Back 14

Organ of Corti

Front 15

Ca dependent synapse with vesicle fusion and glutamate release.

Back 15

Hair cell synapse

Front 16

Nerve fibers from the brain heading toward inner and outer hair cells.

Back 16

2 olivocohlear efferents

Front 17

Innervate inner hair cells.

Back 17

Primary afferents

Front 18

Innvervate outer hair cells.

Back 18

Secondary afferents.

Front 19

Convergence of these fibers. Each cell has 10 outputs to the CNS.

Back 19

Afferent fibers from inner hair cells.

Front 20

Divergence of these fibers. Afferents of about 10 of these cells connect.

Back 20

Afferent fibers from outer hair cells.

Front 21

Change shape (contract/expand) when depolarizaed. Useful for sensitivity, dampening movements, and amplification.

Back 21

Outer hair cells.

Front 22

Loudness/intensity is encoded by?

Back 22

Firing frequency of the APs in the nerve. Linear relationship. Saturation at around 500 Hz

Front 23

Encoding frequency depends on what 2 mechanisms?

Back 23

location of the cell on the basilar membrane and phase locking

Front 24

The mehcanism where if a sinusoidal wave brings info into the membrane and excites the hair cells, the output is locked to the phase of the waves.

Back 24

Phase locking

Front 25

What can shift the dynamic range of afferent nerve fibers?

Back 25

Outer hair cells stimulated directly by efferents.

Front 26

Process of outer hair cells getting eliminating background noise.

Back 26

Antimasking

Front 27

In what 2 ways are outer hair cells important?

Back 27

Amplification of basilar membrane and changing sensitivity of the inner hair cells and their afferent connections to the CNS.

Front 28

Because the cochlear n. is split and sends info to lots of different structures, the inner hair cells have ______ afferents.

Back 28

multiple

Front 29

Mechanism in superior olive for knowing direction from where sound wave is coming from

Back 29

interaural timing differences, which is dependent on angle to midline.

Front 30

In the medial superior olive, cells respond best with _______ input and _______ and _______ innervation.

Back 30

Bilateral; ispilateral; contralateral. Yes, a redundant answer.

Front 31

When will cells in the superior olive respond better?

Back 31

When a signal is less intense from 1 ear than from the other ear.

Front 32

Input of the inf. colliculus

Back 32

lateral lemnisus

Front 33

Cells in inf. colliculus are sensitive to what?

Back 33

Differences in aural delay and intensity. Thought to be involved in localization

Front 34

Main relay station to get info to cortex.

Back 34

Med. geniculate. Some cells sensitive to auditory, some multimodal.

Front 35

Location of main part of auditory cortex

Back 35

temporal lobe

Front 36

Primary auditory cortex in Heschl's gyrus?

Back 36

Area 1

Front 37

Order of cell arrangement in auditory cortex

Back 37

tonotopic

Front 38

Processing of information in auditory cortical neurons.

Back 38

Across frequency, location, and intensity.

Front 39

Area critical to language production and speech production.

Back 39

Broca's area

Front 40

Area critical for speech comprehension

Back 40

Wernicke's area

Front 41

Area of basilar membrane responding to high frequencies.

Back 41

Near oval window. narrow and less flexible.

Front 42

Area of basilar membrane detecting low frequencies.

Back 42

Near apex of cochlea. Wider and more flexible.

Front 43

Present throughout the auditory system. Arrangement of cells to map out tones.

Back 43

Tonotopic map

Front 44

Oscillates differently for different frequencies

Back 44

Basilar membrane.

Front 45

Causes transduction of sound

Back 45

Shearing forces between the cilia and the tectorial membrane

Front 46

Where is endolymph derived from? Where does it reside? What is unique about it?

Back 46

Stria vascularisi, scala media, high K+ concentration

Front 47

Primary cells responsible for collecting auditory information

Back 47

Inner hair cells

Front 48

Cells responsible for modulation of signal

Back 48

Outer hair cells

Front 49

Where does potassium enter the hair cell?

Back 49

Through the stereocilia along a HUGE driving force.

Front 50

Dissipates K depolarization

Back 50

Activation of voltage gated K channels allowing extrusion of K into the perilymph.

Front 51

Largest cilia

Back 51

Kinocilium

Front 52

Shearing between tips of cilia and tect. memb. cause...?

Back 52

Tension on tip link from pressure changes and opening of mechanosensitive K channels

Front 53

Important in encoding frequency

Back 53

Position of hair cell along basilar membrane and properties of basilar membrane. All cells have threshold close to the baseline of sensitivity.

Front 54

Allow a person to bypass hair cells by directly stimulating afferent nerve fibers. A microphone will collect sound and split it into various frequencies and send stimulation to appropriate part of basilar membrane.

Back 54

Cochlear implant