CSD Exam 2 (Pre/Post-Class Quizzes)

When a neuron is activated by a hair cell, or by another neuron...

its firing rate increases above its spontaneous rate

Which order describes the flow of neural inputs in the cortex?

Area 41 -> Area 42 -> Area 22 -> Area 44 -> Area 45

The order of afferent information flow in the auditory system is ____________________________ Abbreviations: A1 - Primary Auditory CortexCN - Cochlear Nucleus IC - Inferior Colliculus LL - Lateral Lemniscus MGB - Medial Geniculate Body SOC - Superior Olivary Complex

CN -> SOC -> LL -> IC -> MGB -> A1

Where does diversification and parallel processing in the auditory system start?

Cochlear Nucleus

What type of auditory fiber is the outer hair cell?

Efferent nerve fiber & Type-II afferent nerve fiber

T/F: Deflection of stereocilia in the inner hair cell towards the modiolus leads to auditory nerve firing.

False (deflection away)

T/F The cochlear traveling wave is the same as a sound wave.

False (it is like a surface wave)

Which nuclei is considered a switchboard to the higher auditory centers?

Inferior colliculus, because auditory inputs from the lower centers converge here

Binaural

Inputs/processing information from both ears

Monaural

Inputs/processing information only from one ear

How does the acoustic reflex change sound transduction through the middle ear?

It attenuates low frequencies

An input sound is played to the ear, causing both the inner and outer hair cells to respond. The sound remains constant, but at some point the activity of the outer hair cells is reduced. Which among the following mechanisms may be responsible for this reduction?

Medial olivocochlear system

What is tonotopic organization?

Spatial arrangement of the basilar membrane based on which frequencies achieve maximal traveling wave amplitude

What property does an fusiform cell demonstrate?

Spectral notch detector

Which among the following statements is true about the IHCs and OHCs? - Both IHCs and OHCs demonstrate electromotility - There is no neural connection (innervation) to the OHCs - Both hair cells are equal in number - There are more OHCs than IHCs

There are more OHC's than IHC's

T/F The pinna helps us in localizing sounds when the sound source is in the median plane.

True

Contralateral

side opposite the stimulation or measurement

What type of auditory fiber does convergence affect?

Type-I afferent nerve fiber

What type of auditory fiber is the inner hair cell?

Type-I afferent nerve fiber

What type of auditory fiber does divergence affect?

Type-II afferent nerve fiber

Which among the following cells are involved in coding interaural time differences? a. Cells in the medial superior olive b. Octopus cells c. Fusiform cells d. Cells in the lateral superior olive

a

Which among the following is not related to frequency coding? a. None of these: all relate to coding of frequency b. Place coding c. Tonotopy d. Temporal coding

a

The amplification and compression in the cochlea leads to:

a large dynamic range of hearing

The activity of the medial olivocochlear neurons (MOC) causes _________________ in the cochlea.

a reduction in outer hair cell amplification

Which of the following are functions of the outer hair cell? (Select all answers that apply.) a. Compression of basilar membrane motion at high sound levels b. Compression of basilar membrane motion at low sound levels c. Sharpening of the basilar membrane response d. Amplification of basilar membrane motion at low sound levels

a, c, & d

The tympanic membrane transfers vibrations from ______ to the ______

air / ossicles

The middle ear matches the impedance (loosely, resistance to the flow of energy) between ___ __ ___ ___ ______ and ____ __ ___ ______.

air in the ear canal / fluid in the cochlea

Which of the following describe differences between the stereocilia of the inner hair cells (IHCs) and outer hair cells (OHCs)? (Select all answers that apply.) a. The stereocilia of the IHCs are on the top (apical part) of the hair cell, whereas the stereocilia of the OHCs are towards the bottom (basal part) of the cell body b. The stereocilia of the OHCs are arranged in a V or W shape, whereas the stereocilia of the IHCs are arranged in a straight or slightly-curved line c. None of these are differences in the stereocilia between IHCs and OHCs d. The stereocilia of the IHCs are not embedded in the tectorial membrane, whereas the stereocilia of the OHCs are

b & d

Which of the following statements about the tuning curve is false? a. A tuning curve tells us the minimum SPL required to activate a given region on the basilar membrane (a.k.a. the threshold) b. A tuning curve tells us the characteristic frequency of a region of interest on the basilar membrane c. A tuning curve tells us how much gain is provided by the inner hair cell d. A tuning curve tells us the bandwidth of the basilar membrane displacement

c

What property does an octopus cell demonstrate?

coincidence detector

Which among the following nuclei is in the midbrain? a. Superior Olivary Complex b. Cochlear nucleus c. Medial Geniculate Body d. Inferior Colliculus

d

Which among the following statements about action potentials is false? a. They work on an "all-or-none" principle b. They are generated by change in movement of ions in and out of the nerve cell c. They are how neurons communicate throughout the brain d. They cannot be generated by neurons in the absence of external stimulation

d

In which of the following nuclei is tonotopy not preserved? a. All of these: tonotopy only happens in the cochlea b. Inferior Colliculus c. Supeior Olivary Complex d. Cochlear Nucleus e. None of these: it is preserved throughout the auditory system

e

Which among the following is not related to frequency coding? a. olley theory b. Place coding c. Temporal theory d. Tonotopy e. None of these: all relate to coding of frequency

e

Phase locking in the auditory nerve (AN) means:

each neuron in the AN tends to fire at a particular phase of the stimulus waveform

T/F: Tonotopy that starts in the cochlea is maintained throughout the auditory system, except the cortex.

false

The large dynamic range in the auditory system is encoded by the auditory nerve using _____________________

fibers that have different spontaneous rates, thresholds, and saturation levels

Frequency tuning in the auditory nerve means that the auditory nerve is:

frequency specific

Which of the following processes is performed by the pinna? (Select all that apply.) - amplification - funneling - filtering - rejection

funneling & filtering

The malleolar-incudal joint is formed by the:

head of malleus and body of incus

The most basal end of the basilar membrane is responsive to ________________ frequencies.

high

The traveling wave starts with ________ velocity, _________ ___________ close to the characteristic frequency place, and has its __________ amplitude close to the characteristic frequency place.

high / slows down / highest

What properties of auditory nerves does a low threshold demonstrate?

high spontaneous rate

What properties of auditory nerves does a small dynamic range demonstrate?

high spontaneous rate

The peripheral auditory system consists of (select all that apply): - the brainstem - the inner ear - the middle ear - the midbrain - the auditory cortex - the external ear

inner ear / middle ear / external ear

Convergence is a property of _____________

inner hair cells & Type-I auditory fibers

The middle ear is important because:

it matches the impedance of the air in the ear canal with the fluid in the cochlea

Which cortical layer receives afferent inputs from the thalamus?

layer 4

The firing rate of auditory nerve fibers encodes _________________ information for the brain.

level

What properties of auditory nerves does a high threshold demonstrate?

low spontaneous rate

What properties of auditory nerves does a large dynamic range demonstrate?

low spontaneous rate

The Jeffress model of coincidence detection for interaural time differences (ITDs) works for birds, but not so well for mammals, because:

mammals do not appear to have a spatial representation of time differences in the brain

Someone shrunk you down to the size of a grain of rice and dropped you into the tympanic cavity. You see a stirrup-shaped bone attached to the wall that you are facing. You also see a translucent membrane lower down, and in between the bone and this translucent window you see a big bulge. You realize you are staring at the __________ wall of the middle ear, and that the translucent membrane is the _________.

medial / round window

As you move from base to apex, the cochlea gets _________ , and the basilar membrane gets _________ and __________.

narrower / wider / looser

Type II auditory nerve fibers innervate which organ of Corti structures?

outer hair cells

Divergence is a property of ___________

outer hair cells & Type-II auditory fibers

The ossicles are connected to the cochlea via the _________________.

oval window

The pushing of the stapes into the oval window causes the __________________ to be pushed out.

round window

When the stapes pushes into the oval window, which membrane pushes out?

round window

Ipsilateral

same side as the stimulation or measurement

Middle chamber of the cochlea

scala media

Bottom chamber of the cochlea

scala tympani

Top chamber of the cochlea

scala vestibuli

The traveling wave occurs because of the pressure differential between:

scala vestibuli and scala tympani

Which of the following parts of the inner ear does not take part in hearing? - scala tympani - scala vestibuli - organ of Corti - semicircular canals

semicircular canals

What property does a spherical bushy cell demonstrate?

sends axons to both the lateral and medial superior olive

What property does a globular bushy cell demonstrate?

sends axons to the contralateral medial nucleus of the trapezoid body

Which structure in the organ of Corti is considered part of the auditory nerve?

spiral ganglion cells

When you are in an airplane and your ears "pop", which part of the middle ear is involved in this "pop"?

the Eustachian tube

The place on the basilar membrane where the characteristic frequency = 1 kHz is:

the place where the movement is maximal when you put in a 1 kHz tone

The fact that perilymph and endolymph have different concentrations of K+ and Na+ ions means:

they enable hair cell depolarization

Phase locking in the auditory nerve helps code _____ & ________

timing / frequency

Deflection of the stereocilia away from the modiolus causes:

tip links to open, leading to depolarization of the inner or outer hair cell

The cochlea is where _______________ occurs. (Select all that apply.) - sound localization - transduction - impedance matching - separation of frequency components

transduction & separation of frequency components

The thumbtack analogy works for the sounds boosted by the middle ear because the _______ is bigger than the ________

tympanic membrane / oval window