06d: Central Auditory System Flashcards Preview

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Flashcards in 06d: Central Auditory System Deck (44):
1

Sensory ganglion cells of auditory system are formally called:

Spiral ganglion cells

2

Several spiral ganglion cells contact one (inner/outer) HC. This results in (high/low) resolution.

Inner;
Higher

3

One spiral ganglion cell contracts several (inner/outer) HCs. This results in (high/low) resolution.

Outer;
Lower

4

Most, (X)%, of spiral ganglia are in contact with (inner/outer) HCs.

X = 90
Inner

5

Only (X)% of spiral ganglia are in contact with (inner/outer) HCs.

X = 10
Outer

6

Spiral ganglia project primarily to (ipsi/contra)-lateral (X).

Ipsilateral;
X = cochlear nucleus

7

Cochlear nuclei neurons project primarily to (ipsi/contra)-lateral (X).

Contralateral (mainly) and ipsilateral;
X = superior olive

8

"Trapezoid body" refers to:

Bundles of crossing axons, projecting from cochlear nuclei to contralateral superior olives

9

Although most input to (X) comes from the (ipsilateral/contralateral) (Y), there are a few axons from cochlear nuclei that project directly to (X). These all travel via (Z).

X = inferior colliculus;
Ipsilateral;
Y = superior olive
Z = lateral lemniscus

10

Bilateral lesion of inferior colliculus will result in:

complete deafness

11

Unilateral lesion of inferior colliculus will prevent (ipsi/contra)-lateral ascending auditory input from reaching cerebral cortex

Neither! Inputs cross midline several times before reaching IC

12

List locations in auditory pathway, before inferior colliculus, where ascending auditory inputs cross midline.

1. trapezoid body
2. nucleus of LL

13

In ascending auditory pathway, neurons of IC project (ipsilaterally/contralaterally/bilaterally) to (X) via (Y).

Ipsilaterally;
X = MGN of thalamus
Y = brachium of IC

14

Bilateral lesion of MGN will result in:

Complete deafness

15

In ascending auditory pathway, neurons of MGN project to (X) via (Y).

X = cerebral cortex
Y = internal capsule

16

L auditory cortex receives input from (R/L) ear.

Both R and L cortices receive input from both R and L ears

17

(Doral/ventral) cochlear nuclei contain(s) tonotopic maps.

Both

18

Projections to (ipsi/contra/bi)-lateral IC comes from (ventral/dorsal) cochlear nuclei.

Ipsi and contralateral;
Dorsal

19

Projections to (ipsi/contra/bi)-lateral superior olivary complex comes from (ventral/dorsal) cochlear nuclei.

Bilateral;
Ventral

20

(Dorsal/ventral) cochlear nucleus receives giant synapses called (X) from (Y).

Ventral;
X = endbulbs of Held
Y = primary sensory afferents

21

(Dorsal/ventral) cochlear nucleus projects to (X) via giant synapses called (Y).

Ventral;
X = SOC
Y = calyceal endings

22

Giant synapses (end bulbs of Held and calcyeal endings) to/from (X) nucleus is important for which reasons?

X = ventral cochlear nucleus

1. Reliability
2. Speed

23

Key function of Superior olivary complex is (X). It does this by which mechanism(s)?

X = detection of localization of sound

1. Interaural time difference (below 3 KHz)
2. Interaural level difference (above 3 KHz)

24

The (X) can localize high frequency (above 3 Hz) sound based on (Y) mechanism. This is a result of sound reaching the two ears with difference in (Z).

X = SOC
Y = ILD (inter aural level difference)
Z = intensity

25

The (X) can localize low frequency (below 3 Hz) sound based on (Y) mechanism. This is a result of sound reaching the two ears with difference in (Z).

X = SOC
Y = ITD (interaural time difference)
Z = time

26

Interaural level difference involves excitation of (ipsi/contra/bi)-lateral (X) and inhibition of (ipsi/contra/bi)-lateral (Y).

Ipislateral;
X = lateral superior olive AND
Contralateral medial nucleus of trapezoid body;

Contralateral;
Y = lateral superior olive (via MNTB)

27

Medial nucleus of trapezoid body, when receiving (stimulatory/inhibitory) input from (ipsilateral/contralateral) cochlear nuclei, projects (stimulatory/inhibitory) output to (ipsilateral/contralateral) (X).

Stimulatory;
Contralateral;
Inhibitory;
Ipsilateral;
X = LSO

28

The localization of sound that's 10 Hz is encoded by (absolute/relative) level of (excitation/inhibition) of (X).

Relative;
Excitation and inhibition
X = ipsi and contralateral LSOs

29

Interaural time difference involves (X) SO nucleus, which has neurons arranged in (Y) fashion.

X = medial;
Y = medial to lateral

30

Interaural time difference: L cochlear nuclei sends output to (R/L) medial superior olive via (X).

Both R and L;
Contralateral output via:
X = trapezoid body

31

In localization of sound based on ITD, the (MSO/LSO) neuron is maximally activated when:

MSO;

Coincident synaptic input reaches neuron from both ipsilateral and contralateral cochlear nuclei

32

(X) is an obligatory relay of ascending auditory inputs.

X = IC and MGN

33

Ascending auditory pathway: Some (X) neurons send axons across midline to contralateral (X) via commissure of (X).

X = IC

34

Ascending auditory pathway: IC projects to (ipsilateral/contralateral) (X) via (Y).

Ipsilateral;
X = MGN;
Y = brachium of IC

35

At (X), there is convergence of binaural inputs, producing topographic map of auditory space.

X = IC

36

In ascending auditory pathway, the (X) plays role in encoding complex sounds of speech.

X = MGN

37

Descending input to MGN from (X) cortex functions to:

X = auditory;

select/control ascending input

38

Primary auditory cortex is also called:

A1 or Brodmann's area 41

39

Primary auditory cortex (above/below) secondary auditory cortex. Both found at which gyrus?

Transverse gyrus (of Heschl)

40

(Primary/secondary) auditory cortex organized so rostral end receives sound that are (X). Caudal end receives sounds that are (Y).

Primary;
X = low in frequency
Y = high in frequency

41

Sounds that vibrate the very base of the basilar membrane will eventually project to (rostral/caudal/middle) of primary auditory cortex.

Caudal

42

The "belt areas", aka (X), receive more (localized/diffuse) input than primary auditory cortex.

X = secondary auditory cortex (or Brodmann's area 42)
Diffuse

43

Wernicke's area is located in (primary/secondary) auditory cortex.

Secondary

44

(X) is the lowest level of ascending auditory system at which binaural input to the same neuron occurs.

X = superior olive