06d: Central Auditory System Flashcards
Sensory ganglion cells of auditory system are formally called:
Spiral ganglion cells
Several spiral ganglion cells contact one (inner/outer) HC. This results in (high/low) resolution.
Inner;
Higher
One spiral ganglion cell contracts several (inner/outer) HCs. This results in (high/low) resolution.
Outer;
Lower
Most, (X)%, of spiral ganglia are in contact with (inner/outer) HCs.
X = 90
Inner
Only (X)% of spiral ganglia are in contact with (inner/outer) HCs.
X = 10
Outer
Spiral ganglia project primarily to (ipsi/contra)-lateral (X).
Ipsilateral;
X = cochlear nucleus
Cochlear nuclei neurons project primarily to (ipsi/contra)-lateral (X).
Contralateral (mainly) and ipsilateral;
X = superior olive
“Trapezoid body” refers to:
Bundles of crossing axons, projecting from cochlear nuclei to contralateral superior olives
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
Bilateral lesion of inferior colliculus will result in:
complete deafness
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
List locations in auditory pathway, before inferior colliculus, where ascending auditory inputs cross midline.
- trapezoid body
2. nucleus of LL
In ascending auditory pathway, neurons of IC project (ipsilaterally/contralaterally/bilaterally) to (X) via (Y).
Ipsilaterally;
X = MGN of thalamus
Y = brachium of IC
Bilateral lesion of MGN will result in:
Complete deafness
In ascending auditory pathway, neurons of MGN project to (X) via (Y).
X = cerebral cortex Y = internal capsule
L auditory cortex receives input from (R/L) ear.
Both R and L cortices receive input from both R and L ears
(Doral/ventral) cochlear nuclei contain(s) tonotopic maps.
Both