W04_03 Hearing Flashcards Preview

Brain and Behaviour > W04_03 Hearing > Flashcards

Flashcards in W04_03 Hearing Deck (24):
1

what range of frequencies do we hear?

20Hz - 20 kHz

2

speed of sound in air?

343 m/s

3

what kind of joints are at the auditory ossicles?

synovial joints;
these can fuse in later years - less flexibility results in hard of hearing.

4

tensor tympani innervated by which CN?

V3 (T rigeminal)

5

stapedius innervated by which CN?

VII (S even)

6

what do you call the perception of loud sound due to lesion of V3 or VII?

hyperacousis

7

middle ear connects to which cavity via eustacian tube?

nasopharynx.

8

fact: tympanic cavity connected to mastoid air cells.

good.

9

the cochlea spirals around this bony core:

modiolus

10

what are the three spaces in the cochlear cross section?

scala vestibuli;
scala media;
scala tympani

11

in the scala vestibuli/tympani is this fluid:

perilymph (~CSF)

12

in the scala media is this fluid:

endolymph (high [K+])

13

endolymph is secreted by which structure?

stria vascularis (along lateral wall of scala media)

14

this bony protrusion extends from the modiolus into the cochlear space:

spiral lamina

15

this opening connects the scala tympani and scala vestibuli:

helicotrema

16

the organ of corti is covered by and intimately connected to this:

tectorial membrane

17

what's another name for the organ of corti?

spiral organ

18

what type of neurons transmit sound sense from the cochlea?

bipolar

19

fact: outer hair cells are connected to the tectorial membrane, while inner hair cells are not.

good.

20

when the basilar membrane moves up, the stereocilia move this way:

outward

21

this structure isolates endolymph from perilymph; is connected to hair cells

reticular lamina

22

how does the transduction of sound energy convert to electrical energy via hair cells?

bending stereocilia opens K+ channels;
depolarization opens v-gated Ca2+ channels;
depolarization increase neurotransmitter release to axon.

23

even though outer hair cells outnumber inner hair cells 3:1, 95% of spiral ganglion neurons get inputs from IHCs. what do outer hair cells do?

amplify movement of basilar membrane, especially in low volume sound.

24

name the auditory pathway

cochlea;
ipsilateral cochlear nucleus;
bilateral inferior colliculus;
MGN of thalamus;
1º auditory cortex