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Flashcards in Exam 3 Deck (194)
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1

Audible range for humans

20 Hz- 20 kHz

2

changes in air pressure from a sound wave change in a ______ manner

sinusoidal

3

Main function of outer ear is to

capture sound and rout it to tympanic membrane

4

Main function of middle ear is

amplification (~200x).

5

Impedance mismatch -

relative difficulty that sound waves have moving through different media. This problem overcome by different mechanisms

6

ossicles-

middle ear bones (malleus, incus, stapes)

7

pressure on tympanic membrane is transferred to smaller surface area of _____

the oval window

8

organ of corgi consists of the ______ membrane, ______ membrane, nerve cells and stereocilia

tectorial
basilar

9

what 2 groups of stereo cilia are there?

inner hair cells and outer hair cells

10

what are the relative shapes of the groups of inner and outer hair cells?

inner hair cells are in a line, outer hair cells are grouped in U shapes

11

Which hair cells are most important in transducing and sending afferent signals?

inner hair cells

12

Tonotopy –

different frequency information conveyed because of maximal displacement variability due to frequency

13

who discovered tonotopy.
what theory did he propose?

Von Bekesy
Tonotopic theory of frequency discrimination

14

Scala media

fluid that is in direct contact with the hair cells.

15

Outer hair cells receive signal from the brain – have a motor response and can change their length and alter the properties of the ________. This increases the ___________ of the auditory system.

-tectorial membrane
-frequency discrimination capabilities

16

Which end of cochlea is most flexible?

apex

17

High Freq. generate max displacement at the _____, Low Freq max is as _____. This physical map of freq is called Tonotopy

-base
-Apex

18

when sound vibrates the basilar membrane, there are 2 phases. In the upward phase, the shear force is towards:
In the downward phase the shear force is towards:

-tallest stereocilia
-shortest stereocilia

19

hair cells are highly specialized ______ cells. Their apical surface contains _________, while the basal surface has the ___________

-epithelial
-The stereocilia
-synaptic end of the cell

20

Hair cells detect changes in water pressure on _______

cupula

21

Ampullae of Lorenzini –

electrodetectors that are used to detect electric fields in the environment (the head of a hammerhead shark)

22

What do vestibular hair cells help do and how do they do it?

they are oriented in different ways in a liquid medium to help with balance

23

what is the really long hair cell in stereocilia bundles?

kinocilium

24

how are stereocilia in hair bundles oriented?

stairstep

25

how does a kinocilium differ from other hair cells?

it contains concentric rings of microtubules

26

shorter hair cells are connected to longer hair cells via

tip links

27

side to side movement does not depolarize. For hair cells to depolarize, movement in what plane must happen?

in the plane of shortest-longest cells

28

Mechanoelectrical transduction –

connecting proteins are thought to act as a ‘spring’ and expand/contract upon movement of hair cells. Expansion opens K+ channels

29

Bundle deflected toward shortest one –
Deflected toward longest one –

-hyperpolarization
-depolarization

30

how many channels does each stereo cilium have?

2