The Ear

Question 1

what are the steps of the auditory pathway

Answer 1

1. auditory receptor (cochlea)
2. brainstem
3. thalamus (medial geniculate nucleus)
4. primary auditoty cortex

Question 2

where does endolymph flow

Answer 2

inside the scala media

Question 3

where does perilymph flow

Answer 3

from scala vestibuli to scala tympany when stapes taps the oval window

Question 4

where are high frequencies detected in the inner ear

Answer 4

near oval window narrow and stiff

Question 5

where are low frequencies detected in the inner ear

Answer 5

Near apex wide and flexible

Question 6

describe transduction in the inner ear

Answer 6

A. Upward displacement of basilar membrane creates a shearing force that leads to lateral displacement of the stereocilia
B. Mechanical displacement of the stereocilia in a lateral direction cause depolarization of the hair cell.
C. Downward displacement of the basilar membrane creates shearing force that results in lateral displacement of the stereocilia in the opposite direction hyperpolarization of the hair cell.

Question 7

how does stereocilia affect depolarization

Answer 7

Cilia bending in one direction: channel opens: K+ influx and cell depolarization
Cilia straight: channel semi-closed: K+
influx at resting potential
Cilia bending in opposite direction:
channel closed: cell hyperpolarization