Organ of Corti

Question 0

Tectorial Membrane

Answer 0

ceiling of the central Scala Media

vibration causes it to move left and right

Question 1

Basilar Membrane

Answer 1

the floor of the central Scala Media or Cochlear Canal

vibration causes it to move up and down

Question 2

Hair Cells

Answer 2

the auditory receptor cells

located between the basilar and tectorial membranes

Question 3

Endolymph

Answer 3

viscous, non-compressible Potassium rich fluid

inside the chamber of the Scala Media

Question 4

Cilia

Answer 4

are slender protuberances that project from the much larger hair-cell body.

arranged short to long

are bent between the basilar and tectorial membrane

Question 5

when bent toward the longest cilium…

Answer 5

…K+ gates open

K+ enters t he cell

influx of K+ DECREASE POLARITY from -60mV

chain reaction involving Second Messengers allow Ca++ to enter cell –» release excitatory NT (GLUTAMATE)

Question 6

the farther the cilia are bent…

Answer 6

…. the greater the impact on the polarity and thus on the release of NT

Question 7

when cilia bent toward shortest cilium,

Answer 7

…K+ leaves cell (per gradients) and Ca++ is actively pumped out, restoring polarity

Question 8

typically hair cell potential….

Answer 8

…oscillates (polarized/depolarized/polarized/etc) repeatedly

releasing at least some NT

Question 9

Hair Cells show ______ hypo-polarization and thus _____ release of NT, depending on ______

Answer 9

graded!

graded!

how far and often Cilia are bent to SPIRAL GANGLIONS

Question 10

Spiral Ganglions

Answer 10

= ANFs = Auditory Nerve Fibers

fire Action Potentials along axons to Brain