Term
| Describe Tonotopic Organization. Where does it occur? |
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Definition
| -it is frequency organized by place among basilar membrane |
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Term
| What contributes to tonotopic organization? |
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Definition
| -MECHANICAL properties of Basilar Membrane |
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Term
| 2 Mechanical Properties of Tonotopic Organization |
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Definition
STIFFNESS GRADIENT-bass stiff, apex less stiff
WIDTH- base is narrow, apex is wide |
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Term
| Describe the Conversion of Mechanical Movement to Electrical Impulses |
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Definition
-As BM vibrates, so does Organ of Corti (sensory organ of hearing)
-Organ of Corti includes *hair cells that are sensory receptors that transduce mechanical motion to electrical charge |
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Term
| Whats the organ of Hearing? What 2 things does it consists of? |
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Definition
Organ of Corti aka spiral organ
-hair cells (4 rows) w/ stereocilia protruding from the top
-Tectorial membrane |
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Term
| Describe the 4 rows of hairs cells in the Organ of Corti...and cell count? |
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Definition
-1 inner row (3500 cells)
-3 outer rows (12000 cells) |
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Term
| Describe the Tectorial Membrane in the Organ of Corti |
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Definition
| Gelatinous structure that overlays hair cells and stimulates them upon acoustics events |
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Term
| Inner hair cells functions |
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Definition
| -transduce mechanical energy vibration into an electrical signal |
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Term
| Outer hair cells function |
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Definition
shrink and expand to fine tune (amplify) the frequency response of the cochlea
-they vibrate! |
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Term
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Definition
-connected w/ a filamentous process called "tip link"
-"tip link" connects from distal end of Sterocilia to the side of the longest adjacent one
-tip link connects to an ion channel on the side |
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Term
| Sounds that the outer hair cells produce? |
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Definition
| otoacoustic emissons (OEAs) |
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Term
| Describe Otoacoustic Emissions. How do these occur? |
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Definition
-sound produced by ear
-originates from OHC in the cochlea as they vibrate in response to incoming sounds.
-emerge at outer canal and are measured by very sensitive microphones |
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Term
| noise exposure and the amount of damage depends on what 2 things? |
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Definition
-duration (time spent)
-amplitude (level of noise) |
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Term
| Cochlear Implant Process (4 steps) |
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Definition
1. microphone picks up sound and sends to speech processor
2.speech processor digitally encodes sound & sends to trasmitter
3.transmitter sends info across skin to revciever/stimulator
4.reciever/stimulator presents info to auditory nerve in form of tiny electrical pulses |
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Term
| Cochlear implants replace what? |
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Definition
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