Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
10/27
Hearing Sciences
| Question | Answer |
|---|---|
| What does potentials mean? | the possibility of electrons to flow |
| What can cause the ions to flow into hair cells? | the stereocilia move away from the modiolus, opening the microchannels |
| What does nature, if unimpeded, do? | it always seeks equilibrium |
| What does an unbalanced condition result in? | electron flow that lasts until the atoms are in a balanced state |
| The greater the disparity of electrons, the greater... | the charge and the potential for electrons to move in the quest for equiliobrium |
| How can the magnitude of the charge be expressed? | as the potential for electrons movement or flow |
| How can the magnitude of the potential be expressed? | in volts (V) |
| How do stereocilia move away from the modiolus? | When the basilar membrane goes up, the stereocilia are moved away |
| What does a small deflection of the basilar membrane do? | it could be insufficient to open the microchannels in the stereocilia |
| What is the general idea of depolarization? | when a hair cell becomes more positive |
| What is the exact definition of depolarization? | Stereocilia move away from the modiolus, microchannels open, potassium and calcium enters the normally negative hair cell, and the cell becomes more positive |
| What causes the hair cell to increase in voltage? | when potassium rushes in due to open microchannels |
| How do you get the stapes to move away from the oval window? | through the rarefaction phase of sound |
| What happens to the tympanic membrane as the stapes moves away from the oval window? | it also moves away |
| What happens as the stereocilia deflect towards the modiolus? | the hair cell can become more negative as the potassium is pumped out |
| What is the cochlear microphonic? | a recording of the fluctuating hair cell polarity (negative to positive) |
| How often do the microchannels open for a 700 Hz tone? | 700 time a second |
| What does a cochlear microphonic do? | it mimics the stimulus |
| What is the name cochlear microphonic derived from? | the experimental protocol where the output from the cochlea was sent to a speaker |
| What is hyperpolarization? | When stereocilia move toward the modiolus, or the inhibitory phase |
| What does CM stand for? | cochlear microphonic |
| What does SP stand for? | summating potential |
| Why does the cochlea act like a microphone? | because of the changes in voltage across the hair cells in the cochlea |
| What is the cochlear microphonic? | the changes in voltage we see when the stereocilia move toward and away from the modiolus |
| What is a summating potential? | The overall change (usually increase) in voltage of a cochlear microphonic |
| What do the hair cells experience in response to sound? | alternating current changes (cochlear microphonic) |
| What is the charge of hair cells during stimulation? | on average, it is more positive |
| What did Guinan et al (2012) study? | outer hair cell motility (motion) |
| What is Prestin? | motor protein of outer hair cells |
| What is conformation? | the way in which something is formed or shaped |
| What causes the Prestin to expand and contract? | the changes in voltage of the outer hair cells |
| What happens due to Prestin expanding and contracting? | outer hair cells expand and contract |
| What happens when the prestins narrow? | when the microchannels open and potassium enters the cell (depolarization) |
| What happens to the body of the outer hair cells when prestin narrows? | the cell shrinks |
| What is another name for depolarization? | the excitatory phase |
| What happens to the microchannels and the stereocilia move toward the modiolus? | they close |
| What happens to Prestin as the microchannels close? | it widens |
| What happens to the outer hair cells when the Prestin widens? | it stretches |
| What is outer hair cell hyperpolarization? | When the microchannels close, Prestin widens, and the outer hair cells stretches |
| What happens to the basilar membrane as the outer hair cells strink? | the basilar membrane moves up |
| What is the sound that hair cells make when they are health? | otoacoustic emissions |
| How do outer hair cells stretch and shrink? | microchannels open and potassium moves in the cell, it shrinks the Prestin protein, which shrinks the outer hair cell. As the microchannels close and the cell becomes more negative, the Prestin protein widens and the outer hair cells stretch |
| Hyperpolarization is associated with? | a decrease in voltage, |
| Depolarization is associated with? | an increase in voltage, K+ and Ca+ entering the hair cell |
| What is the first step in getting the outer hair cell to contract? | The traveling wave causes the basilar membrane to move towards the scala vestibuli (upwards) |
| What is the second step in getting the outer hair cell to contract? | the upward motion of the BM causes the organ of corti to rotate around the foot of the inner pillar, moving the reticular lamina toward the modiolus, which deflects stereocilia in excitatory direction |
| What is the third step in getting the outer hair cell to contract? | the deflection of stereocilia opens the mechano-electrical transduction channels, which increases the receptor current driven into the OHC |
| What is the receptor current? | mechano-electric tranduction current generated when mechanical vibrations from sound cause the stereocilia to bend |
| What is the excitatory direction of the stereocilia? | away from the modiolus |
| How do the stereocilia move away from the modiolus? | the tectorial membrane slides over the reticular lamina in opposite directions |
| What starts the stereocilia deflection? | the upward motion of the basilar membrane that rotates the organ of corti about the foot of the inner pillar |
| What does outer hair cell depolarization cause? | conformational changes in the individual prestin molecules that sum to induce the reduction of outer hair cell length |
| What causes an amplification in basilar membrane motion? | the OHC contraction when the pull on the basilar membrane is in the correct phase |
| How does the reticular lamina move as the outer hair cells contract? | it moves down in the outer hair cell region and up in the inner hair cell region |
| What does the reticular lamino's pivoting and resulting fluid flow do? | it provides an additional mechanism by which outer hair cell motility may enhance the mechanical drive to inner hair cells stereocilia |
| What does subtectorial space mean? | the area below the tectorial membrane |
| What happens if the outer hair cells do not contract and expand for low level sounds? | the inner hair cells will not be stimulated and no signal will be sent to the brain |
| What is a low level sound? | a whisper |
| Ear canal resonance is harmful when? | when listening to high frequency sounds |
| What are neurons? | the fundamental (basic) unit of the nervous system |
| What is the name for the 8th nerve? | the auditory nerve |
| What are the two branches of the 8th nerve? | auditory and vestibular |
| How is the auditory branch of the 8th nerve connected? | connected to the cochlea through the modiolus |
| How si the vestibular branch of the 8th nerve connected? | connected the balance organs of the inner ear |
| What are the two basic types of neurons for the auditory and vestibular branches of the 8th nerve? | afferent and efferent |
| Nearly all of the 8th nerve fiber bundle is composed of what? | bipolar neurons |
| What is the direction of chemo-electrical activity of bipolar neurons? | axon to cell body to axon (one-way path) |
| What is a ganglion? | a group of cell bodies |
| What is the makeup of a bipolar neurons? | an axon on either side of the cell body |
| What is inside the modiolus? | the spiral ganglion |
| What is the cochlear nucleus? | a bunch of cell bodies |
| What do dendrites of afferent nerves fibers do? | they synapse with the hair cell in the cochlea |
| Where is the first axon of afferent nerves fibers found? | in the habenula perforata |
| Where is the cell body of bipolar neurons found? | in the modiolus |
| Where is the second axon of bipolar neurons found? | in the internal auditory canal |
| What does the terminal arbor of bipolar neurons do? | it synapses with the cochlear nucleus in the brain stem |
| What is another name for bipolar neurons? | afferent nerves fibers |
| Why is it called spiral ganglion? | because the nerves spiral around the cochlea on the inside as they come out of the habenula perforata |
| What is the order of the bipolar neurons? | dendrites, axon, cells body, axon, terminal arbor |
| How do you get the signal from a hair cell to the cochlear nucleus? | The signal must travel from the hair cell to the dendrites, then travels down the axon to the cell body, then from the cell body down the next axon to the terminal arbor, which synapses with the cochlear nucleus |
| Where are dendrites found? | along the basilar membrane |
| What does it mean that dendrites are post-synaptic> | they are behind the synapse between the hair cell and nerve. |
| What do dendrites act as? | sensors |
| What are dendrites stimulated by? | a chemical (neurotransmitter) that is emitted from the base of the hair cells |
| What is the course of the first axon of a bipolar neuron? | it extends through the habenula perforata to the cell body found in the modiolus |
| What is the course of the second axon of a bipolar neuron? | it extends from the modiolus into and through the internal auditory canal and is a part of the eighth nerve |
| What does IAC stand for? | internal auditory canal |
| Where are the spiral ganglion found? | in the modiolus of the cochlea |
| What is myelin? | a whitish, fatty substance that coats the axon of a nerve. It acts as insulation that keeps out Na+ |
| What is Na+? | sodium |
| What is K+? | potassium |
| What is Ca+? | Calcium |
| What do the nodes of Ranvier do? | they regulate the speed of neural firing |
| What are the nodes of Ranvier? | the gaps in between myelin |
| What happens if the nodes of Ranvier are close together? | the nerve cells will transit an impulse relatively slowly |
| What happens if the nodes of Ranvier are far apart? | the impulse transmission will occur more quickly |
| Why does the distance of the nodes of Ranvier make sense? | if there are a ton of stops, it takes longer. If there are less stops, it is quicker to get to the destination (think about bus stops) |
| What is Schwann sheathing? | the covering of the myelin |
| What is an acoustic neuroma? | a tumor on the Schwann sheating |
| What is Schwann sheathing made of? | tissue from nearby Schwann cells |
| What happens if Schwann sheathing is damaged or malformed? | the cell will misfire when stimulated |
Created by:
hrshook0104
Popular Speech Therapy sets