hair cell depolarization

[SamarEsawy]

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How would the hair cell depolarize if the potassium coming in from the endolymph through the channels in the sterocilia , leaks out down its concentration gradient to the perilymph of lesser k concentration?
I don't know why most people ignore the contribution of perilymph to the hair cell memrane potential so could you simply explain to me how perilymph affects hair cell depolarization?

 

[tantacles]

 

[SamarEsawy]

please post useful replies , no time for bull****

 

[EazyE1907]

the reason why most people ignore this is because it is a) not high-yield b) not the least bit high-yield and last and most importantly c) NOT RELEVANT FOR BOARDS. sure if you came on here asking something along the lines of the moa of a specific anti-arrythmic and why it acts the way it does then yes you will most likely get a sound answer from one of these helpful people on SDN. do yourself a favor and stop wasting you're time with this bullcrap.

 

[tantacles]

please post useful replies , no time for bullcrap

If you have no time for bullcrap, why are you worrying about this esoteric point that has not only almost zero relevance for boards, but also for clinical practice?

 

[SamarEsawy]

LOL Is it a hard question? I asked this question because I found this point not well explained in my text , which mentions that tight junction between hair cell makes apices dipped in endolymph and bases in perilymph ..

 

[SamarEsawy]

should I post this in Allopathic instead?

 

[Lafakads]

I'll take a stab at it.

Look at the direction its moving, its going from a High Concentration outside the cell to a Low Concentration inside the cell. In other cells its usually the opposite which is why repolarization normally occurs. Since K+ is going into the cell, it functions just like any other cation would and depolarizes the membrane.

Could be wrong but thats how I see it.

 

[Pisiform]

thats too much detail for step 1 but yea i agree with above post

 

[dyspareunia]

How would the hair cell depolarize if the potassium coming in from the endolymph through the channels in the sterocilia , leaks out down its concentration gradient to the perilymph of lesser k concentration?
I don't know why most people ignore the contribution of perilymph to the hair cell memrane potential so could you simply explain to me how perilymph affects hair cell depolarization?

What happens when you bring positive ions into a cell? It depolarizes. I don't understand why you are confused.

 

[SamarEsawy]

What happens when you bring positive ions into a cell? It depolarizes. I don't understand why you are confused.

I'm confused beacause these positive ions leak out of the cell to the perilymph which has lower potassium concentration

 

[dyspareunia]

I'm confused beacause these positive ions leak out of the cell to the perilymph which has lower potassium concentration

They still have to enter the cell before they can diffuse out into the perilymph. Hair cell is transiently depolarized -> Ca2+ influx -> vesicle release.

 

[GadRads]

I'm confused beacause these positive ions leak out of the cell to the perilymph which has lower potassium concentration

There's probably a pump that uses ATP (or some ion transport system) to maintain the correct gradient.

 

[SamarEsawy]

They still have to enter the cell before they can diffuse out into the perilymph. Hair cell is transiently depolarized -> Ca2+ influx -> vesicle release.

or may be because the membrane potential between hair cell and perilymph is more positive than the membrane potential between hair cell and endolymph , may be this is also correct?what do you think?

 

[dyspareunia]

or may be because the membrane potential between hair cell and perilymph is more positive than the membrane potential between hair cell and endolymph , may be this is also correct?what do you think?

It could be anything as long as it triggers calcium influx. Don't really know what to tell you besides this is way too much detail.

 

[Handinhand]

Please stop encouraging this guy. He's been posting almost constantly with this kind of stuff, clearly not Step 1 relevant and doesn't belong on this forum.