Talk:Refractory period

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[edit] Depolarization

When looking at the page depolarization it says that depolarization is only when voltage is heading towards zero volts and never when it is not. So once it crosses zero volts it is actually repolarizing. I'm not an expert on this but there is a very long discussion on it in the site I mentioned, It definitetly needs to be fixed. ArrowStomper 06:46, 15 November 2006 (UTC)

Depolarization is always thought of as the rising phase of an action potential even when it is above 0mv. This is due to the fact that it is still rising in comparison to the resting state of the neuron at -65mv. Therefore the frame of reference is not 0mv but -65mv that is why it is always said to be depolarising in the upward phase.

I may just be reiterating the previous paragraph, but from what I know as long as the voltage of the cell is becoming less negative, e.g. going from -90 to -65, or -90 to 0, or -90 to +100, the cell is said to be DEPOLARIZED. The state of being polarized just means, in the case of the typical cell, that the cellular interior is negative with respect to the extracellular environment, which is less negative (as in -40 or 0 or +60....). Perhaps the discussion of depolarization should say, rather than "the voltage approaches zero upon depolarization," that the inside of the cell simply becomes LESS NEGATIVE. This will encompass the wide range of depolarization values possible. Again, using the example of a resting potential of -90 mV, this could be -89.999 (although this would not reach threshold and cause an AP), or it could be -65 (more likely to reach threshold), or 0, or +100, because all of these values are less negative than -90 mV. If a cell does depolarize to a positive value it is NOT hyperpolarized. Hyperpolarization is when the cell interior becomes less negative than its resting potential, e.g. -90, to say -100 or -120. There's no such thing, to my knowledge, as hyperdepolarization. If the cell's depolarized, it's depolarized. What's important there is whether the cell has reached the threshold for axon potential generation.

Another comment I wanted to make is that, while sexual refractory period is a physiological phenomenon that belongs in discussions of anatomy and physiology, I am not sure whether its location here is appropriate. There are children, probably in middle school and possibly elementary, who might be researching muscle contraction. If the sexual refractory period article did not refer to actions such as masturbation and oral sex, I think it would be okay to know that animals may have refractory periods for physiological processes other than skeletal and cardiac muscle contraction, such as sex. I think Wikipedia is an excellent resource, and I am not to keen on censorship, but I think it would be a shame to expose children to something better learned when they have actually reached puberty. This is a moral question, of course, but it would be unfortunate if children couldn't use Wikipedia because their parents saw such terms in an otherwise harmless article. I think the article would be appropriate in this section if questionable terms such as masturbation and oral-genital stimulation were removed. I am going to remove them, and if the author has a problem, it's a universal website so add them back but please keep this editorial so discussion can be open. —Preceding unsigned comment added by 131.96.30.10 (talk) 15:14, 29 October 2007 (UTC)

It is a moral question that we have already taken a very clear stance on: Wikipedia contains content you may find objectionable. Raul654 15:20, 29 October 2007 (UTC)