How is the potassium channel like a paradox? I know how it works, but have no idea as to why its a paradox.?
818760
It appears to be a paradox because the channel protein seems  able to reconcile high ion selectivity with high throughput, which seems impossible.
306592
Time is cyclic.\nThings are born, they age, they die, they are returned to the earth, they nourish the soil, life begins again.\nTalking backward couldn't happen since that moment in time has already passed.\nThat's the paradox proposed in time travel: If you went back in time, then the moment that led up to you traveling back in time would never happen.\nIn closing, time is real...measuring time is a man-made concept.\n(See, answers can be cyclic, too)
1115590
Your heart has signals that travel to it telling it when to beat.  The things that signal are called nerves, which you probably know, but I am going to explain how I look at it.  The nerves have high  sodium (Na+) on the outside (making it positive).  On the inside of the nerve axon, there are high levels of potassium (K+) (making it negative).  The "inside" and "outside" are seperated by a membrane which has gates and channels that allow the K+ to move out and the Na+ to move in.  When the "charge" changes enough in the axon of the nerve, you get a signal sent "down the line".   If you are low in K+, the signals can't work right because enough K+ doesn't move in/Na+ doesn't move out to cause a signal or signals at the wrong time.  Your heart gets out of sync and things get all messed up, arrhythmias and such.
999507
The flow of an impulse down a neuron is only one way ... so a nerve bundle would have to be oriented to receive a signal and send it down the pathway completely ... the neuron is designed in such where an impulse causes a Na/K Pump to initiate the movement of the signal across the axon.  As Sodium (Na) and Potassium (K) ions move across the myelin-sheathed axon, there is an internal mechanism which prevents the signal from retrograde movement.  This forces the impulse to move down the axon to the terminal points on the neuron.\n\nNerve conduction is dependent upon the individual neuron.  However, you should read the same conduction velocity on a given nerve at various points, keeping in mind that the myelination is equal along the path (myelin assists in the speed of transmission, less myelin means slower movement).  I do not believe that you can successfully send a signal up from the axon back into the nerve body, but I could be mistaken.
1153271
When muscles are stimulated, sodium flows into muscle cells & then potassium flows out. The muscle cell then has a pump (called the Na+-K+ ATPase) that is in charge of pumping the sodium back out of the cell and the potassium back in. During heavy exercise, this pump cannot keep up - so too much potassium ends up outside the cell. This is hyperkalemia.
670939
No, that's not right.  The movement of sodium and potassium across the membrane carries the action potential along the neurite, but not between neurons.  Neurotransmitters-released by one neurons (usually at an axon terminal) crosses the synapse, and binds with specific receptors (usually on the dendrite or axon hillock). Once it binds, it usually opens ligand-gated sodium channels.  \n\nYou asked the name of the chemical, but it's actually a class of chemicals, not one, called neurotransmitters.  Common ones are glutamate, acetylcholine, seretonin, epinephrine and dopamine, but there are literally dozens of them.
142110
I assume you mean resting potential of the cell, for example a neuron.  It is created by biological pumps that pump ions into or out of the cell at to set up a specific electrochemical gradient.  So you get a voltage across the cell membrane along with a concentration gradient of sodium, potassium, chloride, and calcium.  When a signal is present it opens differnt pores that allow ions to cross the membrane quickly which causes an action potential and the desired effect, whether it be neurotransmitter being released, or calcium from the Sarcoplasmic reticulum.  The resting potential is the standard state for a cell maintained by the Na/K pump as well as calcium and chloride pumps that are generally ATP dependent.  ATP is the energy of the cell.  I can't remember off the top of my head if extracellular/intracellular concentrations of K,Na, Ca, and Cl but this shoudl give you the general idea.
307569
http://en.wikipedia.org/wiki/Zeno's_paradoxes
109620
Well, we have the Horse paradox \n \nThe horse paradox is the following (invalid) proof of the statement: All horses are the same colour.\n\nWe use the principle of mathematical induction. As the basis case, we note that in a set containing a single horse, all horses are clearly the same colour. Now assume the truth of the statement for all sets of at most n horses. Let there be n+1 horses in a set. Remove the first horse to get a set of n horses. By the induction assumption, all horses in this set are the same colour. It remains to show that this colour is the same as that of the horse we removed. But this is easy: put back the first horse, take out a different horse and apply the induction principle to this set of n horses. Thus all horses in any set of n+1 horses are the same colour. By the principle of induction, we have established that all horses are the same colour.\n\nThe hole in the above "proof" is easy to spot with a little thought: it makes the implicit assumption that the two subsets of horses to which we apply the induction assumption have a common element, but this fails when n=1.\n\nThus this is not a paradox, but merely the result of flawed reasoning; it exposes the pitfalls arising from failure to consider special cases for which a general statement may be false.\n\nand the horse sense, that it's:\nhorse sense : Common sense; gumption, the ability to make sensible decisions, common sense, judgment, sense, wisdom. \n\nSound practical sense, as in She's got too much horse sense to believe his story. The exact allusion in this term, which dates from the mid-1800s, is disputed, since some regard horses as rather stupid. However, they tended to be viewed more positively in the American West, where the term originated.\n\nThen, I think that horse sense paradox could be the practical sense that acts only by the principle of induction, not considering special cases.
491001
Homework, huh?\n\nWell, it's because K+ contains more electrons than the Na+. Which means that K+ has 3 layers of electrons (filled in the 1s2 2s2 2p6 3s2 3p6) while while Na+ has only 2 layers of Electrons (1s2 2s2 2p6)
1023476
Well, take a look at this:\n\nhttp://www.answersingenesis.org/docs/2.asp
332420
ummm, i dont understand what ur asking, but if u wanna know how its generated, it has something to do with positive ions of a molecule flowing in one direction, and negative ions flowing in either the same of opposite direction forming direct and indirect currents, or at least that's what i think it is
912050
I think D is incorrect.  The inside of the cell is negative compared to the outside of the cell.  Therefore, the electrical gradient of Na+ would want to move Na+ into the cell.
680944
Since the ions are slightly unbalanced between the outside and inside of the cell, a membrane potential develops.  Na/K ATPase continously pumps Na out of the cell and K into the cell, so that the K concentration is aobut 30x bigger inside than outside and Na is about 20x less inside the cell.  and it's an active transport (ATPase...).if it werent' there, it would lead to a flattening of the ion gradient and the membrane potential would break down
186674
That is not an example of Russell's Paradox.\n\nRussell's Paradox (on which I should be writing a paper right now) arises from sets or concepts of the form:\nS ={x: x is a set which is not a member of itself.}\n\nThe paradox arises when you try to decide whether S itself is a member of S.  If S is a member of S, then that means that S is a set which is not a member of itself.  This is a contradiction.\nIf S is not a member of itself, then that means S is a member of itself (because it is not in S).  This too is a contradiction.\nSo, S can neither be in nor not be in S.\n\nTo arrive at an example of Russell's Paradox, you need an instance of negated self-reference.
112461
Aha! The liar paradox rears its ugly head again....\n\nThe asnwer is - neither true nor false. The propositional content and the semantic content of the statement contradict each other.\n\nTo unpick this paradox, you have to separate the statement from the proposition it contains. \nNote that the proposition has a positive truth value - it claims that "[yadda yadda] IS [bladiblah]"\n\nNow...\n\nIf the statment is true, the proposition that it contains is rendered false, leading to a self-contradiction.\nSo [This statement is false.] is false.\nBut if it is false that the statement is false then the proposition it contains is rendered true, and again the statement is rendered self-contradictory.\n\n(Repeat ad nauseum)\n\nIf you got that, ponder this one. It's a doozy:\n\n"This staitmennt contaynes three mistakes"
395513
Hiya\nWe don't see a wave for atrial repolarization as the repolarization wave flowing through the heart isn't in the form of 2 waves for ventricle and auricle and hence flows as a continous wave form the ventricle to the auricle and is seen on the electrocardiogram as a weak wave\nOn the other hand the polarization wave is different for auicale and venricle as is it is separately induced by the SA NODE AND THE AV NODE. \nThus as these 2 polarize separateley with different intensities the graph shows 2 diff waves\nSince the ventricle is longer than the auricle the wave required to polarize it has a higher potential and thus QRS complex is larger than the P complex\nThe same logic cannot be applied for repolarization as the potential required to repolarize the whole heart is weak and does not have much function in the form of closing or opening of valves or anything like that\nHope that answers your question\nGood question though\nHad to think twice before answering it (and I love Biology)\nBest of Luck\nLotza Love\nNick