Linked Questions

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How Fast can the Electrochemical Gradient on a Neuron be Reestablished? [duplicate]

The electrochemical gradient of Na+, K+, Ca2+, and Cl- between the inside and outside of a neuron is vital for its function. When a neuron fires, this gradient reverses. How long does it take for the ...
E Tam's user avatar
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11 votes
1 answer
914 views

Purpose of K+ channels in action potential

I understand that they serve to repolarize the neuron after the Na+ influx. What I don't understand is why this is important. Meaning, let's say all the K+ channels disappeared. So now the ...
Jo.P's user avatar
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4 votes
2 answers
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Sodium concentration during action potential generation

At the peak of the graph, is the concentration of Na+ outside the cell more than inside? That must be to overcome the electrical force in the opposite direction. When is the concentration of Na+ ...
user3733086's user avatar
1 vote
1 answer
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How greater magnitude implies greater frequency of action potential?

Greater the magnitude of receptor potential, greater is the rate of discharge of action potentials in the nerve fibre.1 Now consider a case where stimulus ( strength ) is large , so there is more ...
JM97's user avatar
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2 votes
2 answers
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Why is the resting membrane potential of excitable tissue not affected by the extracellular sodium concentration?

I know that the resting membrane potential for excitable tissue (eg, nerve) is primarily determined by the electronegative difference between the inside and the outside of the membrane for potassium ...
Remoun's user avatar
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6 votes
1 answer
495 views

What Produces the Postive Potenial in the lumen of the thick ascending loop of Henle?

In the Thick Ascending Loop of Henle, Paracellular diffusion of certain Solutes like magnesium and calcium takes place. Such diffusion is a result of the positive lumen potential. Looking at the image ...
Omar Shahaltough's user avatar
4 votes
1 answer
560 views

Are living cells electrically neutral?

I found random scientific table which had a comment attached: the cells must be electrically neutral. Per my knowledge whole intracellular solution contains more electrons than protons (definition ...
Lasha Bukhnikashvili's user avatar
4 votes
1 answer
639 views

How does a neuron recover from after hyperpolarization?

My question is, how does a neuron recover from AHP? It’s been puzzling me for a long time, and I really can’t find a single source that explains it in detail. Apparently the sodium potassium pump ...
NeuroIsHard's user avatar
2 votes
2 answers
866 views

Ambiguity about the relation between membrane potential and concentration gradient in neuron cells

I am stuck in an ambiguity about the equilibrium potentials of neuron cells. The following text is picked up from khanacademy website: In one part it is said that: We'll start out with K at a higher ...
m.taheri's user avatar
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1 vote
1 answer
357 views

Assumptions for Nernst Equation

While I am familiar with some of the conditions for the Nernst Equation, for example: 1) "The membrane is only permeable to one ion even if there are several other ions in the system" there is an ...
S.C.'s user avatar
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0 votes
1 answer
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How is Na concentration re-established after action potential

I understand that the repolarization is because some K+ chanels are opened with the action potential. But whats happens with the sodium chemical gradient that is needed for a new action potential? Are ...
Nicolas Aira's user avatar
3 votes
1 answer
180 views

What is the basis of the endocochlear potential?

I am learning about the endocochlear potential. According to different sources, the ionic composition of perilymph is about as follows (in mM): 150 Na+, 4-5 K+, 1.2 Ca2+, 1 Mg2+, 120 Cl−, and 20 HCO3−;...
Jimmy's user avatar
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1 vote
1 answer
214 views

Why don't membrane potentials violate the principle of electroneutrality?

The principle of electroneutrality states that the number of anions and cations in a solution must be the same, i.e., that there will be no charge excess in any side of the membrane separating two ...
TheAnonymous's user avatar
2 votes
1 answer
106 views

Nernst Equation and Membrane Potential

I am a bit confused on how to use the Nernst equation to determine polarization. I saw in the textbook that if potassium channels were open in a neuron cell, there will be a net diffusion of $\ce{K+}$ ...
Jaehyun Ahn's user avatar
2 votes
1 answer
74 views

Chloride Clamp and Nernst potential

The Nernst potential for chloride is -70 mV. The neuronal Resting Membrane Potential (RMP) is -70 mV. Under this condition, if the chloride channels are open (as it happens in Inhibitory Post Synaptic ...
One Face's user avatar
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