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
  • 822
11 votes
1 answer

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
  • 337
4 votes
2 answers

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

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
  • 4,786
2 votes
2 answers

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
  • 43
4 votes
1 answer

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
6 votes
1 answer

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
2 votes
2 answers

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
  • 121
4 votes
1 answer

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
1 vote
1 answer

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
  • 375
0 votes
1 answer

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

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
  • 31
3 votes
0 answers

Movement of few ion during changes in membrane potential

My question is very simple: why is it sufficient for a very few ions (such as 1 in 100000 K+) to move across the membrane to generate a remarkable variation in the membrane potential (like a change of ...
Ginevra B's user avatar
0 votes
0 answers

Na+ / K+ ATPase: How does it restore resting membrane potential? [duplicate]

Could not find any sources talking about this (in a clear manner). If the Na+ / K+ ATPase pumps 3 Na+ out for every 2 K+ it pumps in, thus making the cell more negative, why is the Na+ / K+ ATPase ...
Ally's user avatar
  • 329
0 votes
0 answers

Doubt related to nerve impulse transmission

Naturally, the extracellular fluid has more sodium ions and the axoplasm has more potassium ions. Since there are more potassium leakage channels than sodium leakage channels on axoplasm, it is more ...
Pratham Hullamballi's user avatar

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