Action potential Definition and 19 Threads

Has anyone else come across the soliton model of the action potential? https://en.wikipedia.org/wiki/Soliton_model_in_neuroscience It seems extremely non-mainstream, especially given that it presented as an alternative to the Hodgkin-Huxley model, which is undoubtedly the most successful...

Hello, I understand that the action potential represents a potential difference variation (depolarization) of the voltage across a cell membrane. This concept is generally presented in the context of nerve cells (neurons) as the change in potential across the axon membrane. What about the...

What does the APD (Action potential duration) determine in a cardiac cell and how can it be changed (do I need to effect any of the phases of the AP)? For example, if the vagal nerve releases acetylcholine here are its effects: Inhibits Atrial Muscle Contraction- Negative inotropic effect...

Hi all, My textbook says that the T tubules, which form an extensive network of transverse tubules that surround myofibrils, can carry the wave of action potential from the surface of the muscle fiber to the cell interior. Could you help me understand the sentence in bold because I'm not sure...

This might be either an obvious one, or I might be totally off track. I haven't seen, or been able to find neural action potentials being referenced as signal transductions. Aren't they signal transductions? And if not (say if action potential is only referenced to the change in potential)...

Hello, I noticed that in Wikipedia, action potential is not solely defined as a neural process, but rather as a process that happens between any cells that can release chemical signals and have target cells that can receive the signals. Is this true? Would we say that endocrine system creates...

I just learned that "action potential is a short-lasting event" (wiki) If someone is experiencing an emotion of sadness, is that same action potential keeps firing many times back to back or can it actually be a possibility that an action potential lasts for a "very long time". I am guessing...

' At the peak of the graph, Is the concentration of Na outside the cell is more than inside? because that must be to overcome the electrical force in the opposite direction but my book says that that inside the cell there are more Na than outside When is the concentration of Na+ greatest inside...

Action potential is defined as" the local voltage change across the cell wall as a nerve impulse is transmitted" Now my question is "why it happens? i.e.,why organism evolves?

Homework Statement Nerve signals in the body occur when a small voltage, called an action potential, is applied across the membrane of a cell. When this action potential is applied across a region of the cell membrane called an ion channel, current in the form of moving potassium ions will be...

Homework Statement During an action potential, Na + ions move into the cell at a rate of about 3 x 10^-7 mol / m^2 s. How much power must be produced by the "active Na+ pumping" system to produce this flow against a + 30 mv potential difference? Assume that the axon is 40cm long and 30 mu m...

Now I follow this pic, there is no mention of opening of calcium channels anywhere. So how do skeletal muscles contract, without calcium. Incontrast action potential of a cardiac muscle has plateu phase and calcium channel involvement. Thanks :smile:

If there a way to affect the action potential propagation across neurons, for better or worse? The organism I have in mind is planaria (flat worm) as they are very simple but can be conditioned (like the Pavlovian dog). I don't think that a non-harmful liquid chemical could have much effect, but...

I'm currently reading Spiking Neuron Models by Gerstner and Kistler: But I've also come across this in a review of Spikes: Question(s) Is this really true? Are all action potentials of a given neuron the same? Is that justification for action potential shape not "carrying any...

Hello guys, Although the response of a motor unit is all-or-none, the strength of the response of the entire muscle is determined by the number of motor units activated. Nerve impulses passing down a single motor neuron will thus trigger contraction in all the muscle fibers at which the...

Hi All, The Action Potential propagation involves a passive event called: Passive Spread or Electrotonic conduction. Here is some references: http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mcb.figgrp.6138...

Hi All, It is a fact that Na+ ions cross the membrane and enter the cell during the rising phase of the action potential. The process happens because Na ions channels are open. Then the ions channels becomes inactivated/closed for a while. What happens to the Na+ ions that entered the cell?

Hi All, I took the following from this page. http://en.wikipedia.org/wiki/Action_potential I'm lost with these comments because I learned that small fibres have low speed and larger ones have a higher one but, in my opinion, since membrane thickness doesn't really vary in unmyelinated...

This is about voltage clamping: When Hodgkin and Huxley voltaged clamped a nerve - when hyperpolarised there was a small inward current, why is that? and when they used a depolarising clamp, there is firstly a brief capacitative current - this current is outwards, why?:confused: