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2answers
42 views

Are Purkinje Action Potentials Neuronal and Cardiac?

I first thought that action potentials of His-bundle i.e. Purkinje fibers are Cardiac. However, I started to think that this is not enough. I think now that they are neuronal and cardiac. My ...
0
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0answers
14 views

Difference between conduction in unmyelinated axon and in myelinated axon [duplicate]

I understand that on axons dendrite, receive the stimulus and through passive conduction/graded potential (i don't quite understand that) summation would reach the trigger zone of the axon or axon ...
1
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1answer
24 views

Confusion over role of current/potential in Nervous system?

I am taking a course on the nervous system and I am do not have any physics background. Therefore, I would like to know, what are we precisely talking about when we talk about current in the nervous ...
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0answers
9 views

Does dendrite have Na/K electrical channels?

Does dendrite have Na/K electrical channels if not so how can we sense the touche/pain/scald in our skin because we learned that Na/K electrical channels are present only in nerve fibers (axon).In ...
0
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1answer
24 views

Cardiac Excitation Threshold - in C++ modelling [closed]

So I am trying to write a code in C++ about the cardiac excitation threshold. I know that this excitation threshold is the shortest stimulus2 value at which it can conduct an action potential (known ...
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1answer
42 views

All or nothing phenomena

We know that an action potential is produced by an active cell membrane when the stimulus reaches a certain threshold. When it does, an action potential fires, and when it doesn't, nothing happens. ...
2
votes
1answer
25 views

What is the mechanism responsible for the 'delay' in delayed rectifier potassium channels?

I've been trying to find a comprehensive explanation concerning the nature of the 'delay' in neurons' delayed rectifier potassium channels. As it's written in my intro to neuroscience textbook, these ...
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0answers
39 views

muscle contractions cell biology questions?

An increase in cAMP/PKA always results in muscle contractions. In smooth muscle contraction, calcium binds to troponin. Stimulation of adrenergic beta receptors on smooth muscles cause muscle ...
6
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3answers
75 views

Can a single axon propagate multiple simultaneous action potentials?

I have not been able to locate any research that indicates whether a single axon of a neuron or nerve cell can conduct multiple simultaneous (i.e. spatially separate) action potentials. I am aware ...
2
votes
1answer
41 views

How does core-conductor model correspond to an actual neuron?

Hi guys, looking at your average neuron, it is very difficult for me to imagine how this could be translated into a core-conductor model On the neuron above, where would be the intracellular ...
3
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0answers
21 views

To measure Na/K channel activation in membrane level?

Assume that there are two different signals going on in the ECG - during depolarisation and repolarisation in the standard ECG. I got an advice that do not use the standard ECG in measuring exactly ...
0
votes
1answer
60 views

Mechanism of antiperistalsis

What is the mechanism of antiperistalsis that occurs during vomiting? Why the peristaltic waves normally don't propagate in anal to oral direction? Please give logical explanation with authentic ...
1
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1answer
35 views

Fastest and slowest action potential

When our instructor asked us about the speed of action potentials in cells, I told him that action potentials and two-wheelers travels at similar speeds. He thought that this is an 'interesting' way ...
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0answers
55 views

What is the nature of action potentials in autonomic nervous system?

My conjuncture is that the natures of sympathetic and parasympathetic action potentials are different. My findings propose me that sympathetic action potential is little longer lasting than ...
1
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1answer
39 views

Sodium-Potassium Pump

From my understanding, in the sodium-potassium pump we have Na+ inside the cell and K+ outside the cell, thus forming a so called "salted banana." After reading my textbook I found many statements ...
6
votes
1answer
108 views

Refractory period in action potential

I know that the part E in this graph is definitely the part of refractory period. My question : Will there be any effect on B,C or D if a stimulus is given at time B,CorD respectively ?
2
votes
1answer
315 views

Action potential and sodium channels

In this video on electro tonic potential, the tutor says that when the potassium channels open the potential drops from +40mV to -80mV, where the sodium channels have already closed at +40mV. Now in ...
5
votes
2answers
86 views

Confused at what is happening with these action potentials

Ok so for a bit of a background, I am doing a science project looking at the action potentials of the earthworm. I anaesthatized the worms then hooked them up to a spiker box ...
1
vote
0answers
92 views

Why are there different types of neurotransmitters?

Why does the type of neurotransmitter matter? If the neurotransmitter just stimulates a dendrite on a neuron which causes electricity to move through via sodium-pottasium pumps and ion gates to ...
0
votes
1answer
46 views

What happens to potassium after an action potential?

If I understand right, after repolarization, much of the potassium is outside the membrane and much of the sodium / calcium is inside. How does it get back to the original concentrations (i.e. ...
1
vote
1answer
287 views

What is the effect of extra-cellular potassium concentration on heart rate and conduction velocity?

If the extracellular potassium concentration surrounding a myocyte increases, then the potassium gradient accross the cell membrane decreases, and therefore the resting membrane potential will become ...
1
vote
1answer
121 views

Do nerve cells cause action potential in cardiac muscle?

I think the answer is no, but I am not 100% sure. If it was yes, then the dendrite of the nerve cell should each time receive a stimulus causing Na+ channels to open, when the contraction happen. ...