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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 ...
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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 ...
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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 ...
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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 ...
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44 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 ...
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1answer
29 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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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 ...
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1answer
36 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 ...
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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 ?
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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 ...
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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 ...
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70 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 ...
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1answer
42 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. ...
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200 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 ...
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119 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. ...