For all question the info is attached for graphs- In Experiment 1, discuss why t

Question

For all question the info is attached for graphs-

In Experiment 1, discuss why the amplitude of the action potential did not increase as stimulation voltage increased above threshold.

In Experiment 1, explain why the membrane potential between the axon hillock and axon either charged or did not change with subthreshold stimulus. Differences of 1.0 mV or less are not significant.

In Experiment 2, explain why the membrane potential between the axon hillock and axon either changed or did not change with threshold stimulus. Differences of 1.0 mV or less are not significant.

In Experiment 2, explain why the number of action potentials generated varied with increased stimulation freguency.

What was the resting membrane potential (no stimulation) recorded in table 3?

At which stimulation voltage(s) did you see decrimental conduction of graded potential from axon hillock to axon?

At what stimulus voltage(s) did an action potential occur?

What was the membrane potential at the axon hillock when the action potential was generated?

For each stimulation voltages, indicate whether it was sub-threshold, threshold, or suprathreshold.

2V:

4V:

6V:

8V:

Explanation / Answer

In Experiment 1, discuss why the amplitude of the action potential did not increase as stimulation voltage increased above threshold.

When the depolarization caused by the stimulus is above threshold, there will not be any change in the size of the resulting action potential. In all or nothing law, as long as threshold is surpassed, additional increases in stimulus strength do not lead to an increase in the magnitude of the voltage deflection of the action potential. The action potential is generated when sodium and potassium ions pass across the membrane, but when threshold had reached, there will be no further movement of ions across the membrane.

Even we can say after refractory period (period after first action potential), difficult to initiate second action potential. During this period, the signals will be transmitted one day, the closing and opening of positive and negative ions, where only K+ movement is seen. When another action potential is initiated during relative refractory period, the Na+ channels will be reset and ions will be rushed inside, now the stimulus will be stronger than normal depolarizing stimulus.

Because of the opening and closing of the positive and negative ions within the neuron when the action potential is initiated during the refractory period so that when another action potential is initiated during the relative refractory period Na+ ions rushing into the cell but, at the same time

In Experiment 2, explain why the membrane potential between the axon hillock and axon either changed or did not change with threshold stimulus. Differences of 1.0 mV or less are not significant.

For voltage gated ion channels to open, the membrane potential needs to change from resting level by a minimum amount (threshold), which causes the channel to open for the passage of ions. In some cases, the resultant change in the distribution of charge will make the membrane depolarize (here membrane potential will be closer to 0 mV) and the trigger being reached either of a threshold and depolarize or not. The threshold stimulus will not have any effect on the membrane during the absolute refractory period as additional depolarizing stimuli will not lead to new action potential (here the Na+ channels are inactivated).

In Experiment 2, explain why the number of action potentials generated varied with increased stimulation frequency.

Nervous system will use the strength of the stimulus to change the frequency of action potential generated. When the stimulus is stronger, the higher the frequency at this action potential is generated and we can say nervous system is frequency modulated. During electrical stimuli, the sodium channel will open and sodium ions will enter inside and channels will be closed. So the polarization and depolarization depends on the stimulation frequency.

What was the resting membrane potential (no stimulation) recorded in table 3?

-67.5 and -67.4

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