Review the effect of increasing the voltage?
Review Sheet Exercise 3 Neurophysiology of Nerve Impulses Eliciting (Generating) a Nerve Impulse 1. Why don’t the terms depolarization and action potential mean the same thing? They require different things. Action potential requires depolarization and repolarization. Depolarization doesn’t require anything. 2. What was the threshold voltage in Activity 1? 3.
0V 3. What was the effect of increasing the voltage? How does this change correlate to changes in the nerve? The action potential increases. 4. How did the action potential generated with the unheated rod compare to the that generated with the heated rod?The action potential increased with the heated rod.
5. Describe the types of stimuli that generated an action potential. The glass rod and glass heated rod, the 3. 0V and higher voltage, the sodium chloride, and the hydrochloric acid. 6.
If you were to spend a lot of time studying nerve physiology in the laboratory, what type of stimulus would you use and why? I would use the glass rod because I would like to see what the results might be if you froze the glass rod instead of heating it. 7. Why does the addition of sodium chloride elicit an action potential?Hint: Think about the sodium permeability of the neuron (Figure 3.
2e). Because of the addition of chloride. Inhibiting a Nerve Impulse 8. What was the effect of ether on eliciting an action potential? There was no action potential. 9. Does the addition of ether to the nerve cause any permanent alteration in neural response? yes 10.
What was the effect of curare on eliciting an action potential? There was action potential. 11. Explain the reason for your answer to question 10 above. Because of the addition of the curare it reacted differently with the nerve. 2. What was the effect of lidocaine on eliciting an action potential? There was no action potential.
Nerve Conduction Velocity 13. What is the relationship between size of the nerve and conduction velocity? The larger the nerve the bigger the conduction velocity. 14.
Keeping your answer to question 13 in mind, how might you draw an analogy between the nerves in the human body and electrical wires? The nerves will be effected more by an increase in size of electrical wires but less with the increase in the size of the nerves. 15.How does myelination affect nerve conduction velocity? Explain, using your data from Chart 1.
It caused the conduction velocity to be higher. For the myelinated frog nerve the conduction velocity was 25. 00 m/sec. The unmyelinated Rat nerve1 it was 16. 48 m/sec.
They were both the same size at medium. 16. If any of the nerves used were reversed in their placement on the stimulating and recording electrodes, would any differences be seen in conduction velocity? Explain. Yes the reverse would be seen in the differences in how the size plays on the conduction velocity.