Neurophysiology of Nerve Impulses

REVIEW SHEET

EXERCISE 3

Neurophysiology of Nerve Impulses

NAME:

LAB TIME/DATE:

Eliciting (Generating) a Nerve Impulse

1. Why don’t the terms depolarization and action potential mean the same thing?

A local depolarization can lead to an action potential. Usually a threshold of depolarization must be met before the propagation can occur.

2. What was the threshold voltage in Activity 1? 3.0

3. What was the effect of increasing the voltage? How does this change correlate to changes in the nerve? The line went up

4. How did the action potential generated with the unheated rod compare to that generated with the heated rod?

The heated line had a rise and a dip

5. Describe the types of stimuli that generated an action potential.

Sodium chloride and increased voltage

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? Sodium chloride and because it generates an action potential

7. Why does the addition of sodium chloride elicit an action potential? Hint: Think about the sodium permeability of the neuron (Figure 3.2e).

Adding NaCl elicits tan action potential because you increase the concentration of sodium ions outside the cell’s equilibrium potential of sodium ions and creating a concentration gradient.

Inhibiting a Nerve Impulse

8. What was the effect of ether on eliciting an action potential?