[PhysioEX Chapter 3 exercise 6] PEX-03-06

Solved by ramonistry

Exercise 3: Neurophysiology of Nerve Impulses: Activity 6: The Action Potential: Coding for Stimulus Intensity Lab Report
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.

1. The time after an action potential when a second action potential cannot be generated no matter how intense the
   stimulus is called the
   You correctly answered: b. absolute refractory period.
2. The time after an action potential when a second action potential can be generated only if the stimulus intensity is
   increased is called the
   You correctly answered: c. relative refractory period.
3. The term frequency refers to
   You correctly answered: c. the number of action potentials per second.
4. The purpose of this activity is to explore
   You correctly answered: b. the relationship between stimulus intensity and the frequency of action potentials.

Experiment Results
You have not completed the Experiment.
Experiment Data:

Post-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.

1. If the interval between action potentials (the interspike interval) is 0.1 (1/10) seconds, what frequency of action potentials
   would be observed?
   You correctly answered: c. 10 Hz
2. With a prolonged stimulus that is just above (more depolarized than) threshold, you would expect to get additional action
   potentials when the membrane has completed
   You correctly answered: b. the absolute and relative refractory periods.
3. Which of the following changes occurs when you increase the stimulus intensity?
   You correctly answered: c. The frequency of action potentials increases.
4. The absolute refractory period is about 3.75 msec. What intensity stimulus would produce action potentials with this
   interspike interval?
   You correctly answered: d. None of these stimuli would produce action potentials at this high frequency.

Review Sheet Results

1. Why are multiple action potentials generated in response to a long stimulus that is above threshold?
   Your answer:
   a long stimulus that is above threshold occurs action potential after the relative refractory period.
2. Why does the frequency of action potentials increase when the stimulus intensity increases? How well did the results
   compare with your prediction?
   Your answer:
   The frequency of action potentials increases because the increasing stimulus intensity can trigger more action potentials
   with the refractory period.
3. How does threshold change during the relative refractory period?
   Your answer:
   Threshold increses.
4. What is the relationship between the interspike interval and the frequency of action potentials?
   Your answer:
   they are interactive.