Physioex 9.0 Exercise 3 Predict/Stop and Think Questions Activity 4

Experiment Results
Predict Question:
Predict Question 1: If you apply TTX between recording electrodes R1 and R2, what effect will the TTX have on the action
potentials at R1 and R2?
Your answer : c. TTX will block the response at R2 but have no effect at R1.

Predict Question 2: If you apply lidocaine between recording electrodes R1 and R2, what effect will the lidocaine have on
the action potentials at R1 and R2?
Your answer : c. Lidocaine will block the response at R2 but have no effect at R1.

Stop & Think Questions:
2. Enter the peak value of the response at R1 and R2 in the field below and then click Submit to record your answer in the
lab report.
You answered: 100 μV

With a slower timescale, the appearance of the action potentials generated at R1 and R2 will appear to
You correctly answered: c. be compressed in time but have the same peak value of response.

Why do you think TTX is not used during dental procedures?
You correctly answered: c. TTX irreversibly blocks voltage-gated sodium channels in axonal membranes.