Nervous System I: The Action Potential - Self Test

NOTE: This quiz is designed to be completed using the InteractivePhysiology CD that you used in the Muscle Lab.  However, you should be able to answer most of the questions without the CD by using your class notes and your textbook.

1. The action potential changes the membrane potential from _______ mV (resting) to _______ mV and back again to the resting membrane potential.

 This results from a change in membrane permeability first to _______ then to _______ due to the opening of what type of ion channels? ______________________

 

2. a. Where is the density of voltage-gated Na+ channels the greatest? __________________

   b. What areas of the neuron generate signals that open these voltage-gated channels? __________________________________________

   c. Opening of these voltage-gated Na+ channels causes the membrane to __________________ (voltage change).

 

3. a. If the membrane reaches the trigger point, known as __________________, what is the name of the electrical potential that is generated? __________________________________________

   b. During the depolarization phase, voltage-gated __________ channels open and _______ enters the cell.

 

    4. What are the two processes that stop the potential from rising above 130 mV?

   a.

   b.

 

5. a. The opening of voltage-gated K+ channels cause the membrane to _____________________.

   b. Does K+ move into or out of the cell? __________________

   c. If the membrane potential becomes more negative than -70 mV, this is called _________.

   d. This potential is caused by what characteristic of K+ permeability? _________
   __________________________________________.   

6. a. After an action potential, the neuron cannot generate another action potential because _______ channels are inactive. This period is called the __________________ period.

   b. During the ______________________ period, the cell can generate another action potential but only if the membrane is ___________ (more or less) depolarized.

 

    7. a. Conduction velocity along the axon is increased by what two characteristics?

    1. ________________________________

    2. ________________________________

   b. Conduction along a myelinated axon is called __________________________
   conduction.