Internet Lesson: Action Potential

Internet Lesson: Action Potential

SCCS Anatomy/PhysiologyName:

Internet Lesson: Action Potential

Go to or link to it directly from the class website

You see an animated woman, showing, her nerves, spinal cord, and brain.

INTRODUCTION:

  1. What part of her body is the woman moving?

Click on the “play” button. You can hit “pause” and “play” to stop and start the animation at each step as you answer questions.

  1. What structures transmit the message from the brain to the foot?
  2. A nerve is a group of ______bundled together.
  3. The neuron’s message is transmitted along its ______.
  4. Where do the axons begin? ______
  5. Where do the axons end?______
  6. Axons conduct electrical messages called ______.
  7. Schwann cells ______axons in order to transmit messages ______.
  8. What creates “electricity?” ______
  9. An action potential is an ______that is traveling down an axon.
  10. A resting neuron is slightly more (positive/negative) inside the axon and slightly more (positive/negative) outside the axon.
  11. An axon potential briefly ______the charge across the membrane as it passes through.
  12. The fluid in and around cells is filled with ______. Ions are ______molecules.
  13. Neurons use ______ions and ______ions to create polarity across the membrane.
  14. The neuron’s membrane has a lot of ______to allow ions to pass through the membrane.
  15. When a neuron is resting, K+ and Na+ ions ______across the membrane.
  16. A pump in the membrane forces K+ and Na+ across the membrane (with/against) the concentration gradient.
  17. In this animation, Na+ atoms are (purple/green) and K+atoms are (purple/green)
  18. Na+ atoms are pumped (out of/into) the cell, and K+ atoms are pumped (out of/into) the cell.

RESTING POTENTIAL

  1. When a neuron is at rest, (K+/Na+) is concentrated inside the cell, and (K+/Na+) is concentrated outside the cell.
  2. At resting potential, the ______of the neuron is positive, compared to the inside.
  3. Complete the mission: place the K+ and Na+ ions on the correct side of the membrane. Click “submit” when you are done. Then click “continue”
  4. What molecule provides energy to drive the Na+/K+ pump?
  5. The first step is sending a signal is called ______, which is when the inside of the cell becomes ______.
  6. Complete the mission: close or open the K+ and the Na+ gates in order to depolarize the membrane.

Which channel did you close? ______

Which channel did you leave open?______

  1. Repolarization means the cell returns to ______potential, with the ______of the cell more negative than the ______.
  2. Complete the mission: restore the polarization across the membrane by closing or opening the K+ and Na+ channels.

Which channel did you close? ______

Which channel did you leave open?______

  1. Click on the membrane protein responsible for restoring the original concentrations of sodium and potassium? ______
  2. An animal (or human) at rest uses ______of his/her energy to power this molecule, which is found in all body cells.
  3. Click “continue”
  4. Click on different sections of the graph to see the stages of an action potential. Follow the movement of the ions, compared to the charge across the membrane.
  5. What is the voltage of resting potential?______(see the number under the red line)
  6. What is the greatest positive charge across the membrane, at the height of depolarization? ______
  7. How low does the voltage across the membrane become as it repolarizes? ______

ACTION POTENTIAL

  1. Neurons cannot ______without keeping the electrical charge difference across their membranes.
  2. The electrical current that passes down an axon is ______and ______.
  3. In this examply, the message travels from the ______to the ______in what seems like an instant.

END

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