Download Action Potential

Action Potential Web Quest
Names ________________________
YOU MAY GO TO OUR WEBSITE AND DOWNLOAD DOC
TO CLICK ON WEBSITES INSTEAD OF TYPING IN THE URL YOURSELF
PART 1 – NEURONS
Go to http://www.childrenshospital.org/research/_neuron/index.html
1. What is a neuron? _________________________________________________________
2. Summarize the function of each of the following parts of the neuron:
Soma (Cell Body)________________________________________________________
Dendrites _____________________________________________________________
Axon _________________________________________________________________
Myelin Sheath _________________________________________________________
Synaptic End Bulbs (Synaptic terminal)_______________________________________
Synapse _______________________________________________________________
3. Draw a neuron below and label the parts in the box below.
Save this website for later, the other tabs have helpful and simplified animations of how a neuron works.
(optional for fun and practice) Go to http://learn.genetics.utah.edu/content/addiction/madneuron/
Play the game “Make A Mad Mad Mad Neuron” with Dr. Dendristein
Part 2 - Resting Potential and Action Potential Videos (short)
Go to http://www.youtube.com/watch?v=YP_P6bYvEjE Watch this video. It shows how membrane
potential (resting potential) develops in the neuron cell.
1. What causes the inside of the cell to be more negative compared to the outside of the cell?
Go to https://www.youtube.com/watch?v=ZAmUjvgoO0A Watch this video. It shows how resting
potential develops as well as how an action potential (impulse) develops.
2. What role does the sodium/potassium pump (Na+/K+ pump) have in creating resting potential?
3. What happens to the inside of the cell when sodium ions flood into the cell?
4. After sodium ions have flooded into the cell and the sodium gates close, what happens to the
potassium ions?
5. How does an action potential conduct along an axon?
6. Describe and draw an action potential.
Part 3 – Ions Control Membrane Potential
Go to http://www.bristol.ac.uk/synaptic/basics/basics-2.html
1. Neurons maintain different concentrations of certain ions across their cell membranes. What ion is in
high concentration outside the neuron? _____________________
2. Which ion is in high concentration inside the neuron? ___________________
3. What specialized protein exists in the neural cell membrane? __________________________
4. What is its function? __________________________________________________________
5. Under resting conditions which ion leaks more, the sodium leaking inward or the potassium leaking
outward? ___________________________________________________________
6. The result of the leaks makes the outside of the cell charged ________ and the inside of the cell
charged ________. The cell is said to be ____________.
7. Since sodium is in high concentration outside of the cell what happens if the sodium channel opens in
the membrane? Which way does the sodium move? ________________________.
8. This makes the neuron momentarily ___________ charged. The cell is said to be ___________.
9. This switch in membrane potential is the _________________________.
10. View the animation to see how the action potential moves down the length of the cell (in one
direction). Summarize what’s happening.
______________________________________________________________________________________
__________________________________________________________________________
11. What is the speed of an action potential directly related to?
__________________________________________________________
12. What type of axon results in fast transmission rates?
________________________________________________________________
13. What substance allows for rapid action potential? _________________________
14. What produces myelin in the Peripheral Nervous System? _____________________ Central
Nervous System? _____________________
15. Where does an action potential take place on a myelinated neuron?
___________________________________________________
16. Why does an action potential happen faster on a myelinated neuron than an unmelinated neuron?
______________________________________________________________________________________
__________________________________________________________________________
17. What does the disease Multiple Sclerosis have to do with all this?
Part 4 – Can You Explain What Is Happening Here?
Go to http://phet.colorado.edu/en/simulation/neuron and run the simulation.
***Under control, make sure all the boxes are checked so you can see all the charts and information.
Zoom into the membrane and slow the simulation down.****
You should be able to explain to your partner the resting potential situation.
Click the Stimulate Neuron button. You should be able to explain to your partner what is happening with
respect to ion channels opening/closing, movement of ions, depolarization/repolarization and return to
resting potential.
Part 5 – If you are having a hard time understanding resting potential, action potential and impulse
transmission, go back to http://apps.childrenshospital.org/clinical/animation/neuron/ and start at the
‘transmission’ tab. Use the 'next' button to follow the steps of the animation.
This website also offers a simple explanation. I expect you already understand diffusion and electrical
charge, so start at “voltage and the axon”
http://psych.hanover.edu/Krantz/neural/actionpotential.html
Part 6 - Video Quizzes
http://highered.mcgrawhill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html
Answers: 1. _____ 2._____ 3.______ 4.______ 5._______
http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter44/voltagegated_channels_and_the_action_potential.html
Answers: 1. _____ 2._____ 3.______ 4.______ 5._______
http://highered.mcgrawhill.com/sites/0072943696/student_view0/chapter8/animation__action_potential_propagation_in_an
_unmyelinated_axon__quiz_2_.html
Answers: 1. _____ 2._____ 3.______ 4.______ 5._______