Download HERE

Neuron & Action Potential Web Quest
Part 1 – Neurons
Go to http://www.childrenshospital.org/research/_neuron/index.html
Read the text associated with each part and answer the following questions.
1. What is a neuron? _________________________________________________________
2. Draw a neuron below and label the parts in the box below.
3. Summarize the function of each of the following parts of the neuron:
Soma (Cell Body)________________________________________________________
Dendrites _____________________________________________________________
Axon _________________________________________________________________
Myelin Sheath _________________________________________________________
Terminal Buttons (End Bulbs) _____________________________________________
Synapse _______________________________________________________________
Go to http://learn.genetics.utah.edu/content/addiction/reward/
Play the game “Make A Mad Mad Mad Neuron” with Dr. Dedristein
4. My score was _____________ because _________________________________________
Part 2 – Other Cells in the Brain & Reward Pathway
Stay on http://learn.genetics.utah.edu/content/addiction/reward/
Click on the “Other Cells in the Brain” link and answer the following questions:
5. There are about ______________ neurons in the brain as well as ______________ of support
cells called _____________________.
6. There are 3 types of glial cells. Name each of the 3 and explain their function:
1. ______________________:
2. ______________________:
3. ______________________:
Use your browser’s BACK button to return to the homepage. Now click on “The Reward
Pathway Reinforces Behavior.”
7. What is the reward pathway?
8. How does it work?
Part 3 – The Nerve impulse & Synapse
Go to http://www.bris.ac.uk/synaptic/public/basics_ch1_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?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Go Back To http://learn.genetics.utah.edu/content/addiction/reward/
Click on “Crossing the Divide: How Neurons Talk to Each Other”
18. Explain the communication process in your own words
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
19. Explain the Reuptake Process
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Part 4
Go to http://www.blackwellpublishing.com/matthews/actionp.html
View this animation. It shows the action potential moving in one direction along the neuron’s
axon.
1. What is happening to the charge on the outside and inside of the cell as the action potential
moves?
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Part 5
Go To Website – http://psych.hanover.edu/Krantz/neurotut.html
Click on > Review of Physical Factors involved in the Action Potential.
Read – Diffusion
1.Give the definition of diffusion._____________________________________________
>Click on Figure 1 Diagram.
2.What is the ultimate goal of diffusion? _______________________________________
> Click on Right Arrow - Diffusion and the Axon
3. Is the inside of the axon more positive or negative during the resting potential?
__________________________________________________________________________
4.What do the colored bars represent? ___________________________ Colored circles?
____________________________________
5.During the resting phase the concentration of ________is greater outside and the
concentration of _______ is greater inside.
> Click on the ion channels and observe Figure 3a
> Click on Left arrow
6. Answer Question 1.
________________________________________________________________________________
________________________________________________________________________________
Click on > Right Arrow - Electrical Charge and Attraction
7. Define Ion.
________________________________________________________________________________
________________________________________________________________________________
8. Opposite charges do what to each other?
________________________________________________________________________________
>Click on Right Arrow
9. Like charges do what to each other?_______________________________________________
Click on > Right Arrow - Voltage and the Axon
10. During the resting potential the axon has a ___________ to __________ voltage comparing
the inside to the outside.
11. So what effect will the voltage difference have on the Na+ ions when the Na+ channels first
open? _____________________
(write and click on the correct answer)
Click on > Back Button then Click on > Right Arrow - Depolarization
12. Describe the axon at the end of the depolarization phase.
__________________________________________________________
13. At the end of the depolarization phase, what is the tendency for movement of a sodium ion
at the mouth of a sodium channel?
________________________________________________________________________________
________________________________________________________________________________
Click on > Right Arrow - Repolarization
14. Describe the events of repolarization.
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
Click on > Right Arrow – The Action Potential
15. Give a brief summary of the overall occurring events involved in the Action Potential.
________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
*********Take the short QUIZ by clicking on Quiz in the left margin. ********