Nervous System

Below you will find the following activities / resources to enhance instruction of the nervous system:  Items with an asterisk are short and can easily be incorporated into class.
1) Neuron model showing action potential* (short once it’s made)
2) Neuro muscular junction flip chart
3) Relevant experiments from The Naked Scientist
4) Songs about the nervous system*

1) NEURON MODEL SHOWING ACTION POTENTIAL
Once you make this you can use it semester after semester for a quick demo of action potential…
Rope Neuron
This giant model of a neuron illustrates the properties of chemical transmission and the action potential. You must construct the neuron before you use it with a group of people. Cut two to three foot lengths of rope to use as dendrites. Another 10-15 foot piece of rope will be turned into the axon. The cell body and synaptic terminal of the neuron can be plastic containers. Drill holes in the plastic containers for the dendrites and axon. To secure the dendrites and axon in place, tie a knot in the ropes so they will not slip through the holes of the containers. The action potential is modeled with a pool float. Thread the pool float onto the axon before you secure the axon in place. Place small plastic balls or ping-pong balls in the synaptic terminal and your model is ready to go!

Set up the model:
1. Get volunteers to hold each of the dendrites.
2. Get one volunteer to hold the cell body and one to hold the synaptic terminal. Make sure the person holding the synaptic terminal keeps his or her hands AWAY from the place the axon attaches (more about this later).
3. Get one volunteer who will hold more molecules of neurotransmitter (more plastic balls) near the people who are dendrites.
4. Get one volunteer to hold the action potential.

Use the model:
1. Have the person holding molecules of neurotransmitter TOSS the plastic balls to the people who are dendrites. The “dendrite people” try to catch the plastic balls. This models the release of neurotransmitters and the attachment (binding) of neurotransmitters to receptors on dendrites.
2. When three plastic balls are caught by dendrites, the person holding the action potential can throw/slide the pool float down the axon. This simulates the depolarization of the neuron above its threshold value and the generation of an action potential.
3. The action potential (pool float) should speed down the axon toward the synaptic terminal where it will slam into the container. This should cause the release of the neurotransmitters (plastic balls) that were being held there.
CAUTION: The pool float will travel very fast! Make sure that the person holding the synaptic terminal keeps his or her fingers and hands AWAY from the pool float.
Rope neuron in action_2
If the entire model is stretched tightly, the pool float should travel down to the terminal smoothly. This model can be used to reinforce the “ALL-OR-NONE” concept of the action potential:
* Once the action potential starts, it continues without interruption.
* The size of the action potential stays the same as it travels down the axon.

Materials:
* Rope (for dendrites and axon)
* Plastic containers (for cell body and synaptic terminal)
* Pool Float (or another object will slide along the rope; for the action potential)
* Plastic balls (for neurotransmitters)
* Volunteers!

retrieved from:
http://faculty.washington.edu/chudler/chmodel.html
retrieved 10/12/10

2) NEUROMUSCULAR JUNCTION FLIP CHART:

This ideas comes from Professor Michele Paradies
professor of A&P at SUNY Orange : Orange County Community College in Middletown, NY
Instructions come first and the lists mentioned in the instructions follow. Thanks Professor Paradies!!

Instructions for NMJ flip chart activity:

This activity is designed to help students review the steps of the generation and propagation of an action potential along a axon as well the activation of the neuromuscular junction.  Students should be familiar with the terminology on the sheets and have gone over the process in class or with the aid of a tutorial CD before doing this activity.

1.  Hand out the cause and effect lists to students.  Have students break up into groups of 3-4.

2.  Have students write the statements on the cause list on white index cards, and the statements on the effect list on colored index cards (or on two sets of colored cards).

3.  Have students spread the white cards out on a table or other surface.  Then, have the students put the cards in order by deciding what happens first, etc.

4.  Check with each group periodically to see how they are progressing.  Suggest moving cards to new locations where appropriate.

5.  Once a group has correctly ordered the first set of cards, have them start to integrate the second set in with the first.  I recommend to students that they keep the first set of cards lined up (they may even want to number them at this point so they can return them to the proper order if the line gets mussed!) then try to match each new card (the effect) to its direct cause, e.g. sodium channels open would be partnered with sodium rushes into the cell.

6.  Again, circulate among the groups offering support and suggestions.

7.  Once both sets of cards are in proper order and all the causes are matched to their effects, the students can make the set of cards into a flip chart.  I bring in some large sheets of card stock that I have sliced into strips.  Students should tape or staple each cause to its effect so that the writing on one side is upside down compared to the writing on the other side.  Then, the cards are stapled or taped to the strip of card stock (taping facilitates better flipping, but is not as sturdy – do what works best for you and your students).  Start by taping/stapling the last set of cards to the strip and work your way to the first, which will end up at the top of the strip.  Make sure the causes are facing you as you connect the cards to the strip.

8.  When you are finished, students can run through the whole procedure as a review by flipping through the completed project!  Make sure you bring enough extra cards and strips of cardstock that everyone can take the material home to make their own flip strip!

Hope you and your students have fun with this!  It was my most popular activity last year by far – students loved the challenge of organizing the cards and seeing how the whole process unfolded.  And they did retain the information very well for the exam and the final.

The ‘Cause’ List:
-Acetylcholine binds to ACh receptors
-Action potential travels progressively through axon
-High levels of sodium inside the axon cause membrane polarity reversal
-Acetylcholine diffuses across the synaptic cleft
-Voltage-regulated sodium channels open in the adjacent sarcolemma
-The sodium potassium pump works
-Voltage-regulated calcium channels in the axon terminal open
-Acetylcholinesterase bind to and breaks down acetylcholine
-Action potential is initiated at the axon hillock
-Voltage regulated potassium ions open
-High calcium levels in the axon terminal initiate synaptic vesicle exocytosis
-Voltage-regulated sodium channels open

The ‘Effect’ List:
– ACh reaches the motor end plate
– sodium ions enter the axon
– the depolarized section of the axon repolarizes
– the action potential eventually arrives at axon terminal
– ACh released into the synaptic cleft
– returns sodium and potassium to the appropriate side of the membrane
– chemically-regulated sodium channels open
– voltage regulated sodium channels activated in the proximal axon
– chemically-regulated sodium channels close
– calcium rushes into the axon terminal
– initiating a wave of depolarization through the sarcolemma
– a section of the axon’s membrane becomes depolarized

3) RELEVANT EXPERIMENTS found on The Naked Scientist
(www.thenakedscientists.com)

A) 2 experiments having to do with the senses that could be done as a quick demo in lab or class:
1) Confusing colors:
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/confusing-colours/

2) Strange textures
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/strange-textures/

B) About the cochlea:

How We Hear, Echolocation and Giant Whoopee Cushions

http://www.thenakedscientists.com/HTML/podcasts/show/2006.10.22/

4)  Songs from “Groovin’ in the Hippocampus“: You are welcome to play these songs in class and to share or project a lyrics sheet, but please do not give the actual song to your students.  The songs are available for download as individual songs on the right side of the home page of this site.
Jerking Me Around (reflexes)
The Brain Song (location and function of parts of brain)
Cranial Nerve Boogie (function and tests of cranial nerves)

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