1. Warm-Up: I think a neuron looks like…
You will each be given a sheet of plain paper.
Using only half of the paper, draw what you think a neuron looks like.
There are markers, rulers, and crayons available for you to use.

3. Domino Lab READ the directions of your lab.
Make sure you answer each embedded question
Exploring with the Model
Interpreting Results
Hold on to your lab when you are done – we will discuss this lab as a class.

4. How do dominoes model the nervous system?
Compare the response of the dominoes when the first one in the line is just barely touched to when you used significant force to flick it. Can you think of a way this models our ability to perceived different stimuli?
Is there a minimum strength of a stimulus we need to feel a feather touching our arm?
Action Potential

5. How do dominoes model the nervous system?
When the dominoes all fall, do they reset themselves? What must happen for them to be in the starting position again?
Hypothesize how this might represent something comparable to the way our nervous system functions.

6. How do dominoes model the nervous system?
When a domino is removed from the center of the line, what happens when you do the exploration?
Can you think of any disease or disorder that this might model?

7. Nervous System and Amputation
What is “Phantom Limb”?
80% of amputees experience phantom limb at some point in their life.
Researchers are still looking for answers about phantom limb.
Nervous system is confused after amputation, and can sense something is different.
Neurons can often mistake this confusion as signals of pain, itchiness, and sensations of movement of the missing limb.

8. Biological Overview of a Neuron
What is a Neuron?

9. Nerve Cells
Cell membrane (cytoplasm) & nucleus, which houses genetic material.
Role: Send and receive information
Collects data from sensory system or from other cells in the body.
Transmits this data to other cells or muscles.

10. Nervous system cells Neuron a nerve cell Structure fits function
signal
direction
dendrites
Structure fits function
many entry points for signal
one path out
transmits signal
cell body
axon
signal direction
synapse
myelin sheath
synapse
dendrite  cell body  axon

11. Structure of a Neuron Dendrites: Axon: Myelin Sheath: Synapses:
Receive information
Axon:
Transmits data
Myelin Sheath:
Insulation to carry signals rapidly
Synapses:
How neurons communicate.
Neurons do not touch – signals cross gap and bind to next neuron

12. Fun facts about neurons
Most specialized cell in animals
Longest cell
blue whale neuron
10-30 meters
giraffe axon
5 meters
human neuron
1-2 meters
Nervous system allows for 1 millisecond response time

13. Transmission of a signal
Think dominoes!
____________________________
knock down line of dominoes by tipping 1st one
 trigger the signal
do dominoes move down the line?
 no, just a wave through them!
before you can do it again, have to set up dominoes again
 reset the axon

14. Transmission of a nerve signal
Neuron has similar system
protein channels are set up
once first one is opened, the rest open in succession
all or nothing response
a “wave” action travels along neuron
have to re-set channels so neuron can react again

15. Reflex Responses
Happen so quickly because the signal from sensors are routed directly to the muscles from the spinal cord, without passing through the brain.

16. Draw a Neuron: Part II
On the other half of your paper, draw what a neuron looks now that we have gone over its structure.
Be sure to label!

17. Comparison
After you have finished your drawing, write a short paragraph (3-5 sentences) describing the difference between your first drawing and your second drawing.

18. Biomechanics