Name: ______Hour: ______
Campbell Biology CD: Chapter 48: Nervous Systems
Anatomy & Physiology/Nervous System
Directions:
1. Insert Campbell Biology CD and the program should start running.
2. Click on the “Launch Campbell Biology” option.
3. From the drop down menu go to “Chapter 48: Nervous Systems”
Activity: Neuron Structure
Directions: Use the drop down menus to select the correct labels for each part of the neuron. When you have everything labeled correctly, raise your hand for you instructor’s signature.
Teacher Initials: ______
Activity: Nerve Signals-Action Potentials
Page 1
Directions: Read the paragraph in the upper right corner. Click on “replay” to watch the animation again.
What causes a resting neuron to have potential energy?
What does the term “polarized” mean?
What is the resting potential of a neuron (in mV)?
Page 2
In a resting neuron, where are most sodium ions found, relative to the membrane?
What causes the resting potential?
Page 3
What is an action potential?
Page 4
What how do channels in the membrane cause an action potential to start?
How does the action potential travel along the axon?
Page 5
What is the approximate voltage across the membrane once the sodium ions have rushed into the cell?
What causes the voltage to decrease back to the resting potential?
Investigation: What Triggers Nerve Impulses?
Part 1: Electrical
1. What was the threshold voltage, or the voltage at which you first saw an action potential?
2. How does the tracing at a higher voltage compare to the one trace that was generated at the threshold voltage? (Hint: look very carefully at the tracings.) What reason can you give for your answer?
3. What is the maximal voltage beyond which no further increase occurs in the peak of the action potential trace?
Part 2: Mechanical
1. What do you see on the oscilloscope screen when the rod touches the nerve? How does this tracing compare with the other tracings that you have generated?
Part 3: Thermal
BROKEN --- SKIP
Part 4: Chemical
1. Does the tracing generated from sodium chloride differ from the original threshold stimulus tracing?
2. Does the tracing generated from hydrochloric acid differ from the one generated by the original threshold stimulus?
3. To summarize your experimental results, what 3 kinds of stimuli can elicit an action potential?
Activity: Signal Transmission at a Chemical Synapse
Page 1
What happens to an action potential when it reaches the axon terminal of a nerve?
Page 2
How do signals travel across a chemical synapse? Please answer with numbered steps. You should have a minimum of five steps.
What happens after an action potential is generated in the next nerve, in order to end transmission?