Autumn.wmf (12088 bytes)Introduction to Organismal Biology (BIOL221) - Dr. S.G. Saupe; Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321;;

Study Guide & Review for Neurons


I. Goal:  The goal of this unit is to provide a basic understanding of the mechanism of electrical signaling in animals (and a few plants)


II. Reading(s):  Chapter 48

III.  ObjectivesUpon completion of this unit you should be able to: 

  1. Compare and contrast the two main signaling methods used by plants and animals.

  2. List and describe the major parts of a neuron and explain the function of each.

  3. Describe the function and location of each type of supporting cell.

  4. Define membrane potential, resting potential and action potential.

  5. Explain why the membrane potential of a resting neuron is typically about -70 mV.

  6. Explain the role of the sodium-potassium pump in maintaining the membrane potential.

  7. Describe the Nernst equation

  8. Compare and contrast leakage (ungated) ion channels, chemically-gated ion channels, and voltage-gated ion channels.

  9. Describe the characteristics of an action potential. Explain the role of voltage-gated ion channels in this process.

  10. Describe the two main factors that underlie the repolarizing phase of the action potential.

  11. Explain how the nervous system distinguishes between stronger and weaker stimuli.

  12. Explain how an action potential is propagated along an axon.

  13. Describe the factors that affect the speed of action potentials along an axon and describe adaptations that increase the speed of propagation.

  14. Compare an electrical synapse and a chemical synapse.

  15. Describe the structures of a chemical synapse and explain how they transmit an action potential from one cell to another.

  16. Explain why an action potential can be transmitted in only a single direction over a neural pathway.

  17. Explain how excitatory postsynaptic potentials (EPSP) and inhibitory postsynaptic potentials (IPSP) affect the postsynaptic membrane potential.

  18. Define summation and distinguish between the two types. Explain how summation applies to EPSPs and IPSPs.

  19. Explain the role of the axon hillock.

  20. Describe the types and properties of the major neurotransmitters.

 IV.  Common Terms/Concepts (can you use the following terms/concepts conversationally?) 


V. Activities (Some learning activities and tips for studying):

  1. Make a concept map for the unit
  2. Be sure to visit the Study Area of the textbook website � the animations are excellent
  3. Also check out the action potential and synaptic transmission animations at:


VI. Questions: After completing the activities, write any question(s) that you still have concerning the objectives or that pertain to related areas.  Check the text or other sources for the answers.  Or, contact me!


VII. Application: Write one or more ways in which you can immediately apply this information to your daily life.


VIII. Assessment: Meet with one or more members of the class to help assess that you have attained the objective and to help deepen your understanding of the material. Answer the questions at the end of the chapters. Write your own exam questions. Visit the text book web.

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Last updated: February 25, 2009        � Copyright by SG Saupe