BI 231 - Human Physiology and Anatomy
Nerve Firing Study Guide

Compiled by Pat Bowne, Sherry Dollhopf,and Justin LaManna, 2007-11


The nervous system is the control center that coordinates homeostasis of all body functions by sensing internal and external conditions, integrating this information, and then controlling responses. How does the nervous system gather information and send signals so rapidly throughout the entire body? The answer begins with the cell membrane and diffusion…

Before class, make sure you:

Can sketch and label the structure of the cell membrane

Can list the functions of membrane proteins

Can explain what osmosis and diffusion do

Tutorials and reading assignment: REVIEW events in nerve firing and neurotransmitter action at:

Chapter 7, pages 172-199

What you should know for the assessment:

Be able to DEFINE the resting membrane potential and explain how it is maintained.

Be able to DESCRIBE and DIAGRAM the events involved in nerve firing.

Be able to EXPLAIN a graph of an action potential (mV vs. Time) and DESCRIBE what is happening in each phase.

Be able to EXPLAIN why myelinated nerve fibers conduct action potentials faster than unmyelinated ones.

Be able to PREDICT the effect of changing the intracellular or extracellular concentrations of H +, Ca+, or K+ on the sensitivity of nerve cells, and make inferences about the signs you will see in the client.

Be able to DIAGRAM and EXPLAIN the mechanisms of neurotransmitter signaling.

Be able to PREDICT the effects of different neurotoxins on the body, based on their interactions with synapses and ion gates.

Terms to know about cell firing

Terms to know about synapses and neurotransmission

Practice Questions

ANSWER questions 4, 5,6, 7, 8, 9, 10, 11, 12, and 13 on p 203 in your textbook

WRITE complete answers to the following questions. Backup your answer with logical arguments based on physiological concepts.

1. What is the function of the Na+/K+ exchange pumps? How do they contribute to the resting membrane potential?What would be the eventual effect on nerve impulse generation if all the Na+/K+ pumps in the body stopped working?

2. A child ingests organophosphate poison. Organophosphates bind to and inhibit acetycholinesterase. What symptoms could endanger this child’s life? Several substances are commonly used when neurotoxins are ingested. Which of the following three substances might help save the child’s life: acetylcholine, curare (which blocks acetylcholine receptors), or KCl. Explain why you think this substance will help.

Practice question with example answer

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