This Assignment for this unit is a Lab that you will complete in

This Assignment for this unit is a Lab that you will complete in WileyPLUS. You will be focusing on action potentials. In order for neurons to communicate with each other, nerve impulses are used. This lab will allow you to measure the amplitude of an action potential,

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as well as be able to measure the effect of increasing frequency of stimulations on the generated action potentials. Action potentials are not something that you really think about in your daily life. You don’t worry that you can move your arm to feed yourself or that your fingers can type a response in the Unit 9 Discussion Board or that you are able to read and understand this paragraph. You just take for granted that this all happens. However, if you did not have action potentials you could not do all that you do. In other words, your brain would not be able to synthesize the information it is flooded with on a daily basis and you would not be able to function. This lab will show you the importance of action potentials and why your body needs them.

This Assignment is due by the end of Unit 9.

To Complete this Assignment:

1.Click on the Read, Study and Practice link in the Course Home. 2.Click on Chapter Opener for any chapter. 3.Click on the PowerPhys link. 4.Click on the PowerPhys Complete Program link 5.Click on the œAction Potentials lab. 6.Complete the entire lab, including the lab report. 7.Export and Save the lab report to an Adobe PDF to submit to the Dropbox.http://edugen.wiley.com/edugen/shared/lws/index.uni?chapter=itm2204371&module=itm2204372&pageid=itm2204373&pagehref=crs7541/ebook/c12/tortora9781118345009c12-sec-0001.xform&scheme=student&navigtion=off&navflag=next

Attachments

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Name__________________________________

 

Unit 9 Worksheet “ Membrane Potentials

 

Each answer is worth 1 point (20 points total)

 

 

To complete this worksheet, select:

Chapter 12: Nervous Tissue
Animations
 

 

Introduction to Membrane Potentials

 

  1. Describe the neuron function.
  2. Contrast graded potentials and action potentials.
  3. a. Describe how there can be an electrical change on either side of a membrane thereby generating a membrane potential.

 

b. What two characteristics must a membrane possess in order to generate and maintain electrical signals critical to nervous tissue?

 

Membrane Transport Proteins

 

  1. What three membrane proteins are required if a membrane is to carry electrical impulses?

 

 

  1. Describe the activity of sodium and potassium ion channels.

 

  1. How do the following differentially affect gated channels?
  • Chemicals (ligands)
  • Voltage changes
  • Mechanical deformation

 
 

 

  1. Where are each of the following types of gated channels located AND what type of function do they serve?

 

Ligand gated “

 

Voltage gated “

 

 

Mechanically gated “

 

 

  1. a. Describe the function of the Sodium/Potassium pump.

    b. How does the sodium/potassium pump action maintain the membrane potential?

 

Resting Membrane Potentials

 

  1. Describe the positive and negative charges on either side of a membrane at resting potential.

 

  1. a. The opposite œpoles of a battery are positively and negatively charged.  Explain why polarized is a good term to describe a membrane with a resting potential.

 

b.   Where, exactly, do the opposing charges exist?  What is the charge of the cytosol and the extracellular fluid?

 

c.    What is the typical resting potential for a membrane?

 

 

  1. Describe how the following contribute to the unequal distribution of ions and charges thereby establishing a resting membrane potential.

 

K+ permeability “

 

Na+/K+ Pump Activity “

 

 

 

 

Graded Potentials

 

  1. Define a graded potential.

 

 

  1. How does opening a gated ion channel affect resting membrane potential?

 

 

 

 

  1. Correlate the name œgraded potential to the affect of stimulus intensity.

 

 

  1. Describe two types of graded potential change.

    hyperpolarization “

 

depolarization “

 

 

 

16. What is the role of graded potentials?

 

 

 

 

 

Action Potentials

 

  1. What is the function of a neuron’s trigger zone?

 

 

 

 

  1. a.    Why are Na+ and K+ gated channels essential for an action potential?

 
b.   Describe the electrical change during an action potential.

 

 

  1. a.    What is the condition of the Na+ gated channels at resting potential?

b.   Explain the importance of stimulus strength.

c.    What effect does hyperpolarization or depolarization less than -55 mV have on Na+ gated channels?

d.   Explain why an action potential is sometimes referred to as an œall or nothing response.
 

e.    Reversal of the membrane charge closes the Na+ gates and opens the K+ gates.  How does this affect the depolarization?   Include the role of the Na+/ K+ pump in your response.

 

 

  1. Describe the refractory period.

 

Attachments

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Guide for filling out the unit 9 worksheet.

 

 

 

Go to the ebook chapter 12: Nervous System from the drop down menu on Unit 9:

 

 

 

 

 

 

 

 

 

Select Animations from the drop down menu under CHAPTER RESOURCES

 

 

 

 

 

 

 

 

 

 

 

From the drop down menu that now appears, select: Animation: Membrane Potentials

 

 

After you watch and fill in your answers, move to the next animation, answer the questions, and continue on until you have completed the worksheet.

 

Good luck!

 

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