Lesson 2.2 Electrical Communication - Overview

Preface

Communication within the human body involves physical, chemical and biological processes. It is a complex series of events that occurs every second we are alive. In this lesson, students will explore communication inside the body by looking at the interaction between the cells of the nervous system, the neurons. The human body has literally billions of neurons, some of which function alone and others that are part of a large complex of neurons working together. These neurons communicate signals to and from the central nervous system and allow humans to respond and react at incredible speeds. An action potential or electrical impulse is created by the exchange of sodium and potassium ions across the cell membrane. This signal propagates down the axon of a neuron. At the axon terminal, the impulse causes the release of neurotransmitters, chemicals that are able to traverse the space, or synapse, between neurons and keep the signal going. In this lesson, students will investigate how, through electrical and chemical signals, neurons are able to send messages and control body functions.

Students will create models of neurons and use interactive websites to visualize just how an electrical impulse can be generated from the movement of ions in a membrane. Students will also be introduced to the role chemicals, specifically neurotransmitters, play in the movement of electrical signals. Response time for both reflex and voluntary actions will be assessed using data acquisition software. Finally, students will investigate what happens when electrical communication breaks down. Playing the role of neurologists, students will analyze case information, provide a diagnosis, demonstrate the breakdown in communication, and present their findings to their peers.

Understandings

Neurons convey information using electrical and chemical signals.
The body’s reaction time to reflex and voluntary actions is related to the degree of processing in the nervous system.
Errors in electrical communication can impact homeostasis in the human body.

Knowledge and Skills

It is expected that students will:

Recognize that the nervous system relies on specialized cells called neurons to pass signals to and from the brain and spinal cord.
Describe how the movement of ions across the cell membrane of a neuron generates an action potential and propogates electrical signals.
Explain how neurons communicate at the synapse.
Describe how brain processing differs in reflex and voluntary responses.
Outline what goes on in the human body from an initial stimulus to a response.
Analyze experimental data to explore reaction time and reflexes in the human body.
Design an experiment to test factors that impact reaction time.
Analyze case studies to determine the effects of a communication breakdown in the nervous system on the human body.

Essential Questions

How does communication happen within the body?
What is the basic structure and function of a neuron?
How do the different types of neurons work together to send and receive signals?
How are electrical impulses created in the human body?
How do neurons convey information using both electrical and chemical signals?
What factors impact our ability to react to a stimulus?
How and why does reaction time differ in reflex and voluntary actions?
How do errors in communication impact homeostasis in the human body?
How can biomedical professionals help treat, cure and improve the quality of life of those suffering from nervous system disorders?

References

BiologyMad. (2004). The human nervous system. Retrieved from http://www.biologymad.com/NervousSystem/nervoussystemintro.htm

Bryn Mawr College – Serendip. (n.d.). Fun facts. Retrieved from http://serendip.brynmawr.edu/bb/kinser/Nerve8.html

Bryn Mawr College – Serendip. (1994). Time to think? Retrieved from http://serendip.brynmawr.edu/bb/reaction/

Eby, J. (2007). A study of failed joints. Retrieved from Cleveland Clinic Lerner Research Center website: http://www.lerner.ccf.org/bme/education/k12/biomaterials/

Energy Information Administration. (2007). Electricity: A secondary energy source. Retrieved from http://www.eia.doe.gov/kids/energyfacts/sources/electricity.html

Exploratorium. (n.d.). Science of baseball: Fastball reaction time. Retrieved from http://www.exploratorium.edu/baseball/reactiontime.html

Genetic Science Learning Center at the University of Utah. (2006). Crossing the divide: How neurons talk to each other. Retrieved from http://learn.genetics.utah.edu/units/addiction/reward/neurontalk.cfm

Johnson, K., & Becker, J. (1995-1999). The whole brain atlas. Retrieved from http://www.med.harvard.edu/AANLIB/home.html

Kosinski, R.J. (2006). Literature review on reaction time. Retrieved from Clemson University website: http://biae.clemson.edu/bpc/bp/Lab/110/reaction.htm

Life Sciences – Howard Hughes Medical Institute Outreach Program. (2005). Action potential. Retrieved from http://outreach.mcb.harvard.edu/animations/actionpotential.swf

National Association of Biology Teachers – Society for Neuroscience. (1996). Neuroscience laboratory and classroom activities. Retrieved from http://www.nabt.org/sites/S1/index.php?p=192

National Institutes of Health – National Institute of Neurological Disorders and Stroke. (2005). The life and death of a neuron. Retrieved from http://www.ninds.nih.gov/disorders/brain_basics/ninds_neuron.htm

NDT Resource Center. (2007). Electricity. Retrieved from http://www.ndt-ed.org/EducationResources/HighSchool/Electricity/electricityintro.htm

Pentilla, N. (2007). Brain ‘circuits’ may hold key to curing disease. Retrieved from The Dana Foundation website: http://www.dana.org/events/detail.aspx?id=4932

Walker, R. (2002). Encyclopedia of the human body. London: DK Publishing.