Download February 27

Lesson 2.2 Electrical Communication
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
1. Neurons convey information using electrical and chemical signals.
2. The body’s reaction time to reflex and voluntary actions is related to the degree
of processing in the nervous system.
3. 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.
© 2014 Project Lead The Way, Inc.
Human Body Systems Lesson 2.2 Electrical Communication – Page 1

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
1. How does communication happen within the body?
2. What is the basic structure and function of a neuron?
3. How do the different types of neurons work together to send and receive signals?
4. How are electrical impulses created in the human body?
5. How do neurons convey information using both electrical and chemical signals?
6. What factors impact our ability to react to a stimulus?
7. How and why does reaction time differ in reflex and voluntary actions?
8. How do errors in communication impact homeostasis in the human body?
9. How can biomedical professionals help treat, cure and improve the quality of life
of those suffering from nervous system disorders?
National and State Standards Alignment
Standards alignment resources are available in the HBS Ongoing Training course in the
myPLTW Learning Management System (LMS) and on the PLTW website. The PLTW
Standards Alignment documents include all alignment information for this course. You
can choose whether you would like to view the standard alignment information
organized by unit or by body of standards.
Day-by-Day Plans
Monday:
 The teacher reviews the Unit 2 Teacher Notes.
 The teacher begins a discussion about the role of electricity and electric signals in
our lives. The teacher may choose to show electricity moving in circuits or in
strings of lights to introduce the idea of pathways of electricity. The teacher
transitions the discussion to the role of electric signals in the human body and
asks Essential Question 1. The teacher helps students see that electric signals
also play a role in communication within the body.
 The teacher reviews basic information about the cell and asks students to
brainstorm why different cells in the body may have different structures. Good
examples of cell types the students may be familiar with are sperm cells, blood
cells, or muscle cells. The teacher asks the question, “What type of cell allows our
body to send electrical signals?” and introduces the neuron.
 Students complete Activity 2.2.1 The Neuron in groups of 2 or 3.
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Human Body Systems Lesson 2.2 Electrical Communication – Page 2
Tuesday and Wednesday: ACT
Thursday
 The teacher reviews the previous day’s activity by asking Essential Questions 2
and 3. Students share flow charts with the class.
 The teacher introduces Activity 2.2.2 The Secret to Signals and distributes Activity
2.2.2 Student Response Sheet.
 Students complete Activity 2.2.2 and record their findings on the response sheet.
 The teacher wraps up the activity by discussing Essential Questions 4 and 5 and
reviewing relevant Key Terms.
Friday:
 The teacher reviews the Logger Pro Resource Sheet (if necessary). Information
from this sheet can be shared with the class.
 The teacher opens the discussion on reflexes by throwing something soft at a
student unexpectedly or watching heads turn as a door is slammed. The teacher
asks the students to explain the difference between a reflex and a reaction.
 The teacher asks students to define the term reflex and give examples of reflex
responses by their bodies.
 The teacher introduces Activity 2.2.3 It’s all in the Reflexes - Logger Pro or Activity
2.2.3 It’s all in the Reflexes - LabVIEW and demonstrates proper use of the probes
and the chosen software interface. The teacher reminds students that since
signals to muscles are electrical in nature; we can monitor and measure this
impulse.
 Students complete Activity 2.2.3.
 The teacher should circulate around the room to monitor student progress and to
assist with the analysis features of the software.
 Students share results and brainstorm answers to Essential Question 7.
 The teacher reviews Key Terms.
© 2014 Project Lead The Way, Inc.
Human Body Systems Lesson 2.2 Electrical Communication – Page 3