Inside Information Part 2

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Objective

SWBAT explain how the pathway of reflex actions and voluntary actions differ.

Big Idea

Students use a simple computer model to determine how information travels in both reflexive and voluntary motor responses.

Warm-up

10 minutes
This lesson was adapted from the NIH module The Brain: Our Sense of
Self. (BSCS. (2005). The Brain: Our Sense of Self. NIH publication No. 05-5171.
Copyright © 2005 by BSCS. All rights reserved.)

The purpose of this lesson is to show students how the brain receives and processes information, specifically the difference between reflex and voluntary actions.  This is part 2 of a 2 part lesson.

Begin by showing students the Two Types of Cells diagram.  Have them briefly explain how neurons transfer information.  This is a reminder of what was learned in the prior lesson.

Part 1: A Reflex Pathway

Ask students to explain the difference between a voluntary response and an involuntary response.

A voluntary response is an action we choose to perform. We do not choose to perform an involuntary response; instead, our bodies respond without a conscious choice.

Ask students to provide examples of voluntary and involuntary responses.

Voluntary responses include walking, talking, eating, or reading books. Involuntary responses include changes in heartbeat, breathing, digestion, or blinking.

Explain to the class that they will investigate an involuntary response known as a reflex action. Ask, “How would you define a reflex action?”

Students should have a general understanding that a reflex involves a quick, automatic response by their bodies to an input from the environment.

Students probably are familiar with the knee-jerk reflex. Ask for student volunteers to describe and/or demonstrate this reflex.

Students may describe the knee-jerk reflex as something they have experienced when they visit the doctor. The doctor taps below their kneecap with a small hammer, and their leg kicks out. Some students may wish to demonstrate this reflex on their own knee. Alternately, you may choose to demonstrate the reflex on yourself by sitting on your desk and tapping your knee. In addition, you may wish to have all students try out this reflex on themselves.

Some students may be unable to get the knee-jerk reflex to work on themselves and may become concerned that there is something wrong with them. Reassure these students by explaining that finding the precise location to tap below the kneecap can be difficult for nonphysicians. Furthermore, if students consciously tighten their leg muscles, the knee-jerk reflex either may not occur or may occur only subtly.

Activity Day 1- Reflex Action

35 minutes

This portion of the activity requires computers with internet access.  This activity is broken into two parts: part 1 for reflex actions and part 2 for voluntary actions.  I suggest giving students one day to complete part 1 and a second day to complete part 2.

This video gives a quick overview of how I used this website with my students (I figured it would be better to see this before reading everything else to provide some context).

Give one copy of the Pathway Building Worksheet, Building a Reflex Pathway and Building a Voluntary Response Pathway to each student.

Explain to students that they will use a website to construct the neural pathway that controls the knee-jerk reflex. After they have constructed the neural pathway, they will draw it on the Building a Reflex Pathway diagram and answer questions about it on the worksheet.

Divide the class into groups of two or three students each. Direct groups to computer stations.

Ask groups to open their Internet browser, go to The Brain: Our Sense of Self and click on “Lesson 3—Inside Information” to bring up the unit’s “desktop.” Students can then click on the link to “Inside Information” and then the link to the reflex pathway.  (If you have a website or LMS, such as Haiku or Blackboard, inserting the link for students is a quicker way to get them to the correct location.)

Instruct students to listen to the audio introduction to the activity.

Students may replay the audio at any time by clicking on the “Replay Audio” button.

Ask students to click on the link for the “Neuroscience Reference Manual.” Explain that the manual contains essential information for constructing neural pathways.

Point out several sections of the manual that will be helpful to students as they construct their neural pathways. Part 1 of the manual describes the parts of the nervous system; Part 2 describes neural signaling and the three main types of neurons; and Part 3 contains details about reflex actions and voluntary actions.

Introducing the reference manual before students start working emphasizes the importance of this resource and encourages students to use this information to help them complete the activity.  Students who do not reference this resource will have a challenging time completing the activity (I know because that is what I tried to do!).  When they struggle, keep referring students to this resource.  For IEP or ELL students, you may want to create a hard copy of this resource with the key information already highlighted for them.  Masters of all resources can be found here for easy printing.

Explain to students that they may navigate through the Neuroscience Reference Manual by clicking on the section names in the manual’s Table of Contents. They may return to the Table of Contents by clicking on the “Back to Main Menu” hotlinks at the end of each section.

Encourage students to take a minute to explore this navigation system.

 

Explain to students that to construct a neural pathway, they will need to select the correct body parts and neurons and place them in the correct position in the figure. Walk students through the process of placing and removing body parts and neurons in the figure on the right side of the Web screen.

Placing and removing body parts:

  • To place a body part on the figure, click on the appropriate body part “box” on the left side of the screen. The body part will appear in the figure.
  • To remove the body part from the figure, click on the body part in the figure or in its box.

Placing and removing neurons:

  • Neurons must be placed across two connection points (red circles) in the body.
  • To place a neuron in the figure, first select the appropriate type of neuron by clicking on its “box” on the left side of the screen. After selecting a neuron, click on a connection point in the figure to place the dendrite end of the neuron at that point. Clicking on a second connection point places the axon end of the neuron at the second point, its target site.
  • To remove a neuron from the figure, click on the neuron within the figure.

Spending time discussing these basic instructions with the class decreases confusion and allows students to focus on the lesson’s content and complete the activity more quickly.

 

Tell students that they are ready to construct the neural pathway for the knee-jerk reflex. Instruct groups to complete the pathway using only those parts that are involved directly in the pathway.

Students should read, interpret, and evaluate information in the Neuroscience Reference Manual to determine how to construct the pathway. Students should pay particular attention to the types of neurons described in Part 2 of the manual, and to the “Reflex Actions” section in Part 3 of the manual. As student groups work, walk around the classroom to monitor their progress. Be available to answer questions, but encourage students to consult the appropriate section(s) of the Neuroscience Reference Manual. Students can

  • replay the reflex animation by clicking on the “Replay Animation” button,
  • test their pathway by clicking on the “Test Pathway” hammer, and
  • reset the entire pathway by clicking on the “Reset Pathway” button.

 A correctly completed pathway should have the following attributes:

  • The pathway should include only the spinal cord, one sensory neuron, and one motor neuron.
  • The sensory neuron should have its dendrites on the thigh and its axon terminals on the pelvic region of the spinal cord.
  • The motor neuron should have its dendrites on the spinal cord and its axon terminals on the thigh muscle.

Refer to the diagram Reflex Diagram to see what the correctly completed pathway looks like.

If the pathway is correct, the following series of events will take place on the Web page when students click on the “Test Pathway” hammer:

  • When the kneecap is hit with the hammer, a spark, representing neural information, travels from the thigh muscle, through the sensory neuron, to the spinal cord.
  • At the spinal cord, the spark transfers to the motor neuron.
  • The spark travels through the motor neuron to the thigh muscle, and the leg kicks out.

Students must use the correct components of the pathway and place them in the correct orientations. This leads to the discovery that information can only travel through a neural pathway in one direction.

If the pathway is built incorrectly, students will receive one of three error messages when they test the pathway, and the Neuroscience Reference Manual will open to the appropriate section.

If the pathway itself is constructed correctly but the spinal cord is not included, or inappropriate body parts (heart, lung, liver) are included, the Web page will provide the following error message:

“Your pathway is not correct. Are you using the right body parts? Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 1: The Central Nervous System.

If the neurons of the pathway are correct but placed in the wrong orientation, the Web page will provide the following error message:

“Your pathway is not correct. Are the neurons placed correctly? Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 2: Signaling and Neurons.

If the neurons of the pathway are incorrect or the brain is included in the pathway, the Web page will provide the following error message:

“Your pathway is not correct. Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 3: Neural Pathways.

When students complete the pathway, remind them to answer the questions on Pathway Building Worksheet, to describe the pathway they have built.

At the end of Part 1, ask students to keep Pathway Building Worksheet, for use in Part 2 of Activity 2 and move to the Wrap-up portion of the lesson.

Wrap-up

5 minutes

At the end of day 1 reflex action reconvene the class. Through discussion, encourage students to examine their pathway-building process critically. Was their group able to make a pathway that worked? What types of pathways did not work? Why?

Students may have made errors as they constructed the correct pathway. Encourage them to share their experiences and explain why certain configurations did not work.  To deepen the discussion consider the use of the following prompts:

  • Can you explain why you chose that configuration?
  • Why do you think...
  • How did you arrive at that conclusion?

At the end of the discussion, students should be able to construct the knee-jerk reflex pathway correctly and describe the flow of information through it.

Students will find that the heart, lungs, liver, and brain were not needed to complete the knee-jerk reflex pathway. In fact, the pathway was marked “Incorrect” if any of these parts were included. It was necessary to leave the heart, lungs, and liver out of the pathway because these body parts are not part of the nervous system. It was necessary to exclude the brain from this pathway because the brain is not involved in the transfer of information in this example.

Activity Day 2 - Voluntary Action

35 minutes

Instruct groups to return to their computers. Ask them to open up their Internet browser and go to the Web page The Brain: Our Sense of Self and click on “Lesson 3—Inside Information.” This brings up the unit’s “desktop,” from which students should click on the link to “Inside Information.” Students then click on the link to the voluntary movement pathway.  Again, providing a link on your website or LMS speeds up the process.

Explain to students that they are to construct a neural pathway for the voluntary leg movement involved in kicking the soccer ball. Instruct groups to complete the pathway using only those parts that are involved directly in the pathway.

Explain to the class that the path of information flow begins with the eyes; that is, seeing the soccer ball coming toward them. The response is moving the leg to kick the ball.

Students should read, interpret, and evaluate information in the Neuroscience Reference Manual to determine how to construct the pathway. Students should pay particular attention to the types of neurons described in Part 2 of the manual, and to the “Voluntary Actions” section in Part 3 of the manual. As student groups work on their pathways, walk around the classroom to monitor their progress. Be available to answer questions, but encourage students to consult the appropriate section(s) of the Neuroscience Reference Manual. Students can

  • replay the animation by clicking on the “Replay Animation” button,
  • test their pathway by clicking on the “Test Pathway” soccer ball, and
  • reset the entire pathway by clicking on the “Reset Pathway” button.

 

A correctly completed pathway should have the following attributes:

  • The pathway includes the brain, the spinal cord, one sensory neuron, one interneuron, and one motor neuron.
  • The sensory neuron should have its dendrites on the eye and its axon terminals on the brain.
  • The interneuron should have its dendrites on the brain and its axon terminals on the pelvic region of the spinal cord.
  • The motor neuron should have its dendrites on the spinal cord and its axon terminals on the thigh.

Refer to the Voluntary Action diagram to see how this looks.

If the pathway is correct, the following series of events will take place on the Web page when students click on the “Test Pathway” soccer ball:

  • As the soccer ball falls toward the figure’s foot, a spark, representing neural information, travels from the eye, through the sensory neuron, to the brain.
  • At the brain, the spark transfers to the interneuron.
  • The spark travels through the interneuron from the brain to the spinal cord.
  • At the base of the spinal cord, the spark transfers to the motor neuron.
  • Finally, the spark travels through the motor neuron to the thigh muscle, and the foot kicks the soccer ball.

Students must use the correct components of the pathway and place them in the correct orientations. This leads to reinforcing the discovery students made in Activity 1 of this lesson, that information can only travel through a neural pathway in one direction.

If the pathway is built incorrectly, students will receive one of three error messages when they test the pathway, and the Neuroscience Reference Manual will open to the appropriate section.

If the pathway itself is constructed correctly but the spinal cord is not included, or inappropriate body parts (heart, lung, liver) are included, the Web page will provide the following error message:

“Your pathway is not correct. Are you using the right body parts? Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 1: The Central Nervous System.

If the neurons of the pathway are correct but placed in the wrong orientation, the Web page will provide the following error message:

“Your pathway is not correct. Are the neurons placed correctly? Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 2: Signaling and Neurons.

If the neurons of the pathway are incorrect or the brain is not included in the pathway, the Web page will provide the following error message:

“Your pathway is not correct. Check the Neuroscience Reference Manual.”

The Neuroscience Reference Manual will open to Part 3: Neural Pathways.

When students complete the pathway, remind them to answer the questions on the Worksheet and draw the path on Building a Voluntary Response Pathway diagram.

At this point, students can turn in the worksheet and their two diagrams for assessment purposes.  

To fully wrap up the lesson, reconvene the class. Through discussion, encourage students to examine their pathway-building process critically. Was their group able to make a pathway that worked? What types of pathways did not work? Why?