October 2014
Food For Thought: What fuels us?
Glucose, the endocrine system, and health
Lesson 3: How does adrenalin have an effect on the body and the brain?
I. Overview
Lesson 3 aims to explore the fight-or-flight response and how it relates to glucose availability in the body
and the brain. Students reflect on personal adrenalin experiences to recognize how their heart rate,
breathing, and memory change in this sympathetic state. Using their personal experiences and the
information learned from lessons 1 & 2, students construct a model to predict how the stress hormone
adrenalin affects the body. Next, students proceed through a series of three checkpoints to test their
model and make revisions as needed. Finally, students use their models to explain, communicate,
predict, and test the effect an adrenal rush has on the endocrine system and the body as a whole.
Connections to the driving question
In this lesson students will learn about the endocrine response to stress by examining adrenalin's ability
to increase glucose availability in the body and the brain. Students ultimately learn how the endocrine
system is able to fuel the brain and the body in order to escape stressful situations and avoid them in
the future.
Connections to previous lesson
Lesson 3 focuses on the adrenalin/glucose model of the fight-or-flight response. In lesson 2, students
learned how the endocrine system regulates blood glucose levels to maintain homeostasis with insulin
and glucagon. In this lesson, students learn how the endocrine system can induce change rather than
maintain stability during stressful situations to increase blood glucose. Building on their previous
knowledge of how the endocrine system functions, students explore how the endocrine response
affects them by discussing past experiences and engaging in the multiple practices of modeling.
II. Standards
National Science Education Standards:
12CLS6.3 Like other aspects of an organism’s biology, behaviors have evolved through natural
selection. Behaviors often have an adaptive logic when viewed in terms of evolutionary
principles.
12CLS6.2 Organisms have behavioral responses to internal changes and to external stimuli.
Responses to external stimuli can result from interactions with the organism’s own species and
others, as well as environmental changes; these responses either can be innate or learned. The
broad patterns of behavior exhibited by animals have evolved to ensure reproductive success.
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October 2014
Animals often live in unpredictable environments, and so their behavior must be flexible enough
to deal with uncertainty and change. Plants also respond to stimuli.
Benchmarks for Science Literacy:
The Human Organism: Basic Functions


The human body is a complex system of cells, most of which are grouped into organ systems
that have specialized functions. These systems can best be understood in terms of the essential
functions they serve for the organism: deriving energy from food, protection against injury,
internal coordination, and reproduction.
Communication between cells is required to coordinate their diverse activities. Cells may
secrete molecules that spread locally to nearby cells or that are carried in the bloodstream to
cells throughout the body. Nerve cells transmit electrochemical signals that carry information
much more rapidly than is possibly by diffusion or blood flow
III. Learning Objectives
Learning Objective
Apply knowledge of the
endocrine system to the
specific hormone
adrenalin.
Assessment
Using their whiteboards, students create predictive
models of how adrenalin is working in the body.
Before moving to the checkpoints, students’
predictive models should include the six main
components of the endocrine system.
Location in Lesson
Activity 1:
Using Models to
Predict
Identify and explain the
somatic effects of the
fight-or-flight response
Student explanations include:
 Epinephrine travels through the blood to act on
many organs including the heart, lungs, liver,
muscle, intestines, eyes, and digestive tract.
 Epinephrine acts in various ways on these
organs to facilitate the flight-or-flight response.
For example: muscle receives more glucose for
energy and breathing rate increases to pull
more oxygen into the lungs.
Activity 2:
Checkpoint A
Explain that epinephrine
improves memory
indirectly by increasing
blood glucose.
Associated Materials: U7_L1_CheckpointA_Student
Sheet
Students should be able to explain that:
 Epinephrine is released by the adrenal glands
into the circulatory system.
 Epinephrine cannot pass the blood-brain
barrier.
 Epinephrine acts indirectly by triggering the
release of glucose from liver cells.
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Activity 2:
Checkpoints B & C
October 2014
 Glucose travels to the brain, passes the bloodbrain barrier and can work to improve memory.
Evaluate the
evolutionary benefits
behind the flight-orflight response and
recognize the influence
the human mind has on
the stress response.
Associated Materials:
 U7_L1_CheckpointB_StudentSheet
 U7_L1_CheckpointC_StudentSheet
In discussion students explain:
 The fight-or-flight response fuels the body to
escape or fight an attacker. Remembering how
to avoid stressful situations and encounters
with attackers would be adaptive for survival.
 The human imagination can induce a stress
response simply by worrying and thinking about
perceived stresses (will be covered in Lesson 5
as well).
Conclusion of Lesson
IV. Adaptations/Accommodations
Whiteboards and dry erase markers are suggested for the main activity because students will need to be
able to revise their models. If individual white boards are not available for student groups, the
classroom whiteboard/chalkboard can be divided up so that each student group can have space to
construct and revise their model.
V. Timeframe for lesson
Opening of Lesson
 Scare activity: 2-5 minutes
 Reflection of past adrenalin rushes: 5 minutes
Main Part of Lesson
 Activity 1 – Using Models to Predict: 20 minutes
 Activity 2 – Using Models to Test: 20
Conclusion of Lesson
 Wrap up discussion: 5 minutes
VI. Advance Prep and Materials
Homework Article:
 U7_L3_Reading_SuperHumanStrength
Opening of Lesson: Scare activity and reflection of past adrenalin rushes
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October 2014
Preparation:
 Prepare a script to help students relax. Refer to the information at this link:
http://www.innerhealthstudio.com/visualization-relaxation.html.
Main Part of Lesson: Adrenalin Modeling
Activity 1: Using Models to Predict
Materials:
 Video of man jumping away from car:
o http://www.youtube.com/watch?v=OdOOIxcUjAs
 U7_L3_StartingImage
 White boards and dry erase markers
Preparation:
 Have video ready to be presented and have U7_L3_StartingImage ready to be projected on
screen.
 Provide enough white boards and dry erase markers as there are student groups (3-5
students per group)
Activity 2: Using models to test
Materials:
 U7_L3_CheckpointA_Slides (PowerPoint: Can be projected on laptops or printed).
 U7_L3_CheckpointA_StudentSheet
 U7_L3_CheckpointB_RatMemoryExperiment
 U7_L3_CheckpointB_StudentSheet
 U7_L3_CheckpointC_WhatATwist
 U7_L3_CheckpointC_StudentSheet
 U7_L3_CheckpointA_StudenSheet_ANSWERS (for teacher reference)
Preparation:
 Print off student sheets and checkpoint materials prior to class. One per student group.
 Print worksheets on different sheets of paper for each Checkpoint. (i.e., Checkpoint A = Red
worksheets, Checkpoint B = Blue, etc.)
 U7_L3_CheckpointA_Slides is a PowerPoint and can be projected or can be printed on
paper in color for students to work through. For continued use, consider laminating these
slides.
Conclusion:
Materials:
 U7_L3_AdrenalinModelChecklist
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October 2014

U7_L3_Image_AdrenalinDiagram
Preparation:
 Print off enough sheets of U7_L3_AdrenalinModelChecklist to have one for each group.
This document will allow students to check if they have everything they need in their
adrenalin model.
 Optional: U7_L3_Image_AdrenalinDiagram is an image of the adrenalin model that can be
projected on the screen during class discussion if students DO NOT have their whiteboards
to reference.
VII. Resources and references
Teacher resources



Cahill, L. Stress Arousal and Effects on Memory and Performance. Found at
http://www.clta.uci.edu/documents/article4.pdf
Korol, D.L. and Gold, P.E. (1998) Glucose, memory and aging. The American Journal of Clinical
Nutrition. 67(suppl):764S-771S. Found as Gold, P.E. and Korol, D.L. (2012) Making Memories
Matter. Frontiers in Integrative Neuroscience. Found at:
http://www.frontiersin.org/Integrative_Neuroscience/10.3389/fnint.2012.00116/abstract
Supplemental information on the blood-brain barrier:
o http://neuroscience.uth.tmc.edu/s4/chapter11.html
o http://www.examiner.com/video/blood-brain-barrier-model-to-test-drugs-for-braindiseases
o http://www.examiner.com/video/blood-brain-barrier-model-to-test-drugs-for-braindiseases
References
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Häggström, M. (Nov 2008). Intestine – sized [Graphic in Public Domain]. Image:
Digestive_system_diagram_en.svg. Retrieved from
http://commons.wikimedia.org/wiki/File:Intestine_-_sized.png
Häggström, M. (Nov 2008). Lungs – sized [Graphic in Public Domain]. Image: Respiratory system
complete numbered.svg. Retrieved from http://commons.wikimedia.org/wiki/File:Lungs__sized.png
Ilic, S., Brcic, I., Mester, M., Filipovic, M., Sever, M., Klicek, R., Barisic, I., Radic, B., Zoricic,Z., Bilic,
V., Berkopic, L., Brcic, L., Kolenc,D., Romic,Z., Pazanin, L., Seiwerth,S., Sikiric, P. (2009) Over-dose
insulin and stable gastric pentadecapeptide BPC 157. Attenuated gastric ulcers, seizures, brain
lesions, hepatomegaly, fatty liver, breakdown of liver glycogen, profound hypoglycemia and
calcification in rats. J Physiol. Pharmacol. 7:107-114.
Inner Health Studio. (2014). Retrieved from: http://www.innerhealthstudio.com/visualizationrelaxation.html
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October 2014
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Lucky man almost hit by car, escapes carnage by inches. (2010). YouTube. Retrieved from:
http://www.youtube.com/watch?v=OdOOIxcUjAs
Morris, K.A., Chang, Q., Mohler, E.G., Gold, P.E. (2010). Age-related memory impairments due to
reduced blood glucose responses to epinephrine. Neurobiology of Aging. 31: 2136-2145.
Sokal, J. E. & Sarcione, E. J. (1959). Effect of epinephrine on glycogen stores. Am. J.
Physiol, 196(6), 1253-1257.
Wise, J. (2009) When Fear Makes Us Superhuman. Scientific American. Found at:
http://www.scientificamerican.com/article.cfm?id=extreme-fear-superhuman&page=2
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October 2014
VIII. Lesson Implementation
**The term adrenalin and epinephrine will be used interchangeably throughout this lesson and
the rest of the unit. Make sure to let students know that these two terms refer to the exact
same chemical**
Prior to Lesson:
To prepare students for the context of the lesson, students should enter the class having read:
U7_L3_Reading_SuperHumanStrength for homework.
Opening of Lesson:
Assume a very calm voice. Have students close their eyes, breath slowly and deeply, and relax. Use the
website http://www.innerhealthstudio.com/visualization-relaxation.html to guide a relaxation
discourse. When students are in a relaxed state and least expect it, make a LOUD NOISE (dropping a
symbol borrowed from the music department has worked wonderfully). This sudden loud noise,
contrasted with the students’ relaxed state, should startle and surprise the students. Commotion will
inevitably arise from this activity, but try to gather the attention of the class as quickly as possible. Ask
the students:


Were you frightened?
Reflect on what is happening to your body right now. What is happening to your body
physiologically?
o Answer: I am sweating, I can feel my heart beating, I am breathing fast and deeply, I am
“on edge”, my heart jumped, I feel anxious, etc.
Explain to the students that when your body encounters surprising, scary, threatening, or intense
stimuli, it has what is known as a fight-or-flight response. The fight-or-flight response is mediated by
both the (1) nervous system and the (2) endocrine system. The endocrine system will be the focus of
this lesson. During a fight-or-flight response, the body will release the hormone adrenalin into the
bloodstream. Have any of you heard of an “adrenalin rush” before?
Teacher Pedagogical Content Knowledge:
It is helpful to choose a limited amount of vocabulary words to be the focus of a unit.
In this way students gain an in-depth understanding of the important terms that
emphasize the main ideas of the unit. The main vocabulary words should be brought
up frequently throughout a unit.
The main vocabulary words for this unit are (words in bold are introduced in Lesson 3):
 Homeostasis
 Negative Feedback
 Insulin vs. Glucagon
 Fight-or-Flight Response
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October 2014
Ask the students:

Can you recall ever having an adrenalin rush? What were you doing? What do you remember
most about it?
o Adrenalin rushes tend to occur very shortly following or during a stressful situation, such
as getting in a car accident. Memories resulting from adrenalin rushes tend to feel
permanent. Small, strange details tend to be remembered, such as the food you had
eaten in the meal before, who you were with, what you were wearing, etc.

For those of you who are engaged in athletic activities, such as swimming, running races,
basketball, or football games do you find you remember meets and/or games more than
practices? Why do you think that is?
o Before competition, adrenalin levels surge to support the upcoming activity. Ideally,
performance should be at its best during competition, and the brain and body can
respond very rapidly to this knowledge within seconds before the start of competition to
ensure efficient energy is available to support these activities. However, since the brain
takes up energy when it is in excess, your memory for these events also tends to be
permanent.

Ask the class if they think adrenalin can affect memory. Does it enhance it or inhibit it? Ask a
few students to state what they think and defend why they think so.
Tell students that today they will be investigating how adrenalin works in the body by constructing a
model similar to the previous lesson.
Main Part of Lesson
Activity 1: Using Models to Predict
Student Misconceptions
Many students believe that an adrenalin rush causes a person’s split-second reaction
to a stressful situation. It is true that adrenalin is released from the adrenal gland the
moment an organism senses a threat or danger. However, a split-second reaction
happens too fast for it to be mediated by the bloodstream and is instead caused by the
sympathetic nervous system. The body releases adrenalin into the bloodstream to
augment the nervous systems response and to signal energy stores to be utilized by
the body – almost like putting the body’s fight-or-flight response into a higher gear.
Show the following video to the class:
http://www.youtube.com/watch?v=OdOOIxcUjAs
Ask students: How was this man able to jump out of the way? Students may reply that it was an
adrenalin rush. This is a common misconception. Ask students: How does adrenalin travel through the
body? bloodstream Do you think that adrenalin could travel throughout your whole body in less than a
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October 2014
second via the bloodstream? no What is the system in the body that can send signals in less than a
second? The nervous system.
Therefore, when the man sees the approaching car, the man’s brain sends nerve signals to different
parts of the body such as his leg muscles to jump out of the way. So if it is the nervous system that is
responsible for this immediate response, where does adrenalin come in? Tell the students that nerve
signals are good for this quick reaction. However, in our evolutionary past if a person needed to get out
of the way of let’s say a bear, chances were, he still needed to “fight” or “flight” from that bear after the
initial reaction. Therefore, the body needs a larger, more longer-lasting boost. Releasing the hormone
epinephrine/adrenalin into the bloodstream provides just this boost.
Project the image: U7_L3_StartingImage. To provide a foundation for
students to begin their models, introduce how epinephrine is released into
the bloodstream. Just as insulin is released from the pancreas, epinephrine
is released from the adrenal gland. The adrenal gland sits right atop the
kidneys. When a person encounters a threatening situation, the brain
instantly sends signals to this gland to release epinephrine into the
bloodstream.
At this point tell the students to get into groups of 3-5. While passing out
whiteboards to the students, inform them that they will be creating a
model for how adrenalin acts in the body. At first, students will be using
their models to predict; they will be constructing an explanation for how
they think adrenalin is acting based on prior knowledge of Lesson 1 & 2
U7_L3_StartingImage
and their own prior experience. Next, students will progress through a
series of three checkpoints to test their model. The first part of the model is already provided by the
teacher through U7_L3_Starting Image illustrating that nerve signals from the brain signal the adrenal
gland to release epinephrine into the bloodstream.
Encourage students by telling them that they already have the knowledge to construct a fairly accurate
model of how adrenalin works without even learning about it specifically. Remind students that they
learned about the main components of the endocrine system in Lesson 2 and encourage them to use
the diagrams they developed. Additionally, students have knowledge on adrenalin rushes from personal
experience, observation, and the initial class discussion. Present the following questions via the
projector to reemphasize these points and to facilitate construction of the adrenalin models:
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October 2014



How can you apply what you learned from the cracker activity (the main steps of the endocrine
system) to your adrenalin model?
Does an adrenalin rush give you more energy? If so, where do you think this “boost” of energy
comes from?
Reflect on your own experiences:
o What happens to your body during an adrenalin rush? Specifically, what organs and tissues
are affected?
o Do you think epinephrine is traveling to these tissues/organs?
REMEMBER:
At this point you are creating a model to make predictions. This is exactly why scientists create models.
They make predictions through observation and from previous scientific knowledge. After using their
models to predict, scientists test their models to see if their predictions are supported or not. If not,
scientists need to revise their existing model in light of new evidence. You will be testing your model in
the second part of this activity.
As student groups self-direct their learning, use the time to formatively assess student progress. Be sure
to be actively moving about the room posing questions and answering questions from students.
Students will be asking you to approve their model before moving from checkpoint to checkpoint, so
make sure to efficiently spread your time about the class.
Assessment (before moving on to Checkpoint A):
Before moving to the first checkpoint, Checkpoint A, student groups must show and discuss their
predictive models with the teacher.

Predictive models should include the six main components of the endocrine system along with
two or three tissues/organs that adrenalin may be affecting.
Teacher Pedagogical Content Knowledge
It is very helpful to ask students questions in order for them to more accurately
complete missing pieces of their model. For instance, for a student group that draws
adrenalin out in the body on its own ask them, “Does adrenalin just diffuse through the
body? How do hormones travel through the body?” This scaffold will make it likely for
the group to realize that they need to add the bloodstream into their model.
Scientific Practices: Developing and Using Models
Active investigation and construction of the adrenalin model follows the dynamic
practice of scientific modeling to reflect the nature of science. Through three
checkpoints, students are given evidence of adrenalin’s actions on the body. It is up to
the students to form a model that holds true to these pieces of evidence, even if this
means revising prior held conceptions of their model.
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October 2014
Activity 2: Using Models to Test
In Activity 1, students will proceed through a series of checkpoints to analyze evidence in order to
support, add to, or revise their model.
Checkpoint A:
Pass out Checkpoint A materials:


U7_L3_CheckpointA_Slides (printed out or presented via computers)
U7_L3_CheckpointA_StudentSheet
Students will compare series of images of two organs/tissues. One of the images shows the
organ/tissue under the influence of epinephrine while the other one shows it under normal
circumstances. Students must decide which image corresponds to the actions of epinephrine. On their
student sheet, students rationalize their answers as to why they think these organ systems are under
the influence of adrenalin.
Before moving onto Checkpoint B:



Students must complete the questions on U7_L3_CheckpointA_StudentSheet.
Ask the students if their model was supported, required additions, or needed revision in light of
new evidence.
At this point, students’ models should include the following:
o Epinephrine traveling to and acting on: the heart, lungs, liver, muscles, intestines, eyes,
and digestive tract. Students should also briefly draw and/or write how these
tissues/organs react to epinephrine.
After all groups are done with Checkpoint A, take a few minutes to discuss with the whole class tissues
that adrenalin is acting on by referencing U7_L3_CheckpointA_StudentSheet_ANSWERS. Most likely
groups will have come to different conclusions for most tissues. Have groups share why they chose one
slide over the other. Be sure to acknowledge that although some groups may have been wrong, they
provided thoughtful solid reasoning. This happens constantly in science, as scientists make inaccurate
predictions that are grounded in good reasoning. It is only through testing our predictions that we come
to a valid explanation.
Checkpoint B:
Pass out the Checkpoint B materials:


U7_L3_CheckpointB_RatMemoryExperiment
U7_L3_CheckpoinB_StudentSheet
Students will read about the effects of epinephrine on memory through the use of a technique called
The Inhibitory Avoidance Task. Students will perform experiments using this task via a computer
simulation later in Lesson 4.
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Before moving onto Checkpoint C:



Students must complete U7_L3_CheckpointB_StudentSheet
Ask the students if their model was supported, required additions, or needed revision in light of
new evidence.
At this point, students’ models should include the following:
o Show that epinephrine is somehow having an action on the brain to enhance memory.
Important: Students will most likely draw epinephrine acting directly on the brain. From
what students have learned about the endocrine system and from the evidence they
have acquired thus far, this is a very reasonable theory. However, in Checkpoint C
students will learn that epinephrine does not act on the brain directly because it cannot
pass the blood-brain-barrier. Therefore, allow them to move onto the next activity even
if they have epinephrine binding to receptors on the brain. Revising their models in
Checkpoint C will further reveal to students how scientific knowledge and scientific
models are subject to change in light of new evidence.
Student Misconceptions
Although epinephrine plays a significant and important role in forming memories, it is
not the only reason why we remember events or knowledge. There are many other
factors including other biological factors, past experiences, levels of attention,
repetition of events, etc.
Checkpoint C:
Pass out the Checkpoint C materials:


U7_L3_CheckpointC_WhatATwist!
U7_L3_CheckpointC_StudentSheet
This checkpoint introduces students to the blood-brain-barrier. Students learn that epinephrine cannot
pass the blood brain barrier, but that glucose can. In addition, students are presented with a graph that
reveals that glucose increases memory similarly to epinephrine.
Before completing Checkpoint C to receive the Adrenalin Model Checklist:



Students must complete U7_L3_CheckpointC_StudentSheet
Ask students if their model was supported, required additions, or needed revision in light of new
evidence.
If students have not done so, at this point models should include the following:
o Epinephrine does not enter the brain because it is blocked by the blood-brain barrier.
Epinephrine is able to enhance memory by increasing blood glucose levels. Having more
glucose traveling through the blood to the brain enhances memory formation.
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Final Model Building:
Once students have completed Checkpoint C, pass out the U7_L3_AdrenalinModelChecklist. At this
point, student models should be almost completely accurate. However, to make sure that students
include the major criteria of the model, and to provide repetition on the information students just
analyzed, students should use the checklist to make sure their model is complete. If possible, groups
should keep their whiteboard drawings for Lesson 4. If this is not practical or possible you can use the
U7_L3_Image_AdrenalinDiagram (Located with Lesson 3 materials as well as Lesson 4) for the following
day. You can also project this image during the conclusion of this lesson.
Conclusion of Lesson
In the past lesson, students saw that insulin and glucagon were released or not released depending on
the amount of glucose in the blood stream. What is the stimulus for the case of adrenalin? Can our
minds regulate blood glucose? Ask the students to contemplate the evolutionary importance of the
fight-or-flight response.



Why would a system like this have evolved? Why might it be evolutionarily advantageous for
adrenalin to increase memory?
o To protect us from predators and famine.
Why might it be evolutionarily advantageous for adrenalin to increase memory?
o Remembering a life-threatening event would help an organism learn to better avoid a
stressful event or to better act during a stressful event.
It seems like everyone in this room has experienced an adrenalin rush. I doubt many of you
have ever been in danger of a saber-tooth tiger. So then, why do you all still experience
adrenalin rushes? What are the stresses of the twenty-first century?
o We can be startled by a friend or a car coming out of nowhere, or maybe we have
encountered life-threatening events. Also, and important to share with the students,
the human brain is so complex that we turn on the same stress response purely
psychologically. Help students to recognize that although there is no saber-tooth tiger
chasing us today, adrenalin can be released by just our state of mind. For instance,
think about the “nerves” one feels before a performance of giving a speech. The
“butterflies” one feels before a game. The “anxiety” before a first date.
Homework and Assessments
Informally assess student learning by observing and questioning how they develop their models.
Student sheets from Checkpoints A, B and C.
 Students or student groups should have completed worksheets. Depending on your grading
policy you may choose to grade for accuracy or completion.
Final Adrenalin Model
 Students should have a completed an adrenalin model that includes all the points asked for in
the U7_L3_AdrenalinModelChecklist.
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Additional Information:
Teacher Content Knowledge
The fight-or-flight response is mediated by the sympathetic nervous system and the
endocrine system. It is important to understand how these two systems work together.
When a person encounters a dangerous situation, his/her brain will release signals (via
the sympathetic nervous system) to the heart, lungs, adrenal gland, digestive system,
eyes, etc. instantaneously. The body is ready to expend large amounts of energy very
quickly. It is as if a person immediately shifts into “second gear.”
This response is vital for the immediate threat, but chances are, if a human encountered
a fight or a bear in the evolutionary past, he or she would need to deal with this threat
for more than just a few moments. The human body now needs to shift to a “third
gear.” This is where the endocrine system comes in. The same sympathetic nerve
signals that travel to the heart and lungs also travel to the adrenal gland. Adrenalin in
the bloodstream may take a few seconds or about a minute to act everywhere in the
body, but it provides the necessary boost to augment the nerve signals from the
sympathetic nervous system. This augmentation is possible because adrenalin acts on
the same receptors that the sympathetic nervous system acts on via the
neurotransmitter epinephrine (or norepinephrine). In addition, adrenalin also activates
cascade reactions in muscle and liver cells to increase glucose availability.
Adrenalin from the bloodstream augments nervous signals from the brain and increases
glucose availability in the body giving the boost and stamina an organism needs to react
in a fight-or-flight situation.
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