CHEMISTRY NOW: The Science of Fear (Grades 5-8)
How fear affects the human body What biochemical changes create the fear response
CHEMISTRY NOW: The Science of Fear
The Science of Fear
How People Respond to Fear
Science as Inquiry
Life Science: Regulation and Behavior
Two 50-minute periods
Overview and Purpose / Objective(s)
(information, concepts to be learned):
Students will understand:
Adrenaline (or epinephrine)—A molecule that acts as both a hormone and a neurotransmitter. Adrenaline is synthesized during times of stress and produces various effects that include increased heart rate, sweating, and increased metabolism.
Fear—A distressing negative sensation induced by a perceived threat. It is a basic survival mechanism occurring in response to a specific stimulus, such as pain or the threat of danger.
Fight or flight—An organism’s response to fear is to make the decision whether to flee or to fight.
Magazines or access to computers with color printers
Lab sheet (included)
ACTIVITY / ENGAGEMENT
(reinforcing lesson, making real-world connection)
Create a discussion about fear with students by asking the following:
- What types of things create fear in humans?
- How do you think humans show fear?
- How does the body react to fear? (talk about fight or flight, adrenaline, etc)
- How do you think humans stop being fearful of something?
Let students know that in people ages 12 and older, the number one fear is not spiders, not snakes or sharks…it’s public speaking!
Teacher’s note—Fear is a chain reaction in the brain that starts with a stressful stimulus and ends with the release of chemicals that cause a racing heart, fast breathing, and energized muscles, among other things; also known as the fight-or-flight response. The stimulus could be a spider, a knife at your throat, an auditorium full of people waiting for you to speak, or the sudden thud of your front door against the door frame.
The brain is a profoundly complex organ. More than 100 billion nerve cells comprise an intricate network of communications that is the starting point of everything we sense, think, and do. Some of these communications lead to conscious thought and action, while others produce autonomic responses. The fear response is almost entirely autonomic: We don't consciously trigger it or even know what's going on until it has run its course.
Because cells in the brain are constantly transferring information and triggering responses, there are dozens of areas of the brain at least peripherally involved in fear.
- Amygdala—decodes emotions; determines possible threat; stores fear memories.
- Hippocampus—stores and retrieves conscious memories; processes sets of stimuli to establish context.
- Hypothalamus—activates “fight-or-flight” response.
- Sensory cortex—interprets sensory data.
- Thalamus—decides where to send incoming sensory data (from eyes, ears, mouth, skin).
The process of creating fear begins with a scary stimulus and ends with the fight-or-flight response. When the hypothalamus tells the sympathetic nervous system to kick into gear, the overall effect is that the body speeds up, tenses up, and becomes generally very alert. The sympathetic nervous system sends out impulses to glands and smooth muscles and tells the adrenal medulla to release epinephrine (adrenaline) and norepinephrine (noradrenaline) into the bloodstream. These “stress hormones” cause several changes in the body, including an increase in heart rate and blood pressure.
The sudden flood of epinephrine, norepinephrine and dozens of other hormones causes changes in the body: heart rate and blood pressure increase, pupils dilate, muscles tense up, and nonessential functions, like the digestion system, shut down to save energy needed for the fight-or-flight response. (Source: HowStuffworks.com)
After the discussion, have students find pictures of things that commonly make people fearful. Have each group of three students collect at least 10 pictures. Note: This can be a homework assignment. Pictures should be in color.
Students will design their own investigation that will help them understand how the human body responds to fear by capturing the heart rates of individuals before and after they have been exposed to something fearful. Using the pictures they have collected, students will set up an investigation by using the group members as subjects.
Students will need to be able to take a pulse. Please refer to the following websites for assistance:
As a conclusion, have students prepare a 5-minute presentation on their findings, based upon their designed investigation.
CONCLUDING DISCUSSION / ACTIVITIES
Have student group representatives present their findings to the class. After the presentations, have the class create one conclusion. What did these investigations conclude? What did the students learn about fear and the body’s response to it?
Student Worksheet for Fear Investigation
Experiment Title: _________________Date: _____Name: ____________________
Student Hypothesis: ___________________________________________________
Data and Observations: