Author: Benjamin Joslin

Date: 01-16-12

Experiment: Beat to Beat

Age range: 4-13 year olds

Time frame: 45-60 minutes

Goals

·  To teach students about the role of their body’s circulatory system with specific detail of the heart

·  To teach students how to measure their pulse using the radial or carotid artery

·  To teach students how certain activities (i.e. exercise vs. lying down) and environmental factors (i.e. music) influence heart rate

·  To make the connection between the brain’s interpretation of music and the heart’s response

Materials

  1. Stopwatch
  2. Pen or pencil and paper
  3. Different types of music (rock, jazz, classical, ect.)
  4. Heart monitors* - A sensor that wraps around the individual’s chest and sends live heart rate measurements to a computer program. Access to these instruments is limited, but the experiment can just as easily be performed without them. Watch monitors may also be purchased and are less expensive than the strap monitors.

Introduction

The circulatory system is a complex organ system in the body so it is important to simplify the lesson for the appropriate age group including additional information only when necessary. Using diagrams of the body, illustrate the complete circulatory system including the heart, arteries, veins, capillaries, kidneys and lungs. Teach the students that the main role of the circulatory system is to transport oxygen, carbon dioxide and other nutrients to and from the body through blood vessels. Describe key components of blood (RBC’s and hemoglobin, WBC’s, and platelets) and their roles. Next, describe the basic structure of the heart and include a conversation about the “Lub-Dub” sound doctors hear when listening to their stethoscope. Begin to discuss various locations to measure pulse; carotid artery, radial artery, ankle. Ask the students what activities could possibly raise or lower heart rate. In the second part of the experiment, students will listen to different types of music and measure their pulse. Ask students to make predictions about what music will do to their pulse. Describe the auditory cortex of the brain and how it is attached to emotion.

Procedure

Part I. Finding Resting Heart Rate without a heart rate monitor

Step 1: Have all the students pair up and distribute a stopwatch to each pair.

Step 2: One student will start and stop the stopwatch while the other counts the number of beats.

Step 3: Teach students the proper location to measure pulse with their index and middle fingers. Have the student sit down and extend one arm out, palm upward and hand relaxed. Using the index and middle fingers from the opposite hand, gently place these fingers on the right side of the arm near the base of the thumb.

Step 4: After the student has found the right spot and their pulse, have the other student start the stopwatch while the other students begins counting the beats. Stop counting after 60 seconds and record this rate, the Resting Heart Rate.

Step 5: Switch partners and repeat the procedure. They can also count for 15 seconds and multiply that number by 4 to calculate their heart rate and practice their multiplication!

Part II. Elevating and decreasing heart rate with various exercises

Step 1: If you have heart monitors, hand them out to the students and help them put them on if they ask. If no heart monitors are available, the following steps can be done using the procedure from Part I, using two fingers and a stop watch.

Step 2: Make sure the heart monitors are working properly with the software before continuing. If a projector is available, a live display of their heart rate can be visible for the class to watch.

Step 3: Have the class sit down for 1 minute and observe their heart rate on the projector or computer screen. Have them compare it to the measurement they found in Part I.

Step 4: Ask students to share their resting heart rates to see who has the lowest.

Step 5: Have the students stand up and show that the heart rate increased. Explain that even the smallest of behaviors can change the heart rate.

Step 6: For 30-60 seconds, have the students jog in place. With the projector, they should be able to watch their heart rate increase.

Step 7: Allow them to catch their breath, and show the decrease in heart rate over time.

Step 8: Have them lie on the floor and do a few pushups and crunches (maybe a competition). Their heart rate should increase during this period of time.

Step 9: Wait for two minutes, using this time to talk more about the importance of a healthy heart rate, then have them observe their heart rate. This is trying to show the Recovery Heart Rate, which is usually taken after an extended period of exercise.

Step 10: Ask them to lie down on the floor for 1 minute and take deep long breaths. They may also hold their breath if they choose. They should be able to observe a decreased heart rate.

Step 11: When the students are back at their desk, ask them to take out a piece of paper and a pen. Then have the boys subtract their age from 220 (220- age) and the girls to subtract their age from 226. This approximate value is their Predicted Maximum Heart Rate (+/- 10 beats).

Part II: Observing how color can affect heart rate

Step 1: Explain that the heart is not only affected by exercise, but our environment too. For instance, suggest how their heart may feel before a test or near their school crush!

Step 2: Hold up pieces of paper with a color on them for 1 minute. Observe whether red increases heart rate and blue decreases it.

Step 3: Hold up different pictures of scenes (i.e. a barking dog, or a baby napping) and see the effects of each picture.

Part III. Observing how music can affect heart rate

Step 1: Bring in an iPod or pull up a variety of songs on a computer. Students can also bring in their own mp3 player or CD player with head phones. Popular songs may work better by eliciting more of a response.

Step 2: For 30 seconds, play a song and observe their heart rates. After 30 seconds, wait for 15 seconds before playing another song.

What happened?

The heart pumps blood throughout the entire body to deliver oxygen to the muscles and help release carbon dioxide through the lungs (gas exchange). When the body is in a resting state and its muscles do not need to be utilized, the heart rate will be slower. However, during strenuous activity, the body’s muscles need more oxygen to contract. To deliver that oxygen, the heart contracts faster thus increasing the heart rate. How different music genres affect heart rate is more complicated, but it most likely connected to the body’s release of adrenaline, a hormone that circulates through the blood, in response to faster tempos.

References

Middle School Psychology Experiments, http://www.ehow.com/list_6635412_middle-school-psychology-experiments.html, 01-06-12

Can different music change your heart rate and does it change by gender?, http://wiki.answers.com/Q/Can_different_music_effect_your_heart_rate_and_does_it_change_by_gender, 01-06-12

Heart Rate 101, http://www.heartmonitors.com/exercisetips/heart_rate_basics.htm, 01-06-12

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