Introduction:

The heart is the hardest working muscle in the human body, pumping out oxygenated, nutrient-rich blood with every beat. But no matter how hard this muscle works each second, it still needs exercise to stay strong. Hearts that get regular exercise to stay strong. Hearts that get regular exercise can pump more blood with less strain. In this activity students will compare ways to measure heart rate (and build their own stethoscopes) to learn how exercise affects heart rate.

National Education Standards:

●6C/M1 ( Grades: 6-8 ): Organs and organ systems are composed of cells and help to provide all cells with basic needs.

●6C/M3 ( Grades: 6-8 ): To burn food for the release of energy stored in it, oxygen must be supplied to cells, and carbon dioxide removed. Lungs take in oxygen for the combustion of food and eliminate the carbon dioxide produced. The urinary system disposes of dissolved waste molecules, the intestinal tract removes solid wastes, and the skin and lungs aid in the transfer of thermal energy from the body. The circulatory system moves all these substances to or from cells where they are needed or produced, responding to changing demands.

NSTA National Science Education Standards

●C.1.5 ( Grades: 5-8 ): The human organism has systems for digestion, respiration, reproduction, circulation, excretion, movement, control, and coordination, and for protection from disease. These systems interact with one another.marks for Science Literacy

●6A/M1 ( Grades: 6-8 ): Like other animals, human beings have body systems for obtaining and deriving energy from food and for defense, reproduction, and the

Materials:

5 sets of 18” of vinyl tubing

5 plastic soda or water bottles

scissors

duct tape

stopwatch

paper and pencils

rubbing alcohol

cotton balls

various exercise equipment (basketballs, jump ropes, hula hoops).

Objective:

SWBAT develop an understanding of the circulatory system, take their pulse, construct their own stethoscope and experiments with how exercise affects heart rate.

Essential Questions:

What is the purpose of the heart?

What is a heart rate?

How do I find my target heart rate?

Instruction:

1.Introduce circulatory system with Brainpop worksheet and have students to the best of their ability fill in responses. Go over results as a group.

2.Ask students to list all the ways to check their heart rates (pulse, stethoscope, heart rate monitor).

3.Have students experiment with the pulse method. Ask students how they could find their resting heart rate by measuring their pulse. *The pulse is found by placing an index and middle finger on the inside of the wrist, just beneath the palm of the hand, and pressing down firmly. Students should count the number of beats for 10 seconds and multiply their results by 6 to get the number of total beats per minute (bpm). Have students seated and clam in order to get the best results for a resting heart rate. Students will need to record their resting heart rates 3 times and average their results.

4.Separate students into small groups and have them draw what a stethoscope looks like. Have them brainstorm a list of the parts needed in order to make their stethoscope from the list of materials listed above. *Students must have a plan before they will receive their materials

5.After stethoscopes have been completed, students should take turns recording a patient's heart rate. Do 3 trials and record all results. Find the average of all trials. *If a heart rate monitor is available take one reading of a student’s heart rate.

6.Compare the two methods of heart rate detection. How accurate are the pulse and stethoscope methods? VS The heart rate monitor?

7.In their same small groups, students will now see how exercise affects heart rate. Have students come up with the exercises that get their heart rates the highest. Things to consider:Types of exercise (running, walking, jump ropes, jumping jacks) Lenght of time spent exercising, method for recording heart rate, recovery time between each activity and how many people can participate in the activity.

8.Have students order the results of their brainstorming in order from highest heart rates to lowest.

9.All students then should calculate the approximate maximum heart rate ( the upper limit your heart can handle while exercising) by using the equation: maximum heart rate= 220-age

10. 10.Find out how hard your heart is working: use the following equation:
    

    intensity level= (heart rate exercise/maximum heart rate)100%

11. Have students record their heart rates after each activity (make sure to use heart rate from earlier).

12. Have each group create a presentation of their data. How did their results compare to their predictions? Which type of exercise raised your heart rate the most? Why? Where does this level fall in you heart rate zone?