In the Beat of a Heart

Purpose: To observe the pulsation of blood in the wrist

Materials

• clay
• paper match
• science journal
• stopwatch or clock with second hand

Procedure

1. Take a small amount of clay and make a ball.
2. Insert the match into the ball and flatten the bottom of the clay.
3. Turn your wrist over and locate your pulse on the thumb side of the wrist.
4. Place the clay over your pulse moving it until the match starts to slowly vibrate.
5. Using a stopwatch or clock with a second hand, count the number of vibrations that the match makes in one minute.
6. Record the number of vibrations in your science journal.
7. Repeat steps 5-6 two more times. Find your heart’s average number of beats.
8. Repeat counting the number of vibrations in 15 seconds. Multiply number by four and record.
9. Repeat counting the number of vibrations in 10 seconds. Multiply number by six and record.
10. Compare your results with your group or class.
11. Determine the average number of beats per minute for group and/or class.
12. Determine the range.

Conclusion

1. Why is the wrist a good place to take your pulse rate?
2. Why does each student’s pulse rate vary?