Classroom
Compass
Fall 1995
Volume 2 Number 1
Howdy Heart
You will need:
- Stethoscopes, one for each student pair
- Cotton pads and alcohol for cleaning the earpieces
- A recording sheet for each student pair with columns for the resting and active
heart rates
Begin by letting each student hold, listen with, and explore with a stethoscope.
Caution the children not to yell into, bang, or squeeze the diaphragm of the
scope. Stethoscopes magnify sounds and such actions could hurt or injure the
wearer's ears. Students can practice wearing the stethoscopes (the hose from the
diaphragm goes to the right ear) and examine the classroom, listening for sounds
in usual and unusual places (clocks, windows, walls). The user should clean the
earpiece with an alcohol pad before another uses the scope. The heart makes a
double beat that sounds like "lub-dub." Tap the sound on the underside of a table
while the children listen with their scopes. Each "lub-dub" counts as a single
heartbeat. The students can practice counting the tabletop heartbeats, starting
with three or four taps and working up to 15.
Experimenting and Recording
Now it is time to locate and listen to human
heartbeats. First, the students listen to each other's hearts. Allow enough time
to be sure everyone can hear and identify the beat. The students will measure
heart rates for a 15-second interval. Let them practice counting the heartbeats
for a timed 15- second interval, then let them "officially" count the number of
heartbeats and record the beats. Students then switch roles and repeat. Ask each
pair to report their findings on their recording sheet. These numbers provide the
data for measuring a "resting" heart beat.
Introducing the Variable
What makes our hearts beat fast? How can we make our
hearts beat faster? To determine if exercise changes the rates just measured, one
student exercises (runs in place or does jumping jacks) for one minute. The
partner then counts the heart rate for 15 seconds and records the result. Give
the "start" signal and warn the listeners to get ready with their stethoscopes.
When the minute is up, give the "count" signal and the students measure
heartbeats for 15 seconds. Have the counter record the heart rate and then let
the students switch roles.
Comparing Results
Upon completion of the exercise, let each pair report its
results on a data table, drawn on the blackboard with columns for resting and
active heart rates.
The Teacher as Facilitator
This activity is adapted from the SAVI/ SELPH activity "Howdy Heart," one of five
activities in the Scientific Reasoning Module developed by the Center for
Multisensory Learning, Lawrence Hall of Science, University of California,
Berkeley CA 94720, (510) 642-8941.
Classroom Compass Back Issues:
Issue 2.1 Contents:
Previous :
|
