Ms. Sharif I sadiasharif@walthampublicschools.org
Biology I Unit: Human Physiology
Biologist: ________________
Lab: Exploring the Human Circulatory System
Part I: Listening to your heart sounds!
A stethoscope is a medical device used to listen to the internal sounds of the human
body. The first stethoscope was invented in 1816 by a French doctor named Rene
Lannec. He named his tool “stethoscope” after the Greek words for “chest” (stethos)
and “examine” (scopeein). Prior to the stethoscope, doctors had to press their ear
directly to their patient's body!
To listen to body sounds, the veterinarian or doctor presses the large round end of the
stethoscope (called the "chestpiece") to the appropriate area of the animal or
person. The flat side of the chestpiece is called the "diaphragm." The diaphragm is
best at picking up higher-pitched sounds, such as heartbeats and breathing. The other
side of the chestpiece is called the "bell." The bell is best at picking up lower-pitched
sounds, such as heart murmurs. The sound then travels from the chestpiece up
through air-filled tubes, which make the sounds louder, and into your ears.
Instructions:
1. Place the earpieces of your stethoscope into your ears and place the large round
circle hanging in the middle onto the left side of your chest, which is where your
heart is.
2. Keep moving it around until you can hear your heartbeat.
3. Count how many beats your hear in one minute. This determines your resting heart
rate in beats per minute. Repeat this four times.
4. Try it on a partner!
Record your resting heart rate here:
Time (seconds)
60
60
60
60
Beats
Average resting heart rate: ___________ (normal range is from 60-100 bpm)
Describe what you hear through the stethoscope. Why do you think the heart is
making these sounds?
______________________________________________________________________
______________________________________________________________________
_____________________________________________________________________
Ms. Sharif I sadiasharif@walthampublicschools.org
Biology I Unit: Human Physiology
Biologist: ________________
Part II: Observing Blood Samples
What do you think your blood looks like? At your lab bench, there are two microscopes
with prepared slides of a normal blood sample and a sickle cell anemia blood sample.
Use the microscope to look at each slide carefully. Recall the rules we learned for using
microscopes in the beginning of the year – do NOT use the blue knob!!
Draw what you observe in the normal blood sample slide:
Magnification: ____________
Describe what you observe in the normal blood sample slide:
Draw what you observe in the sickle cell anemia blood sample slide:
Magnification: ____________
Describe what you observe in the sickle cell anemia blood sample slide: