Keeps on Pumpin'
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Objective Students will measure and calculate heart rates per minute and for other units of time. They will determine the amount of blood pumped by their heart during various intervals of time. |
Key Questions
- How many times will your heart beat in 80 years?
- how much blood is pumped with each beat?
Materials
For every student
- plastic cup
- copy of "Keeps on Pumpin" worksheet
For every two students
- graduated cylinder
- calculator
- plastic cup filled with water
- measuring tape or meter stick
For the class
- clock or watch with a second hand or a digital reading
- water pitchers
- kilogram scale
- nomogram (included in kit)
Procedure
Determine your "at rest" heart rate, then extrapolate to beats per hour and beyond.
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How much blood does your heart pump in one minute? This is called cardiac output.
To
calculate cardiac output you need to know your body surface area in square
meters and your cardiac index (how
much blood is pumped per minute for every square meter of body surface
area).
To
find your body's surface area, first use the scale and measuring tape
to determine your weight in kilograms and your height in centimeters.
Weight =____ (kilos) Height = ____(cm)
On a nomogram, find your weight in the right column and your height in the left column. Place a straightedge on the nomogram so the weight and height are connected. The point where the straightedge crosses the center column denotes your body's surface area in square meters.
How much blood the heart pumps for every square meter of surface area (cardiac index) varies with the age of the individual. For children ages 1013, the average cardiac index is 2.75 liters/m2/minute at a resting state.
Multiply your body surface area by the cardiac index (2.75 l/m2/minute) to determine the liters of blood pumped by your heart in one minute (cardiac output).
2/minute= ____liters per minute.
How does your volume per minute compare to a 2 liter beverage bottle?
.How much blood is pumped in an hour and in a day?
How much blood does your heart pump in one beat? This volume is called stroke volume.How would you calculate stroke volume? (Answer: liters pumped per minute divided by beats per minute).
What is your stroke volume?____
Convert the stroke volume to milliliters.
____liters per minute x 1000 = ____ml per beat
Use
a graduated cylinder to carefully measure this amount of water. Pour it
into a cup. 
This
is the volume of blood pumped by your heart in one beat. Compare this
to the volumes of other classmates.
Extensions
A mouse's heart beats about 700 times per minute and an elephant's about 30. A mouse lives less than three years, an elephant more than 60. What's the connection?
Compare the heart rates of various animals. Is there a relationship between size of animal and heart rate?
Research the longevity of various animals and compare this to their heart rate. Is there a relationship between the average lifetime of an animal and its heart rate?
Notes to the teacher:
Over 1,500 Gallons of Blood Pumped Daily
The heart is a powerful muscle that beats without stopping throughout
a lifetime. It pumps about 55-80 ml (1/3 cup) of blood with each beat
for adults and around 25-85 ml per beat for children. An adult heart pumps
about 6,000-7,500 liters (1,500-2,000 gallons) of blood daily. The average
adult body contains about five quarts of blood which continually circulates
throughout the body. The shortest trip to the heart muscles takes only
a few seconds. The trip to the toes takes over a minute.
WebLinks
How Your Heart Works: Interesting Heart Facts
http://www.howstuffworks.com/heart6.htm Dr. Carl Bianco, M.D., is at it again, as he informs his fantastic fans about the heart's fabulous, fun facts.
The Implantation of a Heartmate
http://www.smm.org/studio3d/julie/heartmate.htm
A live video of the implantation of a heartmate!
Heart Transplant
http://www.smm.org/studio3d/julie/mov/julie/htransplant.htm
A live video of a heart transplant!
| lesson 1: Pulse of Life| lesson 2: Keeps on Pumpin' | lesson 3: Under Pressure | lesson 4: Sounds of the Heart | lesson 4a: Valves and Pumps | lesson 5: Lub Dub (valves) | lesson 5a: The Heart as a Pump | lesson 6: Go With the Flow | lesson 7: Lung Model | lesson 8: Ins and Outs of Respiration | lesson 9: Catch Your Breath | lesson 10: O2 CO2 Skit | lesson 11: X-Rays |
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