Download A Model of the Pumping Heart

Learning Goal
• Use a model to explore the double-pump
action of the heart.
• Determine the direction of the flow of blood
through the heart.
• Recognize that humans have a closed
circulatory system.
• Understand the purpose of valves in the heart.
Review
• The Arteries carry blood Away from the heart.
• The VeINs carry blood INto the heart.
• Our blood supply is constant – you have about
2-3 liters; an adult has 5-6 liters.
• The same blood circulates throughout your
body.
Your heart valves
at work
Materials
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2 plastic cups
2 heart pumps
1 plastic box
Water
Lab sheet
Read your entire lab sheet.
• Try to picture what you will set up.
• Notice, you need to draw a picture of your setup on the back before you clean up and put it
away.
• Also note that you need to show your system
to Mrs. Ryan and explain it to her before you
can add water.
• Fill cups only halfway with water.
The Pump Action
• The heart (plastic pumps) pump blood to CUP
1 – THE LUNGS.
• The lungs add oxygen.
• The pump sends the oxygen-rich blood to CUP
2 – THE BODY.
• The body uses the oxygen then returns it to
the heart.
• The heart pumps it to CUP 1 – THE LUNGS
again and the cycle repeats.
Possible Answers
• What causes the sounds that you hear when operating
the heart?
The vibrations resulting from the closing of the valves.
As the ventricles contract, the valves between the atria
and ventricles close (the “lub”); when the atria
contract, the valves between the ventricles and arteries
close (“dub”)
• B. Why is the heart considered a double-pump?
The right side pumps blood to the lungs; the left side
pumps blood to the rest of the body
• C. What is the function of the valves
The valves prevent the backflow of blood into the
heart. (heart murmur)
• D. What do we mean when we say humans have a
“closed” circulatory system?
Human blood is confined within vessels.
Blood Pressure
Blood Pressure
• The force exerted by the blood on the walls of
the arteries.
• Brainpop: Blood Pressure click Tim
• Think of water being pumped through a hose
– the narrower the hose, the greater the
pressure inside of it; the farther the water
travels from the pump – the lower the
pressure becomes..
Blood Pressure Disorders
• Hypotension – low blood pressure
– Sometimes from old age
• Hypertension – high blood pressure
– Race, diet, age, heredity, stress, obesity, salt, inactive
lifestyle, some medications, smoking
• Atherosclerosis - hardening or narrowing of the artery
walls; plaque forms
– Brainpop: fats
• Aneurysm - bulging weak spot on artery walls
• Stroke – ruptured blood vessel or clot that blocks the
passage