Fremont Magnet Elementary

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Circulatory System

Standard 2b - Students know how blood circulates through the heart chambers, lungs, and body and how carbon dioxide (CO2) and oxygen (O2) are exchanged in the lungs and tissues.

1. Photosynthesis Review

Last week you learned about photosynthesis.  You learned that plants and people need each other to live. 


Which of the following gas do people produce when they exhale (breath out)?

Carbon dioxide

What do you inhale (breath in)?



2. What is a circulatory system?

  G30_l.jpgYour body has many systems.  One very important system is the circulatory system. 

The circulatory system is made up of your heart, blood, and blood vessels. 

Your circulatory system is a little like the mailman.  It delivers things you need and then picks up and takes away things you don't need. 

Click here to see an animation

Entire Cardiovascular System

3. How does it work?

Your heart pumps blood through blood vessels to all the parts of your body.

Your blood has oxygen in it.  When blood travels through your body, it delivers oxygen and nutrients to your body parts.

On its way back to the heart, your blood picks up waste so that your body can get rid of the things it doesn't need.

Click here to see an animation

Click here to see a movie

4.  How does oxygen get into my blood?

Animation of man's lungs expanding and contracting within his chest Take a deep breath.  Where does that air you breath in go?  That's right, into your lungs, but that's not the end!  Your heart pumps blood into your lungs and the blood mixes with the oxygen you just breathed.  Click here to see how that works.


After your blood picks up oxygen, it goes back into your heart.  Then your heart sends it through your arteries so that oxygen is delivered to all the cells in your entire body.
The blood cells also pick up waste (stuff our body doesn't need), like carbon dioxide, and brings it back to your lungs so that you can exhale (breath it out) to get rid of it.

Click here to see a picture

Here is a movie that shows your blood moving through your body

BrainPop Circulatory System


5. What is blood?

Blood is made of different kinds of cells.  The 3 main cells are red blood cells, white blood cells and platelets.
Red Blood Cells, colorized, Credit: MicroAngela



PhotoCredit: MicroAngela 

Red blood cells have 2 jobs, delivery like a mail carrier, and collect waste like a trash collector.

Red blood cells deliver oxygen to your cells.

Red blood cells carry carbon dioxide from your cells to your lungs

A white blood cell scanning electron micrograph. Credit:Nanaworld,
Photo credit: NANOWORLD
White blood cells are like your personal army. They fight infections and diseases.  Did you know that sometimes white cells actually eat bad germs?
The arrow points to a platelet. Credit:Nanaworld,
Photo credit: NANOWORLD
Platelets help your body repair itself when you get hurt. They cause your blood to clot so that you stop bleeding when you get a cut.  If you had no platelets you would bleed to death if you got a cut or scraped your knee.

Click here to go to BrainPop Blood and learn more.


Here are a few additional links to help you understand how the cardiovascular system works.

Model of a heart

Simple Cardiovascular System


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