The Circulatory System




Reading Passage and Practice: The Circulatory System
Math: Interpreting and representing fractions
Vocabulary: Circulatory System Terms
: Description of a village, showing causes
Project: Graphs of heart beat and blood pressure
Game: Heart Puzzle



 Click on the words highlighted in yellow to get a definition.

In the In the circulatory system, blood leaves the heart and returns to it. It delivers oxygen and nutrients to the organs and tissues.  The blood also picks up wastes from the body. The blood leaves the heart through the arteries.  It returns to the heart through the veins. The heart muscle is constantly squeezing and relaxing.  In this way, the heart moves blood through the body. The heartbeat is the sound of the heart’s actions. 

A: Right auricle      C: Left Ventricle
B: Right Ventricle D: Left Auricle

The tubes in the drawing are the blood vessels: the arteries and the veins.


The heart is basically a double pump.  Each side of the heart has two parts, an auricle and a ventricle.  The auricles draw blood into the heart; the ventricles push blood out of the heart.  

The right side of the heart handles deoxygenated blood. The left side of the heart handles oxygenated blood. On the right side of the heart, the auricle receives deoxygenated blood from the body.  It then flows to the right ventricle.  From there it is pushed out to the lungs to get oxygen and to get rid of wastes.  From the lungs, the oxygen-rich blood goes to the left auricle where it flows down to the ventricle and is pushed out to the body.  The blood then returns to the right auricle. This cycle is repeated again and again.


The circulatory system does many other important things.  Blood carries disease fighters to the parts of the body that need them.  Blood also helps form clots in areas that are bleeding.  Blood flow also controls body temperature.

When the heart pumps steadily, all is well.  When the heart stops pumping blood, the person dies within 4 to 5 minutes. The heart is vital to survival and cannot rest. Perhaps this is why the heart always symbolizes the best and strongest parts of human beings. 




   Heart and Lungs


Brain Gym

Vowel Switch

Change only one vowel and keep the rest of the word spelling exactly the same to fill the blanks.


Our High School    lost     last   year's final game.
(Spend some time thinking about the answer before checking it!)

1.  That         a huge hole under the fence!

2.  Tent is one of many words that begin      with the same letter.

3.  Is there a good handyman that I can      in town?

Now try a few sentences of your own. List a few words that change meaning by just changing one vowel. Then write a sentence that uses both next to each other.