BODY SYSTEMS FOR THIRD GRADERS

1. OUR BODIES
UNIT 2

2. BODY SYSTEMS
● Your body is like a complex machine. It has lots
of parts that work together. The most important
parts are called organs. Different organs form
different systems.

3. CIRCULATORY SYSTEM
● The circulatory
system moves
BLOOD through the
HEART and around
the body in the
VEINS and
ARTERIES. Blood
gives your body
nutrients and
oxygen.
The heart is
divided into four
parts:
●
The left and
right atriums
●
The left and
right ventricles.

4. video
RESPIRATORY SYSTEM
● The respiratory system
helps you breathe. You
breathe in air (oxygen)
through your nose and
mouth. The air goes
down the trachea into
your lungs. The
oxygen goes to the
circulatory system.
● When you breathe out
you release carbon
dioxide.

5. DIGESTIVE SYSTEM● The digestive system is a group of
organs. These organs work together to
digest food. You take in food through your
mouth. When you swallow it, the food
passes down the oesophagus and into
your stomach and then it goes to your
small intestine and after that it goes to
your large intestine. The intestines
separate the nutrients from the waste
and expel the waste from your body. The
nutrients are absobed into the circulatory
system.
video

6. THE EXCRETORY SYSTEM
●
The excretory system eliminates
waste products from your body.
The kidneys clean the waste
combines with water to make
urine. Urine collects in the
bladder- whe the bladder is full,
your body tells you that you
need to go to the toilet. Your
body also eliminates waste
throuhgh the skin: it is the
sweat. video

7. REPRODUCTION
● When you grow
up your
reproductive
organs develop.
Men and
women have
different
reproduction
system.

8. STAGES OF THE LIFE

9. FOOD GROUPS