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Taking Out the Garbage
Taking Out the
Garbage
Have you ever wondered what happens to the trash you throw
away? Most communities have a system for removing waste.
Garbage trucks usually drive around town to collect trash from
garbage cans. They might carry this waste to a station where it is
sorted. A transfer truck might dispose of the waste in a landfill.
A waste removal system helps keep a community clean.
Just as people produce waste in a town, your cells produce waste
inside your body. Your cells are constantly carrying out activities
to keep you alive. They make energy and fight germs. They help
you move, feel, and breathe. When your cells do these jobs, they
produce things you need. But they also produce waste. This waste
must be removed from your cells. And then it must be excreted, or
released from your body.
Your body has a waste removal system to do these things. It is
called the excretory system. Your excretory system helps keep
you healthy. If wastes were not taken out of your body, they would
make you very sick. Some organs in the excretory system are the
kidneys, bladder, skin, and lungs.
Your blood carries materials from your cells to your kidneys.
When blood flows into the kidneys, it is sent through tiny
filters. The filters remove waste from the blood. The
kidneys mix the wastes with water to make urine. Urine
flows out of the kidneys and down tubes into the bladder.
The bladder stores urine until you release it from your
body.
Your body removes wastes when
you urinate.
Your blood also carries waste materials to your lungs.
Your cells produce carbon dioxide waste when they use
oxygen from the air. Your blood takes carbon dioxide to
your lungs. You release the carbon dioxide waste when
you exhale.
Your lungs remove wastes when you exhale.
Sweat glands in your skin filter out waste materials and
water from your blood. This waste and water form a liquid called
sweat. Sweat moves out of your body through tiny pores in your
skin. You excrete wastes from your body when you sweat.
Discovery Education Science
© 2007 Discovery Communications, LLC
Page 1 of 2
Taking Out the Garbage
Your blood is like the garbage trucks
that travel around a town collecting
waste. Inside your body, blood carries
waste from cells to organs of the
excretory system. These organs are like
the sorting station. They filter out waste
and prepare it to be delivered out of the
body. Urine, sweat, and exhaled air are
like the transfer trucks. They take the
waste products away from the body.
The excretory system helps keep your
body healthy.
As these athletes sweat, wastes are being removed
from their bodies.
Discovery Education Science
© 2007 Discovery Communications, LLC
Page 2 of 2