The
Respiratory System
One of the
most important elements your body needs is oxygen and the system that brings
oxygen into your body is the respiratory system.
Air, which contains oxygen, enters the body
through the mouth or nose. It then travels down a tube in your throat called
the trachea. You can feel your trachea by touching your neck just above your
chest.
Your trachea
branches into two parts just before the lungs called the bronchial tubes. Once
the air enters the lungs, these tubes continue to branch into smaller
bronchiole tubes, ending at small sacs know as alveoli. As this point, the
oxygen in the air enters the bloodstream and the carbon dioxide, a waste
product from your body, leaves the blood and takes the reverse route out of the
body.
How often you
breathe is determined by your breathing rate. Your brain sends a signal to take
a breath every time the amount of carbon dioxide in your body increases. This
happens many times every minute. The signal travels to the diaphragm, a long
muscle located under your lungs. The diaphragm pulls down, making the lungs
expand which causes air to enter your mouth or nose.
Parts of the respiratory system
The
lungs are the main organs of the respiratory system. In the lungs oxygen is
taken into the body and carbon dioxide is breathed out. The red blood cells are
responsible for picking up the oxygen in the lungs and carrying the oxygen to
all the body cells that need it. The red blood cells drop off the oxygen to the
body cells, then pick up the carbon dioxide which is a waste gas product
produced by our cells. The red blood cells transport the carbon dioxide back to
the lungs and we breathe it out when we exhale
2. Trachea
The
trachea (TRAY-kee-uh} is sometimes called the windpipe. The trachea filters the
air we breathe and branches into the bronchi.
The bronchi (BRAHN-ky) are two air tubes
that branch off of the trachea and carry air directly into the lungs.
4.
Alveoli
Alveoli are tiny sacs within our lungs
that allow oxygen and carbon dioxide to move between the lungs and bloodstream
Breathing
starts with a dome-shaped muscle at the bottom of the lungs called the diaphragm
(DY-uh-fram). When you breathe in, the diaphragm contracts. When it contracts
it flattens out and pulls downward. This movement enlarges the space that the
lungs are in. This larger space pulls air into the lungs. When you breathe out,
the diaphragm expands reducing the amount of space for the lungs and forcing
air out. The diaphragm is the main muscle used in breathing.
Source :
http://hes.ucfsd.org
http://mrsbader.com/grade5science1.html
http://hes.ucfsd.org
http://mrsbader.com/grade5science1.html
