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Respiratory system
Most of you seem unsatisfied with the information here so I thought I'd
add a little. Feel free to e-mail me if you need anything specific, I just
may be able to help you and I check my e-mail around 4 or 5 times a day.
THE RESPIRATORY SYSTEM The respiratory system is the name given to the
system in the body involved with breathing. The lungs process the air that
the body needs to survive. The air we breathe enters through the nose and
travels down the trachea (windpipe). The trachea is made up of rings of
cartilage which are tough and flexible. The trachea splits into two tubes
called the bronchi (singular bronchus). Each bronchus leads into one of
the lungs and branches out into smaller tubes called bronchioles. The bronchioles
branch out into smaller and smaller tubes until they end at the alveoli
(air sacs). When the air enters the lungs it is cleaned, warmed and moistened
so it does not damage the sensitive lining of the lungs. Fine hairs and
mucus inside the nose filter out dust and other particles. In the alveoli
gas exchange occurs. Oxygen is taken in and absorbed by the blood and Carbon
Dioxide is given out. The exchange of gas occurs through the capillaries
(tiny blood vessels) which cover the surface of the alveoli. The oxygen
is carried by the blood to the parts of the body where it is used in the
process that supplies us with energy. The way we breathe is partly controlled
by a thin curved sheet of muscle called the diaphragm. When we inhale the
chest moves outwards as the diaphragm flattens and the lungs get bigger.
When we exhale the diaphragm relaxes and curves up, making the lungs smaller.
Contributed by: Lara Lawler <lawler_lara@yahoo.com>
Country: australia
Age: 13
Wednesday, March 01, 2000 at 16:59:06 (EST)
The respiratory system main task is to supply oxygen to the blood and
getting rid of waste gases. Carbon dioxide is the primary gas that the
blood gets rid of. The upper structures of the respiratory system are combined
with the sensory organs of smell and taste and the digestive system. When
you inhale (breathing in) your skeletal muscle and the diaphragm contract,
which then enlarge the chest cavity and cause the lungs to draw in air.
This creates a partial vacuum in the thoracic cavity, air passes through
the nose, pharynx, larynx, trachea, and then into the two bronchi to the
lungs. Oxygen and carbon dioxide pass between the blood and the air in
the alveoli, which are at the end of the smallest bronchi. Oxygen diffuses
from the inhaled air through the alveoli walls into the capillaries. The
lungs contain more than 300 million alveoli. When you exhale or breathe
out, your skeletal muscles and diaphragm return to the relax position which
decrease the size of the chest cavity and therefore pushes the air out
of the lungs. The rib cage serves as a structural support for the whole
thoracic arrangement, and peural membranes help provide lubrication for
the respiratory organs so that they are not chaffed during respiration.
The air we exhale contains 100 times more carbon dioxide than inhaled air.
In a resting position a healthy individual will inhale and exhale approximately
16 time per minute.
Contributed by: Mitchell Benfer <kbenf@earthlink.net>
Country: usa
Age: 12
Wednesday, April 29, 1998 at 23:42:02 (EDT)
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