Did you ever wonder why it is that we need the air we breathe? I mean
sure, you think of course, we need it to survive. Well, yes, that is true,
but did you ever think why it keeps us alive or how our body uses it?
Oxygen is a necessity by all living organisms. Your metabolism, or burning
of nutrients, depends on the oxygen we breathe. It releases the energy needed
to grow, reproduce, and maintain life through many reactions. What we breathe
out is a waste product formed by the combination of carbon from food and
oxygen during the metabolism process, also formally known as carbon dioxide.
Your breathing is accomplished through the functioning of your respiratory
system. Your respiratory system is your apparatus for bringing in oxygen
and releasing carbon dioxide and water vapor.
Your respiratory system consists of the nasal cavity, pharynx (throat),
larynx (voice box), trachea (windpipe), bronchi, and the most known one,
the lungs. Now, when the process
of breathing begins, air is taken in through the mouth and nose up through
the nasal cavity. Breathing through your nose is best for you since it has
a layer of hair in it. This collects any dust or other particles keeping
them from reaching your lungs. After the air has traveled through your nose
and mouth it all comes together in a point of your throat called the pharynx.
At this point there are two routes, one for food and one for air.
We'll explore the one for air right now. At the top of the air passage lies
the larynx, which is your voice box. The voice box contains membranes that
are called your vocal cords. So thanks to these vibrating vocal cords, the
fat lady can sing and you can shout all you want.
The vocal cords vibrate when they are close together. The pitch of the sound
is determined by how close and how tight these membranes are. At this point
air reaches the trachea, which if dissected has rings of cartilage that
distinguishes it from the esophagus. The trachea leads to the bronchi which
lead to bronchial which leads to bronchioles. Easy, right? Then, at the
end of the bronchioles lies the smallest parts, the alveoli. These are filled
with capillaries. I'm sure you know someone that has asthma. Or, you may
just be one of those unfortunate people yourself. Asthma is caused when
the muscular walls in your bronchioles constrict. Last, the blood that first
leaves your heart carrying carbon dioxide passes to the alveoli exchanging
the carbon dioxide for yummy oxygen, which finally gets to every single
cell in your body.
"Lighting Up" a cigarette, cigar, or pipe has been a tradition
for over 500 years, but the health hazards of this practice are only now
being realized. Some people who smoke do so because they have developed
a craving, or addiction for tobacco, or actually the nicotine and tar in
the tobacco. This craving makes it very difficult and sometimes painful,
for
some people to give up the harmful habit. In recent years the effects of
smoking, how it leads to different diseases, why people start smoking, and
how smokers can be helped to quit have been studied extensively.
In 1956 the United States Public Health Service began to study the effects
of smoking. They have found that the tars found in the tobacco have been
labeled as carcinogens that cause cancer over time. The committee said that
smoking is a major cause of cancer of the lung, mouth, throat, and other
organs, and it also said that smoking was a major cause of chronic bronchitis
and emphysema that makes breathing very difficult, and that it is a significant
cause of heart and blood vessel disease. The American Cancer Society blames
3 out every 4 lung cancer deaths to cigarette smoke. Smoking during pregnancy
is associated with miscarriages, premature births, and small babies.
But the U.S. government is trying very hard to curb smoking. In 1970 it
enacted a law that prohibits the advertising of cigarettes on radio and
television and required a message to be printed on every pack of cigarettes.
It says "Warning: The Surgeon General Has Determined That Cigarette
Smoking Is Dangerous to Your Health."
Another concern is the risk of second hand smoke. Scientific testing shows
that people with heart and lung disease or with allergies can be made sick
by inhaling second hand smoke. So, more than 1/2 the states have made laws
prohibiting smoking in public places such as restaurants and stores.
Also a concern is smoking by young people and women. Boys ages 12-18 have
continued to smoke at about the same rate over the years, but girls have
showed a great increase. One advantage for people who smoke is a decrease
in the strength of many cigarettes. They contain less tar and nicotine than
years ago. Also researchers are trying to find new ways to help smoker "kick"
the habit gradually. Nicotine patches and gum have been developed. Also,
smokers are being hypnotized in order to stop smoking.
The campaign against smoking has been very successful. Television ads and
billboards are displaying that smoking is not "cool" and warnings
on cigarette packs are being taken more seriously. Now, more than 65 percent
of adults in the U.S. are non-smokers, and the time has come when people
are becoming aware of the danger that smoking causes to themselves as well
as to others.
The reason you breathe harder after a basketball game or track meet is
because your blood has an increased level of carbon dioxide in it. The base
part of your brain, the medulla oblongata, is the respiratory center for
your body. This is what signals the rapid breathing and the deeper breaths.
When the level lowers, signals are sent that slow the breathing along the
impulses in your nerves.
The process of taking air into the lungs is known as inspiration and the
release of it is expiration. You may know this as inhaling and exhaling.
These two combined make the act of one breath. Your lungs are never completely
expelled of air. Even after some vigorous, hard work you still contain air
in your lungs.
The ordinary grown up human takes approximately 16 full breaths in one minute
when awake. During sleep, that may lower to six to eight. When under stress
the rate may shoot up to even 100 per minute. So, gray hairs and baldness
aren't the only thing that may come to mind when your parents file taxes.
Have you ever seen your belly while you were breathing? If not, take a look.
When you inhale, your stomach goes out and when exhaling the opposite occurs.
Your chest cavity is a box formed by your ribs and its surrounding muscles,
including the lower one, the diaphragm. This cavity holds your two lungs
and one heart. See, when you inhale, your ribs go up and your diaphragm
falls down, enlarging the size of your chest cavity. Plus, the air pressure
in your lungs is reduced as the air flows in. During exhalation, the rib
muscles and diaphragm relax, allowing the ribs to go back down and the diaphragm
to go back up. Furthermore, the chest constricts along with the lungs, pushing
the air outwards.
With all these motions and structures, you can breathe our somewhat fresh
air. However, you may not always be so fortunate to have your respiratory
system to always perform 100%. Asthma is one respiratory disease that may
be very serious. It is catergorized as an allergic disease. Your breathing
is also harmed when you catch the cold and flu viruses. In addition, bacterial
infections such as TB (tuberculosis) and pneumonia may be gathered also.
Emphysema and lung cancer are examples of horrible conditions that destroy
the lungs. These may be brought on by smoking and pollution. They take lives
every year. Sometimes people are given artificial structures and machines.
Your respiratory system is a very important yet vulnerable part of you.
Take care of it!
Images copyright PhotoDisc, Inc., 1996.
Images copyright T/Maker Company, 1996.
New Book of Knowledge, 1987. Grolier Inc.