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,
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.