Friday, August 1, 2008

Exactly how does Cigarette smoke cause lung cancer


Exactly how does Cigarette smoke cause lung cancer?
I know it does something to the cilia. But then, how come there have been people who have smoked their whole life and dont get cancer?
Medicine - 4 Answers
Random Answers, Critics, Comments, Opinions :
1 :
the process for cancer relies on the fact that cigarette smoke contains many agents that cause chronic lesion to the cells lining the respiratory tract. the constant injury requires these cells mutate at first into mature cells (metaplasia) but as the process continues they will mutate repeatedly into displasias and neoplasias (immature, pleomorfic atypical cancer cells). the mutation itself requires much nuclear activity, of course. this guides into the activation of protooncogenes (cancer related genes that reside inactive). if you lack certain protooncogenes you've very little risk of developing lung cancer. that's a brief way of putting it. now, cigarette smoke isn't only a risk factor for lung cancer so you might feel safe thinking you don't have the genes but you could develop many other types of cancer. also, cancer is only one of the dozens of complications of cigarette. this is where the cilia really take place: COPD (chronic obstructive pulmonary disease). when you smoke you paralize these cilia, which are meant to sweep particles outward. it's a protective mechanism. otherwise you will produce more mucus and develop bronchiectasias, bronchitis, etc. cigarette smoke also induces activation of alfa-1-antitrypsine which is an elastase- it tears appart the fibers that guarantee alveolar elasticity. you'll develop emphysema this way.
2 :
If you kept yourself and your car running in an air-tight garage, you would be killed eventually. The smoke from cigarette is similar to the smoke from your car, but it doesn't kill you right away. Medically, the cigarette smoke is a slow death, no matter the name is Lung Cancer or any other name. Economically, it's a waste of money (product costs, taxes, medical costs, loss of taxes you have paid for your retirement, etc.) Socially, it is a skunk in your mouth.
3 :
Cigarette smoke contains many things besides nicotine (the addictive substance which gets a really bad rap...). Nicotine affects the nervous system by binding to receptors on nerves called nicotinic receptors. The result is stimulatory and becomes addictive like other drugs like opiates (heroin, morphine etc.) and alcohol (which produces opiate like substances upon ingestion in many people and especially alcoholics) Upon burning, tobacco and tobacco paper give off many toxins, some of which are carcinogenic (cancer causing). In the not so distant past, and even today, additives such as ammonia and other chemicals are added to cigarettes for various purposes. Tar is a major offender and reeks havoc in the respiratory system (you can take it from me... my cadaver in medical school was Rod Serling). The mechanisms that cause cancer are largely unknown, but are a combination of heredity (genetics), environmental exposure, and lifestyle. Cancer is not one disease but a host of diseases which share as a common factor the abnormal growth of cells and disruption of normal cellular processes. By far and away, the chief cause of lung cancer is smoking (especially in post-menopausal women). People that smoke their whole life may not get cancer because of a genetic predisposition or protective factor that we have yet to discover, however we do know that the drawbacks of smoking are numerous both on health, life events, behavior, and life events. Jeez. Who wants yellow teeth, coughing, weight loss, circulatory effects, shortened life span and the whole laundry list of maladies suffered by smokers? Not me. It's not very attractive to boot.
4 :
The answer I just read, the detailed one is perfect. What amazes me is that there is *ARSNIC* in cigarettes and people do it anyway? I would think that alone would be enough to cause cancer since it is a poison. Don't believe me? Research.



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