MECHANICS OF BREATHING

MECHANICS OF BREATHING

Breathing is accomplished by changes in the size of the chest cavity.

Surrounding-and guarding-the lungs have twelve pairs of ribs. They are joined to the spine at the back and curve around the chest to form a cage. In front, the top seven pairs are connected to the breastbone. The next three pairs are connected to the rib above. 

The last two pairs, unconnected in front, are called floating ribs. The entire cage is flexible and can be expanded readily by special muscles. In addition to the rib cage, which forms the wall of the chest, there is the dome-shaped diaphragm, which forms the floor of the chest cavity. The diaphragm is attached to the breastbone in front, the spinal column in back, and the lower ribs on the sides. The lungs do not suck in air; all the work is done for them by the diaphragm and muscles of the rib cage. When you inhale, muscle fibers of the diaphragm contract and the sheet of tissue is drawn downward; at the same time, rib muscles pull the ribs upward and outward.

This expands the chest cavity and lowers the pressure within it to below that of the atmosphere. This causes the lungs to expand, too; and the tiny air sacs in the lungs also become a little bigger. Air then rushes into the lungs to fill the extra space. When you exhale, just the opposite series of events occurs. Muscles of the diaphragm relax; so do those of the rib cage. The chest becomes smaller; the elastic tissue of the lungs returns to its original shape, making the air sacs smaller; and the air is driven out. 

The rate of breathing varies with age. In a baby the rate is about 45 times a minute; by age 6, it is down to about 25; between ages 15 and 25, it drops to about 18. There is some tendency for it to increase again with advanced age.

The rate of breathing is also influenced by the carbon dioxide content of the blood. If you hold your breath, carbon dioxide accumulates in the blood until, finally, it so strongly stimulates the respiratory control center of the brain that you are forced to breathe again. 

The length of time the breath can be held varies from 25 to 75 seconds. Mothers sometimes become alarmed when children hold their breath during crying spells or temper tantrums. There is no real danger of suffocation; when the child really needs air, he will be forced to inhale. In any condition leading to elevation of body temperature, the respiration rate is always increased. 

How to quit Smoking? Tips to quit smoking

HOW TO QUIT

Some find the quitting process relatively easy; many do not. But it would be a mistake to believe that if you have tried to quit in the past and have failed, you are doomed to go on smoking. If you have failed before, that in itself does not mean that you are hopelessly weak-willed. Beyond determination alone, you need insight, a plan, and a constructive attitude. 

One of the most important factors in quitting is to view the process positively. If you look upon it as simply giving up something of value, you may feel sorry for yourself. Rather, you have to view the process as Smoking one of teaching yourself-because of knowledge that it will represent a tremendous gain-a more rewarding behavior pattern.

There have been many methods suggested for quitting, and the American Cancer Society has compiled the recommendations of recognized experts in cigarette-withdrawal programs. To begin with, set a date when you plan to quit. Call it a day; that will be complete quitting day. You may want to give yourself as much as a month to get ready for the day. And getting ready can involve a gradual reduction in the number of cigarettes you smoke day by day. 

A good system is to determine that you will smoke only once an hour or that you will stop smoking between the hours of 9 and 10, 11 and 12, 12 and I, 1 and 2, 3 and 4, etc. And then extend the nonsmoking time by half an hour, an hour, and more. You may find it helpful, too, to smoke just half of each cigarette.

Deliberately, make it an effort to light a cigarette. If you habitually carry your pack in a certain pocket, now start using another pocket so you have to do some fumbling for a smoke. If you habitually use your right hand to bring a cigarette to your mouth, determine to use the left hand. Wrap your pack in several sheets of paper so it becomes an involved process to get at a cigarette. Shift from a brand you like to one you don't like.

 Each time before actually lighting up, make it a point to ask you a direct question: Do I really want this cigarette right now, or am I just lighting up out of habit? For whatever else it is, cigarette smoking is a habit, and anything you can do to put even small crimps in the automation involved can be a help. Undertake something else preparatory to the day.

Smoking studies and research on lung cancer and cardio problems

A United States study found death rates for men aged 45 to 64 to be 6.6 times as high for smokers; in the age group 65 to 84, 11.4 times as high. For women smokers, it is, overall, 4.9 times as high as for nonsmokers and 7.4 times as high for the heavier smokers.

Smoking: American heart Association authorities stated that 100,000 preventable deaths each year are associated with cigarette  as published by the National Cancer Institute, "Smoking in the Death Rates of One Million Men and Women," the conclusions were reached: In the 45 to 54 year age group, deaths from coronary heart disease are 2.8 times as high for men as high for women smoking a pack or more of cigarettes or nonsmokers. 

The greater the number of cigarettes smoked, the inhalation, and the earlier the age when smoking starts, better the death rate. And autopsies of people dying from diseases him coronary heart disease show more plaques, or roughened, on which clots can develop and much more extensive atherosele - the coronary arteries of smokers than nonsmokers.

Many studies show that smokers have larger amounts of cholesterol in the blood than nonsmokers. Other studies indicate that smoking prevent clotting of blood, which increases risk of clot formation in the coronary arteries. Smoking also increases the work load of the heart, forcing it to pump more blood more rapidly because the carbon monoxide from smoke reduces the oxygen-carrying capacity of the blood and impairs the elasticity and gas-exchange capacity of the lungs. 

There is evidence, too, of an association between cigarette smoking and strokes, which annually kill 200,000 Americans. An American Cancer society study found that stroke death rates are 74 percent higher among women and 38 percent higher among men who smoke cigarettes than among nonsmokers.