Smoking and Disease
Tobacco Smoke
Tobacco smoke is composed of 'mainstream' smoke (from the filter or mouth end) and 'side-stream' smoke (from the burning tip). When a person smokes, about 85% of the smoke that they release is side stream smoke. Many of the toxic ingredients are in a higher concentration in side-stream than in mainstream smoke. Breathing someone else's cigarette smoke is called passive smoking. There are three components in cigarette smoke that pose a threat to human health. They are:
The gaseous exchange system is naturally efficient and adaptable and training can improve its function and, thereby, our general health. Healthy people breathe with little conscious effort; for people with lung diseases every breath may be a struggle. Chronic (long-term) obstructive lung diseases, such as asthma, chronic bronchitis and emphysema, ar enow prevalent as a result of atmospheric pollution from vehicle and industrial emissions and smoking.
Chronic Bronchitis
Tar in cigarette smoke stimulates goblet cells and mucous glands enlarge and secrete more mucus. Tar also inhibits the cleaning action of the ciliated epithelium that lines the airways. It destroys many cilia and weakens the sweeping action of those that remain. As a result mucus accumulates in the bronchioles and the smallest of these may become obstructed. As mucus is not moved dirt, bacteria, and viruses collect and block the bronchioles. This stimulates 'smoker's cough' which is an attempt to move mucus up the airways. This damage and blocking of the airways is called chronic bronchitis. Sufferers have a severe cough, producing large quantities of phlegm, which is a mixture of mucus, bacteria, and some white blood cells.
Emphysema
The inflammation of the constantly infected lungs causes phagocytes to leave the blood and line the airways. Phagocytes are white blood cells that remove bacteria from the body. To reach the lining of the lungs from the capillaries, phagocytes release the protein-digesting enzyme elastase. This enzyme destroys elastin in the walls of the alveoli so making a pathway for the phagocytes to reach the surface and remove bacteria. Elastin is responsible for the recoil of the alveoli do not stretch when we breathe out. With much smaller quantities of elastin in the alveolar walls in the alveoli do not stretch when we breathe in and out. As a result, the bronchioles collapse during exhalation trapping air in the alveoli, which often burst. Large spaces appear where they have bursts and reduces the surface area for gaseous exchange. This condition is called emphysema. As lung function deteriorates, wheezing occurs and breathlessness becomes progressively worse. It may become so bad that people cannot get out of bed.
Chronic bronchitis and emphysema often occur together and constitute a serious risk of health. The term chronic obstructive pulmonary disease refers to the overall condition, which is progressively disabling disease.
Cardiovascular Diseases
Cardiovascular diseases are degenerative diseases of the heart and circulatory system, such as coronary heart disease and stroke. They are the major cause of death and disability. CArdiovascular diseases are multifactorial, meaning that many factors contribute to the development of these diseases. Smoking is just one among several risk factors that increase the chances of developing one of the cardiovascular diseases.
Atherosclerosis
The main process that leads to cardiovascular diseases is the accumulation of fatty material in the artery walls. This reduces the flow of blood to the tissues and may also increase the chance of blood clots forming within the artery, obstructing the flow of blood altogether. if blood cannot flow into capillaries, the surrounding tissue does not receive enough nutrients and oxygen, and may die. The build up of atheroma, which contains cholesterol, fibres, dead muscle cells, and platelets, is termed atherosclerosis.
Coronary Heart Disease
Two coronary arteries branch from the aorta to supply all the muscles of the atria and the ventricles. Coronary heart disease is a disease of these arteries that causes damage to, or malfunction of, the heart. Coronary heart disease develops if the blood supply to the heart muscle is reduced. There are three forms of coronary heart disease.
A stroke occurs when an artery in the brain bursts so that blood leaks into the brain tissue (a brain hemorrhage) or, more commonly, when there is a blockage in the brain artery due to atherosclerosis or a thrombus. The brain tissues in the area supplied by the artery is starved of oxygen and dies (cerebral infarction). A stroke may be fatal or cause mild or severe disability. The effect of stroke are unable to control body parts, loss of memory, loss of the ability to speak, and personality change.
Tobacco smoke is composed of 'mainstream' smoke (from the filter or mouth end) and 'side-stream' smoke (from the burning tip). When a person smokes, about 85% of the smoke that they release is side stream smoke. Many of the toxic ingredients are in a higher concentration in side-stream than in mainstream smoke. Breathing someone else's cigarette smoke is called passive smoking. There are three components in cigarette smoke that pose a threat to human health. They are:
- Tar (a mixture of aromatic compounds) settles on the lining of the airways in the lungs and simulates a series of changes that may lead to obstructive lung disease and lung cancer. This connection was recognized in the 1950's.
- Carbon Monoxide diffuses across the walls of the alveoli and into the blood in the lungs. It diffuses into red blood cells where it combines with hemoglobin to form the stable compound carboxyhemoglobin. This means that hemoglobin does not become fully oxygenated. Carbon monoxide also damages the lining of the arteries.
- Nicotine is the drug in tobacco. It is absorbed very readily by the blood and travels to the brain within a few seconds. It simulates the nervous system to reduce the diameter of the arterioles and to release the hormone adrenaline from the adrenal glands. As a result, heart and blood pressure increase and there is a decrease in blood supply to the extremities of the body reducing their supply of oxygen. Nicotine also increases the 'stickiness' of blood platelets, so increasing the risk of blood clotting.
The gaseous exchange system is naturally efficient and adaptable and training can improve its function and, thereby, our general health. Healthy people breathe with little conscious effort; for people with lung diseases every breath may be a struggle. Chronic (long-term) obstructive lung diseases, such as asthma, chronic bronchitis and emphysema, ar enow prevalent as a result of atmospheric pollution from vehicle and industrial emissions and smoking.
Chronic Bronchitis
Tar in cigarette smoke stimulates goblet cells and mucous glands enlarge and secrete more mucus. Tar also inhibits the cleaning action of the ciliated epithelium that lines the airways. It destroys many cilia and weakens the sweeping action of those that remain. As a result mucus accumulates in the bronchioles and the smallest of these may become obstructed. As mucus is not moved dirt, bacteria, and viruses collect and block the bronchioles. This stimulates 'smoker's cough' which is an attempt to move mucus up the airways. This damage and blocking of the airways is called chronic bronchitis. Sufferers have a severe cough, producing large quantities of phlegm, which is a mixture of mucus, bacteria, and some white blood cells.
Emphysema
The inflammation of the constantly infected lungs causes phagocytes to leave the blood and line the airways. Phagocytes are white blood cells that remove bacteria from the body. To reach the lining of the lungs from the capillaries, phagocytes release the protein-digesting enzyme elastase. This enzyme destroys elastin in the walls of the alveoli so making a pathway for the phagocytes to reach the surface and remove bacteria. Elastin is responsible for the recoil of the alveoli do not stretch when we breathe out. With much smaller quantities of elastin in the alveolar walls in the alveoli do not stretch when we breathe in and out. As a result, the bronchioles collapse during exhalation trapping air in the alveoli, which often burst. Large spaces appear where they have bursts and reduces the surface area for gaseous exchange. This condition is called emphysema. As lung function deteriorates, wheezing occurs and breathlessness becomes progressively worse. It may become so bad that people cannot get out of bed.
Chronic bronchitis and emphysema often occur together and constitute a serious risk of health. The term chronic obstructive pulmonary disease refers to the overall condition, which is progressively disabling disease.
Cardiovascular Diseases
Cardiovascular diseases are degenerative diseases of the heart and circulatory system, such as coronary heart disease and stroke. They are the major cause of death and disability. CArdiovascular diseases are multifactorial, meaning that many factors contribute to the development of these diseases. Smoking is just one among several risk factors that increase the chances of developing one of the cardiovascular diseases.
Atherosclerosis
The main process that leads to cardiovascular diseases is the accumulation of fatty material in the artery walls. This reduces the flow of blood to the tissues and may also increase the chance of blood clots forming within the artery, obstructing the flow of blood altogether. if blood cannot flow into capillaries, the surrounding tissue does not receive enough nutrients and oxygen, and may die. The build up of atheroma, which contains cholesterol, fibres, dead muscle cells, and platelets, is termed atherosclerosis.
Coronary Heart Disease
Two coronary arteries branch from the aorta to supply all the muscles of the atria and the ventricles. Coronary heart disease is a disease of these arteries that causes damage to, or malfunction of, the heart. Coronary heart disease develops if the blood supply to the heart muscle is reduced. There are three forms of coronary heart disease.
- Angina Pectoris, the main symptom of which is severe chest pain brought on by exertion. The pain starts when exercising , but goes away when resting. The pain is caused by severe shortage od blood to the heart tissue but there is no death of heart tissue.
- Heart Attack which is also known as myocardial infarction. When a moderately large branch of a coronary artery is obstructed by a blood clot, part of the heart muscle is starved of oxygen and dies. This causes sudden and serve chest pain. A heart attack may be fatal, but many people survive if they are treated immediately.
- Heart Failure due to the blockage of a main coronary artery and the resulting gradual damage of heart muscle. The heart weakens and fails to pump efficiently.
A stroke occurs when an artery in the brain bursts so that blood leaks into the brain tissue (a brain hemorrhage) or, more commonly, when there is a blockage in the brain artery due to atherosclerosis or a thrombus. The brain tissues in the area supplied by the artery is starved of oxygen and dies (cerebral infarction). A stroke may be fatal or cause mild or severe disability. The effect of stroke are unable to control body parts, loss of memory, loss of the ability to speak, and personality change.