OCR AS Biology - Smoking Overview of smoking and its effects. 3.0 / 5 based on 6 ratings ? BiologyAS Created by: IzzyCreated on: 08-04-12 10:58 Short term effects Chemicals Increases the diffusion distance in the alveoli. The chemicals may cause an allergic reaction. Tar paralyses or destroys the cilia meaning that mucus cant be moved. This means that mucus collects in the airways. Bacteria and viruses become trapped in the mucus. This means that smokers are more likely to catch diseases such as influenza and pneumonia. 1 of 5 Long term effects Smokers cough, to move the excess mucus from the lungs. The coughing can damage the lining of the airways. Smooth muscle thickens and reduces the lumen of the airway. Enzymes to fight the virus may digest some of the airway lining. This can lead to bronchioles collapsing. 2 of 5 Lung Cancer Cigarette smoke contains a large number of carcinogenic compounds (that cause cancer). They enter the nucleus and have an effect on the genetic material. This is called a mutation. This can cause an uncontrolled cell division which is cancer. 3 of 5 Chronic Bronchitis It is the inflammation of the lining of the airways. The damage of the cilia and overproduction of mucus leads to an build up of mucus in the lungs. Irritation of the lungs, continual coughing and coughing up mucus filled with bacteria and red blood cells. They are some of the symptoms. It leads to an increased risk of lung infection. 4 of 5 Emphysema Loss of elasticity in the alveoli causing them to burst.This causes a reduced surface area. It can cause someone to be out of breath more easily and can be hard to exhale. In severe cases the breathing will become shallow and more rapid. The blood is less well oxygenated and fatigue occurs. 5 of 5
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