2.49: Understand the Biological Consequences of Smoking in Relation to the Lungs and the Circulatory System, Including Coronary Heart Disease

CONSEQUENCES OF SMOKING

EFFECT ON AIR PASSAGES: Tar in cigarettes destroy the Cilia (which carries away dust and microbes trapped in Mucus), therefore causing the buildup of Mucus and increasing risk of Bronchitis Tar in cigarettes contain carcinogens that increases risk of Lung Cancer

EFFECT ON ALVEOLI: Tar in cigarettes break down Alveoli walls and causes them to merge together, decreasing the surface area to volume ratio for gas exchange Insufficient gas exchange will increase the risk of Emphysema - shortness of breath due to insufficient Oxygen transport in blood

EFFECT ON CIRCULATORY SYSTEM: Nicotine in cigarettes causes blood vessels to narrow, placing strain on circulatory system and results in the increase in blood pressure Narrowing of blood vessels also causes the build-up of Fat globules, increasing risk of Coronary Heart Disease (CHD) CHD involves the blockage of Coronary Artery by Fat globules (forming plaques), causing insufficient Oxygen transport in blood leading to increased anaerobic respiration (due to lack of Oxygen) Increase in anaerobic respiration causes build-up of Lactic acid which creates acidic environment for enzymes to denature, hence causing strokes Carbon Monoxide from cigarette smoking will bind irreversibly to Haemoglobin, reducing capacity of Oxygen transport by Red blood cells and hence increases the risk of Emphysema - shortness of breath due to insufficient Oxygen transport in blood