1. Smoking and heart and lung disease

2. Chronic Bronchitis Chronic diseases develop gradually over time but are long term or persistent The symptoms of chronic bronchitis are frequent coughing and bringing up a lot of mucus Why do these symptoms occur? Which components of cigarette smoke lead to bronchitis?

3. Emphysema Also known as COPD Alveoli have lost elastic tissue because phagocytes have secreted elastase enzyme in order to pass from the blood to the alveoli to combat lung infections caused by chronic bronchitis. Which component of cigarette smoke leads to emphysema?

4. Emphysema Small airways collapse trapping air in the alveoli. Breathing out requires more force. Can be an inherited tendency to develop emphysema due to a metabolic disorder. Symptoms-shortness of breath, hyperventilation and an expanded chest (barrel chest) to start with, then a blueness of the skin(cyanosis) and extreme breathlessness and tiredness in the more advanced stages

5. Lung Cancer Uncontrolled cell division. Stimulated by chemicals in tar eg. Benzopyrene Symptoms dry cough, wheezing (if the tumour is obstructing air flow), coughing up blood, shortness of breath, weight loss. Some people have no symptoms- the tumour is discovered on a chest x- ray.

6. Nicotine Found in cigarette smoke and enters the blood circulation by being absorbed in the alveoli. Addictive - stimulates nervous system. Stimulates the release of adrenaline which causes vasoconstriction. This raises blood pressure. Hypertension may cause damage to the endothelium of arteries starting off the deposition of atheromas. This may lead to coronary heart disease or strokes. Nicotine increases the stickiness of platelets in the blood, increasing the likelihood of blood clots

7. Carbon monoxide Has a higher affinity for haemoglobin than oxygen. Forms carboxyhaemoglobin –less oxygen carried in the person’s blood Damages the endothelium of the arteries

8. Cardiovascular disease Coronary heart disease is one example of cardiovascular disease. Atherosclerosis can occur in any arteries. It leads to hypertension and reduced blood flow. Atherosclerosis builds up over many years. Minerals like calcium are deposited in atheromas causing the artery walls to harden and become less flexible (arteriosclerosis) so they don’t expand and recoil with each heart beat. The heart has to work harder to pump the blood around and there is more friction between blood and artery walls

9. Stroke May be caused by a blood clot in an arteriole in the brain, or bleeding from a ruptured arteriole Symptoms sudden weakness on one side of the face or body Sudden confusion or difficulty in speaking Blurred vision Severe headache

10. Evidence Why is it difficult to obtain experimental evidence of the effects of diet and smoking on health? Because it takes a long time for illnesses like type two diabetes, heart disease and cancer to develop. It is unethical to give people something that may harm them in order to find out the effects. Animal research used to be used but it is now considered unethical to get dogs or rabbits to smoke cigarettes-what do you think?

11. Epidemiological evidence Instead of setting up an experiment and controlling the variables-it is possible to collect data in studies where diet or smoking habits are surveyed and then health is measured in some way. Epidemiology is the branch of medicine that deals with the study of the causes, distribution, and control of disease in populations. Data is collected and statistical methods are used to see if trends could be considered significant or not. If some factors appear to be linked to increased cases of a disease then these are called risk factors eg smoking cigarettes is a risk factor for lung cancer.

13. Smoking and lung cancer statistics More than a quarter (29%) of all UK cancer deaths are linked to smoking More than one in five (21%) British adults currently smokes Smoking is linked to around 90% of lung cancer deaths in men and more than 80% of lung cancer deaths in women in the UK Smoking prevalence (any tobacco product) in British men was 30% in 2002 compared with 82% in 1948 source Cancer Research UK