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  • Created by: Shannon
  • Created on: 01-06-14 13:00

Short Term Effects - Tar

Cigarette smoke includes:

  • Tar
  • Carbon Monoxide
  • Nicotine


  • Settles on the lining of the airways and alveoli
    • This increases diffusion distance for oxygen entering the blood and carbon dioxide leaving the blood
  • Tar can cause the smooth muscle in the walls of the airways to contract
    • This causes the lumen of the airway to get narrower which restricts the flow of air to the alveoli
  • Tar paralyses or destorys the cilia on the surface of the airway, so they are unable to move the layer of mucus away
  • Tar also stimulates the goblects cells to release more mucus and this mucus colelcts in the airways
  • Bacteria trapped in the mucus is not removed so multiply and block bronchioles as well as causing the lungs to be more susceptiable to infection
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Longer-term effects

  • Smoker's cough is an attempt to shift the bacteria mucus that collects in the lungs
    • It results from irritation of the airways, as well as from the need to clear the airways in order to get air down into the alveoli
  • The cough damages the delicate lining of the airways and alveoli
    • The lining gets replaced by scar tissue which is thicker and less flexible 
    • Layer of smooth muscle in the all of the bronchioles thickens which reduces the lumen of the airway and the flow of air is permanetly restricted
  • Alveoli and bronchioles loses it elastic tissue
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Lung Cancer

  • Carcinogenic compounds cause cancer - found in tar
  • They enter the cells of the lung tissues
  • They enter the nucleus and have a direct effect upon the genetic material
  • Any changes to the genetic material is called a mutation
  • if the mutations affect the genes that control cell division, then uncontrolled cell division takes place - this is cancer
  • The tumour grows uncontrollably blocking air flow to areas of the lungs which decreases gas exchange and leads to shortness of breath
  • The tumour uses lots of nutrients and energy to grow, which causes weight loss
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Chronic Bronchitis

  • The inflammation of the lining of the airways 
  • Accompanied by the damage to the cilia and the overproduction of mucus, so that mucus collects in the lungs - caused by cigarette smoke
  • Symptoms are:
    • Irritation in the lungs 
    • Continual coughing
    • Coughing up mucus that is often filled with bacteria and white blood cells
    • Lung infection 
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  • the loss of elasticity in the alveoli, which causes the alveoli to burst 
  • The lungs have reduced surface area as larger air spaces are formed
    • this decreases the rate of gaseous exchange
  • Symptoms:
    • Shortness of breath
    • Increased breathing rate as they try to increase the amount of air reaching their lungs 
    • The blood is less well oxygenated and fatigue occurs 
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Nicotine and Carbon Monoxide

  • Nictotine
    • Increases the heart rate
    • Increases breathing rate
    • Constriction of arterioles - this raises the blood pressure 
    • Makes the platelets sticky - increases the of bloodclots forming
  • Carbon Monoxide
    • Enters the red blood cells and combines with haemoglboin
    • Carboxyhaemoglobin reduces the oxugen carrying capacity of the blood
    • Damages the lining of the arteries 
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  • Carbon monoxide can damage the inner lining (endothelium) of the arteries
  • If the person also has high blood pressure, this will add to such damage
  • The damage is repaired by the action of white blood cells 
  • This encourages the growth of smooth muscle and deposition of fatty substances
  • High blood pressure also increases the deposition of cholesterol - atheromas 
    • This process of deposition is called atherosclerosis - the hardening of arteries due to the formation of atheromas 
  • Build-up of atheromas occurs under the endothelium, in the wall of the artery 
    • Atheroma forms plaque which reduces the size of the lumen which reduces blood flow 
  • Symptoms:
    • High blood pressure
    • Hypertension 
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  • When the coronary arteries have lots of atheromas in them. This restricts blood flow to the heart
  • The lumen of the coronary artery is narrowed by plaques, this reduces the blood flow to the heart muscles, which receive less oxygen for respiration 
  • This can cause:
    • Angina - severe pain in chest
    • Heart attack 
    • Heart failiure
  • Smoking increass the risk of CHD bc carbon monoxide irreversibly combines with haemoglobin which reduces the amount of oxygen transported in the blood
  • Nicotine in cigarette smoke makes platelets sticky which increases the chance of blood clots forming - if this happens in the coronary arteries then it could cause a heart attack
  • Presence of atheromas also increases the risk of blood clots forming 
  • Symptoms
    • difficult to exercise
    • Shortness of breath
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  • Rapid loss of brain function due to a disruption in the blood supply to the brain
  • Can be caused by a blood clot in an artery leading to the brain, which reduces the amount of blood and oxygen that can reach the brain
  • Nicotine increases the risk of stroke because it increases the risk of clots forming
  • Carbon monoxide also increases the risk of stroke because it reduces the amount of oxygen avaliable to the brain by combining with haemoglobin 
  • Symptoms
    • numbness of face
    • Difficulty to speak
    • Difficulty to see
    • Difficulty to walk
    • Servere headache
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CHD is a multifactoral disease. The risk factors are:

  • Age
  • Sex
  • Cigarette smoking
  • Obesity
  • High blood pressure
  • High blood cholesterol concerntration
  • Lack of exercise
  • Diet high in saturated fat
  • A high salt intake
  • Absence of polyunsaturated fats
  • Genetic factors
  • Diabetes
  • Stress
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