Biology AS: F212: Smoking

  • Created by: phoebc
  • Created on: 08-04-15 19:54

Short term effects of smoking


  • settles on lining of alveoli - increases diffusion distance for oxygen entering blood and COD leaving blood
  • can cause an allergic reaction if lieing on the surface
  • causes smooth muscle to contract
  • causes lumen to get smaller - resticts flow of air to alveoli
  • stimulates goblet cells to enlarge and secrete more mucus - mucus thne gets trapped in air way - so bacteria and viruses cannot be removed
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Long term effects of smoking

Smokers cough:

  • attempt to move bacteria that is trapped in airway 
  • smokers cough comes from irratation of airways by the mucus and bacteria plus the needed to clear airways 

If cough is constant:

  • damages delicate lining of airways
  • alveoli lining becomes damaged
  • lining replaced by scar tissue - thicker and less flexible
  • smooth muscle thickens - lumen narrows - air flow to alveoli is constantly restricted

Long term presence of bacteria and viruses in the mucus in the airways leads to:

  • damages layer of epithelium 
  • loss of elastic tissue in alveoli means that during exhalation alveolus wallas do not recoil and push air out 
  • bronchioles collapse - traps air in alveoli 
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Lung cancer - long term effects of smoking

Carcogenic compounds in cigareetes is the reason smoking can cause lung cancer:

  • in tar
  • enter the cells of lung tissue
  • enter the nucleus of these cells - direct affect on genetic material
  • mutations occur
  • if mutation effects genes that control cell division then uncontrolled cell division may take place = lung cancer 

Lung cancer symptoms:

  • contiual coughing
  • shortness of breath
  • pain in chest
  • blood coughed up in septum
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Chronic bronchitis - long term effects of smoking

  • inflammation to lining of airways
  • damage to cilia
  • overproduction of mucus
  • leads to increased lung infection


  • irritation in lungs
  • continual coughing
  • coughing up mucus filled w/ bacteria and white blood cells 
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Emphysema - long terms effects of smoking

  • loss of elascitiy in alveoli
  • alveoli can potentially burst
  • more spaces in lungs - lungs have reduced surface area for gaseous exchnage


  • short of breath
  • harder to exhale 
  • breathing more shallow and rapid
  • fatigue
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Effects of nicotine on the cardiovascular system

  • causes the addiction
  • nicotine mimics the action of transmitter substances at the synapses between nerves - so nervous system feels more alert
  • releases hormone adrenlate - heart rate, breathing rate increases
  • reduces blood flow and oxygen delivering to the extremities
  • makes platelets sticky - increase risk of blood clots 
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Effects of carbon monoxide on the cardiovascular

  • carbon monoxide combines with haemoglobin in red blood cells
  • problem: carbon monoxidea can combine with haemoglobin much more readily than oxygen
  • carboxyhaemoglobin formed
  • reduces oxygen carrying capacity of the blood
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How atherosclerosis evolves from smoking

1. carbon monoxide damages inner lining of arteries

2. white blood repair damage - encourage growth and deposit fatty substances (LDLs)

3. build up of atheromas under endothelium/inner lining of artery

4. atheroma eventually forms a plaque - stick out into lumen of artery

 5. artery wall less flexible and lumen size reduced 

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How coronary heart disease evolves from smoking

  • after atherosclerosis - lumen of coronary artery reduced
  • reduces blood flow to the cardia muscle
  • less oxygen flow to heart and less CO2 removed from heart

CHD can take 1 of 3 forms:

1. angina = severe pain in chest

2. heart attack/ myocardial infarction = death of part of the heart muscle 

3. heart failure - heart cannot sustain pumping due to blockage in coronary artery 

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How stroke evolves from smoking

Stroke = death of part of the brain tissue - cuased by th eloss of blood flow to the part of the brain 

2 possible causes:

1. blood clot floating around in blood blocks an artery leading to part of the brain

2. artery leading to brain bursts 

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