Smoking

Smoking

Tar
1. settles in lining of airways + alveoli
  1. increases diffusion distance
2. Short term effects
  1. allergic reactions
    1. causing smooth muscle in airways to contract
      1. lumen gets smaller
      2. restricted airflow to alveoli
  2. paralyses/destroys cilia on airway surface
    1. unable to waft mucus up airway
  3. stimulates goblet cells to produce more mucus
    1. collects in airways
      1. traps bacteria/viruses
        lungs more vulnerable to infection
      2. can block bronchioles
3. Long term
  1. smokers cough
    1. tries to shift bateria/mucus in lungs
    2. irritation of airways by build up
    3. tries to get air to alveoli
    4. damages lining of airways + alveoli
      1. replaced by scar tissue
        thick, less flexible
    5. smooth muscle in bronchiole wall thickens
      1. reduces airway lumen
  2. infections from bacteria/viruses in mucus
    1. inflame airway lining
    2. damage epithelium layer
    3. attracts white blood cells
      1. release enzymes to digest parts of lining of lungs to pass through air spaces
        enzyme elastase damages elastic tissue of lungs
        reduced elasticity of alveolus wall
        no recoil
        bronchioles collapse, trapping air in alveoli
        alveoli can burst due to increasing lung pressure
4. mixture of chemicals - carcinogens
Lung cancer
1. caused by carcinogenic compounds
  1. Benzopyrene = most harmful
  2. in tar - lies on lung surfaces
  3. enter nucleus of lung tissue cells
  4. causes mutations upon entering nucleus'
    1. mutation affects genes that control cell division = uncontrollable cell division is cancer
2. starts at bronchi entrance
3. takes 20-30 years to develop
4. symptoms
  1. continual coughing
  2. shortness of breath
  3. pains in chest
  4. blood
Diseases
1. chronic bronchitis
  1. inflammation of airway lining
  2. damage to cilia and extra mucus build up in lungs
  3. symptoms
    1. lung irritation
    2. continual coughing
    3. cough mucus
  4. leads to increased risk of lung infection
2. emphysema
  1. loss of elasticity of alveoli
  2. alveoli burst
  3. lungs have less surface area
  4. symptoms
    1. shortness of breath
3. COPD
  1. combination of diseases
  2. chronic bronchitis, emphysema + asthma
Nicotine
1. chemical = addiction
2. mimics action of trasmitter substances at synapses
  1. nervous system more sensitive
  2. smoker more alert
3. release adrenaline
  1. increase breathing/heart rate
    1. constricts arterioles = raises blood pressure
4. constriction of arterioles leading to extremities
  1. reduces blood flow + oxygen delivery
5. makes platelets sticky
  1. blood clot/thrombus
Carbon monoxide
1. enters red blood cells, combines with haemoglobin
  1. carboxyhaemoglobin
  2. reduces oxygen carrying capacity in blood
2. damages artery linings
CHD
1. atherosclerosis
  1. carbon monoxide damages endothelium of arteries
  2. damage repaired by phagocytes
    1. encourages smooth muscle growth and fatty substance deposition
      1. cholesterol - LDLs
      2. also encouraged by high blood pressure
  3. atheromas (deposits)
    1. fibres
    2. dead blood cells/platelets
    3. cholesterol
    4. build up under endothelium in arterty
      1. can break through inner lining
      2. forms plaque, sticking out into lumen
        artery wall = less flexible, smaller lumen, reduced blood flow
2. Thrombosis

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	Created by Gemma Bradford about 11 years ago