analysing data on lung disease

• Spirometer


  Device used to measure lung capacity
• Using a spirometer


  1. Take a deep breath

  2. Blow out as hard as possible through mouth

  3. Wear nose clip to prevent air entering/escaping through nose
• Spirometer graph


  • Shows breathing in and out normally (tidal volume)
  • Shows maximum inhale and exhale (vital capacity)
  • Shows residual volume (air permanently remaining in lungs)
  • Total lung capacity is vital capacity plus residual volume
• Pulmonary ventilation


  Total volume of air that moves in and out of the lungs in one minute
• To calculate pulmonary ventilation


  Multiply tidal volume by breathing rate (breaths per minute)
• Bronchial tube of someone with bronchitis


  • Narrowed lumen due to inflammation, reduces gas exchange
• Bronchioles of someone with asthma


  • Narrowed lumen due to inflammation, reduces gas exchange
• Alveoli of someone with emphysema

  • Alveoli walls break down, fewer and larger air sacs, reduced surface area for gas exchange
• Lungs of someone with pulmonary fibrosis

  • Alveoli walls thicken, reduced expansion, reduced surface area for gas exchange
• More cigarettes smoked per year

  Higher lung cancer deaths per 100,000 people
• The data shows a positive correlation between cigarettes smoked per year and lung cancer deaths
• The data overlaps between 2000-3500 cigarettes per year, suggesting no clear correlation in that range
• Correlation does not prove causation - other factors may contribute to lung cancer deaths
• No correlation coefficient statistic is provided, so the significance of the correlation is unknown