respiratory system

• Respiratory system


  Nose and mouth -> trachea -> bronchi -> bronchioles -> alveoli
• Characteristics that enable gaseous exchange to occur

  • One cell thick - small distance from oxygen to pass through faster
  • Large surface area large area for gas exchange / more gas exchange
  • Walls of alveoli are most - gases dissolve to pass through
• Long term effects of exercise and training on the respiratory system


  • Strength of muscles involved in breathing increases
  • Vital capacity increases
  • Minute ventilation increases
• Breathing volumes

  • Tidal capacity - volume of air you inhale during normal breathing. Increased exercise
  • Vital capacity the maximum amount of air you can breathe out after breathing in
  • Residual volume - the volume of air left in your lungs after breathing out
  • Minute ventilation - the volume of air that you breathe per minute. Increases w exercise
• Mechanics of breathing - Inhaling (breathing in)


  1. The rib cage: moves up and out as intercostal muscles contract

  2. The diaphragm contracts and flattens

  3. Effect: lungs draw in air containing oxygen

  4. Volume of lungs: increases

  5. Pressure of lungs : decreases
• Mechanics of breathing - Exhalation (breathing out)

  1. The rib cage moves down and inwards as the intercostal muscle relaxes

  2. The diaphragm relaxes and domes upwards

  3. Effect: air containing CO2 is forced out the body

  4. Volume of lungs: reduces

  5. Pressure of lungs : increases