Mechanics of breathing

• OXYGEN TRANSPORT

  • Diffuses from high conc. in alveoli to low in capillaries
  • Oxygen combines with haemoglobin which transports oxygen
• BREATHING

  • Inspiration - inhaling air increasing chest volume
  • Expiration - exhaling air decreasing chest volume
  • Involve use of diaphragm and intercostal muscles
• INSPIRATION

  • Diagraph - contracts, flattens
  • Intercostal muscles - contracts, ribs move up and out
  • Increases volume of chest - reduces pressure
• EXPIRATION

  • Diagraphm and intercostal muscles relax
  • Diagraphm returns to dome
  • Chest volume decreases - increased pressure of air in lungs
  • Ribs move in and down
• CHANGES DURING EXERCISE

  • Inspiration uses sternocleidomastoid and pectorals
  • Expiration uses abdominal muscles