The document summarizes the mechanisms of human ventilation and breathing. It describes how inspiration and expiration occurs through contractions of the diaphragm and intercostal muscles, which increase and decrease the thoracic cavity volume. This causes changes in lung pressure that draw air in and push it out. Other topics covered include lung capacities such as tidal volume and vital capacity, and how spirometry can measure these.

3. The mechanism of ventilation Your lungs contain elastic tissue – they have no muscle. So how are you able to breathe in an out?

4. The intercostal muscles

13. Describe what this spirogram shows…

14. Work out the missing… a b c d f e

15. Which factors affect lung volume? people living at low altitudes people living at high altitudes non-athletes professional athletes heavy smokers Non - smokers shorter people tall people females males Smaller volumes Larger volumes

16. Working out lung capacities Find spirograms from different types of people

17. Effects of exercise on ventilation NAS p14