1. The Mechanism of Breathing
L.O: to describe the steps in inspiration and expiration
to define and calculate pulmonary ventilation
Starter: Recall knowledge from last lesson and answer this exam q worth 5 marks:

2. How do we breathe?

3. Mechanism of Breathing
Inspiration
Expiration
External intercostal muscles
Internal intercostal muscles
Ribs
Diaphragm
Volume of thorax

4. Mechanism of Breathing
Inspiration
Expiration
External intercostal muscles
Contract
Internal intercostal muscles
Relax
Ribcage
Up and out
Diaphragm
Volume of thorax
Increases

5. Mechanism of Breathing
Inspiration
Expiration
External intercostal muscles
Contract
Relax
Internal intercostal muscles
Ribcage
Up and out
Down and in
Diaphragm
Volume of thorax
Increases
Decreases

6. Under Pressure

7. Under Pressure

8. Pulmonary Ventilation
Pulmonary = Tidal x Ventilation
Ventilation Volume Rate
Total volume of air moved into the lungs in one minute
Volume of air in each breath
Number of breaths in one minute
dm3 min -1 dm3 min-1

9. Past Exam Question

13. Now leave your work from today on my desk please. Thank you 