1. Pulmonary ventilation

3. What you need to do: Count the number of breaths in a minute 1 minute countdown! Make a note, this is your ventilation rate

4. Ventilation Rate (Breathing Rate): The number of breaths taken in one minute. (This is usually 12-20 breaths in a healthy adult). Pulmonary Ventilation: The total volume of air that is moved into the lungs during one minute. Pulmonary ventilation = tidal volume x ventilation rate (dm 3 min -1 ) (dm 3 ) (min -1 )

5. A peak flow meter and a clean mouthpiece can be used to measure your tidal volume (this is usually between 0.45 – 0.5dm 3 ). Tidal Volume: The volume of air breathed in (or breathed out) during a single breath when at rest. Today, do the calculation using 0.5dm 3 as the tidal volume (Note: this is the same as 500cm 3 ).

6. Other pulmonary measurements A spirometer is a machine that measures volumes of air inhaled and exhaled, it produces a trace of these volumes on graph paper or recorded on a computer. The vital capacity is the maximum amount or air that can be breathed out of your lungs in one breath, following the deepest intake of air possible. (It is not the total volume of the lungs, as there is always a small volume of air that cannot be expelled - called the residual volume). Note the significant difference between the tidal volume and the vital capacity on the following trace:

7. Breathing Volumes EXPIRATORY RESERVE INSPIRATORY RESERVE TIDAL VOLUME Total Lung capacity breathing in breathing out INSPIRATORY RESERVE = Extra air breathed in on a deep inspiration. EXPIRATORY RESERVE = Extra air expired, ie. Over the normal 0.5dm 3 0 0.5 3.0 2.5 2.0 1.5 1.0 0.5 1.0 1.5 2.0 Residual volume Vital capacity

8. Read ‘Deep Breathing’ and do Q4 p68-69 (Bill Indge textbook). Spirometer trace

9. Trace from a spirometer, measuring a person’s lung volumes before and during exercise.

10. a)0.5 dm 3 b)12 breaths per minute c)12 X 0.5 = 6 dm 3 min -1 d) 2.6 dm 3 e)From 0.5 to 2.6 = 2.1increase, so 2.1 divided by 0.5 x 100 = 420% increase f) 3.8dm 3 g) 5 dm 3 % increase = difference X 100 original value

11. Do the 4 summary Qs on p77. Do the 3 summary Qs on p75. End.

14. Control of breathing After exercise