What can be used to measure lung volume
A spirometer
How is oxygen consumption measured
By using soda lime, which absorbs carbon dioxide
What precautions should be taken when using a spirometer
- Sterilised mouth piece
- Soda lime must be fresh and functioning
- Water chamber must not be overfilled
What is the equation for total lung volume
Vital capacity + Residual volume
What is vital capacity
The maximum volume of air moved by the lungs in one breath
How is vital capacity measured
By taking a deep breath and expiring as much air as possible
What does vital capacity depend on
- Exercise level
- Age and gender
- Size
What is the average vital capacity figure
2.5-5dm3
What is residual volume
The volume of air that remains in the lungs after forced expiration
What is the average residual volume figure
1.5dm3
What is tidal volume
The volume of air moved in a normal breath
What is the average tidal volume figure
0.5dm3
How else can breathing rates be measured
Through a spirometer trace
How does a spirometer trace work
By counting the number of peaks in each minute
What causes increased oxygen uptake
- Increased breathing rate
- Deeper breathing
