Ways to measure the volume of air drawn into and out of the lungs
- a peak flow meter - measures the rate of expellation of air
- vitalographs - sophisticated peak flow meters
- spirometer - investigates breathing patterns
What is tidal volume?
Volume of air that moves into + out of the lungs with each resting breath - about 15% of vital capacity
What is vital capacity?
Volume of air that can be exhaled when the deepest possible intake of breath is followed by the strongest exhalation
What is inspiratory reserve volume?
Maximum volume you can breathe in, over and above normal exhalation
What is expiratory reserve volume?
Extra amount of air you can force out over and above normal tidal volume of air you breathe out
What is residual volume?
Volume of air left in the lungs once exhaled out as hard as possible, cannot be directly measures
What is total lung capacity?
Sum of vital capacity and residual volume
What is breathing rate?
Number of breaths per minute.
What is ventilation rate?
Total volume of air inhaled in 1 minute:
Ventilation rate = Tidal volume X Breathing rate
What happens during exercise?
The body demands change. Breathing rate, tidal volume and ventilation rate all increase, to keep up with the extra oxygen demands.