7.3 Measuring The Process Flashcards
What is lung capacity and what do you use to measure it
The volume of air drawn in and out can be measured by:
Peak flow meter - device that measures rate at which air can be expelled from lungs. Often used my people with asthma.
Vitalographs - more sophisticated version of PFM. Patient being tested breaths out quickly as they can through a mouthpiece. Instrument produces graph of amount of air exhaled & how quickly it is breathed out. (This volume of air is called the forced expiratory volume in 1 second).
Spirometer - commonly used to investigate breathing patterns and lung volumes. Can show the different lung capacities
What is Tidal volume
Volume of air that moves in and out of lungs with each resting breath.
On average, it’s around 500cm^3 in adults at rest, which uses around 15% of vital capacity.
What is Vital capacity
Volume of air that can be breathed in with the strongest inhale and exhale
What is Inspiratory reserve volume
Maximum amount of air that can be breathed in above a normal breath
What is Expiratory reserve volume
Extra amount of air you can force out of your lungs above normal exhale.
What is Residual volume
Volume of air left in the lungs after a forceful, deep exhale.
Cannot be measured directly
What is Total lung capacity
Sum of vital capacity and residual volume
What is breathing rate and ventilation rate
Pattern and volume of breathing changes as the body demands change.
Breathing rate is the number of breaths taken per minute.
Ventilation rate is the total volume of air inhaled in one minute.
Ventilation rate = tidal volume x breathing rate (per min)
What happens when the O2 demands of the body changes
When the O2 demands increase (like during exercise), the tidal volume with each breath can increase from 15% to 50% of the vital capacity.
