Investigating Breathing Rate Flashcards
What is oxygen consumption
The volume of oxygen used by the body, expressed as a rate
What is respiratory minute ventilation and how to calculate
The volume of gas breathed in or out in a minute
Tidal volume x breathing rate (breaths per minute)
What does spirometer allow measurement of
Tidal volume, breathing rate, oxygen consumption and respiratory minute ventilation
How does spirometer work
Oxygen filled chamber with a movable lid, person breathes through a tube connected to the oxygen chamber
-as they breathe in the lid of chamber moves down, when breathe out it moves up
-movements recorded by pen attached to lid of chamber which writes on rotating drum creating spirometer trace
Why does volume of gas in chamber decrease over time
Because the air that’s breathed out is a mixture of oxygen and carbon dioxide but the carbon dioxide is absorbed by the soda lime in the tube meaning only oxygen in the chamber which person inhaled from, used up by respiration
Why does person wear nose clip when using spirometer
So all their breathing occurs through their mouth
Role of soda lime in respirometer
Absorbs carbon dioxide breathed out
When line moves up what’s happening
Exhalation
What happens when line moves down
Inhalation
How to find tidal volume from spirometer trace
Peak to trough of average breath
How to get vital capacity from spirometer trace
Peak to trough of forced breath
How to get breathing rate from spirometer trace
Number of peaks in time corresponding to a minute
