vital capacity, tidal vol, breathing rate & oxygen uptake

• pulmonary ventilation = the volume of air taken into the lungs in one minute
• tidal volume = volume of air in each breath
• ventilation rate = number of breaths per minute
• pulmonary ventilation (per min) = tidal volume x ventilation rate
• spirometer = a device used to measure the volume of air breathed in and out
• how a spirometer works:

  • static lower half filled with water
  • mobile upper half is full of oxygen
  • breathing out into tank - upper half rises
  • breath in from tank - upper half falls
  • trace marker attached to mobile upper half
• spirometer trace - slants down with successive cycles

  • oxygen is removed
  • CO2 is absorbed by soda lime
  • chamber does not rise as high
• vital capacity = largest volume of air that can be breathed in and out in one breath
• inspiratory reserve volume = maximum volume of air you can breathe in over and above normal inhalation
• expiratory reserve volume = maximum volume of air that you can force out of your lungs over and above the normal tidal volume of air you breathe out
• residual volume = volume of air that is left in your lungs when you have exhaled as hard as possible - this cannot be measured directly
• total lung capacity = total potential amount of air in the lungs at any one time

  • sum of the vital capacity and the residual volume
• peak flow meters = measures rate at which the rate at which air can be expelled from the lungs
• vitalograph = more complex version of peak flow meter, produces a graph about the volume of air that is being breathed in and out and how quickly