spirometers

• what is vital capacity?

  the maximum volume of air that can be exhaled from the lungs in one breath
• what is tidal volume?

  the volume of air that moves into and out of the lungs with each resting breath

  the volume of air in each breath at rest
• what is residual volume?

  the volume of air that is left in your lungs when you have exhaled as hard as possible

  cannot be measured directly
• what is total lung capacity?

  the sum of the vital capacity and residual volume
• what is ventilation rate and how can you calculate it?

  the total volume of air inhaled in one minute

  ventilation rate= tidal volume x breathing rate per min
• how do you calculate breathing rate from a spirometer graph?

  counting how many full peaks and troughs there are
• oxygen uptake will increase when the ventilation rate increases

  e.g during exercise
• why do many athletes have bradychardia?


  as they are so fit that there cardiac muscle can contract harder and thus fewer contractions are required