Lung Volumes

What does a spirometer do?

Measures lung volumes, eg. tidal volume, vital capacity etc.

What is Tidal Volume?

Volume of air moving in and out of lungs each breath.

What are the Expiratory and Inspiratory reserve volumes?

Expiratory reserve volume - volume of air that could be used when breathing out.

Inspiratory reserve volume - volume of air that could be used when breathing in.

What is Vital Capacity?

Maximum volume of air that can be breathed in and out.

VC = TV + ERV + IRV

What is residual volume and why is it important?

Volume of air left in the lungs after breathing out.

Important as if there was no air left in the lungs, they would collapse and stick together and would be very difficult to reinflate.

What is Minute Ventilation?

Volume of air being breathed out of the lungs per minute.

MV = TV x breathing rate.

What factors affect Tidal Volume?

• Height

• Age

• Sex

How does tidal volume increase during exercise?

During exercise, tidal volume increases as you start to used your reserves - IRV and ERV.