Tidal volume of your lungs

How can you measure the tidal volume of your lungs? Find out with our experiment!

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion. This method has con­traindi­ca­tions. Ask your doc­tor!

Equip­ment

  • two bot­tles;
  • lid;
  • two tubes (sil­i­cone or straws); any sealant;
  • wa­ter:
  • mea­sur­ing cup;
  • scis­sors or an awl.

Step-by-step in­struc­tions

Fill a bot­tle with wa­ter us­ing a mea­sur­ing cup, mark­ing each 1/4 pint. Make two holes in the bot­tle cap, thread a tube through each, and seal. Cap the wa­ter bot­tle and in­sert the free end of one of the tubes into an emp­ty bot­tle.Take a deep breath and ex­hale into the oth­er tube. Wa­ter is leak­ing into the sec­ond bot­tle!

Process de­scrip­tion

The mea­sure­ment of lung vol­ume is an in­te­gral part of the study of lung func­tion. On av­er­age, hu­man lungs have a to­tal vol­ume of 4–6 liters. How­ev­er, the lungs usu­al­ly do not work to their full ca­pac­i­ty. More­over, the vol­ume of the lungs may change, for ex­am­ple, due to a res­pi­ra­to­ry dis­ease. Lung vol­ume is the sum of four in­di­ca­tors: tidal vol­ume, in­spi­ra­to­ry re­serve vol­ume, ex­pi­ra­to­ry re­serve vol­ume, and resid­u­al vol­ume. Our ex­per­i­ment mea­sures tidal vol­ume, which is de­fined as the amount of air in­haled and ex­haled dur­ing nor­mal res­pi­ra­tion. On av­er­age, this ranges from 300 to 500 mL (about 0.6 to 1 pint).

Cool med­i­cal prac­tice is wait­ing for you in the MEL MED sub­scrip­tion!

Try it