spirometer....measuring tidal volumes....

[hassam]

fow do we use spiro meter to measure tidal volumes,lung capacity.....whats a kymogrph...what changes are brought to kymograph during exercising and why....

 

[zahraahmed]

in the spirometer a person breathes O2 from a tube . his nose is clipped and the oxygen comes from a chamber which floats on water. soda lime absorbs CO2 released. this means that the O2 chamber( floating) moves during breathing. these movements are recorded on a kymograph. a kymograph is not an instrument its the name given to the result of spirometer (just like chromatograph for chromatography) . on the kymograph the height of kymograph trace keeps on falling due to decrease in the volume of O2 in the O2 chamber.
We measure vital capacity and tidal volume from the kymograph trace.
during exercise the tidal volume would increase. if youre still confused just go through page 146 of mary jones a level bio book ( the black one)