The trace goes down as the oxygen gets used up...the amount of CO2 never decreases...though it is absorbed of course by the soda lime ...so doesn't affect oxygen volumes which can be measured ...i.e. consumption of O2 in dm3 per minute
Brave teacher saying a textbook is wrong, not sure which book either as there are a few for the course! All I can say is that as you breath in (inspiration) your lung volume increases the spirometer volume decreases. If you take an extra deep breath in the spirometer will continue to decrease (inspiratory reserve volume).
Great vid, one question, my biology teachers told us the ocr biology text book is wrong and inspiratory reserve volume and expiratory reserve volume is the opposite on the spirometer trace, confused. Thanks
+Laura Choi going off of the notes i made during the video, a counter balance removes the resistance for breathing, without it, the subject would be forcefully breathing in and out, this would mean it would not be showing a clear result of tidal volume, as tidal volume is a normal breath rather than a forced or strenuous one, so yes, it does ensure tidal volume :)
