# Respiration experiment questions

**URL:** <https://boards.straightdope.com/t/respiration-experiment-questions/428123>\
**Category:** Factual Questions\
**Created:** [November 29, 2007, 1:40am UTC](https://boards.straightdope.com/t/respiration-experiment-questions/428123 "2007-11-29T01:40:13Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![solkoe](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@solkoe](https://boards.straightdope.com/u/solkoe)\
**Post date:** [November 29, 2007, 1:40am UTC](https://boards.straightdope.com/t/respiration-experiment-questions/428123/1 "2007-11-29T01:40:13Z")

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First off, I am a teacher not a student so please don’t give me the homework lecture. I have just finished a respiration experiment that yielded surprising results. With no teacher manual, I will turn to the Dope for help.  
The experiment has four parts.

1. The students find their normal relaxed breathing rate.
2. The students force hyperventilate (10 quick deep breathes) then immediately find their breathing rate. In this case, I thought the breathing rate would decrease as more CO2 is removed from the blood. Most students had the opposite happen.
3. The students hold their breath for 45 seconds then immediately find their breathing rate. I thought that their breathing rate would increase as CO2 levels increase. Most students had the opposite happen.
4. The students breathe into a paper bag for 3 minutes then find their breathing rate. Again, I thought the breathing rate would increase but the results were mixed.

My major conclusion from all this is that my students can’t count but I am looking to see if there is a mistake in my understanding of this topic. Thanks.

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**Author:** ![picunurse](https://avatars.discourse-cdn.com/v4/letter/p/7bcc69/32.png) [@picunurse](https://boards.straightdope.com/u/picunurse)\
**Post date:** [November 29, 2007, 2:55am UTC](https://boards.straightdope.com/t/respiration-experiment-questions/428123/2 "2007-11-29T02:55:15Z")

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Because breathing is both voluntary and involuntary, it’s hard to monitor one’s own respiratory rate.  
PaCO2 self corrects very quickly, so 10 breaths may just not cause enough of a change to notice.

To really know if you’re actually causing respiratory alkalosis, you’d need to be able to test the pH of the blood.

Here’s an article discussing [respiratory alkalosis](http://www.emedicine.com/ped/topic70.htm). For the most part, it addresses blood pH in the critically ill, so it might not be of much help.

I’ll keep looking.

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**Author:** ![Anaglyph](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Anaglyph](https://boards.straightdope.com/u/Anaglyph)\
**Post date:** [November 29, 2007, 7:51am UTC](https://boards.straightdope.com/t/respiration-experiment-questions/428123/3 "2007-11-29T07:51:27Z")

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I find that if I repeat the experiment myself, after holding my breath, I take much deeper (larger breath volume) and therefore slower breaths, and after hyperventilation, I take shallower, and therefore (somewhat) faster breaths

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**Author:** ![solkoe](https://avatars.discourse-cdn.com/v4/letter/s/919ad9/32.png) [@solkoe](https://boards.straightdope.com/u/solkoe)\
**Post date:** [November 30, 2007, 12:09pm UTC](https://boards.straightdope.com/t/respiration-experiment-questions/428123/4 "2007-11-30T12:09:00Z")

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I’m just giving this one more try. Are my assumptions correct at least?