Quiz - 8 - Diving Knowledge Workbook - Diving Physiology

[Pedro Burrito]

From the Diving Physiology Section of the PADI Diving Knowledge Workbook Version 2.02 © PADI 2009:

2.2 Question 1

The practice of breathing deeply when scuba diving is important in order to compensate for the:

a. increased dead-air space resulting from the snorkel or regulator.

b. reduced lung volume resulting from compression of the chest.

c. increased amount of alveolar carbon dioxide.

d. All of the above are correct.​

I will post a daily question from my exams to help newer divers and to encourage more experienced divers to interact gracefully and helpfully with the newer divers.

Reminder - this is a post in the Basic Forum and it is a green zone. Please be nice and on topic.

Thank you for your patience while we try to give people something to discuss other than Covid-19 and/or Politics. I will post the answer covered by the spoiler tag later today.

 

[D_Fresh]

Yahoo!!!! 1 to 1 when I answered! I happen to catch this one at the beginning; I'm excited!

 

[TMHeimer]

I think this one may be a little controversial. Let's see.

 

[Storker]

I'd like to point at @Dr Simon Mitchell 's many excellent posts and publications on the issue of CO2 retention, regardless of the phenomena listed in the available answers

 

[scubadada]

Spoiler

I will go out on a limb and predict a failing score by SB for this question. Of course, I've been wrong before

 

[Ukmc]

It looks like a tie between a and d, can not wait to see the answer on this one

 

[Pedro Burrito]

Spoiler: Answer

d. All of the above are correct.

Deep breathing helps exchange more air, reducing the effect of increased dead-air spaces. It also compensates for the reduction in lung volume caused by the increased pressure on the chest (thorax) due to submersion. Finally, deep breathing helps eliminate the higher than normal level of carbon dioxide in the alveoli brought about by the increased resistance of breathing while submerged.

 

[scubadada]

Disappointing answer. Gas is delivered at ambient pressure, why should there be pressure on the chest wall? Effort underwater is controlled, why would there be a higher pCO2 in the alveoli?

So, this is now the 3rd question for which I have disagreed with the answer. @Pedro Burrito keep them coming

 

[TMHeimer]

Disappointing answer. Gas is delivered at ambient pressure, why should there be pressure on the chest wall? Effort underwater is controlled, why would there be a higher pCO2 in the alveoli?

So, this is now the 3rd question for which I have disagreed with the answer. @Pedro Burrito keep them coming

Yes. One also could make an argument for a., since from what I recall, this is the MOST important reason. Actually to be semantically exact, since d. is "all of the above are correct"----how can ANY of the above be marked wrong?
On the OW test I took (2005) a similar question saw me answer d. "all..." and get it marked wrong. a. was marked correct ("too deep, too long, fast ascent causes DCS"). b. and c. were "possible additional causes"-- like sick, cold water, hungover, etc.
That's why I got 98% instead of 100. The instructor said she would have marked me correct if she could. I answered backward.

 

[Couv]

So, this is now the 3rd question for which I have disagreed with the answer.

Again I advise you not to look at my paper.