The Effects of Immersion on the Cardiovascular and the Respiratory System

[Brett Hatch]

Do you realize that there is a difference in physiological response depending upon whether the diver is on scuba or is breath-holding and swimming to depth? I think the two are mixed up in the above posts. We need to know which type of diver is being profiled here.

SraRat

I would expect that the effects due to mammalian response and temperature would be the same for a free diver vs a scuba diver. And that the effects due to pressure would be near nil for a scuba diver, but increase linearly with depth for a free diver. I am not an expert in physiology -- for the actual experts in the room, is this the case?

 

[outofofficebrb]

I am not an expert in physiology -- for the actual experts in the room, is this the case?

I feel like this should be moved to Marine Science and Physiology (general) or to Diving Medicine forum. Folks there would know for sure!

 

[Bigbella]

There is also the related subject of bradycardia; its connection to the mammalian diving reflex; and its rather unpleasant association with the use of full face masks, should the need ever arise for the removal of the mask, under cold water conditions -- anything below 20˚C, which isn't really that cold.

That sudden exposure of the face; the accompanying lowered heart rate, via the trigeminal and vagus cranial nerves -- that kicking-in of the sympathetic nervous system, could cause a temporary inhibition to breathing, when switching to a safe second and conventional "split" mask.

When we trained on the full face masks, years ago, it was striking how much of an inhalation inhibition there was, while switching to a safe second, after the FFM removal. It took a couple of attempts, on my part, and the liberal use of the purge button, to get things going, in an unheated pool, at about 15˚C. A couple of the others were unable to complete that task and surfaced . . .

 

[David Novo]

Do you realize that there is a difference in physiological response depending upon whether the diver is on scuba or is breath-holding and swimming to depth? I think the two are mixed up in the above posts. We need to know which type of diver is being profiled here.

SraRat

Which of the questions asked is dependent on whether it is related to a scuba or freediver?

 

[John C. Ratliff]

Which of the questions asked is dependent on whether it is related to a scuba or freediver?

Almost all he questions will have different answere, dependent upon whether the diver is a scuba diver or a freediver.

SeaRat

 

[David Novo]

Almost all he questions will have different answere, dependent upon whether the diver is a scuba diver or a freediver.

SeaRat

I am looking for the answers for a scuba diver but if you could indicate the difference vs freediving, it would be interesting.

 

[John C. Ratliff]

I am looking for the answers for a scuba diver but if you could indicate the difference vs freediving, it would be interesting.

David,

This will take some time to differentiate the two, and I'll do it over the next couple of days.

SeaRat

 

[dmaziuk]

Do you realize that there is a difference in physiological response depending upon whether the diver is on scuba or is breath-holding and swimming to depth? I think the two are mixed up in the above posts. We need to know which type of diver is being profiled here.

Since breath-holding diver isn't breathing, expiratory volumes and alveolar function don't matter much. They should be much more concerned with lung compression and resulting trauma would be my guess.