How to we breath before birth ?

[Dan Partelly]

Well, this is a question for the physiologists on this board. Im pretty interested to know how the hell do we breath and get gas exchange before we are birth, in our mothers wombs , and our lungs are not yet working.

It's fascinating for me to know that one minute we dont need to use lungs, the next we do. Can somone please tell me a bit more about this ?

[db8us]

You get the oxygenated blood via the umbilical directly in your body.
So you are like a surface-supplied diver with an umbilical :-) but of course without the helmet !

The blood when it reaches the heart is NOT going into the lungs then (because that would be useless) but instead it goes through an openeing directly on the "other"-side of the heart.
So there is a kind of short-cut via a hole in your heart.
This is the important part for divers !!!
This hole, when not closed properly is later called a PFO (the opening is the foramen ovale) and might cause trouble because bubbles can bypass the lung which acts as a filter. So with relatively harmless venous bubbles, you suddenly end up to have them on the arterial side (where the oxygenated blood is). Now the bubbles move on here and the blood vessels get smaller and smaller and the bubble get stuck and causes problems.

This is it in a VERY small nutshell :-)

Michael

[Graham Mills]

i never knew that just goes to show you; you can learn something every day :D

[Dan Partelly]

So there is a kind of short-cut via a hole in your heart.
This is the important part for divers !!!

Michael
Well, I heard about PFO and the fact that we all are born with one, but had no ideea at what it serves, and its used before getting closed. Its fascinating.

Thanks Michael

[Gazza]

Hi Dan

If you get the chance there is a must see GUE production called the Mysterious Malady. Interviews and discussion with the world leaders in Dive physiology and hyperparic science. I believe the PFO and other mysterious topics are well discribled and explained in this DVD.
Regards
G :)