Ask A Scientist General Science Archive

name         Holly S.
status       student
age          18

Question -   Could a human body learn to breath under water without
using scuba gear? I only ask this because humans technically human babies
breath under water the first 8 or 9 months of their life while in the
womb, right? So, could the human body learn to breath under water?
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The lungs of a fetus do not function in oxygen transport...NO BREATHING
OCCURS IN UTERO. The fetus receives oxygen from the mothers blood by
diffussion across the placenta. When the baby is born the first breaths are
taken. 

Pf
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Holly,
 
Babies in the womb "breathe" via an umbilical cord which brings in oxygen and nutrients and 
serves as a conduit to discharge waste products.
 
No, humans couldn't learn to breathe underwater for at least two important reasons. First, 
the amount of oxygen that dissolves in water is far too low to sustain human life -- and, the 
lungs were not designed to extract oxygen from a liquid medium.
 
The other reason has to do with the physics of respiration. Contrary to what one sees in 
cartoons wherein Sylvester pussycat breathes through a long reed as he walks along the bottom 
of a pond while stalking Tweetybird on a nearby overhanging branch.
 
The pressure of the water against the chest even a few feet below the surface is far too great 
to allow one to expand the lungs. That's why you never see snorkelers swimming at depth and 
breathing through a long snorkel tube.
 
Regards,
ProfHoff 797
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No.  Babies don't "breathe underwater" in the womb.  Their lungs are not functional until they 
are born.  When babies are "slapped on the bottom" at birth, the doctor is trying to get the
baby to take its first breath and inflate the lungs.  Fetuses get their oxygen from their 
mother through the umbilical cord.  The protein in your blood that carries oxygen and makes 
it red is called hemoglobin.  When you were a fetus your hemoglobin was a little different 
than it is now-it was able to bind and carry oxygen more efficiently so could survive on 
less oxygen.  Just before birth and shortly after the hemoglobin begins to change to the 
adult form that is used when breathing air.  Also, you can't "teach" an organism to do 
something they are not genetically programmed or physiologically capable of doing.  Either 
they can do it, or they can't do it.  If you were to take a human that has been born and put 
them under water, they would drown.
 
vanhoeck
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Dear Holly,


This indeed is a common misconception.  Babies are not breathing water while
in the mother's womb.  All oxygenated blood is being provided by mom and
sent through the umbilical cord.  Amniotic fluid is not breathable.  The
lungs are machines made for working in air not water.  The movie "The Abyss"
makes use of this notion.  But, alas, it is only fiction.


Hope this helps straighten some stuff out.
Martha Croll
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