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Re: Sauropod drinking
Don't get too dense, just think & you'll overcome
Michael E Teuton wrote:
> There may be some confusion here. There are no changes in pulmonary artery or
> venous pressures at reasonable depths. Therefore, no hemorrhaging into
> I'm not sure about depths below 100 ft or so in regards pulmonary circulation
> pressures. What you do is add dead space with a snorkel.
> Michael Teuton
> Richard Keatinge wrote:
> > In article <35AC07C0.247FC09@erinet.com>, Jonathon Woolf
> > <email@example.com> writes
> > >C. Laibly wrote:
> > >
> > >> I remember reading an article in my Princ. of Paleontology course
> > >> concerning a professor who tried testing the plausibiliy of this theory
> > >> (large sauropods breathing while bodily immersed in water). He breathed
> > >> through a hose that would supposedly have given him relative fresh
> > >> air and pressure amouns to deal with as that of a submersed sauropod.
> > >> He died from congestive heart failure in the process. Then again, a
> > >> plesiosaur could breathe. Hmmm. Something to think about...
> > >>
> > >
> > >What makes breathing in water difficult is the external pressure
> > >_differential_
> > >between the intake (nostrils) and the lungs. The nostrils are in air at
> > >normal
> > >atmospheric pressure of 14.7psi. The lungs -- well, the pressure on them
> > >depends on how deep underwater they are, and how dense the water is. As a
> > >general rule of thumb, the pressure increases one atmosphere for every ten
> > >meters of water. A mere five feet of water, about 2.5psi of added pressure
> > >differential, is more than the average human's lungs can overcome.
> > >Anything
> > >that wants to breathe with its nose at the surface and its lungs ten or
> > >twenty
> > >feet down had better have Brobdignagian lung muscles.
> > 'snot the lung *muscles* that are the problem. Lungs work by having a
> > really thin (=not very strong) membrane across which gases diffuse
> > readily. The air on one side of the membrane (if you're snorkeling) is
> > at atmospheric pressure; the blood on the other side is at atmospheric
> > pressure, plus whatever blood pressure is required to drive the
> > pulmonary circulation, PLUS the external water pressure. I really can't
> > see any way round that for any credible design of lung; you can't
> > snorkel more than a couple of feet or so down, without either collapsing
> > your lungs (if you're lucky) or breathing out most of your circulating
> > blood volume into what's meant to be air space, like the good professor
> > presumably did (I heard the same story in medical school). And neither
> > could a sauropod.
> > back to lurking...
> > --
> > Richard Keatinge
> > homepage http://www.keatinge.demon.co.uk
Fight Fugue----remain irrational