Pressure
and Your Body Although
you don't usually
notice it, air constantly
exerts pressure on
you. If youve walked
against a strong wind,
though, youve felt
its force, demonstrating
that air can exert
pressure.The air pressure
that surrounds you
now is simply the
air's weight - the
result of gravity
holding the atmosphere
against the earth.
You don't usually
feel pressure, though,
because your body
is primarily liquid
which is incompressibte
and distributes pressure
equally throughout
your entire body.
The few air spaces
your body does have
a vour ears, sinuses
aad lungs have air
inside them edual
in pressure to the
external air pressure.
Although air is compressible,
you don't notice pressure
in body air spaces
as long as the pressure's
the same inside and
out-side. But if the
pressure changes,
such as when you ascend
to and from a higher
altitude by flying
or driving through
mountains, the air
in body air spaces
changes volume, and
you feel it in your
ears. and sometimes
in vour sinuses.Just
as air exerts pressure
on you. so does paten
when ynu submerg
But
because water m much
denser and heavier than
air. pressure changes
much more signifi cantly
for a gk en distance
ascent or descent. As
with air pressure, you
don't teccl water presure
except in your body
3nd one of the first
things wull nmice is
that ,you'll feel changes
Quickly even when you
ascend or descend only
a metre These changes
have some associated
problem that you'll
learn to avoid later
in this section and
during confined water
dives.
Atlantis International
Bali Dive Center
Jl. By Pass Ngurah Rai #350 Sanur, Bali
Phone : +62-361-284312
Fax : +62-361-282824
Mobile : +62-81-2380 5767
e-mail : info@balidiveaction.com