In <912196374.3097.0.nnrp-05.d4e44203 at news.demon.co.uk> "Andrew K
Fletcher" <andrew.k.fletcher at naturesway.demon.co.uk> writes:
- - - - - - -(snip) - - - - - - - - - - - - - - -
>could we please have someone put on record the current accepted
mechanism
>for cerebrospinal fluid circulation and formation? We need to have an
>accurate benchmark, so that a new theory for fluid transport may be
offered
>for discussion.
Your idiosyncratic use of the term "benchmark" is a small
thing, but alert readers mauy see this as an indication that we
are dealing with yet another example of a "private" way of
thinking with many implicit private definitions and beliefs
which will be impervious to reasoned arguments and evidence
which does not fit your private (solipsistic?) "system".
However, I'll point out that while one does need to know a
current theory if one wants to explicitly argue against it, one
can state a new theory with or without knowing the old theory.
If you have something to say, SAY it.
It is my belief that a new understanding of this phenomenon
>will reverse a complete spinal cord injury.
> Surely you do not mean the understanding would reverse it
(faith healing?). Perhaps you mean that this understanding
would lead too the development of effective treatments. If you
think you have a "new understanding" and if you think you see a
therapeutic method based on this understanding, SAY SO. (And
give at least a hint what the new understanding is and what the
new therapy might be).
- - - - - - -(snip) - - - - - - - - - - - - -
I'll repeat my previous comment:
>I'd be surprised if the processes were the same (I.e. water
transport in trees, CSF formation and transport and
absorption). What is your thesis re relevance of CSF
circulation to MS? to spinal cord injury?
- - - - - - -(snip) - - - - - - - - - - - - - -
>Are you familiar with the limit of 33 feet in physics for lifting
water up a
>single tube under normal atmospheric pressure RE:Galileo and
Torricelli?
Is this some kind of a joke? (No, unfortunately, it is not; I
know that. I just used a common rhetorical device to express
incredulity that someone purporting to understand physical
principles better than anyone else would say this.)
In physics (as in a few other things), SCALE is all-important.
Given a tube wide enough so that surface tension effects are
negligible, they will not be sufficient to draw fluid along the
surface of the tube, hence the alternative method of exhausting
the air above the column so that the weight of the air on the
fluid communicating with the base of the tube will force it up;
the limit, of course, is set by the height of the atmosphere
and thereby the weight of the column of air.
With a sufficiently small tube, surface tension effects are
very large relative to the total mass of fluid, and draw the
fluid along the tube (up, down, or sideways, depending on the
orientation of the tube)--process known as "capillary action"
But what does ANY of this to do with fluid movement in brain
ventricles? We are not "pumping" 33 ft using atmospheric
pressure, and we are not (so far as main movement through the
ventricles is concerned) dealing with tubules so fine as to
make us invoke capillary action as a mechanism.
F. Frank LeFever, Ph.D.
New York Neuropsychology Group
