RE: The heart of a Brachiosaurus

["Stewart, Dwight" <Dwight.Stewart@VLSI.com>]

> -----Original Message-----
> From: John Bois [SMTP:jbois@umd5.umd.edu]
> Sent: Wednesday, November 25, 1998 2:24 PM
> To:   GGreyOwl@aol.com
> Cc:   dinosaur@usc.edu
> Subject:      Re: The heart of a Brachiosaurus
> 
> 
> I don't know the answer to your question.  But here are some things to
> think about.  Much depends upon whether or not the animal raised its head
> directly above its body, or whether it browsed closer to the ground.  In
> the first case one would expect high blood pressure or some fantastic
> adaptation (eg., 7 neck hearts) to get the blood all the way up.  I
> believe brain tissues (for example) in all creatures are equally prone to
> bursting (as in strokes).  Therefore, if excessive pressure was needed to
> pump blood up then one would expect an excessively high rate of strokes. 
> We have no way of knowing whether or not this occurred.  I wonder if 
> giraffes experience more of these difficulties?
> 
> Either way, moving blood around a huge body was just one of the
> physiological problems to be solved by these gigantic creatures.  Indeed,
> one could argue, as I have, that being big was a rather pathological
> condition.
        ########################


        The good ole Animal Channel had a recent show about giraffes & they
are well adapted for their
        15 ft + heights.  The neck vertebrae are VERY robust, as are the
soft tissue connections.
        Their hearts are powerful & can push out a high volume of blood very
efficiently.  Of course,
        their hearts are large.  The blood vessels in their neck is adapted
to handle the higher pressure.
        Who knows, but one would think that sauropods & other tall dinosaurs
might have similar
        adaptations?

        Cheers!
        Dwight