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From: jgro@ur-tut.UUCP (Jeremy Grodberg)
Newsgroups: sci.bio,sci.med
Subject: Re: HEART RATE
Message-ID: <823@ur-tut.UUCP>
Date: Sun, 2-Nov-86 17:23:51 EST
Article-I.D.: ur-tut.823
Posted: Sun Nov  2 17:23:51 1986
Date-Received: Tue, 4-Nov-86 01:26:31 EST
References: <768@mtx5w.UUCP> <1154@masscomp.UUCP>
Reply-To: jgro@ur-tut.UUCP (Jeremy Grodberg)
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Organization: Univ. of Rochester Computing Center
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Xref: mnetor sci.bio:11 sci.med:157

>> Does anyone know the underlying mechanism that
>> "causes" the heart to beat faster during exercise?

>  I don't know for sure how this information
>gets to the heart itself, but presumably it is carried by sympathetic nerves
>to the pacemaker region of the heart, causing it to speed the heartbeat.

While some of the information may be carried by nerves, I am pretty sure that
chemical signals, such as adrenalin, play an important role in raising heat
rate.  Heart transplant patients do not have their new hearts nerves connected,
and rely solely on chemical signals to change heartbeat in response to stress.


        --Jeremy Grodberg

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