[sci.bio] A Sneeze

news@santra.UUCP (news) (04/12/88)

>>In article <6753@ames.arpa> howard@pioneer.UUCP (Lauri Howard) writes:
>>I would be interested to
>>hear any suggestions why sudden exposure makes you sneeze in the first place.

>I was told it's genetic.

I find it a little bit hard to believe that it's genetic. That would imply
that seeing the sun is the only stimulus, which in turn starts the "sneezing-
mechanism". I relate inhereted behaviour to cases (for example) like beeing
afraid or cautious when confronting a snake, even if you have never seen one
in your life and you're too young to have learned that snakes are supposed to
be dangerous.
	Of course, I could be wrong ! Then the reaction beeing inhereted 
would be a neat explanation. If it is genetic another interesting question
arises : what possibly could be the function of this reaction ?

PS. "Lauri" sounds like a Finnish name to me - perhaps you, your parents or
your grandparents origin from Finland ? Do you understand any Finnish ?
(answer via e-mail, please)

briscoe-duke@CS.YALE.EDU (Duke Briscoe) (04/13/88)

The only times I've noticed the sneezing reaction is when I am looking up into
a bright sky, usually towards the sun.  It is pretty clear to me that there is
a genetic basis to this reaction, and that its purpose is to keep you from
looking at light so bright that it could damage your retina.  The bit about the
sneezing occurring upon sudden exposure to bright light would be related to the
fact that your pupil has not yet adjusted to the intensity change.

ccjoan@ucdavis.ucdavis.edu (Joan Gargano) (04/15/88)

In article <27047@yale-celray.yale.UUCP> briscoe-duke@CS.YALE.EDU (Duke Briscoe) writes:
>The only times I've noticed the sneezing reaction is when I am looking up into
>a bright sky, usually towards the sun.  It is pretty clear to me that there is
>a genetic basis to this reaction, and that its purpose is to keep you from
>looking at light so bright that it could damage your retina.  The bit about the
>sneezing occurring upon sudden exposure to bright light would be related to the
>fact that your pupil has not yet adjusted to the intensity change.

This actually has to do with the stimulation of a nerve in the eye by
the bright light.  This nerve also passes through the nasal area.  The
stimulation then causes you to sneeze.

-- 
Joan Gargano * Univ. of Calif., Davis, Computing Services * (916) 752-2591
Internet   jcgargano@ucdavis.ucdavis.edu
BITNET     jcgargano@ucdavis
UUCP       {ucbvax, lll-crg, sdcsvax}!ucdavis!jcgargano

callele@bnr-di.UUCP (David Callele) (04/15/88)

I have been told that the reason I (almost invariably) sneeze when I go out
into the sun is because I have descended from a frog. Actually, the eye
muscles that control the iris spasm and put pressure on the top of the
sinus cavities. This stimulates the sneeze response. I had it explained
to me as analogous to the way a frog swallows - you ever notice how their
eyes sink into their skulls to help push the food down? I was told that this
is a similar mechanism.

Who knows - maybe I was lied to?