Sneezing is caused by irritation to the mucous membranes of the nose or
Like burping and farting, sneezing is
simply one of those necessities that can take one by surprise in a variety of
awkward situations -- at rest or at work, or even in the throes of passion.
It can be very bothersome, but is generally not a sign of a serious
To most modern sneezers, it seems
obvious that the primary function of the sneeze is to expel offending particles
from the upper resperatory system, a cleansing mechanism. Likewise, ancient
sneezers considered that the true function was to drive out evil spirits which
had invaded the body -- more or less the same thing.
The sneeze occurs when the nerve endings of the mucous membrane of the nose are
irritated. This irritation then stimulates your trigeminal nerve, sending
impulses through the trigeminal ganglion to a set of neurons located in the
brainstem that collectively are termed the "sneezing center". These neurons send
new impulses along the facial nerve back to the nasal passages and the face,
causing the nasal passages to secrete fluid and become congested.
The eyes may
also tear. At the same time, the "sneezing center" also sends impulses to your
respiratory muscles via the spinal cord. It is these impulses that create the
deep inbreath and forceful outbreath, or the paroxysm of the sneeze itself. Meanwhile, the impulses travelling through the facial nerve happen to stimulate
nerves which govern the reflex response we call the the blink. So, essentially,
one message is sent, but two listeners receive it, and act on it. Hence the