Because of the chemical nature of impulse and the axon-dendrite structure. Because of the chemical nature of impulse and the axon-dendrite structure. http://www.biologymad.com/nervoussystem/nerveimpulses.htm (Best technical explanation and excellent graphics and animations)
Newborns may sneeze, and this is typically attributed to the irritation of their nasal passages. The most common irritants, explains Dr. Iannelli, are smoke (and simply smoking outside is not enough), animal dander from pets in the house, dust mites, and mold.
Two major viral infectious agents that cause cat sneezing are feline calicivirus and feline herpesvirus. Both present with similar symptoms, sneezing accompanied by discharge from the eyes and nose. The feline calicivirus may also bring with it fever and ulcerous lesions in a catâs mouth or on a catâs tongue.