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.
Much like in sword swallowing, this can take a lot of practice. The sneeze reflex is one of your body's defense mechanisms against bacteria and viruses-- when you sneeze, you forcibly expel particles that could make you sick.In other words, a human blockhead ignores one of the tools the body uses to prevent illness.neezing is a largely reflexive act that usually occurs when something irritates your nasal passageways. As with all reflexes, sneezing involves a reflex arc consisting of a receptor, a sensory nerve, an integration center, a motor nerve and an effector. Here's what happens: