What Exactly Happens When We Sneeze?


Sneezing is a defensive mechanism that the body does in order to rid the respiratory tract from irritant materials. The explosive exhalation that occurs during a sneeze serves to clear the upper airway. Our nose does a fine job in protecting us, as it filters dust and large airborne particles, preventing them from entering the lungs. In addition, it adjusts air to body temperature before it enters the lungs.




Sneezing helps dislodge accumulated particles in the nose, preventing congestion of this most important of filtering apparatuses. Most of the compressed air from a sneeze escapes from the mouth but a sizeable percentage leaves through the nose travelling at a speed of up to one hundred miles per hour. Sneezing occurs as a result of reflex reaction which is triggered by the sensory nerve endings in the lining of the nasal cavity which are in turn triggered by inhalation of fine particles in the air such as dust, hair, smoke or aerosol sprays. This gives rise to the ticklish sensation which you often feel prior to the relieving sneeze.


At the exact same time these sensory nerve endings transmit nerve impulses to the respiratory centre of the brain. The brain relays these nerve impulses to the respiratory muscles, triggering them to contract thus causing the body to inhale, close the airways, squeeze the chest and then exhale rapidly and with gusto expelling the excess secretion along with trapped particles through the nose and mouth. The voluntary part of the brain is not involved in any of this process which is why we have absolutely no control over sneezing.




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What Exactly Happens When We Sneeze?