When you sneeze, sensory signals from irritated nasal passages travel to the "sneezing center" located in the lateral medulla of your brain. This area of the brainstem acts as a command center for the sneeze reflex. Once these signals reach a critical threshold, the reflex is triggered. This triggers a complex sequence of events leading to the forceful expulsion of air from your lungs.
The Neurological Process of Sneezing
The process is more than simply a reflex arc; it involves intricate brain activity:
- Sensory Input: Irritants like dust, pollen, or even bright light stimulate nerve endings in the nasal passages.
- Signal Transmission: These sensory signals are transmitted along cranial nerves to the brainstem.
- Sneeze Center Activation: The brainstem's "sneezing center" integrates this information and initiates the motor response.
- Motor Output: Signals are sent to muscles involved in breathing, facial muscles, and the diaphragm, coordinating the forceful expulsion of air.
The precise neural mechanisms underlying the sneeze reflex are still being researched, as evidenced by studies exploring the role of specific peptides in activating the sneeze response in mouse brains, as noted in the WashU Medicine article.
While the common belief that your heart stops when you sneeze is a myth, the act of sneezing does cause transient changes in your body's physiology. For example, studies suggest that sneezing temporarily increases cerebral blood flow.
It's important to note that the ability to sneeze is involuntary; we cannot consciously choose to initiate a sneeze. This is in contrast to coughing, which exhibits more nuanced control, according to Nature magazine's article on the brain's differentiation of coughs and sneezes.
Sources indicate that the intensity and frequency of sneezing depend on the nature and severity of the irritant triggering it. The brain's processing of these irritants, ultimately determines the strength of the sneeze response.
