A single sneeze requires the coordinated effort of more than 20 different muscles.

The sneezing reflex, scientifically known as sternutation, is triggered when the trigeminal nerve detects irritants in the nasal mucosa. This signal travels to the sneeze center located in the medulla oblongata of the brainstem. Once activated, the brain coordinates a massive physical response involving the intercostal muscles, the diaphragm, and even the muscles at the back of the throat.During the initial phase, you take a deep breath which builds up pressure in the lungs. The vocal cords then close tightly while the abdominal and chest muscles contract violently. This creates a high-pressure chamber that is suddenly released when the throat muscles relax and the vocal cords open. This explosive release can propel droplets at speeds reaching 100 miles per hour.Research published in the Journal of Applied Physiology highlights that more than 20 muscle groups are involved, including those that control the eyelids. This is why most people instinctively close their eyes during a sneeze. The entire process is a vital part of the body's immune defense, clearing out pathogens and foreign particles that could cause infection.Interestingly, the 'photic sneeze reflex' affects about 18 to 35 percent of the population. This condition causes people to sneeze when suddenly exposed to bright light, such as sunlight. This phenomenon suggests that the brain's wiring for the sneeze reflex is closely linked to the optic nerve, demonstrating the intricate complexity of our cranial nerve pathways.