Sneezing (Q46972)

Sneezing is one of the most fundamental airway reflexes, which is characterised by a deep preparatory inspiration followed by an abrupt increase in subglottic pressure reflecting a forceful, active expiration rather similar to coughing. Chemical or physical stimuli to the nasal mucosa may initiate potent respiratory and cardiovascular reflexes via stimulation of trigeminal nerves. Mild stimuli result in sneezing and nasal hypersecretion. These reflex responses protect the lower airways from inhalation of physical and chemical irritants.