The intranasal trigeminal system: roles in rhinitis (allergic and non-allergic).

The aim of this paper is to review intranasal trigeminal system and associated reflexes. The literature survey was performed on PubMed, ProQuest Central database of Kirikkale University and Google Scholar. The intranasal trigeminal system and associated reflexes play an important role in humans in both health and disease, including in rhinitis of non-allergic and mixed type. The intranasal trigeminal nerve provides sensory perception to the lining of the nose, supplying information on how patent the nasal airway is and responding to various chemical signals. The reflexes known to exist within the intranasal trigeminal system are nasobronchial reflex, trigemino-cardiac reflex, nasogastric reflex, and nasal cycle. The intranasal trigeminal system and its reflexes play a vital role in normal human physiology. Alterations in how this system operates may underlie multiple forms of rhinitis and more research is needed to fully understand the mechanisms involved.