Alteration in Nasal Cycle Rhythm as an Index of the Diseased Condition

Breathing is the vital function based on the conductance of air through a system of branch- ing tubes that taper off and eventually connect to the alveoli. Nose act as an interface between atmospheric air and lower respiratory system, constitute the moist respiratory epithelium, which performs various vital physiological functions like filtering the inspired air, warming, and humidifying. Several anatomical and physiological factors are responsi - ble for the passage of airflow in two nostrils, which are asymmetric in nature. The inequal ity airflow passage in both the nostrils exists for a specific duration. This phenomenon of altering asymmetrical airflow from one nasal passage to the other is called ‘nasal cycle’. For every regular interval of time period, the swap of predominant nasal airflow between two nostrils determines the nasal patency. This cycle is controlled by the central regulator located at hypothalamus by coordinating the autonomic nervous system that comprises sympathetic and parasympathetic nerves that clog the nasal mucosa. The nostril decongest when the sympathetic nerves in one nostril become active. In this biorhythm, if the sym - pathetic nerves of one nostril drop, immediately the parasympathetic nerves take over, so that the other nostril congests. It is unclear why these cycles exist but the total nasal airway resistance is almost unchanged. There are a range of activities and reflexes, which can affect the nasal airway. This biorhythm is categorized under ultradian cycle since the mean dura - tion of nasal cycle is about two and a half hours. In this study, it observed changes in nasal airflow duration, pattern, and rhythm that correspond to various disease states in human.