Some factors affecting the maintenance of upper airway patency in man

This paper describes some of the anatomical and physiological factors affecting the maintenance of upper airway patency in man. Such factors have particular relevance to the mechanisms responsible for maintaining upper airway patency during sleep, and the failure of these mechanisms in patients with the clinical syndrome of obstructive sleep apnoea: a condition in which repeated episodes of sleep-related inspiratory oropharyngeal collapse lead to recurrent hypoxaemia, disturbed sleep patterns and other clinical sequelae. The relationships between upper airway geometry, negative intrapharyngeal pressure, activation of upper airway dilator muscles, and sleep state are important factors affecting the maintenance of upper airway patency. The aim of this paper is not to consider such factors in isolation but to consider their interaction in affecting the adequacy of the upper airspace as a conduit for airflow.