Cough is an airway defensive reflex consisting of an inspiratory phase followed by a forced expiratory effort initially against a closed glottis, followed by active glottal opening and rapid expiratory flow. The expiration reflex (ER) differentiates from cough for the lack of a preparatory inspiration. The reflexes subserve different functions: cough will clear the lower airways from debris and mucus, while the expiration reflex will prevent aspiration. Clinically, a cough epoch is a sequence of motor acts resulting from a combination of true coughs and ERs that need to be accurately identified and measured for adequate quantitative description.
KeywordsCough Expiration reflex
The author is grateful to Prof. John Widdicombe who has inspired many of the concepts presented in this article.
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