Changes in the electrical activity of the respiratory muscles of cats during coughing

Summary

Acute experiments were carried out on cats. Coughing was induced mechanically by the application of a nylon thread to the mucosa of the nasopharynx and the laryngeal area or to the bifurcation of the trachea and bronchi Electrical activity of the inspiratory and expiratory muscles became much more intense during the cough. Inspiratory activity was predominant during a cough induced by mechanical stimulation of the nasopharynx or of the larynx. The reciprocal relationship between inspiration and expiration was disturbed. In this type of cough the electrical activity of the expiratory muscles was increased at a time when the intrapleural pressure failed to indicate active respiration. When the cough was caused by mechanical stimulation of the mucosa at the bifurcation of the bronchi action potentials of large amplitude and high frequency occurred in long groups of discharges, in which expiratory activity prevailed. Under such conditions the normal relationship between inspiration and expiration were maintained.