Cough reflex

The cough reflex is an involuntary ( polysynaptic ) protective reflex that runs through several switching stations , which frees the airways from foreign bodies, accumulations of secretions and other harmful stimuli ( cough stimuli ).

The receptors for coughing stimuli are located in the mucous membrane of the upper airways, especially in the larynx , the windpipe and the larger bronchi . They are also found in smaller numbers in the small bronchi and the pulmonary membrane . The afferent leg of the reflex runs via viscerosensitive nerve fibers of the vagus nerve ( cranial nerve X) into the "cough center" in the respiratory center of the medulla oblongata . In the nucleus ambiguus , the motor core area of the vagus nerve and the glossopharyngeal nerve , the excitation is switched to the efferent thigh . Via the superior laryngeal nerve , activation of the cricothyroid muscle (one of the larynx muscles ) triggers a narrowing of the glottis and, in the best case, explosive exhalation transports the foreign body to the outside.

Centrally effective cough suppressants such as codeine inhibit the cough reflex at the level of circuitry in the brain stem .