Yskänrefleksiä

Yskänrefleksiä, known in English as the cough reflex, is a vital protective mechanism in the respiratory system. It is a complex, involuntary reflex that helps clear the airways of irritants, foreign particles, mucus, and pathogens. This reflex is crucial for preventing aspiration, which is the entry of foreign material into the lungs, and for maintaining lung health.

The cough reflex is initiated when sensory receptors, called cough receptors, located in the lining of the respiratory tract are stimulated. These receptors are found in the pharynx, larynx, trachea, bronchi, and even the bronchioles. Upon stimulation, they send signals via the vagus nerve to the brainstem, specifically to the cough center in the medulla oblongata.

In response, the cough center orchestrates a series of coordinated muscular actions. First, there is a deep inhalation, followed by the forceful closure of the glottis (the opening between the vocal cords). This is followed by a rapid and forceful exhalation against the closed glottis, leading to a significant increase in intrathoracic pressure. When the glottis suddenly opens, the trapped air is expelled at high velocity, carrying with it any irritants or excess secretions from the airways.

Several factors can trigger the cough reflex, including dust, smoke, allergens, infections, and irritants introduced into the airway. Conditions like bronchitis, pneumonia, asthma, and postnasal drip can also lead to persistent coughing. While generally beneficial, a chronic or severe cough can be debilitating and may indicate an underlying medical issue requiring attention.