AP BIOLOGY

Detailed explanation-1: -Like cough (Ch. 2), sneezing is a complex reflex process characterized by a powerful expiratory effort preceded by one or several deep inspirations. Together with cough, it is one of the most important defensive reflexes of the respiratory tract (Ch. 1.21), but it has been studied incomparably less than cough.

Detailed explanation-2: -Although sneezing is a protective reflex response, little else is known about it. A sneeze (or sternutation) is expulsion of air from the lungs through the nose and mouth, most commonly caused by the irritation of the nasal mucosa.

Detailed explanation-3: -Coughing is an important defensive reflex that occurs through the stimulation of a complex reflex arc. It accounts for a significant number of consultations both at the level of general practitioner and of respiratory specialists.

Detailed explanation-4: -The cough reflex is initiated by activation of bronchopulmonary C-fibers and the mechanically-sensitive cough receptors. Stimuli initiating cough through activation of one or both of these vagal afferent nerves include capsaicin, acid, bradykinin, cinnamaldehyde, cigarette smoke and non-isotonic aerosols.