Yawning occurs– A)due to excess concentration of CO2 in blood B)due to excess concentration of CO2 in lungs C)due to excess concentration of O2 in lungs D)None of these
Option A) yawning occurs when one’s blood contains increased amounts of carbon dioxide and therefore becomes in need of the influx of oxygen (or expulsion of carbon dioxide) that a yawn can provide. A yawn is a reflex of simultaneous inhalation of air and stretching of the eardrums, followed by exhalation of breath. Pandiculation is the act of yawning and stretching simultaneously
