as peripheral chemoreceptors are stimulated by hypoxia?
Chemosensitive cells are located in the carotid bodies and the aortic body. These cells respond to changes in pH status and blood O2 tension. At an arterial partial O2 pressure (PaO2) of less than 50 mm Hg or in conditions of acidosis, the chemoreceptors send their impulses along the sinus nerve of Hering (a branch of the glossopharyngeal nerve) and the tenth cranial nerve to the chemosensitive area of the medulla. This area responds by stimulating the respiratory centers and thereby increasing ventilatory drive. In addition, activation of the parasympathetic system ensues and leads to a reduction in heart rate and myocardial contractility.