Branch of glossopharyngeal nerve to carotid sinus Branch of glossopharyngeal nerve to carotid sinus The branch of glossopharyngeal nerve to the carotid sinus (Hering's nerve) is a small nerve in the neck, that innervates the carotid sinus and the carotid body. It is a branch of the glossopharyngeal nerve that runs downwards, anterior to the internal carotid artery. It communicates with the vagus nerve and sympathetic trunk and then divides in the angle of the bifurcation of the common carotid artery to innervate the carotid body and carotid sinus. It carries impulses from the baroreceptors in the carotid sinus to the vasomotor center in the brainstem (to
Carotid body central chemoreceptors in the medulla oblongata that are primarily sensitive to changes in pH and P (a decrease in pH and an increase in P). The carotid body chemoreceptors are also sensitive to pH and P, but only secondarily. More specifically, the sensitivity of carotid body chemoreceptors to decreased P is greater when pH is decreased and P is increased. The output of the carotid bodies is low at an oxygen partial pressure above about 100mmHg (13,3 kPa) (at normal physiological pH), but below 60mmHg the activity of the type I (glomus) cells increases rapidly due to a decrease in