Carotid sinus nerveThe carotid branch of the glossopharyngeal nerve is a small branch of the glossopharyngeal nerve (cranial nerve IX) that innervates the carotid sinus, and carotid body.AnatomyCourse and relationsIt runs downward anterior to the internal carotid artery. It communicates with the vagus nerve and sympathetic trunk before dividing in the angle of the bifurcation of the common carotid artery to innervate the carotid body, and carotid sinus.FunctionIt conveys information from the baroreceptors of the carotid sinus to the vasomotor center in the brainstem, and from chemoreceptors of the carotid body.