Carotid canal the cranium, as well as the carotid plexus of nerves traveling on the artery. Sympathetics to the head from the superior cervical ganglion also pass through the carotid canal. They have several motor functions: raise the eyelid (superior tarsal muscle), dilate pupil, innervate sweat glands of face and scalp and constricts blood vessels in the head. Carotid canal The carotid canal is the passageway in the temporal bone through which the internal carotid artery enters the middle cranial fossa from the neck. The canal starts on the inferior surface of the temporal bone at the external opening of the carotid
Carotid sinus regulation of the body in sync to external conditions). The carotid sinus contains numerous baroreceptors which function as a "sampling area" for many homeostatic mechanisms for maintaining blood pressure. The carotid sinus baroreceptors are innervated by the sinus nerve of Hering, which is a branch of cranial nerve IX (glossopharyngeal nerve). The glossopharyngeal nerve synapses in the nucleus tractus solitarii (NTS) located in the medulla oblongata of the brainstem. The NTS indirectly modulates the activity of sympathetic and parasympathetic (vagal) neurons in the medulla and pons through the hypothalamus. These neurons then regulate the autonomic control of the heart and