Internal carotid artery of the posterior communicating artery to the bifurcation of the internal carotid artery. The named branches of the communicating segment are: The internal carotid then divides to form the anterior cerebral artery and middle cerebral artery. The internal carotid artery can receive blood flow via an important collateral pathway supplying the brain, the cerebral arterial circle, which is more commonly known as the Circle of Willis. The following are the branches of the internal carotid artery, listed by segment: The sympathetic trunk forms a plexus of nerves around the artery known as the carotid plexus. The internal carotid nerve arises
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