Common carotid artery its right side below is the brachiocephalic trunk, and above, the trachea, the inferior thyroid veins, and the remains of the thymus; to its left side are the left vagus and phrenic nerves, left pleura, and lung. The left subclavian artery is posterior and slightly lateral to it. The cervical portions of the common carotids resemble each other so closely that one description will apply to both. Each vessel passes obliquely upward, from behind the sternoclavicular joint to the level of the upper border of the thyroid cartilage, where it divides. At the lower neck the two common carotid arteries
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