The carotid arteries (also called the common carotid arteries) are a pair of arteries which supply oxygenated blood to the neck, head and brain.
While both carotid arteries travel virtually the same path and fulfil the same functions, they do differ in their origin points. While the right carotid artery branches off from the brachiocephalic artery at the base of the neck, the left carotid artery originates in the chest at the thoracic section of the aorta. It travels up past the sternum, the trachea and the esophagus to reach the neck, at which point it mirrors the path of the right carotid arteries. Both arteries move up the neck, separated only by the trachea at first, before being pushed further apart to opposite sides of the neck by the larynx and the pharynx.
Protected by a sheath which also contains the jugular vein, both carotid arteries divide once they reach the fourth vertebra of the neck, separating into external and internal carotid arteries. The external carotid artery travels close to the surface of the neck and branches many times to supply the face and neck, while the internal carotid artery follows a deeper path along the skull, where it supplies blood to the brain. There can be some slight variations in origin points and division points between individuals, but the carotid arteries always serve the same purpose.
A thick and easily accessible artery, the carotid artery is often used to measure the pulse and to assess cardiac function when scanning technology is unavailable. It is also one of the primary sites used by medical practitioners when administering a hypospray injection.