The common carotid artery arises from the brachiocephalic artery on the right at the level of the sternoclavicular joint and directly from the arch of the aorta on the left (at the level of T3).
Both arteries pass superiorly within the carotid sheath giving no branches within the neck (although variations have been noted with any of the branches of the external carotid artery actually arising from the common carotid artery). The common carotid artery usually divides into internal and external carotids at the level of C4.
The artery is palpable against the anterior tubercle of the transverse process of C6 (known as Chassaignac’s tubercle). It is here that they artery can be massaged in a hope to slow an abnormally fast heart rate.
During its course the artery lies medial to the internal jugular vein and it is this close proximity that puts the artery at risk during central line insertion.
Both omohyoid and the ansa cervicalis lie anterior while the recurrent laryngeal nerve crosses posterior to the artery.
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