carotidi

Carotidi refers to the carotid arteries, the major vessels that supply the head and neck. In humans there are right and left common carotid arteries, which run upward in the neck within the carotid sheath alongside the internal jugular vein and the vagus nerve. The right common carotid typically originates from the brachiocephalic trunk, while the left arises directly from the aortic arch. Each artery ascends to about the level of the fourth cervical vertebra (C4) before dividing into its two terminal branches, the internal and external carotid arteries.

The internal carotid artery enters the skull through the carotid canal and largely supplies the brain, contributing to the cerebral circulation via the circle of Willis. It gives no branches in the neck. The external carotid artery supplies the face and neck through multiple branches, including the superior thyroid, lingual, facial, occipital, posterior auricular, maxillary, and superficial temporal arteries.

Near the bifurcation, the carotid arteries encompass two important sensors: the carotid sinus and the carotid body. The carotid sinus contains baroreceptors that help regulate blood pressure, sending signals primarily via the glossopharyngeal nerve (CN IX). The carotid body is a chemoreceptor that monitors blood oxygen, carbon dioxide, and pH, sending information mainly through CN IX and CN X.

Clinical relevance includes carotid artery disease (often due to atherosclerosis), which can lead to transient ischemic attacks or stroke, and carotid dissection or aneurysm in rare cases. Palpation of the carotid pulse is a common physical exam maneuver. Diagnostic imaging includes duplex ultrasonography, CT angiography, and MR angiography. Variants include carotid body tumors (paragangliomas) at the bifurcation.