Common carotid artery

In anatomy, the left and right common carotid arteries (carotids) (English: /kəˈrɒtɪd/^[1]^[2]) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.^[3]^[4]

"Carotid" and "carotids" redirect here. For the parotids (salivary glands), see Parotid gland.

Common carotid artery

Aortic arch 3

Aortic arch, brachiocephalic artery

Internal carotid artery, external carotid artery

Internal jugular vein

Head and neck

arteria carotis communis

Internal relations of organs present inside the carotid sheath

two external relations of carotid sheath

Collateral circulation[edit]

The chief communications outside the skull take place between the superior and inferior thyroid arteries, and the deep cervical artery and the descending branch of the occipital artery; the vertebral artery takes the place of the internal carotid artery within the cranium.

Variation[edit]

Origin[edit]

The right common carotid may rise above the level of the upper border of the sternoclavicular joint; this variation occurs in about 12 percent of cases.

In other cases, the artery on the right side may arise as a separate branch from the arch of the aorta, or in conjunction with the left carotid.

The left common carotid varies in its origin more than the right.

In the majority of abnormal cases it arises with the brachiocephalic trunk; if that artery is absent, the two carotids arise usually by a single trunk.

It is rarely joined with the left subclavian artery, except in cases of transposition of the aortic arch.

Point of division[edit]

In the majority of abnormal cases, the bifurcation occurs higher than usual, the artery dividing opposite or even above the hyoid bone; more rarely, it occurs below, opposite the middle of the larynx, or the lower border of the cricoid cartilage. In at least one reported case, the artery was only 4 cm in length and divided at the root of the neck.

Very rarely, the common carotid artery ascends in the neck without any subdivision, either the external or the internal carotid being absent; and in a few cases the common carotid has itself been found to be absent, the external and internal carotids arising directly from the arch of the aorta.

This peculiarity existed on both sides in some instances, on one side in others.

Occasional branches[edit]

The common carotid usually gives off no branch previous to its bifurcation, but it occasionally gives origin to the superior thyroid artery or its laryngeal branch, the ascending pharyngeal artery, the inferior thyroid artery, or, more rarely, the vertebral artery.

Clinical significance[edit]

The common carotid artery is often used in measuring the pulse,^[3] especially in patients who are in shock and who lack a detectable pulse in the more peripheral arteries of the body. The pulse is taken by palpating the artery just deep to the anterior border of the sternocleidomastoid muscle at the level of the superior border of the thyroid cartilage.

Presence of a carotid pulse has been estimated to indicate a systolic blood pressure of more than 40 mmHg, as given by the 50% percentile.^[7]

Carotidynia is a syndrome marked by soreness of the carotid artery near the bifurcation.

Carotid stenosis may occur in patients with atherosclerosis.

The intima-media thickness of the carotid artery wall is a marker of subclinical atherosclerosis and it increases with age and with long-term exposure to particulate air pollution. ^[8]