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]

Common carotid artery
The common carotid artery arises directly from the aorta on the left and as a branch of the brachiocephalic trunk on the right.
Blausen 0170 CarotidArteries
The common carotid artery and its main branches
Precursoraortic arch 3
Sourceaortic arch, brachiocephalic artery
Branchesinternal carotid artery, external carotid artery
Veininternal jugular vein
Supplieshead and neck
LatinArteria carotis communis
Anatomical terminology


The common carotid arteries are present on the left and right sides of the body. These arteries originate from different arteries but follow symmetrical courses. The right common carotid originates in the neck from the brachiocephalic trunk; the left from the aortic arch in the thorax. These split into the external and internal carotid arteries at the upper border of the thyroid cartilage, at around the level of the fourth cervical vertebra.

The left common carotid artery can be thought of as having two parts: a thoracic (chest) part and a cervical (neck) part. The right common carotid originates in or close to the neck and contains only a small thoracic portion. There are studies in the bioengineering literature that have looked into characterizing the geometric structure of the common carotid artery from both qualitative and mathematical (quantitative) standpoints.[4]

The average diameters of the common carotids in adult males and females are 6.5 mm and 6.1 mm respectively.[5]

In the chest

Only the left common carotid artery has a substantial presence in the thorax. It originates directly from the aortic arch, and travels upward through the superior mediastinum to the level of the left sternoclavicular joint.

During the thoracic part of its course, the left common carotid artery is related to the following structures: In front, it is separated from the manubrium of the sternum by the sternohyoid and sternothyroid muscles, the anterior portions of the left pleura and lung, the left brachiocephalic vein, and the remains of the thymus; behind, it lies on the trachea, esophagus, left recurrent laryngeal nerve, and thoracic duct.

To 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.

In the neck

Arteries of the neck. The right common carotid artery – labeled Common caroti in the figure – divides into the right internal carotid artery and external carotid artery.

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 are separated from each other by a very narrow interval which contains the trachea; but at the upper part, the thyroid gland, the larynx and pharynx separate the two arteries.

The common carotid artery is contained in a sheath known as the carotid sheath, which is derived from the deep cervical fascia and encloses also the internal jugular vein and vagus nerve, the vein lying lateral to the artery, and the nerve between the artery and vein, on a plane posterior to both. On opening the sheath, each of these three structures is seen to have a separate fibrous cover.

At approximately the level of the fourth cervical vertebra, the common carotid artery splits ("bifurcates" in literature) into an internal carotid artery (ICA) and an external carotid artery (ECA). While both branches travel upward, the internal carotid takes a deeper (more internal) path, eventually travelling up into the skull to supply the brain. The external carotid artery travels more closely to the surface, and sends off numerous branches that supply the neck and face.

Superficial dissection of the right side of the neck, showing the carotid and subclavian arteries

At the lower part of the neck the common carotid artery is very deeply seated, being covered by the integument, superficial fascia, the platysma muscle, deep cervical fascia, the sternocleidomastoid muscle, the sternohyoid, sternothyroid, and the omohyoid; in the upper part of its course it is more superficial, being covered merely by the integument, the superficial fascia, the platysma, deep cervical fascia, and medial margin of the sternocleidomastoid.

When the sternocleidomastoid muscle is drawn backward, the artery is seen to be contained in a triangular space known as the carotid triangle. This space is bounded behind by the sternocleidomastoid, above by the stylohyoid and the posterior belly of the digastric muscle, and below by the superior belly of the omohyoid.

This part of the artery is crossed obliquely, from its medial to its lateral side, by the sternocleidomastoid branch of the superior thyroid artery; it is also crossed by the superior and middle thyroid veins (which end in the internal jugular vein); descending in front of its sheath is the descending branch of the hypoglossal nerve, this filament being joined by one or two branches from the cervical nerves, which cross the vessel obliquely.

Sometimes the descending branch of the hypoglossal nerve is contained within the sheath.

The superior thyroid vein crosses the artery near its termination, and the middle thyroid vein a little below the level of the cricoid cartilage; the anterior jugular vein crosses the artery just above the clavicle, but is separated from it by the sternohyoid and sternothyroid.

Behind, the artery is separated from the transverse processes of the cervical vertebrae by the longus colli and longus capitis muscles, the sympathetic trunk being interposed between it and the muscles. The inferior thyroid artery crosses behind the lower part of the vessel.

Medially, it is in relation with the esophagus, trachea, and thyroid gland (which overlaps it), the inferior thyroid artery and recurrent laryngeal nerve being interposed; higher up, with the larynx and pharynx. Lateral to the artery, inside the carotid sheath with the common carotid, are the internal jugular vein and vagus nerve.

At the lower part of the neck, on the right side of the body, the right recurrent laryngeal nerve crosses obliquely behind the artery; the right internal jugular vein diverges from the artery. On the left side, however, the left internal jugular vein approaches and often overlaps the lower part of the artery.

Behind the angle of bifurcation of the common carotid artery is a reddish-brown oval body known as the carotid body. It is similar in structure to the coccygeal body which is situated on the median sacral artery.

The relations of the cervical region of the common carotid artery may be discussed in two points:

  • Internal relations of organs present inside the carotid sheath
  • two external relations of carotid sheath

Collateral circulation

After ligature of the common carotid, the collateral circulation can be perfectly established, by the free communication which exists between the carotid arteries of opposite sides, both without and within the cranium, and by enlargement of the branches of the subclavian artery on the side corresponding to that on which the vessel has been tied.

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.



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

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

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

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.[6]

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, it increases with age and with long-term exposure to particulate air pollution. [7]



Magnetic Resonance Angiography

Ao Carotide Nle

Normal carotidal arteriography


Common carotid artery


Common carotid artery – right view


Brachial plexus and common carotid artery


Common carotid artery


Common carotid artery


Right and left common carotid arteries

See also


  1. ^ OED 2nd edition, 1989.
  2. ^ Entry "carotid" in Merriam-Webster Online Dictionary.
  3. ^ a b Ashrafian H (March 2007). "Anatomically specific clinical examination of the carotid arterial tree". Anatomical Science International. 82 (1): 16–23. doi:10.1111/j.1447-073X.2006.00152.x. PMID 17370446.
  4. ^ a b Manbachi A, Hoi Y, Wasserman BA, Lakatta EG, Steinman DA (December 2011). "On the shape of the common carotid artery with implications for blood velocity profiles". Physiological Measurement. 32 (12): 1885–97. doi:10.1088/0967-3334/32/12/001. PMC 3494738. PMID 22031538.
  5. ^ J. Krejza; M. Arkuszewski; S. Kasner; J. Weigele; A. Ustymowicz; R. Hurst; B. Cucchiara; S. Messe (April 2006). "Carotid Artery Diameter in Men and Women and the Relation to Body and Neck Size". Stroke. 37 (4): 1103–1105. doi:10.1161/01.STR.0000206440.48756.f7. PMID 16497983.
  6. ^ Deakin CD, Low JL (September 2000). "Accuracy of the advanced trauma life support guidelines for predicting systolic blood pressure using carotid, femoral, and radial pulses: observational study". BMJ. 321 (7262): 673–4. doi:10.1136/bmj.321.7262.673. PMC 27481. PMID 10987771.
  7. ^ Provost, E; Madhloum, N; Int Panis, L; De Boever, P; Nawrot, T (2015). "Carotid Intima-Media Thickness, a Marker of Subclinical Atherosclerosis, and Particulate Air Pollution Exposure: the Meta-Analytical Evidence". PLOS ONE. 10 (5): e0127014. doi:10.1371/journal.pone.0127014. PMC 4430520. PMID 25970426.

External links


The aorta ( ay-OR-tə) is the main artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

Aortic arch

The aortic arch, arch of the aorta, or transverse aortic arch (English: ) is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea.

Brachiocephalic artery

The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an artery of the mediastinum that supplies blood to the right arm and the head and neck.

It is the first branch of the aortic arch, and soon after it emerges, the brachiocephalic artery divides into the right common carotid artery and the right subclavian artery.

There is no brachiocephalic artery for the left side of the body. The left common carotid, and the left subclavian artery, come directly off the aortic arch. However, there are two brachiocephalic veins.

Branch of glossopharyngeal nerve to carotid sinus

The branch of glossopharyngeal nerve to the carotid sinus (Hering's nerve) is a small nerve in the neck, that innervates the carotid sinus and the carotid body.

It is a branch of the glossopharyngeal nerve that runs downwards, anterior to the internal carotid artery. It communicates with the vagus nerve and sympathetic trunk and then divides in the angle of the bifurcation of the common carotid artery to innervate the carotid body and carotid sinus. It carries impulses from the baroreceptors in the carotid sinus to the vasomotor center in the brainstem (to help maintain a more consistent blood pressure) and from chemoreceptors in the carotid body (mainly monitoring blood gas PaO2 and PaCO2 levels). Hering's nerve responds to both increases and decreases in blood pressure while the baroreceptors in the aortic arch respond only to increases in blood pressure.

Cardiac nerve

The cardiac nerves are autonomic nerves which supply the heart. They include:

Superior cardiac nerve (nervus cardiacus cervicalis superior)

Middle cardiac nerve (nervus cardiacus cervicalis medius)

Inferior cardiac nerve (nervus cardiacus inferior)The nerves go down to the root of the neck with these following association:

Posterior: "prevertebral fascia overlying anterolateral surface of vertebral bodies"

Superior: "common carotid artery"

Inferior: "subclavian artery"

Laterally: "sympathetic trunk"

Carotid artery

Carotid artery may refer to:

Common carotid artery, often "carotids" or "carotid", an artery on each side of the neck which divides into the external carotid artery and internal carotid artery

External carotid artery, an artery on each side of the head and neck supplying blood to the face, scalp, skull, neck and meninges

Internal carotid artery, an artery on each side of the head and neck supplying blood to the brain

Carotid artery stenosis

Carotid artery stenosis is a narrowing or constriction of any part of the carotid arteries, usually caused by atherosclerosis.

Carotid endarterectomy

Carotid endarterectomy (CEA) is a surgical procedure performed by vascular surgeons used to reduce the risk of stroke by correcting stenosis (narrowing) in the common carotid artery or internal carotid artery. Endarterectomy is the removal of material on the inside (end(o)-) of an artery.

Atherosclerosis causes plaque to form within the carotid artery walls, usually at the fork where the common carotid artery divides into the internal and external carotid artery. The plaque build up can narrow or constrict the artery lumen, a condition called stenosis. Rupture of the plaque can cause the formation of a blood clot in the artery. A piece of the formed blood clot often breaks off and travels (embolizes) up through the internal carotid artery into the brain, where it blocks circulation, and can cause death of the brain tissue, a condition referred to as ischemic stroke.

Sometimes the stenosis causes temporary symptoms first, known as TIAs, where temporary ischemia occurs in the brain, spinal cord, or retina without causing an infarction. Symptomatic stenosis has a high risk of stroke within the next 2 days. National Institute for Health and Clinical Excellence (NICE) guidelines recommend that patients with moderate to severe (50–99% blockage) stenosis, and symptoms, should have "urgent" endarterectomy within 2 weeks.When the plaque does not cause symptoms, patients are still at higher risk of stroke than the general population, but not as high as patients with symptomatic stenosis. The incidence of stroke, including fatal stroke, is 1–2% per year. The surgical mortality of endarterectomy ranges from 1–2% to as much as 10%. Two large randomized clinical trials have demonstrated that carotid surgery done with a 30-day stroke and death risk of 3% or less will benefit asymptomatic patients with ≥60% stenosis who are expected to live at least 5 years after surgery. Surgeons are divided over whether asymptomatic patients should be treated with medication alone or should have surgery.In endarterectomy, the surgeon opens the artery and removes the plaque. The plaque forms and enlarges in the inner layer of the artery, or endothelium, hence the name of the procedure which simply means removal of the endothelium of the artery. A newer procedure, endovascular angioplasty and stenting, threads a catheter up from the groin, around the aortic arch, and up the carotid artery. The catheter uses a balloon to expand the artery, and inserts a stent to hold the artery open. In several clinical trials, the 30-day incidence of heart attack, stroke, or death was significantly higher with stenting than with endarterectomy (9.6% vs. 3.9%).The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) funded by the National Institutes of Health (NIH) reported that the results of stents and endarterectomy were comparable. However, the European International Carotid Stenting Study (ICSS) found that stents had almost double the rate of complications.

External carotid artery

The external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it splits into the external and internal carotid artery. It supplies blood to the face and neck.

Internal jugular vein

The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck.

The vein runs in the carotid sheath with the common carotid artery and vagus nerve.

List of arteries of the human body

This is a list of arteries of the human body.

The aorta

The arteries of the head and neck

The common carotid artery

The external carotid artery

The triangles of the neck

The internal carotid artery

The arteries of the brain

The arteries of the upper extremity

The subclavian artery

The axilla

The axillary artery

The brachial artery

The radial artery

The ulnar artery

The arteries of the trunk

The descending aorta

The thoracic aorta

The abdominal aorta

The common iliac arteries

The hypogastric artery

The external iliac artery

The arteries of the lower extremity

The femoral artery

The popliteal fossa

The popliteal artery

The anterior tibial artery

The arteria dorsalis pedis

The posterior tibial artery

Middle cardiac nerve

The middle cardiac nerve (great cardiac nerve), the largest of the three cardiac nerves, arises from the middle cervical ganglion, or from the trunk between the middle and inferior ganglia.On the right side it descends behind the common carotid artery, and at the root of the neck runs either in front of or behind the subclavian artery; it then descends on the trachea, receives a few filaments from the recurrent nerve, and joins the right half of the deep part of the cardiac plexus.

In the neck, it communicates with the superior cardiac and recurrent nerves.

On the left side, the middle cardiac nerve enters the chest between the left carotid and subclavian arteries, and joins the left half of the deep part of the cardiac plexus.

Muscular triangle

The inferior carotid triangle (or muscular triangle), is bounded, in front, by the median line of the neck from the hyoid bone to the sternum; behind, by the anterior margin of the sternocleidomastoid; above, by the superior belly of the omohyoid.

It is covered by the integument, superficial fascia, platysma, and deep fascia, ramifying in which are some of the branches of the supraclavicular nerves.

Beneath these superficial structures are the sternohyoid and sternothyroid, which, together with the anterior margin of the sternocleidomastoid, conceal the lower part of the common carotid artery.

This vessel is enclosed within its sheath, together with the internal jugular vein and vagus nerve; the vein lies lateral to the artery on the right side of the neck, but overlaps it below on the left side; the nerve lies between the artery and vein, on a plane posterior to both.

In front of the sheath are a few descending filaments from the ansa cervicalis; behind the sheath are the inferior thyroid artery, the recurrent nerve, and the sympathetic trunk; and on its medial side, the esophagus, the trachea, the thyroid gland, and the lower part of the larynx.

By cutting into the upper part of this space, and slightly displacing the sternocleidomastoid, the common carotid artery may be tied below the omohyoid.

Precerebral artery

A precerebral artery is an artery leading to the cerebrum, but not in the cerebrum.

In the human they are:

Vertebral artery

Basilar artery

Common carotid artery

Internal carotid artery

Richard Zedník

Richard Zedník (born January 6, 1976) is a Slovak former professional ice hockey winger. He had a 15-year career in the National Hockey League (NHL), playing for the Washington Capitals, Montreal Canadiens, New York Islanders and Florida Panthers.

Zedník is known for sustaining and surviving a life-threatening injury during a February 2008 NHL game when the skate of his teammate Olli Jokinen accidentally sliced his common carotid artery.

Stellate ganglion

The stellate ganglion (or cervicothoracic ganglion) is a sympathetic ganglion formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion, which exists in 80% of cases. Sometimes the second and the third thoracic ganglia are included in this fusion. Stellate ganglion is relatively big (10-12 x 8-20 mm) compared to much smaller thoracic, lumbar and sacral ganglia and it is polygonal in shape (lat. stellatum meaning star-shaped). Stellate ganglion is located at the level of C7, anterior to the transverse process of C7 and the neck of the first rib, superior to the cervical pleura and just below the subclavian artery. It is superiorly covered by the prevertebral lamina of the cervical fascia and anteriorly in relation with common carotid artery, subclavian artery and the beginning of vertebral artery which sometimes leaves a groove at the apex of this ganglion (this groove can sometimes even separate the stellate ganglion into so called vertebral ganglion).

Relations of the apex of the stellate ganglion:

• covered by the endothoracic fascia and parietal pleura

• right stellate ganglion is in relation with right brachiocephalic vein anteriorly

• right stellate ganglion is in relation with sternal part of subclavian artery anteriorly

• laterally: first intercostal artery

• medially: longus colli muscle

Subclavian artery

In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplies blood to the right arm, with some branches supplying the head and thorax. On the left side of the body, the subclavian comes directly off the aortic arch, while on the right side it arises from the relatively short brachiocephalic artery when it bifurcates into the subclavian and the right common carotid artery.

The usual branches of the subclavian on both sides of the body are the vertebral artery, the internal thoracic artery, the thyrocervical trunk, the costocervical trunk and the dorsal scapular artery, which may branch off the transverse cervical artery which is a branch of the thyrocervical trunk. The subclavian becomes the axillary artery at the lateral border of the first rib.

Superior cardiac nerve

The superior cardiac nerve arises by two or more branches from the superior cervical ganglion, and occasionally receives a filament from the trunk between the first and second cervical ganglia. It runs down the neck behind the common carotid artery, and in front of the Longus colli muscle; and crosses in front of the inferior thyroid artery, and recurrent nerve. The course of the nerves on the two sides then differs.

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