The external carotid artery is a major

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...

of the head and neck. It arises from the

common carotid artery In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
internal carotid artery. External carotid artery supplies blood to the face and neck.

Structure

The external carotid artery begins at the upper border of

thyroid cartilage The thyroid cartilage is the largest of the nine cartilages that make up the ''laryngeal skeleton'', the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilage ...

, and curves, passing forward and upward, and then inclining backward to the space behind the neck of the

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

, where it divides into the

superficial temporal In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic arch ...

and

maxillary artery The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches of the external carotid artery ...

within the

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...

. It rapidly diminishes in size as it travels up the neck, owing to the number and large size of its branches. At its origin, this artery is closer to the skin and more medial than the internal carotid, and is situated within the

carotid triangle The carotid triangle (or superior carotid triangle) is a portion of the anterior triangle of the neck. Coverings and boundaries It is bounded: * Posteriorly by the anterior border of the Sternocleidomastoid; * Anteroinferiorly, by the superior bel ...

Development

In children, the external carotid artery is somewhat smaller than the

internal carotid The internal carotid artery (Latin: arteria carotis interna) is an artery in the neck which supplies the anterior circulation of the brain. In human anatomy, the internal and external carotids arise from the common carotid arteries, where these ...

; but in the adult, the two vessels are of nearly equal size.

Relations

At the origin, external carotid artery is more medial than internal carotid artery. When external carotid artery ascends the neck, it lies more lateral than internal carotid artery. The external carotid artery is covered by the skin, superficial fascia,

platysma muscle The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effect ...

, deep fascia, and anterior margin of the

sternocleidomastoid The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the access ...

; it is crossed by the

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated by ...

, by the lingual,

ranine The lingual veins begin on the dorsum, sides, and under surface of the tongue, and, passing backward along the course of the lingual artery, end in the internal jugular vein. The vena comitans of the hypoglossal nerve (ranine vein), a branch of co ...

common facial The facial vein usually unites with the anterior branch of the retromandibular vein to form the common facial vein, which crosses the external carotid artery and enters the internal jugular vein at a variable point below the hyoid bone. From near ...

, and

superior thyroid vein The superior thyroid vein begins in the substance and on the surface of the thyroid gland, by tributaries corresponding with the branches of the superior thyroid artery, and ends in the upper part of the internal jugular vein. It receives the supe ...

s; and by the

digastricus The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...

and stylohyoideus muscles; higher up it passes deeply into the substance of the

, where it lies deep to the

facial nerve The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of tas ...

and the junction of the temporal and internal maxillary veins. Medial to it are the hyoid bone, the wall of the

pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its struc ...

, the

superior laryngeal nerve The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and in its course receives a branch from the superior cervical ganglion of the sympathetic nervous system. The superi ...

, and a portion of the

. Posterior to it, near its origin, is the

; and higher up, it is separated from the

by the

styloglossus The styloglossus, the shortest and smallest of the three styloid muscles, arises from the anterior and lateral surfaces of the styloid process near its apex, and from the stylomandibular ligament. Passing inferiorly and anteriorly between the int ...

and

stylopharyngeus muscle The stylopharyngeus is a muscle in the head that stretches between the temporal styloid process and the pharynx. Structure The stylopharyngeus is a long, slender muscle, cylindrical above, flattened below. It arises from the medial side of the ...

s, the

glossopharyngeal nerve The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper Medulla oblongata, medulla, just anterior (closer to the nose) to t ...

, the pharyngeal branch of the

vagus The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right v ...

, and part of the parotid gland.

Branches

As the artery travels upwards, it gives the following branches: * In the

:Human Anatomy – Lab 25 Step 12
/ref> **

Superior thyroid artery The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland. Structure From its origin under the anterior border of the sternocleidomastoid the sup ...

, arising from its anterior aspect **

Ascending pharyngeal artery The ascending pharyngeal artery is an artery in the neck that supplies the pharynx, developing from the proximal part of the embryonic second aortic arch. It is the smallest branch of the external carotid and is a long, slender vessel, deeply se ...

- arising from medial, or deep, aspect **

Lingual artery The lingual artery arises from the external carotid artery between the superior thyroid artery and facial artery. It can be located easily in the tongue. Structure The lingual artery first branches off from the external carotid artery. It runs ...

- arising from its anterior aspect **

Facial artery The facial artery (external maxillary artery in older texts) is a branch of the external carotid artery that supplies structures of the superficial face. Structure The facial artery arises in the carotid triangle from the external carotid arte ...

- arise from its anterior aspect **

Occipital artery The occipital artery arises from the external carotid artery opposite the facial artery. Its path is below the posterior belly of digastric to the occipital region. This artery supplies blood to the back of the scalp and sternocleidomastoid musc ...

- arising from its posterior aspect **

Posterior auricular artery The posterior auricular artery is a small artery that arises from the external carotid artery, above the digastric muscle and stylohyoid muscle, opposite the apex of the styloid process. It ascends posteriorly beneath the parotid gland, along t ...

- arising from posterior aspect The external carotid artery terminates as two branches: *

Maxillary artery The maxillary artery supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches of the external carotid artery ...

Superficial temporal artery In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic a ...

Anastomoses

The superior thyroid artery anastomoses with

inferior thyroid artery The inferior thyroid artery is an artery in the neck. It arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle. It then turns medially behind the carotid sheath and its contents, and als ...

, where the latter arises from

thyrocervical trunk The thyrocervical trunk is an artery of the neck. It is a branch of the subclavian artery. It arises from the first portion of this vessel, between the origin of the subclavian artery and the inner border of the scalenus anterior muscle. It is ...

of the subclavian artery. Terminal branch of facial artery anastomose with

ophthalmic artery The ophthalmic artery (OA) is an artery of the head. It is the first branch of the internal carotid artery distal to the cavernous sinus. Branches of the ophthalmic artery supply all the structures in the orbit around the eye, as well as some s ...

of internal carotid artery. Posterior auricular artery anastomose with occipital artery, another branch of external carotid artery. One of the branches of superficial temporal artery anastomose with lacrimal and palpebral branches of ophthalmic artery.

Additional images

File:External carotid artery with branches.jpg, Branches of external carotid artery File:mra1.jpg,

Magnetic resonance angiography Magnetic resonance angiography (MRA) is a group of techniques based on magnetic resonance imaging (MRI) to image blood vessels. Magnetic resonance angiography is used to generate images of arteries (and less commonly veins) in order to evaluate ...

References

External links

* * ()
Diagram at umich.edu
{{DEFAULTSORT:External Carotid Artery Arteries of the head and neck