In
Human Anatomy , the is a major
Artery of the head and neck. It arises from the
Common Carotid Artery when it bifurcates into an internal and external branch.
The external carotid artery begins opposite the upper border of the
Thyroid Cartilage , and, taking a slightly curved course, passes upward and forward, and then inclines backward to the space behind the neck of the mandible, where it divides into the superficial temporal and internal maxillary arteries.
It rapidly diminishes in size in its course up the neck, owing to the number and large size of the branches given off from it.
In the child, it is somewhat smaller than the
Internal Carotid ; but in the adult, the two vessels are of nearly equal size. At its origin, this artery is more superficial, and placed nearer the middle line than the internal carotid, and is contained within the
Carotid Triangle .
The external carotid artery is covered by the skin, superficial fascia,
Platysma , deep fascia, and anterior margin of the
Sternocleidomastoideus ; it is crossed by the
Hypoglossal Nerve , by the
Lingual ,
Ranine ,
Common Facial , and
Superior Thyroid Vein s; and by the
Digastricus and
Stylohyoideus ; higher up it passes deeply into the substance of the
Parotid Gland , where it lies deep to the
Facial Nerve and the junction of the temporal and internal maxillary veins.
Medial to it are the
Hyoid Bone , the wall of the
Pharynx , the
Superior Laryngeal Nerve , and a portion of the
Parotid Gland .
Lateral to it, in the lower part of its course, is the
Internal Carotid Artery .
Posterior to it, near its origin, is the
Superior Laryngeal Nerve ; and higher up, it is separated from the
Internal Carotid by the
Styloglossus and
Stylopharyngeus , the
Glossopharyngeal Nerve , the pharyngeal branch of the
Vagus , and part of the parotid gland.
