The external carotid artery is one of the two main branches into which the common carotid divides, the other being the internal carotid artery. It supplies oxygenated blood to the face, mouth, tongue and external parts of the head.
The external carotid originates at the level of the upper border of thyroid cartilage. Then it runs upward in the neck, first slightly anterior to the internal carotid, then lateral to it. At the end of its course, when it reaches the level of the ear, it forks into the superficial temporal and maxillary artery within the parotid gland.
In
its first portion, the external carotid artery lies superficially and
is covered by platysma and the superficial layer of the cervical fascia.
Then, as it ascends, it passes behind the posterior belly of the
digastric muscle and the stylohyoid muscle. Slightly higher, it fits
into the retromandibular fossa in which it enters the parotid gland.
Branches
As it runs up the neck, the external carotid artery gives off six smaller branches: 1) the superior thyroid artery, which supplies the thyroid gland; 2) the ascending pharyngeal artery, which irrigates the pharynx; 3) the lingual artery, supplying the tongue; 4) the facial artery, which provides a large area of face with oxygenated blood; 5) the occipital artery; and 6) the posterior auricular artery.
Below, schematic pictures of the external carotid artery and its branches
